- Helmholtz-Zentrum Potsdam

Transcription

- Helmholtz-Zentrum Potsdam
23. Kolloquium Elektromagnetische Tiefenforschung, Heimvolkshochschule Seddiner See
28. September bis 2. Oktober 2009
Montag, 28.9.: Anreise und gemeinsames Abendessen um 18:30
Freitag, 2.10.: gemeinsames Frühstück und Abreise
Zeit
7:00-8:30
08:30
08:50
09:10
09:30
09:50
10:10-10:30
10:30
10:50
11:10
11:30
11:50
12:30-14:00
14:00
14:20
14:45 - 16:00
16:00-16:20
16:00-18:00
18:30-19:30
19:30-21:00
Dienstag, 29.9.
Begrüßung
V1, Heise
V2, Diaz
V3, Häuserer
V4, Meqbel
V5, Bhatt
V6, Streich
V7, Hanstein
V8, Kalscheuer
V9, Hoerdt
Hördt, V10, Pedersen
V11, Pedersen
Posterkurzvorstellungen
Kaffee
Poster
Diskussionsbeiträge
PW1, Hanstein
PW2, Tezkan
PW3, Spitzer
PW4, Pek
PW5, Weckmann
PW6, Hördt
Mittwoch, 30.9.
Frühstück
V12, Strack
V13, Schwalenberg
V14, Lippert
V15, Hölz
V16, Bücker
Kaffee
V17, Miensopust
V18, Weckmann
V19, Worzewski
V20, Adao
Vorstellung Wanderung
Mittagessen
Wanderung
Abendessen
Mitgliederversammlung
(für Alle!)
Donnerstag, 1.10.
V21, Streich
V22, Schwarzbach
V23, Kütter
V24, Moorkamp
V25, Roux
V26, Yogeshwar
V27, Abdelfettah
V28, Gurk
V29, Hendricks
V30, Rabenstein
V31, Stoll
V32, Virgil
Posterkurzvorstellungen
Kaffee
Poster
Diskussionsbeiträge
D3, Tezkan
D4, Weckmann
D5, Gang
D1, Tezkan
D2, Ritter
Posterbeiträge / Kurzvorstellung
P1, Kenkel
P2, Bairlein
P3, Rödder
P4, Treichel
P5, von Papen
P6, Widodo
P7, Bosch
P8, Neska
P9, Przyklenk
P10, Ehmann
P11, Hofmeister
P12, Steuer
P13, Schaumann
P14, Chen, J.
P15, Tietze
P16, Tripaldi
P17, Nube
P18, Becken
P19, Bhatt
P20
P21, Hanstein
P22, Kirchner
P23, Weißflog
P24, Lehmann-Horn
P25, Afanasjew
P26, Ren
P27, Meqbel
P28, Heincke
P29, Mandolesi
P30, Chen, X.
P31, Cerv
P32, Schäfer
P33, Eydam
P34, Kapinos
P35, Munoz
P36, Kalberkamp
P37, Mütschard
P38, Brändlein
P39, Le Pape
P40, Ritter
ID
Name
First Name
co-authors
Type
Title
D01
D02
D03
D04
D05
Tezkan
Ritter
Tezkan
Weckmann
Yu
Bülent
Oliver
Bülent
Ute
Gang
P01
P02
P03
Kenkel
Bairlein
Rödder
Johannes
Katharina
Annika
T. Hanstein, Z. X He, I. M. Þorbergsdóttir, K.M. Strack, and H. Tulinius
Hördt, A.
Hördt, A., Kenkel, J.
Tezkan, B.,
P04
Treichel
Andrea
Steuer, A., Blindow, N.
P
P05
P06
von Papen
Widodo
Michael
Widodo
Gurk, M., Tezkan, B.
P
P
P07
Bosch
Frank
Gurk, M.
P
On the anaysis of LOTEM time series from Israel and the preliminary 1D inversion of data
Site Effect Assessment in The Mygdonian Basin (EUROSEISTEST area, Northern Greece) Using TEM and RMT
Soundings
Hidden Mine Shaft Detection with Remote Radio Transmitter Electromagnetic and Self-Potential Method
P08
P09
Neska
Przyklenk
Anne
Anita
Hördt, A.
P
P
Subsurface conductivity obtained from DC railway signal propagation with a dipole model
Übergangsimpedanzen von Elektroden zur Bestimmung elektrischer Widerstände von Monden und Kometen
P10
Ehmann
Sebastian
Hördt, A., Virgil, C., Leven, M., Steveling, E.
P
Störkörperdetektion mittels 3-Komponenten-Magnetometerdaten
P11
Hofmeister
Paul
Grosse, J., Hördt, A., Glassmeier, K.H.
P
Räumlich hochauflösende Vermessung magnetischer Anomalien mit einem unbemannten Luftschiff
P12
Steuer
Annika
Siemon, B., Grinat, M.
P
P13
Schaumann
Gerlinde
Steuer, A., Siemon, B., Wiederhold, H.
P
P14
P15
Chen
Tietze
Jin
Kristina
Jegen-Kulcsar, M.
Ritter, O., Weckmann, U.
P
P
Die deutsche Nordseeküste im Fokus von aero-elektromagnetischen Untersuchungen:
I. Erkundung der Süßwasserlinsen von Borkum
Die deutsche Nordseeküste im Fokus von aero-elektromagnetischen Untersuchungen - II. Elbemündung und
Langeoog mit Wattenmeer
The Empirical Mode Decomposition and Spectra based on Direct Quadrature in MT data processing
Substitute models for static shift (in 2D)
P16
Tripaldi
S.
Siniscalchi, A., Spitzer, K.
P
A method to determine the magnetotelluric static shift from DC resistivity measurements in practice
P17
Nube
Andreas
P
Magnetotelluric measurements across the southern Barberton greenstone belt: Data analysis
P18
P19
P21
P22
P23
P24
Becken
Bhatt
Hanstein
Kirchner
Weißflog
Lehmann-Horn
Michael
K. Mangal
Tilman
Judith
Julia
Jochen
Weckmann, U., Ritter, O., Chen, X., Deacon,
J., MacLennan, S., Moodley, L., DeWit, M.,
Willkommen, G., Barth, R., Streich, R.,
Tietze, K.
Streich, R., Ritter, O.
Hördt, A., Hanstein, T.
P
P
P
P
P
P
Aufbau einer Controlled Source Magnetotellurik am GFZ
Analysis of seafloor marine EM data with respect to motion-induced noise
TEM with anomalous diffusion in fractional conductive media
1D – Simulation von Bohrlochtransientelektromagnetik zur CO2 – Sequestrierung
Die Felder des horizontalen elektrischen Dipols im geschichteten Halbraum
Hybrid electromagnetic modelling of large surface loops on rugged terrain
Börner, R.-U., Spitzer, K.
Börner, R.-U., Spitzer, K.
D
D
D
D
D
Geophysikalischer Gerätepool Potsdam: Bedarf der Arbeitsgruppe?
Permanente Remote Referenzstationen in Deutschland – eine konzertierte Aktion des AK EMTF?
Interpretation der magnetotellurischen Anisotropie: Ansätze nach Ulrich Schmucker
What you always wanted to know about…
Geothermal exploration using MT and gravity techniques at Szentlőrinc area in Hungary
P
P
P
Zweidimensionale SIP-Modellierung mit anisotroper Leitfähigkeit
Untersuchungen zur Genauigkeit der Spektralen Induzierten Polarisation
SHOTEM Messungen im Arava Valley, Dead-Sea Transform Verwerfung, Jordanien
-Vorbereitung der Wiederholungsmessungen im Dezember 2009 Transienten Elektromagnetik und Geoelektrik zur hydrogeologischen Erkundung in der Haseldorfer Marsch
P25
Afanasjew
Martin
P
Advances in the Numerical Solution of the 3-D TEM Forward Problem
Zhengyong
Börner, R.-U., Eiermann, M., Ernst, O.G.,
Spitzer, K.
Kalscheuer, T., Maurer, H.R.
P26
Ren
P
Meqbel
Naser
Ritter, O., Egbert, G., Siripunvaraporn, W.
P
P28
P29
P30
P31
Heincke
Mandolesi
Chen
Cerv
Björn Henning
Eric
Xiaoming
Vaclav
Jegen, M., Moorkamp, M.,
Jones, A. G., Roux, E., Lebedev, S.
Weckmann, U., Tietze, K.,
Kovacikova, S., Menvielle, M., Pek, J.
P
P
P
P
P32
P33
Schäfer
Eydam
Anja
Diane
Brasse, H., Houpt, L., Weichelt, D.
Brasse, H.,
P
P
P34
Kapinos
Gerhard
Brasse, H.,
P
P35
Muñoz
Gerard
Bauer, K., Moeck. I., Ritter, O.
P
P36
Kalberkamp
Ulrich
P37
P38
Mütschard
Brändlein
Lutz
Dirk
Brasse, H.
Ritter, O., Krings, T., Weckmann, U.
P
P
P39
Le Pape
Florian
Jones, A. G., Vozar, J., INDEPTH MT Team
P
P40 Ritter
PW1 Hanstein
Oliver
Tilman
Rybin, A., Muñoz, G., Batalev, V.
Edge-based boundary element method for 3D RMT modelling incorporating surface
topography - a theoretical study
A scheme to invert magnetotelluric data in two and three dimensions on parallel computer architectures:
Concepts and applications
Comparison of different coupling strategies in joint inversions
Common Structure in Different Physical Properties: Electrical Conductivity and Wave S-Velocity
Working towards modeling of phases over 90° with 2D anisotropic inversion
Thin sheet conductance models from geomagnetic induction data: Study of induction
anomalies at the transition from the Bohemian Massif to the West Carpathians
Magnetotelluric investigation of the Sorgenfrei-Tornquist Zone and the NE German Basin.
Imaging fluids and melts in the crust and upper mantle of the Bolivian Orocline, Central Andes (18°S) –
Interpretation of magnetotelluric data
Results of an amphibious magnetotelluric experiment at the South-Central
Chilean continental margin
Combining magnetotelluric and seismic models for exploration of the Groß Schönebeck
geothermal site: a statistical approach
Magnetotelluric measurements to explore for deeper structures of the Tendaho geothermal field, Afar, NE
Ethiopia
Magnetotellurics at the Central American margin in Costa Rica and Nicaragua
New Data from a permanent array of magnetotelluric stations located at the South
American subduction zone in Northern Chile
Evolution of the crust and upper mantle structure beneath the Kunlun Shan in Northern Tibet from INDEPTH
magnetotelluric data
Magnetotelluric data from the Tien Shan and Pamir continental collision zones, Central Asia.
P27
PW2 Tezkan
Bülent
P
P
PW
PW
PW3 Spitzer
Klaus
PW
PW4
PW5
PW6
V01
Pek
Weckmann
Hördt
Heise
Josef
Ute
Andreas
Wiebke
Caldwell, T.G., Bibby, H.M., Bennie, S.L.
PW
PW
PW
O
V02
V03
Diaz
Häuserer
Daniel
Michael
Brasse, H., Banaszak, M.
Junge, A.
O
O
V04
Meqbel
Naser
O
V05
Bhatt
K. Mangal
Ritter, O., Weckmann, U., Becken, M.,
Munoz, G.
Hördt, A., Weidelt, P., Hanstein, T.
O
28 Jahre mit Peter Weidelt: Von der Betreuung der Diplomarbeit bis zu gemeinsamen Forschungsaufenthalten in
Indien
Konjugierte Gradienten
Peter Weidelt's Anisotropy Studies
A direct inversion? Application of Propagation Number Analysis - in remembrance of Peter Weidelt
3-D conductivity image of the deep magma sources of the Taupo Volcanic Zone, New Zealand
Magnetotelluric study of Lascar volcano, Central Andes
Dominant phase split in MT data from the Western branch of the East African Rift in Uganda explained by a
preliminary three dimensional model with an electrically anisotropic lithosphere
The electrical conductivity structure of the Dead Sea Basin derived from 2D and 3D inversion of magnetotelluric
data
Motionally Induced Electromagnetic Field within the Ocean
V06
Streich
Rita
V07
Hanstein
Tilman
Löhken, J., Löhken, I., Mollidor, L., Qian, W.,
Ellingsrud, S., Yu, G., Strack, K.M.
O
V08
Kalscheuer
Thomas
Garcia, M., Meqbel, N., Pedersen, L.B.
O
V09
V10
V11
V12
Hördt
Hördt
Pedersen
Strack
Andreas
Andreas
Laust B.
Kurt
Weidelt, P., Przyklenk, A.
V13
Schwalenberg
Katrin
Engels, M., Deppe, J., Jegen, M. and the
New Vents Working Group
O
V14
Lippert
Klaus
Tezkan, B., Bergers, R., Gurk, M., v.Papen,
M., Yogeshwar, P.
O
Marine CSEM activities at BGR:
- Gas hydrate studies in New Zealand
- Instrument developments: A new bottom-towed multi-receiver system
Erkundung eines Aquifers unter dem Mittelmeer vor der israelischen Küsten mit LOTEM.
V15
Hölz
Sebastian
O
Harmonic oscillations in EM-signals measured on the "North Alex" mud-volcano
V16
V17
V18
V19
Bücker
Miensopust
Weckmann
Worzewski
Matthias
Marion
Ute
Tamara
Kenkel, J., Hördt, A., Hanstein, T.
et al.,
Becken, M., Ritter, O., de Wit, M.
Jegen, M., Kapionos, G., Brasse, H.
O
O
O
O
V20
Adão
Filipe
Heise, W.
O
V21
Streich
Rita
Becken, M.,
O
Einfluss von Bathymetrie auf marine CSEM Messungen im Zeitbereich
Magnetotelluric study in northeastern Botswana
Imaging the Kaapvaal Craton boundary, South Africa, using Magnetotellurics
Using Amphibious Magnetotellurics to image Hydration and Dehydration of the Costa Rican Subduction Zone and
to demonstrate the bathymetric effect on marine data
3-D model study to determine the mantle conductivity of the SW Iberian Peninsular using
phase tensor methods
EM fields generated by finite-length wire sources in 1D media: comparison with point dipole solutions
V22
V23
Schwarzbach
Kütter
Christoph
S.
Börner, R.U., Spitzer, K.
Franke-Börner, A., Börner, R.-U., Spitzer, K.
O
O
V24
Moorkamp
Max
O
V25
V26
Roux
Yogeshwar
Estelle
Pritam
Jegen, M. Hobbs, R. W., Roberts, A.,
Heincke, B.
Moorkamp, M., Jones, A. G.,
Tezkan, B., Israil, M.
V27
Abdelfettah
Yassine
Tarits, P., Hautot, S., Maia, M., and Tiercelin,
J-J.
O
V28
Gurk
Marcus
V29
V30
V31
V32
Hendricks
Rabenstein
Stoll
Virgil
Stefan
Lasse
Johannes
Christopher
O
Hanstein, T., Yu, G.
O
PW
O
O
O
O
O
Haas, C., Rabenstein, L., Lobach, J.
Hendricks, S., Haas, C., Lobach, J.
Hördt, A., Leven, M., Steveling, E.
O
O
O
O
”Air waves” in marine controlled-source electromagnetics
- The potential of Peter Weidelt’s work
From LOTEM to Marine tCSEM™ for hydrocarbon exploration: concepts and realization
Smoothness-constrained model error and resolution estimates from the inversion of direct current resistivity and
radiomagnetotelluric data
Die Übergangsimpedanz einer kapazitiv angekoppelten Elektrode
Nachruf Peter Weidelt
Some remarks on Peter Weidelt’s influence on Scandinavian EM research
Full Field EM Monitoring
A 3-D Model Study for Marine EM Using Vector Finite Elements
Three-dimensional FE simulation of magnetotelluric fields using digital terrain models exemplified for Stromboli
volcano
Towards 3D joint inversion of full tensor gravity, magnetotelluric and seismic refraction data
Joint Inversion of Magnetotelluric and Surface Wave Data in an Anisotropic Earth
Grundwasserkontamination bei Roorkee/Indien:
2D Joint Inversion von Radiomagnetotellurik und Gleichstromgeoelektrik Daten
Improvement of the geophysical imaging by MT and Gravity joint inversion: Application to Turkana region,
Northern Kenya
Integrated nonseismic geophysical studies to assess the site effect of the EUROSEISTEST area in Northern Greece
(IGSEA)
Airborne EM sea ice thickness sounding: Forward modelling and hardware developments
Development and test of a fixed wing AEM sea ice thickness sounder
Orientation Tracking Method for mobile geophysical measuring systems
Durchführung und Auswertung von dreikomponentigen Bohrlochmagnetometermessungen
ID
Name
First Name
co-authors
Type
Tarits, P., Hautot, S., Maia, M., and Tiercelin,
J-J.
Heise, W.
O
P
Katharina
Michael
Börner, R.-U., Eiermann, M., Ernst, O.G.,
Spitzer, K.
Hördt, A., Kenkel, J.
Streich, R., Ritter, O.
Improvement of the geophysical imaging by MT and Gravity joint inversion: Application to Turkana region,
Northern Kenya
3-D model study to determine the mantle conductivity of the SW Iberian Peninsular using
phase tensor methods
Advances in the Numerical Solution of the 3-D TEM Forward Problem
P
P
Untersuchungen zur Genauigkeit der Spektralen Induzierten Polarisation
Aufbau einer Controlled Source Magnetotellurik am GFZ
Bhatt
Bhatt
Bosch
K. Mangal
K. Mangal
Frank
Hördt, A., Hanstein, T.
Hördt, A., Weidelt, P., Hanstein, T.
Gurk, M.
P
O
P
Analysis of seafloor marine EM data with respect to motion-induced noise
Motionally Induced Electromagnetic Field within the Ocean
Hidden Mine Shaft Detection with Remote Radio Transmitter Electromagnetic and Self-Potential Method
P38
Brändlein
Dirk
Ritter, O., Krings, T., Weckmann, U.
P
V16
P31
Bücker
Cerv
Matthias
Vaclav
Kenkel, J., Hördt, A., Hanstein, T.
Kovacikova, S., Menvielle, M., Pek, J.
O
P
P14
Chen
Jin
Jegen-Kulcsar, M.
P
New Data from a permanent array of magnetotelluric stations located at the South
American subduction zone in Northern Chile
Einfluss von Bathymetrie auf marine CSEM Messungen im Zeitbereich
Thin sheet conductance models from geomagnetic induction data: Study of induction
anomalies at the transition from the Bohemian Massif to the West Carpathians
The Empirical Mode Decomposition and Spectra based on Direct Quadrature in MT data processing
P30
V02
Chen
Diaz
Xiaoming
Daniel
Weckmann, U., Tietze, K.
Brasse, H., Banaszak, M.
P
O
Working towards modeling of phases over 90° with 2D anisotropic inversion
Magnetotelluric study of Lascar volcano, Central Andes
P10
Ehmann
Sebastian
Hördt, A., Virgil, C., Leven, M., Steveling, E.
P
Störkörperdetektion mittels 3-Komponenten-Magnetometerdaten
P33
Eydam
Diane
Brasse, H.,
P
V28
Gurk
Marcus
O
P21 Hanstein
PW1 Hanstein
V07 Hanstein
Tilman
Tilman
Tilman
V03
Häuserer
Michael
Löhken, J., Löhken, I., Mollidor, L., Qian, W.,
Ellingsrud, S., Yu, G., Strack, K.M.
Junge, A.
P
PW
O
Imaging fluids and melts in the crust and upper mantle of the Bolivian Orocline, Central Andes (18°S) –
Interpretation of magnetotelluric data
Integrated nonseismic geophysical studies to assess the site effect of the EUROSEISTEST area in Northern Greece
(IGSEA)
TEM with anomalous diffusion in fractional conductive media
P28
V01
V29
P11
Heincke
Heise
Hendricks
Hofmeister
Björn Henning
Wiebke
Stefan
Paul
Jegen, M., Moorkamp, M.,
Caldwell, T.G., Bibby, H.M., Bennie, S.L.
Haas, C., Rabenstein, L., Lobach, J.
Grosse, J., Hördt, A., Glassmeier, K.H.
V27
Abdelfettah
Yassine
V20
Adão
Filipe
P25
Afanasjew
Martin
P02
P18
Bairlein
Becken
P19
V05
P07
V15 Hölz
PW6 Hördt
V09 Hördt
Sebastian
Andreas
Andreas
Weidelt, P., Przyklenk, A.
O
Title
From LOTEM to Marine tCSEM™ for hydrocarbon exploration: concepts and realization
O
Dominant phase split in MT data from the Western branch of the East African Rift in Uganda explained by a
preliminary three dimensional model with an electrically anisotropic lithosphere
P
O
O
P
Comparison of different coupling strategies in joint inversions
3-D conductivity image of the deep magma sources of the Taupo Volcanic Zone, New Zealand
Airborne EM sea ice thickness sounding: Forward modelling and hardware developments
Räumlich hochauflösende Vermessung magnetischer Anomalien mit einem unbemannten Luftschiff
O
PW
O
Harmonic oscillations in EM-signals measured on the "North Alex" mud-volcano
Die Übergangsimpedanz einer kapazitiv angekoppelten Elektrode
V10
P36
Hördt
Kalberkamp
Andreas
Ulrich
V08
Kalscheuer
Thomas
Garcia, M., Meqbel, N., Pedersen, L.B.
O
P34
Kapinos
Gerhard
Brasse, H.,
P
P01
P22
V23
Kenkel
Kirchner
Kütter
Johannes
Judith
S.
Hördt, A.
Börner, R.-U., Spitzer, K.
Franke-Börner, A., Börner, R.-U., Spitzer, K.
P
P
O
P39
Le Pape
Florian
Jones, A. G., Vozar, J., INDEPTH MT Team
P
P24
V14
Lehmann-Horn
Lippert
Jochen
Klaus
P29
P27
Mandolesi
Meqbel
Eric
Naser
V04
Meqbel
Naser
V17
V24
Miensopust
Moorkamp
Marion
Max
P35
Muñoz
Gerard
P37
P08
P17
V11
PW4
P09
Mütschard
Neska
Nube
Pedersen
Pek
Przyklenk
Lutz
Anne
Andreas
Laust B.
Josef
Anita
Brasse, H.
V30
P26
Rabenstein
Ren
Lasse
Zhengyong
Hendricks, S., Haas, C., Lobach, J.
Kalscheuer, T., Maurer, H.R.
O
P
D02
P40
P03
Ritter
Ritter
Rödder
Oliver
Oliver
Annika
Rybin, A., Muñoz, G., Batalev, V.
Tezkan, B.,
D
P
P
V25
P32
Roux
Schäfer
Estelle
Anja
Moorkamp, M., Jones, A. G.,
Brasse, H., Houpt, L., Weichelt, D.
O
P
PW
P
Tezkan, B., Bergers, R., Gurk, M., v.Papen,
M., Yogeshwar, P.
Jones, A. G., Roux, E., Lebedev, S.
Ritter, O., Egbert, G., Siripunvaraporn, W.
Ritter, O., Weckmann, U., Becken, M.,
Munoz, G.
et al.,
Jegen, M. Hobbs, R. W., Roberts, A.,
Heincke, B.
Bauer, K., Moeck. I., Ritter, O.
et al.,
Hördt, A.
P
O
P
P
O
O
O
P
P
P
P
O
PW
P
Nachruf Peter Weidelt
Magnetotelluric measurements to explore for deeper structures of the Tendaho geothermal field, Afar, NE
Ethiopia
Smoothness-constrained model error and resolution estimates from the inversion of direct current resistivity and
radiomagnetotelluric data
Results of an amphibious magnetotelluric experiment at the South-Central
Chilean continental margin
Zweidimensionale SIP-Modellierung mit anisotroper Leitfähigkeit
1D – Simulation von Bohrlochtransientelektromagnetik zur CO2 – Sequestrierung
Three-dimensional FE simulation of magnetotelluric fields using digital terrain models exemplified for Stromboli
volcano
Evolution of the crust and upper mantle structure beneath the Kunlun Shan in Northern Tibet from INDEPTH
magnetotelluric data
Hybrid electromagnetic modelling of large surface loops on rugged terrain
Erkundung eines Aquifers unter dem Mittelmeer vor der israelischen Küsten mit LOTEM.
Common Structure in Different Physical Properties: Electrical Conductivity and Wave S-Velocity
A scheme to invert magnetotelluric data in two and three dimensions on parallel computer architectures:
Concepts and applications
The electrical conductivity structure of the Dead Sea Basin derived from 2D and 3D inversion of magnetotelluric
data
Magnetotelluric study in northeastern Botswana
Towards 3D joint inversion of full tensor gravity, magnetotelluric and seismic refraction data
Combining magnetotelluric and seismic models for exploration of the Groß Schönebeck
geothermal site: a statistical approach
Magnetotellurics at the Central American margin in Costa Rica and Nicaragua
Subsurface conductivity obtained from DC railway signal propagation with a dipole model
Magnetotelluric measurements across the southern Barberton greenstone belt: Data analysis
Some remarks on Peter Weidelt’s influence on Scandinavian EM research
Peter Weidelt's Anisotropy Studies
Übergangsimpedanzen von Elektroden zur Bestimmung elektrischer Widerstände von Monden und Kometen
Development and test of a fixed wing AEM sea ice thickness sounder
Edge-based boundary element method for 3D RMT modelling incorporating surface
topography - a theoretical study
Permanente Remote Referenzstationen in Deutschland – eine konzertierte Aktion des AK EMTF?
Magnetotelluric data from the Tien Shan and Pamir continental collision zones, Central Asia.
SHOTEM Messungen im Arava Valley, Dead-Sea Transform Verwerfung, Jordanien
-Vorbereitung der Wiederholungsmessungen im Dezember 2009 Joint Inversion of Magnetotelluric and Surface Wave Data in an Anisotropic Earth
Magnetotelluric investigation of the Sorgenfrei-Tornquist Zone and the NE German Basin.
P13
Schaumann
Gerlinde
Steuer, A., Siemon, B., Wiederhold, H.
P
V13
Schwalenberg
Katrin
Engels, M., Deppe, J., Jegen, M. and the New
Vents Working Group
O
V22 Schwarzbach
PW3 Spitzer
P12 Steuer
Christoph
Klaus
Annika
Börner, R.U., Spitzer, K.
V31
V12
V06
Stoll
Strack
Streich
Johannes
Kurt
Rita
Hanstein, T., Yu, G.
O
O
O
V21
Streich
Rita
Becken, M.,
O
Siemon, B., Grinat, M.
O
PW
P
D01 Tezkan
D03 Tezkan
PW2 Tezkan
Bülent
Bülent
Bülent
P15
P04
Tietze
Treichel
Kristina
Andrea
Ritter, O., Weckmann, U.
Steuer, A., Blindow, N.
P16
V32
P05
D04
PW5
Tripaldi
Virgil
von Papen
Weckmann
Weckmann
S.
Christopher
Michael
Ute
Ute
Siniscalchi, A., Spitzer, K.
Hördt, A., Leven, M., Steveling, E.
P
O
P
D
PW
V18
Weckmann
Ute
Becken, M., Ritter, O., de Wit, M.
O
P23
P06
Weißflog
Widodo
Julia
Widodo
Börner, R.-U., Spitzer, K.
Gurk, M., Tezkan, B.
P
P
V19
Worzewski
Tamara
Jegen, M., Kapionos, G., Brasse, H.
O
V26
Yogeshwar
Pritam
Tezkan, B., Israil, M.
O
D05
Yu
Gang
T. Hanstein, Z. X He, I. M. Þorbergsdóttir, K.M. Strack, and H. Tulinius
D
D
D
PW
P
P
P
O
D
PW
Die deutsche Nordseeküste im Fokus von aero-elektromagnetischen Untersuchungen - II. Elbemündung und
Langeoog mit Wattenmeer
Marine CSEM activities at BGR:
- Gas hydrate studies in New Zealand
- Instrument developments: A new bottom-towed multi-receiver system
A 3-D Model Study for Marine EM Using Vector Finite Elements
Konjugierte Gradienten
Die deutsche Nordseeküste im Fokus von aero-elektromagnetischen Untersuchungen:
I.
ErkundungTracking
der Süßwasserlinsen
von Borkum
Orientation
Method for mobile
geophysical measuring systems
Full Field EM Monitoring
”Air waves” in marine controlled-source electromagnetics
-EM
Thefields
potential
of Peter
Weidelt’s work
generated
by finite-length
wire sources in 1D media: comparison with point dipole solutions
Geophysikalischer Gerätepool Potsdam: Bedarf der Arbeitsgruppe?
Interpretation der magnetotellurischen Anisotropie: Ansätze nach Ulrich Schmucker
28 Jahre mit Peter Weidelt: Von der Betreuung der Diplomarbeit bis zu gemeinsamen Forschungsaufenthalten in
Indien
Substitute models for static shift (in 2D)
Transienten Elektromagnetik und Geoelektrik zur hydrogeologischen Erkundung in der Haseldorfer Marsch
A method to determine the magnetotelluric static shift from DC resistivity measurements in practice
Durchführung und Auswertung von dreikomponentigen Bohrlochmagnetometermessungen
On the anaysis of LOTEM time series from Israel and the preliminary 1D inversion of data
What you always wanted to know about…
A direct inversion? Application of Propagation Number Analysis - in remembrance of Peter
Weidelt
Imaging the Kaapvaal Craton boundary, South Africa, using Magnetotellurics
Die Felder des horizontalen elektrischen Dipols im geschichteten Halbraum
Site Effect Assessment in The Mygdonian Basin (EUROSEISTEST area, Northern Greece) Using TEM and RMT
Soundings
Using Amphibious Magnetotellurics to image Hydration and Dehydration of the Costa Rican Subduction Zone and
to demonstrate the bathymetric effect on marine data
Grundwasserkontamination bei Roorkee/Indien:
2D Joint Inversion von Radiomagnetotellurik und Gleichstromgeoelektrik Daten
Geothermal exploration using MT and gravity techniques at Szentlőrinc area in Hungary
Poster
Oral
Diskussionsbeitrag
Kurzbeitrag zu Peter Weidelt
Dienstag 29.9. – 8:50 – 12:10
V01
3-D conductivity image of the deep magma sources of the Taupo Volcanic Zone, New Zealand
HEISE Wiebke1, 2, CALDWELL T. Grant1, BIBBY Hugh M.1, BENNIE Stewart L.1
1
GNS Science, Lower Hutt, New Zealand
2
Universidade de Lisboa, CGUL-IDL, Lisbon, Portugal
The Taupo Volcanic Zone (TVZ), in the North Island, New Zealand is a continental back arc rift
associated with the subduction of the Pacific Plate under the Australian Plate and is characterised by the
eruption of large volumes of rhyolitic magma during the last 1.6 Ma and an exceptionally high presentday heat flow. Magnetotelluric data had been collected in the TVZ since 1997 to study the deep structure
and volcanism of the TVZ but also for exploration of the geothermal systems. We present results from
over 200 magnetotelluric soundings covering the central (rhyolitic) part of the TVZ. The data were
analysed using 3-D inverse resistivity modelling and phase tensor visualisation techniques.
The inverse modelling results show areas of high conductivity in the lower crust and upper-mantle along
the central rift-axis that correlate with a zone of high phase observed at long periods. These conductors
are interpreted as the magma reservoirs which are the source for large scale rhyolitic eruptions that occur
in the TVZ. The varying conductivity along the rift axis represents different percentages of eruptible
magma in the mush zone. A deep reaching conductor suggests that we observe a plume of hot magma
recharging the magma reservoir.
V02
Magnetotelluric study of Lascar volcano, Central Andes.
D. Diaz1, H. Brasse1, M. Banaszak2
1
Freie Universität Berlin, Fachrichtung Geophysik, Malteserstr. 74-100, 12249 Berlin, Germany
([email protected])
2
Universität Göttingen, Geowissenschaftliches Zentrum Göttingen, Abt. Geochemie, Goldschmidtstr. 1,
37077 Göttingen
In the study of volcanoes and hydrothermal systems, magnetotellurics has been widely used considering
the different electrical properties expected in these structures, due to hydrothermal fluids, gas or melt in
contrast with the surrounding rocks (see, e.g., Heise et al., 2008; Müller et al., 2004).
This investigation considers the zone around Lascar volcano (5592 m, 23°22’S, 67°44’W), located on the
eastern side of the Salar de Atacama basin in northern Chile, as part of the volcanic arc which defines the
western border of the Altiplano-Puna plateau. It has been one of the most active volcanoes of the central
Andes in the last years, which recent activity has been characterized by repetitive dome growth and
subsidence, accompanied by degassing and explosive eruptions of various magnitudes (Pavez et al.,
2006).
During October and November 2007, 13 AMT (250 Hz-1000s) sites were built around the Lascar
volcano, while 11 LMT (10s-10000s) sites were built as an E-W profile, crossing the Salar de Atacama
basin and the volcanic arc, reaching the Puna.
To obtain the apparent resistivity curves from the time series, the real and imaginary parts of the
impedance tensor were calculated with the robust processing from Egbert (Egbert, 2002). Analysis of the
induction vectors, phase tensor ellipses and strike direction (Smith, 1995) were developed, obtaining a
consistent 2D regional behavior for the periods between 100s and 1000s.
2D inversion developed for the LMT profile shows the main geological features of this zone, such as the
Salar de Atacama basin, the Precordillera and the Atacama block, as well as a large conductive body
under the Altiplano-Puna plateau, a result which is in good agreement with previous studies in the Central
Andes (Brasse et al., 2008). For the AMT data, a 2D inversion was also obtained, showing a shallow
conductive zone (2-3 km) under the volcanic edifice, and extending deeper to the SE. Based on these
results and considering petrologic and geochemical studies in the area, 3D forward modeling have been
under development using the AMT stations closest to the volcano, obtaining the best results (until now)
for a synthetic magma chamber elongated to the south.
References
-Brasse H, Eydam D (2008) Electrical conductivity beneath the Bolivian Orocline and its relation to
subduction processes at the South American continental margin. Journal of Geophysical Research, 113,
B07109, doi:10.1029/2007JB005142.
-Egbert G D (2002) Processing and Interpretation of Electromagnetic Induction Array Data. Surveys in
Geophysics, 23: 207-249.
-Heise W, Caldwell T G, Bibby H M & Bannister S C (2008) Three-dimensional modeling of
magnetotelluric data from the Rotokawa geothermal field, Taupo Volcanic Zone, New Zeland.
Geophysical Journal International, doi:10.1111/j.1365-246X.2008.03737.x
-Müller A, Haak V (2004) 3-D modeling of the deep electrical conductivity of Merapi volcano (Central
Java): integrating magnetotellurics, induction vectors and the effect of steep topography. Journal of
Volcanology and Geothermal Research, 138: 205-222.
-Pavez A, Remy D, Bonvalot S, Diament M, Gabalda G, Froger J-L, Julien P, Legrand D & Moisset D
(2006) Insight into ground deformations at Lascar volcano (Chile) from SAR interferometry,
photogrammetry and GPS data: Implications on volcano dynamics and future space monitoring. Remote
Sensing of Environment, Volume 100, Issue 3: 307-320.
-Smith J.T (1995), Understanding telluric distortion matrices, Geophysical Journal International, 122,
219-226.
V03
Dominant phase split in MT data from the Western branch of the East African Rift in Uganda
explained by a preliminary three dimensional model with an electrically anisotropic lithosphere
Michael Häuserer, Andreas Junge
Long Period Magnetotelluric (LMT) measurements were performed at up to 14 sites simultaneously
within an area of 150 km x 80 km east of the Rwenzori Mountains during 2 field campaigns in 2007 and
2008. The Rwenzories are located in the western branch of the East African Rift in the west of Uganda
near the Congo border. Altogether at eight sites time variations of both Magnetic and Telluric fields were
recorded, whereas at 15 sites only the Electric field components were observed. MT transfer functions
and phase tensor ellipses were estimated at all sites in the period range 10-10000s due to a rather
homogeneous source field. Large distortions of the transfer functions indicate a complicated three
dimensional conductivity structure within the crust predominantly at the transition zone between the
Rwenzori Mountains and the Rift shoulder to the North East. The overall pattern of the phase tensor
ellipses shows a consistent split of the minimum and maximum phase for all sites at periods >100s. The
high maximum phases >60° are associated with currents perpendicular to the Rift Valley and the
minimum phases (45°) with currents parallel to the Rift. The high phase component over the period range
100-10000 sec indicates a downwards decreasing conductivity within the lithosphere. The constant phase
split over a large lateral distance and the small vertical magnetic filed components at long periods can be
explained by a model with anisotropic conductivity in the lithosphere. Generally all impedance phases
increase above 45° for periods longer than 2000 s denoting an increase of the conductivity beneath the
lithosphere.
V04
The electrical conductivity structure of the Dead Sea Basin derived from 2D and 3D inversion of
magnetotelluric data
Meqbel N., Ritter O., Weckmann U., Becken M. and Muñoz G.
V05
Motionally Induced Electromagnetic Field within the Ocean
K. M. Bhatt, A. Hördt, P.Weidelt (Inst. f. Geophysik u. Extraterrestrische Physik, TU Braunschweig),
T. Hanstein (KMS Technologies - KJT Enterprises Inc.)
The contribution of motionally induced electromagnetic (EM) fields at the seafloor is generally
considered small, but since the characteristic reservoir signal in marine controlled source electromagnetic
(mCSEM) data is also small, the inclusion of the motional induction contribution in modelling estimate
will enhance the probability of reservoir detection. Here, we have studied the electromagnetic induction
caused by ocean water flow with in earth’s magnetic field.
When a charge particle moves with certain velocity in earth’s magnetic field, it experiences a Lorentz
force. The action of Lorentz force generates a secondary electric field through galvanic and inductive
processes. For the mathematical formulation, thus, we considered Lorentz electric field as a source in the
corresponding set of Maxwell’s equations. First, we solve these Maxwell's equations for a 1D model and
velocity structure. Further, we extend our formulation for 1D model and 2D velocity structure. Here,
Maxwell’s equations are solved by disintegrating them into TM and TE mode. For a vertical earth
magnetic field, the TM and TE mode is energised respectively by horizontal and vertical component of
velocity.
The simulations indicate that for practical cases at greater transmitter-receiver (T-R) separations, the
motionally induced electric and magnetic field contribution is relevant for reservoir detection. For
example, a surface wave of height 1 m propagating with velocity 25 cm/s of 0.04 Hz within an ocean of
conductivity 3.33 S/m, in an ambient earth’s vertical magnetic field of 50000 nT, contributes an electric
field of amplitudes 2 nV/m at the seafloor 1000 m below sea-surface. This amplitude corresponds to the
signal amplitude measured at 7000 m distance from a transmitter with a dipole moment of 104 Am.
V06
”Air waves” in marine controlled-source electromagnetic - The potential of Peter Weidelt’s work
Rita Streich
In applications of marine controlled-source electromagnetics (CSEM) for hydrocarbon exploration,
energy propagating through the air (the “air wave”) often obscures subsurface signals. This has triggered
a variety of hands-on industry approaches for handling airwave effects in CSEM data. These include the
selection of frequency and distance windows that contain little airwave signal, up-down separation of EM
fields, and related approaches similar to seismic predictive deconvolution. In contrast, Peter Weidelt(1)
provides a comprehensive mathematical analysis of the nature and properties of air-related CSEM signals,
which may lead to a deeper understanding and development of new approaches for dealing with the
airwave problem. In this presentation, I attempt to provide an overview and illustration of Weidelt’s
treatment of airwaves in 1D media, relate this to some of my own CSEM modeling test cases, and discuss
potential consequences and future applications of this work in hydrocarbon exploration.
(1) Weidelt, P., 2007, Guided waves in marine CSEM, Geophysical Journal International 171, 153-176
V07
From LOTEM to Marine tCSEM™ for hydrocarbon exploration: concepts and realization
T. Hanstein, J. Löhken, I. Löhken, L. Mollidor, W. Qian, S. Ellingsrud, G. Yu, K.M. Strack
The depth of interest for hydrocarbon exploration is from one to several kilometres. Transient
electromagnetic techniques with controlled source as LOTEM and tCSEM™ for land and marine surveys
are designed to reach this depth of penetration. The long offset and the conductive environment is
convenient for acquiring the transient response as time series, which are processed by robust stacking and
optimized filter techniques.
Although in time domain the decay of the electromagnetic fields after a switch off the transmitter current
is diffusive, assumptions and ideas of the seismic world is influencing the explanations for the response.
Especially the concept of waves is used to describe the signal response of the ocean, the target and the airsea interface with reflection and the refraction at the boundaries. Some aspects of the wave propagation
explain the transient behaviour well but there are other aspects which are not consistent with the wave
concept.
The hydrocarbon target is often described as a thin resistive layer with finite horizontal dimensions. A thin
and horizontal elongated rectangular resistor embedded in depth of 2 km below the seafloor has been
applied for numerical experiment. Two tow lines have been modelled across the long side and the short
side of the rectangular prism. The 3-D numerical modelling has been done with Comsol Mulitphysics and
SLDMEM3T. The comparison of the results shows that both numerical method – finite element and finite
difference with the Lanczos decomposition – are in good agreement.
V08
Smoothness-constrained model error and resolution estimates from the inversion of direct-current
resistivity and radiomagnetotelluric data
Thomas Kalscheuer, Institute of Geophysics, ETH Zurich, Sonneggstr. 5, 8092 Zurich, Switzerland;
Maria de los Angeles Garcia Juanatey, Department of Earth Sciences, Uppsala University, Villavagen 16,
75236 Uppsala
Naser Meqbel, GeoForschungsZentrum Potsdam, Geophysical Deep Sounding, Telegrafenberg, 14473
Potsdam, Germany;
Laust B. Pedersen, Department of Earth Sciences, Uppsala University, Villavagen 16, 75236 Uppsala
V09
Die Übergangsimpedanz einer kapazitiv angekoppelten Elektrode
Andreas Hördt, Peter Weidelt, Anita Przyklenk
Institut für Geophysik und extraterrestrische Physik, TU Braunschweig
Bei geoelektrischen Messungen über sehr schlecht leitendem Untergrund kann es von Vorteil sein, den
Strom kapazitiv anzukoppeln. Dabei wird ein hochfrequentes Wechselfeld an eine Elektrode angelegt, die
keinen direkten Kontakt mit dem Untergrund hat. Eine genaue Berechnung der Übergangsimpedanz einer
solchen Elektrode ist notwendig, um zu beurteilen, unter welchen Bedingungen eine kapazitive
Ankopplung einer galvanischen überlegen ist. Für die praktische Umsetzung ist die Frage von Bedeutung,
ob es günstig ist, eine kapazitive Elektrode zu isolieren und einen galvanischen Kontakt auszuschließen.
Die Standardformeln für die Ankopplung kapazitiver Elektroden sind allerdings nur für hohe
Leitfähigkeiten des Untergrundes gültig.
Es wird eine Möglichkeit vorgestellt, die Impedanz einer Kreisscheibe zu berechnen, die an einen
Halbraum mit endlicher Leitfähigkeit angekoppelt ist. Basierend auf den Maxwellgleichungen wird eine
Integralgleichung für die Ladungsdichte q auf der Kreisscheibe aufgestellt. Mit der Randbedingung, dass
das Potential auf der Scheibe konstant ist, kann die Ladungsdichte und damit die Gesamtladung bestimmt
werden. Es zeigt sich, dass der Übergang von aufliegender zu angehobener Platte stetig als Funktion des
Abstandes verläuft. Zudem nimmt die Impedanz als Funktion des Abstandes zu, d.h. die Ankopplung
einer kapazitiv angekoppelten Elektrode kann niemals geringer sein, als die einer aufliegenden mit
gleicher Fläche. Je nach Modellparametern kann die Impedanz jedoch innerhalb weniger Nanometer über
Größenordnungen variieren, so dass es dennoch günstig sein kann, die Elektrode zu isolieren, um starke
Schwankungen der Impedanz zu vermeiden.
V10
Nachruf Peter Weidelt
Andreas Hördt
V11
Some remarks on Peter Weidelt’s influence on Scandinavian EM research
Laust Pedersen
I met Peter Weidelt and Ulrich Schmucker first time at the Ottawa Induction Workshop in 1974 a few
years after I joined Aarhus University in Denmark. Shortly after both of them, much to my surprise,
accepted an invitation to come to Aarhus to teach EM induction theory to a small, but dedicated group of
students, including myself. The well-known Aarhus Lecture notes from the spring of 1975 is the legacy
from those intensive lectures which went on for 2 times six weeks.
During my presentation I will mention some important outcomes in terms of Scandinavian people and
papers resulting directly or indirectly from especially Peter’s lectures.
Mittwoch 30.9. – 8:30 – 11:50
V12
Full Field EM Monitoring
K.-M. Strack, T. Hanstein and G. Yu
KMS Technologies – KJT Enterprises Inc., Houston, Texas, USA
Increasing production efficiency and monitoring water/steam/CO2 floods are key issues to be addressed
with borehole and surface technologies and measurements. At the same time linking the information to 3D
surface seismic data and borehole seismic data is required to extrapolate in the inter-well space, find the
sweat spots between wells, and in the 3D reservoir space. Controlled source electromagnetic has the
strongest coupling to the fluid content of the reservoir while seismic can delineate impedance contrasts or
lithological boundaries.
Present logging technologies only reach about 3 meters away from the well bore. Deep reading
techniques are still in commercial field trial stage. Surface electromagnetic techniques are presently
proposed and only used for monitoring application in engineering geophysics. The reason lies in the
higher order sensitivity and resolution decay with distance from the target. A logical conclusion is to
combine methods not only to sense different physical reservoir properties but also to overcome the
weakness of each method and to approach the problem in a more synergetic fashion.
We evaluated several reservoir dynamics monitoring methods and technologies leading us to a practical
concept of Full Field Fluid Monitoring (F3M). Our implementation includes marine and land sources and
receivers, surface-to-borehole arrays and single well system that can look tens or even 100 m around the
wellbore and ahead of the drill bit. Except for the single well component, all systems are well past the
research phase and we have carried out various parts of field trials.
The enabling technology is a multi-component cable we are building for marine application which can
measure magnetotellurics as well as controlled source EM signals. It allows much denser data collection,
operational cost efficient, and semi-permanent or permanent operation ,and it can also be combined with
nodes to cover a larger footprint with wider spacing. Similar technology with a variety of fit-for-purpose
telemetry can be used onshore. For borehole use we are combining our EM sensor packages with
borehole seismic acquisition system or build special purpose LWD sub-assemblies. In all case the data
can be acquired and streamed over the internet to allow efficient operation and real time control of the
water/steam/CO2 floods.
One of the major learnings during the various projects was that surface electromagnetic methods alone are
ambiguous if they are not used in combination with surface-to-borehole measurements. The reason lies in
the up-scaling issues associated with the inherent averaging nature that EM methods do.
V13
Marine CSEM activities at BGR:
- Gas hydrate studies in New Zealand
- Instrument developments: A new bottom-towed multi-receiver system
Katrin Schwalenberg, Martin Engels, Joachim Deppe, Marion Jegen, and the New Vents Working Group
V14
Erkundung der Süßwassergrenze des unterseeischen Aquifers vor der Küste Israels mit der
LOTEM-Methode.
K. Lippert, B. Tezkan, R. Bergers, M. Gurk, M. v. Papen, P. Yogeshwar Institut für Geophysik und
Meteorologie, Universität zu Köln
Im Rahmen dieses BMBF-geförderten Projektes kommt die Long-Offset Transient Elektromagnetik
(LOTEM) Methode zum ersten Mal in mariner Umgebung zur Erkundung von Grundwasseraquiferen
zum Einsatz. Hauptziel des Projektes ist die Detektion der Süßwassergrenze unter dem Mittelmeer an der
Küste Israels.
Zu diesem Zweck wurden Hardware-Modifikationen durchgeführt und bereits in einer ersten Testmessung
in Israel erprobt. Des weiteren werden die Interpretationen der ersten Testmessung sowie die
Modellierungsergebnisse des Küstenabschnitts vorgestellt, welche zur Planung der Hauptmessung wichtig
sind.
V15
Harmonic oscillations in EM-signals measured on the "North Alex" mud-volcano
Sebastian Hölz
Ocean bottom MT-measurement (OBMT) taken at six locations on the "North Alex" mud-volcano in the
Mediteranean Sea repeatedly show oscillations in the EM-fields. These oscillations typically last several
hours and can be characterized in spectrograms by peaks at periods of 3s, 6s and 12s. We will present
evidence that these signals are neither caused by mechanical instability of our OBMT-stations, nor due to
regular MT-signals. Instead we propose that these signals are triggered by activity of the mud volcano
itself.
V16
Einfluss von Bathymetrie auf marine CSEM Messungen im Zeitbereich
Bücker, M., Kenkel, J., Hördt, A. (Institut für Geophysik und extraterrestrische Physik, TU
Braunschweig)
Hanstein, T. (KMS Technologies – KJT Enterprises Inc.)
V17
Magnetotelluric study in northeastern Botswana
Marion P. Miensopust, Alan G. Jones, Mark R. Muller, Mark P. Hamilton, Xavier Garcia, Rob L. Evans,
Patrick Cole, Tiyapo Ngwisanyi, David Hutchins, C.J.S. Fourie, Heilke Jelsma, Theo Aravanis, Wayne
Pettit, Sue Webb, Jan Wasborg, and The SAMTEX Team
The proposed boundaries of geological terranes in northeastern Botswana are mainly based on regional
magnetic and gravity data, because there are not many outcrops available due to the thick Phanerozoic
cover rocks. The extent of the Zimbabwe craton into Botswana as well as the location of the boundaries to
its neighbouring mobile belts (Limpopo Belt, Magondi Mobile Belt and Ghanzi-Chobe Belt) are not very
well known. Magnetotelluric (MT) profiles of the Southern African MagnetoTelluric Experiments
(SAMTEX) are present in this area and provide information about lithospheric strike directions and the
resistivity distributions as well as possible locations of terrane boundaries, which verify some of the
proposed terrane boundaries and suggest modification for others.
V18
Imaging the Kaapvaal Craton boundary, South Africa, using Magnetotellurics
U. Weckmann, M. Becken, O. Ritter & M. de Wit
Within the framework of the German-South African geo-scientific research initiative Inkaba yeAfrica
several magnetotelluric (MT) field experiments were conducted along the Agulhas- Karoo transect in
South Africa. This 600 km long transect is designed to cross several continental collision zones, in
particular the boundary of the Kaapvaal Craton with the Namaqua Natal Mobile Belt. MT data from 120
sites across the craton boundary were inverted to obtain a two dimensional electrical conductivity
distribution on a lithospheric scale. The most intriguing feature of the inversion model is the distinct
difference between relatively high conductivities of the metamorphic rocks of the mobile belt und the
extremely resistive rocks of the Kaapvaal Craton. The area of the craton transition is characterized by
resistive blocks extending into the Earth’s mantle intersected by zones of higher conductivity which seem
to correlate with thrust and fault systems of the Gordonia Subprovince and the Marydale Terrane. Both
tectonic structures are believed to have experienced a similar stress field to the adjacent Kaapvaal Craton.
Petrological and seismological data in the area also show strong similarities with measurements on the
craton rather than with results from the mobile belt. Based on the electrical conductivity of the Gordonia
and Marydale rocks we believe that their composition is much more comparable to that of the Archean
Kaapvaal rocks than to rocks of the Namaqua Natal Mobile Belt. With our MT results the discussion of
the location of the craton boundary at depth is resumed.
V19
Using Amphibious Magnetotellurics to image Hydration and Dehydration of the Costa Rican
Subduction Zone and to demonstrate the bathymetric effect on marine data
T. Worzewski1, M. Jegen1, G.Kapinos2, H. Brasse2
1
SFB574, IFM-Geomar, Kiel
2
FB Geowissenschaften, Freie Universiät Berlin
We present an image of the electrical structure of the Costa Rica subduction zone based on an amphibious
magnetotelluric (MT) profile.
In the framework of SFB 574 (‘Volatiles and Fluids in Subduction Zones’), we deployed 11 stations on a
200km long marine profile, where the Cocos Plate subducts beneath the Caribbean plate.
We will present the marine data and its processing, with special focus on the recorded transfer functions
having unusual shape in relation to a bathymetric effect that shall be discussed.
We also will show final modeling results and their interpretation:
The data set revealed a very low electrically conducting oceanic lithosphere entering the subduction zone.
Upon entering the subduction, near the trench, the oceanic lithosphere undergoes a moderate
enhancement in conductivity down to deep crustal and upper mantle regions, which may be attributed to
hydration caused by water penetrating along bending related faults and cracks. A first accumulation of
free water caused by subsequent dewatering reactions is observed in the forearc sediments above the
décollement updip of the seismogenic zone.
Further inland, a well conducting zone in the overriding plate, at about 20-30 km depth, may be
interpreted as a fluid trap, while a conductive zone underneath, at about 120km depth, might hint at
dehydration of crust and deserpentinization of mantle.
This feature in 20-30 km depth is observed in land MT measurements on subduction zones all over the
world in comparable distances to the volcanic arc, and thus seems to be a robust feature, but was yet not
recognized as such.
V20
3-D model study to determine the mantle conductivity of the SW Iberian Peninsular using phase
tensor methods
ADÃO Filipe, HEISE Wiebke
Universidade de Lisboa, CGUL-IDL, Lisbon, Portugal
The phase relationship between the horizontal electric and magnetic fields represented by the phase tensor
is undistorted by the heterogeneities present in a geological medium. Its graphical representation allows
the detection of structure in depth and lateral discontinuities of resistivity, like a regional strike or the
presence of an ocean (Caldwell et al., 2004). To test these capabilities, a synthetic 3-D model, based on
the model of Santos et al. (2001), was made to obtain synthetic phase tensors, geographically placed in
the same location as the stations from the profiles I, S, P,O e L, defined by Muñoz et al. (2008), using the
3-D finite difference algorithm described by Mackie et al. (1994). The superior mantle (30-80 km)
resistivity value was alternated between 500, 5000 and 50000 Ωm, in order to observe the resistivity
effect on the rendered phase tensors. The calculated phase tensors were also compared with the real phase
tensors obtained in the field in order to establish common points between model and reality.
Donnerstag 1.10. – 8:30 – 14:45
V21
EM fields generated by finite-length wire sources in 1D media: comparison with point dipole
solutions
R. Streich, M. Becken
In present-day land and marine controlled-source electromagnetic (CSEM) surveys, EM fields are
commonly generated using wires that can be hundreds of meters long. Nevertheless, when simulating
CSEM data, e.g., for the purpose of feasibility studies or within inversion algorithms, these sources are
often approximated as point dipoles. Such an approximation is justified if the source-receiver distance is
sufficiently large and the frequency sufficiently low. However, real surveys often include frequencies and
distances at which the dipole approximation is inaccurate.
We consider horizontally layered media, for which EM fields can be computed using well-known quasianalytical solutions that involve numerical evaluation of Bessel function integrals. In CSEM simulations,
such 1D solutions are also an important component for computing background fields in higherdimensional modeling and inversion. Using these 1D solutions, EM fields due to finite-length wire
sources can be synthesized by representing the wire as a line of infinitesimal dipoles and integrating over
the dipole fields. However, this procedure is computationally expensive, since it requires a large number
of numerical integrations. We employ a more efficient formulation that contains explicit contributions
from the end points of the wire and involves fewer integrals over the wire itself than a corresponding
integration over point dipole fields. With our formulation, we can efficiently simulate complicated wire
geometries by segmenting the wire and computing responses for each segment separately. This is
particularly important for real field conditions on land, where kilometre-long current cables can usually
not be laid out in an exactly straight line. Furthermore, our formulation permits to place both the wire and
the receivers at any depth within the layered medium, an important aspect for marine applications as well
as for borehole geometries. We will show examples of EM fields due to finite-length wires in various
settings over the frequency and distance ranges of typical CSEM surveys, including surface-based and
borehole geometries, and discuss differences to the fields due to infinitesimal dipoles.
V22
A 3-D Model Study for Marine EM Using Vector Finite Elements
Schwarzbach, C., Börner, R.-U., and Spitzer, K. (TU Bergakademie Freiberg)
V23
Three-dimensional FE simulation of magnetotelluric fields using digital terrain models exemplified
for Stromboli volcano
Kütter, S., Franke-Börner, A., Börner, R.-U., Spitzer, K. (TU Bergakademie Freiberg)
V24
Towards 3D joint inversion of full tensor gravity, magnetotelluric and seismic refraction data
Max Moorkamp (1), Marion Jegen (1), Richard W Hobbs (2), Alan Roberts (2) and Bjorn Heincke (1)
1. IFM-GEOMAR, Wischhofstrasse 1-3, 24149 Kiel, Germany.
2. Department of Earth Sciences, University of Durham, Durham, United Kingdom.
Joint inversion of different datasets is emerging as an important tool to enhance resolution and decrease
inversion artifacts in structurally complex areas. Performing the inversion in 3D allows us to investigate
such complex structures but requires computationally efficient forward modeling and inversion methods.
Furthermore we should be able to flexibly change inversion parameters, coupling approaches and forward
modeling schemes in order to find a suitable approach for the given target.
We present a 3D joint inversion framework for scalar and full tensor gravity, magnetotelluric and seismic
data that allows us to investigate different approaches. It consists of two memory efficient gradient based
optimization techniques, L-BFGS and NLCG, and optimized parallel forward solvers for the different
datasets. In addition it provides the necessary flexibility in terms of model parameterization and coupling
method by completely separating the inversion parameters and geometry from the parameterization of the
individual method. This separation allows us to easily switch between completely different types of
parameterizations and use structural coupling as well as coupling based on parameter relationships for the
joint inversion.
First tests on synthetic data with a fixed parameter relationship coupling show promising results and
demonstrate that 3D joint inversion is becoming feasible for realistic size models.
V25
Joint Inversion of Magnetotelluric and Surface Wave Data in an Anisotropic Earth
E. Roux (1), M. Moorkamp (2), A.G. Jones (1)
(1) Dublin Institute for Advanced Studies, School of Cosmic Physics, 5 Merrion Square, Dublin 2,
Ireland
(2) IFM Geomar, Wischhofstrasse 1-3, 24148 Kiel, Germany
This work involves inverting simultaneously surface waves dispersion curves and long-period
magnetotelluric measurements (sensitive to shear-wave velocity and electrical measurements
respectively) in a one-dimensional anisotropic media. Assuming that seismic and electrical anisotropy
have a common origin, we can thus expect superior resolution of azimuthal anisotropy for lithospheric
and sub-lithospheric depths combining these two techniques.
We have examined the capabilities and limitations of this new approach with synthetic datasets and
obtained encouraging results.
Another convincing way to validate the algorithm is to apply it to real datasets. However, finding a
suitable site to apply this new method remains challenging as we need good quality MT and seismic
measurements for coincident sites. Central Germany is a good candidate for such an inversion because of
existing knowledge and data.
Here, we present some tests with synthetics datasets as well as a first application of such a joint inversion
in anisotropic media to a real dataset from Central Germany.
V26
“Grundwasserkontamination bei Roorkee/Indien: 2D Joint Inversion von Radiomagnetotellurik
und Gleichstromgeoelektrik Daten”
P. Yogeshwar1, B. Tezkan2, M. Israil3
Universit¨at zu Köln, Institut f¨ur Geophysik und Meteorologie
1
: [email protected], 2: [email protected],
3
: [email protected] (Institute of Earth Sciences, IIT Roorkee/India)
Die hier vorgestellte Arbeit wurde in Zusammenarbeit mit dem IIT-Roorkee (Indian Institute of
Technology/ Roorkee) im Rahmen eines deutsch-indischen Partnerprojektes mit dem Titel: “Groundwater
contamination due to waste disposal and aquifer characterization around Roorkee using integrated
Geolelectric techniques” durchgeführt.
Das Hauptanliegen des Projektes besteht in der Anwendung geophysikalischer Methoden zur
Abschätzung der Gefährdung der Aquifersysteme der Region um Roorkee. In der landwirtschaftlich
geprägten Region um Roorkee ist der Einsatz von Düngemittel sowie die Bewässerung der Felder mit
Abwasser gängige Praxis, wobei das Abwasser durch offene, teilweise nicht betonierte Kanäle
transportiert wird. Die umliegende Landbevölkerung bezieht ihr Frischwasser oftmals aus Brunnen, die
aus oberflächennahen Aquiferen gespeist werden. Eine Gefährdung dieser oberflächennahen
Aquifersysteme durch den praktizierten Umgang mit Abwasser und Düngemittel ist nicht auszuschließen.
Im Rahmen dieser Arbeit wurde ein landwirtschaftlich genutztes und stark mit Abwasser bewässertes
Gebiet nahe einer Müllkippe mit den Methoden der Gleichstromgeolelektrik und der
Radiomagnetotellurik profilhaft vermessen. Hierbei wurde das vierkanalige RMTF Gerät der Universität
zu Köln benutzt, welches im erweiterten Frequenzbereich von 10 kHz bis 1 MHz misst. Die einzelnen
Profile wurden neben Benutzung von gängiger 1D und 2D Auswertesoftware mittels eines neu
entwickelten 2D Joint Inversionsprogrammes invertiert und interpretiert. Das Ziel ist durch die
Anwendung der 2D Joint Inversion verbesserte Untergrundmodelle zu erhalten und eine Aussage über die
Kontaminationsverbreitung und gegebenfalls Ausbreitungsrichtung von Kontaminationsfahnen machen
zu können.
V27
Improvement of the geophysical imaging by MT and Gravity joint inversion: Application to
Turkana region, Northern Kenya.
Abdelfettah1,* Y., P. Tarits1, S. Hautot1, M. Maia1 and J-J. Tiercelin2
1
IUEM-UBO, UMR CNRS 6538 “Domaines Océaniques”, Plouzané, France
2
Géosciences Rennes, UMR6118, Université de Rennes, France
*
Now he is in Neuchatel University, Suisse
Understanding geology from geophysical investigation is best when information is obtained from
different kinds of data. A single method may not have sufficient resolution to provide the expected
information. Joint inversion is a step forward to quantitatively combine data of different nature. Here, we
present a solution for the joint inversion between MT and gravity data. The depth resolution but poor
spatial coverage of MT data may be complementary of gravity data with excellent spatial coverage but
little vertical resolution. Joint inversion may be considered in two different ways, petrophysical or
structural. Joint inversion technique based on structural approach is developed and applied to crust and
upper mantle imaging of the Turkana Rift (North of Kenya), in the East African Rift. The Turkana area is
the transition zone between the Eastern and Main Ethiopian rifts. The geology is comprised of thick basalt
layers on top of sandstones and bedrock. Seismic studies suggested the presence of Paleogene sediments
underneath the sandstones but this still remains uncertain because of the poor data quality due to the
important basaltic cover. We jointly inverted magnetotelluric (MT) and gravity data collected along
profiles on the western bank of Lake Turkana. To achieve this result, we developed a joint inversion
algorithm based on a common structure approach for both MT and gravity. A preliminary MT model is
obtained from which a prior density model is derived from the joint MT-gravity inversion. The aim of
work is focused on two scales: the basins and the crust. We imaged two basins in the area where the data
are acquired. The result confirms some previous information and brings new information for the basin's
structure. For the crust, the models obtained showed conductive bodies with low densities in the lower
crust. These anomalies can be related with a melt material which might come from the upper mantle.
V28
Integrated nonseismic geophysical studies to assess the site effect of the EUROSEISTEST area in
Northern Greece (IGSEA)
Marcus Gurk
This project aims to assess site effects in the surrounding area of the EUROSEISTEST site in Northern
Greece by means of low-cost integrated nonseismic geophysical methods that are capable of detecting
vertical geotectonic boundaries and fault zones with high accuracy and are able to confine and improve
one of the first 3D resistivity inversion models of the area. Engineering seismology is a multidisciplinary
field of research, covering the entire spectrum of the seismic-hazard assessment problem: earthquake
source (seismicity, detph range, etc.), propagation path (seismic-wave propagation and attenuation) and
local site effects (faulting mechanism, fault geometry, geophysical parameters for the layers down to the
top of basement, water migration, hydrothermal activity, etc.).
To overcome problems in the MT database and to confine the 3D resistivity model, IGSEA will use a
magnetic survey aimed to identify differences between the MT model and the magnetic maps that can be
associated with vertical structures and to perform a joint 2D inversion of MT and magnetic data along
hereafter selected profiles. In a second stage of IGSEA, Radio-Frequency Electromagnetic techniques
(RF-EM & RF-EM_grad), novel Transient Electromagnetic methods (TEM, Hoerdt et al., 2000; Scholl et
al., 2008) and Radio- Magnetotelluric (RMT; Bastani, 2001) will be applied to map and image the
identified vertical structures followed by an integrative self-potential tomography to estimate the actual
hydrothermal regime.
V29
Airborne EM sea ice thickness sounding: Forward modelling and hardware developments
S. Hendricks1, C. Haas1,2, L. Rabenstein1, J. Lobach3
1) Alfred-Wegener-Institute for Polar and Marine Research, Bremerhaven, Germany
2) University of Alberta, Dept. of Earth & and Atm. Sciences, Edmonton, Alberta, Canada
3) Ferra Dynamics Inc., Mississauga, Ontario, Canada
In the recent years, airborne frequency-domain EM has became the de-facto standard for regional sea ice
thickness surveys and a validation tool for satellite observations in the Polar Regions. The Alfred Wegener
Institute operates single-frequency Birds (4 kHz) with Helicopters and with a DC3-Turbo aircraft in the
Arctic since 2009.
In general the conductivity of sea ice is negligible compared to the high conductivity of sea water.
Therefore, the vertical conductivity distribution of a level ice floe can be approximated by a homogenous
halfspace, whereas the sea water represents the only conducting layer. This 1D approach allows efficient
sea ice thickness retrieval. Frequent ice deformation zones however, feature significant sub-footprint scale
variability of sea ice thickness and conductivity. A 3D forward model, based on the finite-elements
toolbox Comsol Multiphysics, is used to assess the error of the 1D method over deformed ice.
In the future, the forward model should be used to estimate the feasibility of enhanced data processing
over deformed ice. Especially the internal conductivity of blocky ice structures is of interest, which can be
related to the internal sea water content. The large interface surfaces between ice and water of these
structures are vulnerable to melt processes in the warming Arctic Ocean.
V30
DEVELOPMENT AND TEST OF A FIXED WING AEM SEA ICE THICKNESS SOUNDER.
Lasse Rabenstein, Alfred-Wegener-Institute, Bussestr. 24, 27570 Bremerhaven, Germany
Stefan Hendricks, Alfred-Wegener-Institute, Bussestr. 24, 27570 Bremerhaven, Germany
Christian Haas, University of Alberta, 1-26 Earth Sciences Building, Edmonton, AL, Canada, T6G 2E3
John Lobach, Ferra Dynamics Inc., Mississauga, ON, Canada, L5L 3B9
With five years of successful helicopter electromagnetic (HEM) sea ice thickness measurements the
Alfred Wegener Institute (AWI) decided to construct an EM platform on a fixed wing aircraft in an
attempt to overcome the helicopter flight range restrictions. The system operates in the frequency domain
with 1990 Hz and a vertical coplanar coil configuration. The primary field voltage is electrically
attenuated on the receiver coil which allows for increased amplification and resolution of the much
smaller amplitude secondary field voltage. Before data are converted to ice thickness a correction for
electronic drift and orientation effects is applied. First test flights show that the ice thickness accuracy of
the fixed-wing system lies only between 1 m and 2.5 m in comparison to 0.1 m for the HEM systems. The
lower accuracy is probably caused by electrical noise of the airplane engines and coil motion.
V31
ORIENTATION TRACKING METHOD FOR MOBILE GEOPHYSICAL MEASURING
SYSTEMS
Johannes B. Stoll, Celle
Inertial orientation tracking is based upon the same methods and algorithms as those used for missiles,
aircraft, ships, manned and unmanned vehicles. Inertial angle tracking involves placing multiple
magnetic, angular rate and gravity sensor units strapped down on a moving body. Integration of angular
rate sensor data provides the information necessary to calculate the attitude of the moving body with
respect to a fixed coordinate system, e.g. Earth reference. In combination with geophysical sensors (e.g.
fluxgate, coil systems) inertial orientation tracking is an essential tool for geophysical sensor reorientation with respect to a north-east-down (NED) coordinate system. The algorithm to derive the
orientation of the three-dimensional motion of a borehole tool sensed by a triple of fibre optic rate sensors
is discussed and an instructive example is given.
V32
Durchführung und Auswertung von dreikomponentigen Bohrlochmagnetometermessungen
Virgil, C., Hördt, A., Leven, M., Steveling, E.
Dienstag 29.9. – Poster (16:00 – 18:00)
P01
Zweidimensionale SIP-Modellierung mit anisotroper Leitfähigkeit
Kenkel, J., Hördt, A.
P02
Untersuchungen zur Genauigkeit der Spektralen Induzierten Polarisation
K. Bairlein, A. Hördt, J. Kenkel (TU Braunschweig, IGEP)
P03
SHOTEM Messungen im Arava Valley, Dead-Sea Transform Verwerfung, Jordanien
-Vorbereitung der Wiederholungsmessungen im Dezember 2009 A. Rödder, B. Tezkan
Im Zuge des DESERT Projektes wurden im April 2004 bereits SHOTEM Messungen im Arava Valley
gemacht. Hierbei wurde festgestellt, dass sich die oberflächennahe Seismik gut zusammen mit den
SHOTEM Ergebnissen interpretieren lässt.
Die neuen Profile sollen die alten zu einem 3D Grid ergänzen, geplant ist mit einer 50mx50m
Senderspule und einem Stationsabstand von 50m zu messen.
Desweiteren soll eine Wiederholungsmessung eines Profils durchgeführt werden, um eventuelle saisonale
Effekte in der Hydrologie zu sehen.
P04
Transienten Elektromagnetik und Geoelektrik zur hydrogeologischen Erkundung in der
Haseldorfer Marsch.
Andrea Treichel, Annika Steuer, Norbert Blindow
P05
Data Processing of TEM timelines from first Israel measurement campaign
Michael von Papen
The 2008 measurement in Ashquelon, Israel produced TEM data with a specially developed transmitter in
water and receiver stations on land as well as under water measuring horizontal electric and perpendicular
magnetic components. Offsets vary between 200m and 550m. In this poster data processing of these
timelines – done with SegyPro is decribed and a first Occam inversion is shown. The data is being sorted
by on and off switches (50% duty cycle), levelled, filtered, stacked and analysed by clustering and with
quantiles of normal distribution. This is the basis for upcoming measurements as introduced by K.
Lippert.
P06
Site Effect Assessment in The Mygdonian Basin (EUROSEISTEST area, Northern Greece) Using
TEM and RMT Soundings)
Widodo Widodo, Markus Gurk, Bulent Tezkan
During the project “Euroseistest Volvi-Thessaloniki”, a strong-motion test site (EUROSEISTEST) for
Engineering Seismology was installed in the Mygdonian Basin between the two lakes Volvi and Lagada
ca. 45 km northeast of Thessaloniki (Northern Greece). The basin itself is a neotectonic graben structure
(5 km wide) with increased seismic activity along distinct normal fault patterns. Fluvioterrestrial and
lacustrien sediments (approximately 350-400 m thick) are overlying the basement consisting of gneiss
with schist. To improve the seismic wave propagation model it is vital to know about site effects, e.g. the
geotectonic properties of the area such as the top-of-basement, vertical tectonic boundaries (faults and
basement fracturation) and the geothermal regime.
Preliminary results of the site effects assessment in the EUROSEISTEST accomplished by TEM and
RMT soundings are presented in this poster.
P07
Hidden Mine Shaft Detection with Remote Radio Transmitter Electromagnetic and Self- Potential
Method
Frank Bosch and Marcus Gurk
Abandoned near subsurface mining constructions from the 19th and early 20th century in urbanized areas
placed upon former ore mines near the city of Aachen (Germany), and in many other regions of the world,
provide hazardous risks concerning possible collapses. In many cases, the exact locations of such
constructions are not known anymore. For instance, to map covered shafts of one meter diameter on large
survey areas, high resolution methods with rapid measurement progress are necessary. Enhanced
developments of the traditional Very Low Frequency (VLF) technique such as VLF-gradient and
Radiomagnetotellurics (RMT) fulfill these requirements and can be used as inexpensive survey tools to
characterize the investigation site and to suggest drilling positions and/or other geotechnical intrusive
investigations. Continuous ground-contactless VLF-gradient survey quickly provides maps indicating the
lateral electrical resistivity heterogeneity distribution. Inversions of RMT data provide 2D-resistivitydepth sections and also the interpretation of Self-Potential (SP) data gives information about the nature of
the VLF-gradient anomalies. The successful combination of the three methods for detecting mineshafts is
presented for both an electromagnetic undisturbed and noisy location.
P08
Subsurface conductivity obtained from DC railway signal propagation with a dipole model
Anne Neska
P09
,,Übergangsimpedanzen von Elektroden zur Bestimmung elektrischer Widerstände von Monden
und Kometen.“
A.Hördt, A.Przyklenk (IGEP, TU Braunschweig)
P10
Störkörperdetektion mittels 3-Komponenten-Magnetometerdaten
Sebastian Ehmann1, Andreas Hördt1, Christopher Virgil1, Martin Leven², Erich Steveling1
1: TU Braunschweig
2: Universität Göttingen
P11
Räumlich hochauflösende Vermessung magnetischer Anomalien mit einem unbemannten
Luftschiff.
Paul Gerke Hofmeister, Jan Grosser, Andreas Hördt, Karl-Heinz Glassmeier
Institut für Geophysik und extraterestrische Physik Technische Universität zu Braunschweig
[email protected]
Auf einem Poster soll das unbemannte Luftschiff "Laputa" vorgestellt werden. Es dient der räumlich
hochauflösenden Vermessung magnetischer Anomalien. Aus den Messungen sollen die Lag, Geometrie
und physikalischen Parameter der Störkörper, die die magnetischen Anomalien verursachen, bestimmt
werden. Die magnetische Kartierung von Flächen mit einigen Hektar Größe ist in einer Auflösung, wie
sie bei Messungen mit handgeführten Magnetometern erziehlt wird, in kürzerer Zeit als bei
bodengestützten Messungen möglich. Zudem können schwer begehbare Areale einfach vermessen
werden.
P12
Die deutsche Nordseeküste im Fokus von aero-elektromagnetischen Untersuchungen:
I. Erkundung der Süßwasserlinsen von Borkum
Annika Steuer1, Bernhard Siemon2 und Michael Grinat1
1
2
Leibniz-Institut für Angewandte Geophysik (LIAG), Hannover
Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Hannover
Die Insel Borkum ist die größte der Ostfriesischen Inseln. Sie besteht ausschließlich aus quartären
Sedimenten, wie Sanden, Tonen und Schluffen. Bis Mitte des 19. Jahrhunderts war Borkum zweigeteilt in
Ostland und Westland, getrennt durch einen Priel. Jeder Teil hatte seine eigene Süßwasserlinse. In der
heute zusammengewachsenen Insel äußert sich die ehemalige Zweiteilung noch durch zwei separate
Süßwasserlinsen.
Durch den Orkan Kyrill Anfang 2007 gelangten Salzwassereinbrüche bis an den Rand des inneren
Dünengürtels. Solche Ereignisse, aber auch der Tourismus in den Sommermonaten und der damit
einhergehende verstärkte Wasserverbrauch gefährden die Süßwasserlinsen. Noch kann die gesamte
Trinkwasserversorgung mit inseleigenem Grundwasser erfolgen.
Von besonderem Interesse sind mögliche Veränderungen der Süßwasserlinsen. Daher erfolgten im Jahr
2008 an insgesamt 36 Schlumberger-Sondierungspunkten der Jahre 1991-1995 Wiederholungsmessungen.
Es wurden keine signifikanten Veränderungen der Mächtigkeit der Süßwasserlinsen nachgewiesen.
Mithilfe von hubschrauber-elektromagnetischen (HEM) Messungen konnte die Ausdehnung der
Süßwasserlinsen flächendeckend kartiert und damit das potentielle Trinkwasservolumen der Insel
abgeschätzt werden. Unter Berücksichtigung zusätzlicher Erkundungstechniken, wie der
Gleichstromgeoelektrik, dem Direct-Push Verfahren und Bohrungen, konnten die Ergebnisse der HEM
präzisiert werden.
P13
Die deutsche Nordseeküste im Fokus von aeroelektromagnetischen Untersuchungen:
II. Elbemündung und Langeoog mit Wattenmeer
Gerlinde Schaumann1, Annika Steuer1, Bernhard Siemon2 und Helga Wiederhold1
1
Leibniz-Institut für Angewandte Geophysik (LIAG), Hannover, Germany
Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Hannover, Germany
2
Hubschrauber-Elektromagnetische Untersuchungen bieten ein großes Potential für die flächendeckende
Kartierung der Sedimente der ersten hundert Meter des Untergrundes. Sie sind für hydrogeologische
Fragestellungen von großer Bedeutung, da mithilfe des spezifischen Widerstands die Verteilung sandiger
und tonhaltiger Sedimente im Untergrund sowie Versalzungszonen ermittelt werden können.
Im Jahr 2008 wurden im Rahmen des DAERO-Projektes Vermessungen zu Salz-/Süßwasserfragestellungen im küstennahen Bereich, auf den ostfriesischen Inseln und im Wattenmeer sowie
zur Grundwasserversalzung im Bereich der Elbemündung durchgeführt.
Erste Ergebnisse werden in Form von Karten des scheinbaren spezifischen Widerstands und der
Schwerpunktstiefe für die verschiedenen Messfrequenzen vorgestellt.
P14
The Empirical Mode Decomposition and Spectra based on Direct Quadrature in MT data
processing
Jin CHEN, Marion JEGEN-KULCSAR
SFB 574, IFM-GEOMAR, Wischhofstr.1-3, 24148, Kiel, Germany
Here we present a data processing approach based on the EMD method which can deal with nonstationary MT time series. First, we use the EMD method to decompose the time series into several
Intrinsic Mode Functions (IMFs), then construct the direct quadrature to each IMF to calculate the
instantaneous frequency and instantaneous amplitude, finally, we calculate the marginal spectra to
determine the impedance tensor. We tested the method with synthetic time series and real field time
series. The comparison of the results with the traditional method is given at the end.
P15
Substitute models for static shift (in 2D)
Kristina Tietze, Oliver Ritter, Ute Weckmann
MT practitioners often down-weight apparent resistivity TE mode data prior to 2D inversion to avoid
problems with static shift, obviously assuming that static shift of the TM mode is handled automatically
by the inversion. Static shift is caused by conservation of charges at local conductivity discontinuities
which are small with respect to the inductive scale length. Here we present a class of shallow conductivity
anomalies which can produce significant up- or downwards shifted TM mode apparent resistivity curves
(static shift in the TE mode cannot be simulated with 2D modeling). We examine how this static shift is
reproduced by 2D inversion and show that the results are strongly influenced by grid design and
regularization. We conclude that modern 2D inversion packages are not optimized to handle static shift.
Our results also indicate that it is no good reason to assume that static shift is 0 on average.
P16
A method to determine the magnetotelluric static shift from DC resistivity measurements in
practice
Tripaldi, S., Siniscalchi, A., and Spitzer, K.
P17
Magnetotelluric measurements across the southern Barberton greenstone belt: Data analysis
A. Nube1,2 , U. Weckmann1,2, O. Ritter1, X. Chen1,2 , J. Deacon3, S. MacLennan4, L. Moodley4, M. DeWit4,
G. Willkommen2 , R. Barth2 , R. Streich1,2, K. Tietze1
The Kaapvaal Craton of South Africa is one of the oldest well-preserved continental fragments on our
planet and thus is a key area for studies of geodynamic processes of the early Earth. One major
controversy concerns the importance of plate tectonic processes in Archean times and the time when this
may have been first initiated. Several potential ancient suture zones have been identified at the surface
within the Barberton greenstone Belt, and these provide an ideal natural laboratory to test for possible
subsurface remnants of mid-Archean plate tectonic processes on lithospheric scale.
Within the framework of the German-South African geo-scientific research initiative Inkaba yeAfrica a
high resolution magnetotelluric (MT) field experiment, ELIBABA, was carried out in April/May 2009 in
the Barberton/Badplaas area, eastern Mpumalanga, RSA. A 120 km long profile and two complementary
shorter 60 km long profiles with nearly 100 MT sites provide a good areal coverage of the Barberton
suture and its complex geology.
Strong cultural electromagnetic noise, possibly originating from nearby mines and the DC railway
system, is present in the entire area of investigation. As this man-made noise is much larger than the
natural electromagnetic signal, which we use to calculate the magnetotelluric transfer functions, advanced
data processing schemes have to be used to obtain the cleanest possible sounding curves. This is of major
importance for all later analysis steps as we have to make sure that our impedance tensor represents the
conductivity structure of the subsuface and does not mirror the electromagnetic noise. We present first
results of a standard data analysis in comparison with the remote reference technique and give an outlook
on other approaches aiming to improve the data quality.
P18
Aufbau einer Controlled Source Magnetotellurik am GFZ
M. Becken, R. Streich, O. Ritter
Im Rahmen des Verbundvorhabens GeoEn, welches als Brandenburger Pilotprojekt im BMBF-Pogramm
„Spitzenforschung und Innovation in den Neuen Ländern“ gefördert wird, wird in der MT Gruppe am
GFZ Controlled Source MT (CSMT) etabliert. Ziel in GeoEn ist der kombinierte Einsatz aktiver und
passiver MT zur Abbildung der elektrischen Leitfähigkeitsverteilung im Untergrund zur Erkundung und
Überwachung von CO2-Speichern, geothermischen Reservoiren und unkonventionellen Gaslagerstätten
(shale gas). Im Vergleich zur passiven MT besitzen CSMT-Messungen im Nahfeld von galvanisch
eingespeisten Strömen ein anderes Sensitivitätsmuster, und zeichnen sich v. a. durch erhöhte
Sensitivitäten gegenüber schlechten Leitern aus. Darüberhinaus sind Messungen in urbanen Gebieten mit
passiver MT allein oftmals aufgrund des hohen Rauschpegels schwierig. Insofern sind aktive und passive
MT komplementäre Verfahren zur Erkundung der oberen Kilometer der Erdkruste. Zur Erreichung
unserer Ziele erfolgen parallel technische und methodische Entwicklungen zur CSMT. Dies beinhaltet
einen Stromsender, der von der Firma Metronix neu entwickelt wird, Stromelektroden mit geringem
Ankopplungswiderstand, Feldlogistik und Messtrategien, Datenprozessing sowie numerische
Simulationsrechnungen und Inversionen. In unserem Beitrag stellen wir den Stand der Entwicklungen
und die Projektziele vor.
P19
Analysis of seafloor marine EM data with respect to motion-induced noise
K. M. Bhatt, A. Hördt, (Inst. f. Geophysik u. Extraterrestrische Physik, TU Braunschweig)
T. Hanstein (KMS Technologies - KJT Enterprises Inc.)
P20
Donnerstag 1.10. – Poster (16:00 – 18:00)
P21
TEM with anomalous diffusion in fractional conductive media
T. Hanstein
P22
1D-Simulation von Bohrlochtransientelektromagnetik zur CO2-Sequestrierung
Kirchner, J., Börner, R.-U., und Spitzer, K. (TU Bergakademie Freiberg)
P23
Die Felder des horizontalen elektrischen Dipols im geschichteten Halbraum
Weißflog, J., Börner, R.-U., und Spitzer, K. (TU Bergakademie Freiberg)
P24
Hybrid electromagnetic modelling of large surface loops on rugged terrain
Jochen Lehmann-Horn
P25
Advances in the Numerical Solution of the 3-D TEM Forward Problem
Afanasjew, M., Börner, R.-U., Eiermann, M., Ernst, O. G., Spitzer, K.
TU Bergakademie Freiberg, Germany
Electromagnetic methods have recently gained much broader recognition in the exploration industry.
However, challenging problems in the field of numerical simulation still remain. In this paper we address
recent developments in numerical techniques which are most suitable for an efficient solution of the 3-D
induction problem using transient dipole sources.
We consider the numerical solution of electromagnetic induction due to a transient dipole source located
on the surface of a half-space with an arbitrary 3-D conductivity structure. The spatial discretization
requires an artificial boundary condition to be imposed at the air-earth interface to avoid discretizing the
non-conducting air region. Such an exact boundary condition necessitates an efficient implementation of
Fourier transforms on graded meshes. To avoid the undesired numerical overhead arising from using an
FFT on non-uniform meshs, we precompute the action of the Fourier transform and interpolation
operators on the discretized fields. Since these operators only depend on the mesh size, which remains
constant throughout the time-stepping, the discrete action of the transform and interpolation can be
formally expressed by a matrix-vector product. We give examples which illustrate the gain in efficiency
of the time-stepping of Maxwell’s equations.
As a further aspect, we consider time-stepping via Krylov subspace methods. These are generalizations of
the well-known SLDM method, for which we have developed memory efficient restarting techniques and
a-posteriori error bounds. The time evolution of the electric and/or magnetic field can be expressed
formally by an ordinary differential equation which incorporates a large sparse matrix representing the
discrete curl-curl operator. Its solution is the matrix exponential applied to the vector of initial values.
There exist a number of numerical techniques to approximate solutions to such problems involving matrix
exponentials. Various implementations of this class of techniques will be discussed with respect to
memory requirements, numerical efficiency, and accuracy.
P26
Edge-based boundary element method for 3D RMT modelling incorporating surface topography - a
theoretical study
Zhengyong Ren, Thomas Kalscheuer, Hansrudolf Maurer, Institute of Geophysics, ETH Zurich,
Sonneggstr. 5, 8092 Zurich, Switzerland
P27
A scheme to invert magnetotelluric data in two and three dimensions on parallel computer
architectures: Concepts and applications.
Meqbel N., Ritter O., Egbert G. and Siripunvaraporn W.
P28
Comparison of different coupling strategies in joint inversions
B. Heincke, M. Jegen and M. Moorkamp
Joint inversion is a very powerful strategy to integrate different geophysical data sets. In joint inversions
model resolution of the used methods are generally improved and final results are less ambiguous than the
results from the individual methods. One critical issue, however, is to find an adequate strategy to link
data sets from the considered methods, if the methods are sensitive to different physical parameters (e.g.
resistivity, seismic velocity and density). For subsurface conditions where all considered physical
parameters strongly correlate with each other, one straight-forward implementation is to link the
parameters in the inversion by fixed relationships. This strong but rigid coupling usually provides high
model resolution, but introduces hardly predictable errors if the real parameter relationships differ
strongly from the considered relationships in parts of the investigated region. In such cases strategies with
weaker coupling are preferable.
In this contribution we compare two different coupling strategies for joint inversion: a) Link by a fixed
parameter relationship and b) the use of the relationships as mutual constrains in otherwise separate
inversions. For comparing these two ways of coupling we use a joint inversion of MT and seismic
traveltime tomography and gravity data. Both joint inversion methods are applied to a synthetic 2-D
model that can be associated with a typical sub-basalt problem. We discuss resolution and quality for both
coupling strategies. Moreover, we investigate for both coupling strategies the effects onto the joint
inversion results, if there are significant deviations from the assumed parameter relationships in parts of
the model. For the joint inversion with coupling constraints it is also important to investigate how to find
an adequate weighting of the coupling constrains relative to the data misfit - too weak coupling reduces
the model resolutions, but too strong coupling introduces errors if significant deviations from the assumed
relationships are present in the models.
P29
Common Structure in Different Physical Properties: Electrical Conductivity and Wave S-Velocity
Eric Mandolesi, A.G.Jones, E.Roux, S.Lebedev
Recently different studies were undertaken on the correlation between diverse geophysical datasets. Joint
inversion of different datasets in which a common structure is recognizable reduces non-uniqueness and
may improve the quality of interpretation when different datasets are sensitive to different physical
properties with an underlined common structure. In this poster the possibility to constrain inversion of
magnetotelluric (MT) inversion results using seismic dataset is proposed and tested.
Structural approach proposed by Haber and Oldenburg (1996) is tested; this approach suggest to minimize
difference in structure, following the basic idea that change in physical properties occur at the same
spatial locations.
P30
Working towards modeling of phases over 90° with 2D anisotropic
Inversion
X. Chen1,2 , U. Weckmann1,2, K. Tietze1
1
Helmholtz Centre Potsdam - German Research Center for Geosciences, Potsdam, Germany
2
University of Potsdam, Institute of Geosciences, Germany
Within the framework of the German - South African geo-scientific research initiative Inkaba yeAfrica
three magnetotelluric (MT) field experiments were conducted along the Agulhas-Karoo Transect in South
Africa. This transect consists of several continental collision zones and its respective units (Cape Fold
Belt, Namaqua Natal Mobile Belt and Kaapvaal Craton). Along the profile we can identify areas (>10km)
where phases over 90° occur. Due to the dense site spacing we are able to observe this behaviour
consistently at several sites. Here we focus on the profile section between Prince Albert to Mosselbay.
Isotropic 2D inversion is adequate to explain most parts along the profile but not the abnormal phase
behavior which hints at electrical anisotropy. In order to develop a 2D inversion with spatially constraint
anisotropy, resolution tests and synthetic modeling studies are necessary. In a first step towards the
constraint anisotropic inversion zones with electrical anisotropy were included in a 2D isotropic inversion
model in a trial and error approach to fit the phase curves > 90°.
P31
Thin sheet conductance models from geomagnetic induction data: Study of induction anomalies at
the transition from the Bohemian Massif to the West Carpathians
Cerv, V., Kovacikova, S., Menvielle, M. and Pek, J.
Thin sheet approximation of Earth's conductive structures made it possible to quantitatively estimate
effects of lateral conductivity variations in the Earth long before full 3-D electromagnetic modeling was
practicable. The thin sheet approach is still useful when induction data with limited vertical resolution are
to be interpreted on a surface. It especially refers to collections of long period induction arrows across
large areas and geological units. For this purpose, inverse procedures, both linearized and stochatic, for a
conductance distribution in a thin sheet have been suggested recently. We present a stochastic Monte
Carlo inversion of geomagnetic induction data based on the bayesian formulation of the inverse problem.
An example of the inversion of practical induction data from the transition zone between the Bohemian
Massif and the West Carpathians suggests that an SW-NE anomalous induction zone observed above the
eastern slopes of the Bohemian Massif admits explanation in terms of a phantom effect due to the
superposition of fields of the strong SE-NW Carpathian conductivity anomaly to the east with NW-SE to
W-E trending conductivity zones to the west that conform with the fault pattern of the eastern Bohemian
Massif.
P32
Magnetotelluric investigation of the Sorgenfrei-Tornquist Zone and the NE German Basin
Schäfer, A., Brasse, H., Houpt, L., Weichelt, D.
P33
Imaging fluids and melts in the crust and upper mantle of the Bolivian Orocline, Central Andes
(18°S) – Interpretation of magnetotelluric data
D. Eydam & H.Brasse
Long-period magnetotelluric data were obtained between 2002 and 2004 in the Central Andes to study the
electrical conductivity structure with focus on subduction related processes. The profile extends from the
chilean Coastal Cordillera, crosses the Western Cordillera as the recent volcanic arc and the Altiplano
high plateau in Central Bolivia and ends in the Eastern Cordillera. Horizontal components and the vertical
magnetic field were measured at 30 stations with a spacing of about 10 km.
Subduction related features near the slab like fluid curtains and fluid or melt pathways are best resolvable
by the forearc stations. These stations had to be discarded from further interpretation by 2-D inversion,
due to significant 3-D effects.
However, the inversion revealed severeal features among which the most prominent is a huge conductor
in the upper mantle below the high plateau which may be interpreted as an image of partial melt triggered
by fluid influx from the subducting slab. The high conductivities range up to 0.2 S/m and indicate high
melting rates of more than 6vol%.
The melt should be stabilised by lithospheric mantle material beneath the high plateau which may trap hot
mantle fluids and with this, probably prevent wide-scale crustal melting like this is the case in the
southern Altiplano. Fluids and melts can be transported by mantle convection westward to the arc where
they may be stored in MASH-zones near the crust-mantle boundary; only few material should cross the
thick crust. Some fluids and melts may rise up to the Eastern Cordillera.
This “scenario” indicates a widely hydrated crust and upper mantle beneath the high plateau, which is
consistent with other, significant geophysical anomalies measured here, like high heat flow densities, very
negative Bouguer anomalies, very slow seismic velocities in a highly absorbing crust, elevated
conductivities and a strong mantle signatur of geothermal fluids.
But an interesting question is, how the water, released in the dehydrating slab, may supply a source region
which is more than 50 km (lateral) away? Or in other words, why does the peridotite melt so far away
from the water front?
Some possible answers are presented.
P34
Results of an amphibious magnetotelluric experiment at the South-Central Chilean continental
margin
Gerhard Kapinos and Heinrich Brasse
FU Berlin, FR Geophysik, Malteserstr. 74-100, 12249 Berlin, Germany
P35
Combining magnetotelluric and seismic models for exploration of the Groß Schönebeck geothermal
site: a statistical approach
Gerard Muñoz, Klaus Bauer, Inga Moeck, Oliver Ritter
Geophysical exploration for geothermal resources is often challenging because information on the
parameters of interest such as porosity, permeability, fluid content, etc., cannot be observed directly.
Conventional (seismic) structure images are usually not sufficient to locate potential geothermal targets.
Magnetotelluric (MT) and seismic methods provide information about the resistivity and velocity
distributions of the subsurface in similar scales and resolution. The lack of a fundamental law linking the
two parameters, however, limits a joint interpretation to a more qualitative analysis. Using a statistical
approach in which resisitivity and velocity models are investigated in the joint parameter space, we can
identify regions of high correlation between the two model parameters. Back-mapping of these regions
onto the spatial domain allows us to identify common classes which can then be compared with
lithological information. Application of this technique to a seismic – MT profile in the area of the Groß
Schönebeck geothermal site, allows us to identify a number of classes in accordance with local geology.
In particular, a high velocity – low resistivity class is interpreted as related to salt lows, where highly
fractured anhydrite might produce enhanced permeability.
P36
Magnetotelluric measurements to explore for deeper structures of the Tendaho geothermal field,
Afar, NE Ethiopia
Ulrich Kalberkamp
BGR, Hannover
Electrical conductivity of the subsurface is usually one indicative parameter for geothermal resources.
Due to the high temperatures of around 250 °C encountered at the Tendaho geothermal field (Afar
depression) lacustrine sediments, highly mineralised waters, alteration products (Smectite) as well as
molten or partly molten magma may contribute to low resistivities at various depths.
The Tendaho geothermal field is located in the Afar depression within an area of active extensional
tectonics where the Main Ethiopian Rift, the Red Sea and the Gulf of Aden form a triple junction. The
Tendaho rift is part of the Tendaho-Goba'ad discontinuity where open fissures and active faults are
observed, associated with hydrothermal manifestations.
Previous DC geoelectrical soundings could not achieve penetration depths exeeding 500 m due to
extremely well conducting surface layers. To reach a depth of exploration beyond 5 km the
magnetotelluric method has been applied in a frequency range from 10 kHz to 0.01 Hz (100 s). 33
magnetotelluric soundings have been recorded and 2-dimensionally inverted. Within the modeled
resistivity distribution the shallow (200 to 400 m depth) reservoir can be distinguished from the heat
source, which is forming a dyke-like structure at depths below 7 km. This structure may be interpreted as
part of the NW-SE trending Tendaho rift. In its northwesterly continuation the Dabbahu rift structure is
hit, whose volcanic eruption in 2005 is thought to have formed new oceanic crust on continental
litosphere (Wright et al. 2006).
The MT survey in Ethiopia has been carried out as part of a technical cooperation project with the
Ministry of Mines and Energy represented by the Geological Survey of Ethiopia (GSE) and the Federal
Institute for Geosciences and Natural Resources (BGR) as part of the BGR GEOTHERM programme.
GEOTHERM is a technical cooperation programme financed by the Federal Ministry for Economic
Cooperation and Development (BMZ) to promote the use of geothermal energy in partner countries
(www.bgr.de/geotherm/).
Reference:
Wright, T.J., Ebinger, C., Biggs, J., Ayele, A., Yirgu, G., Keir, D. & Stork, A., 2006, Magma-maintained
rift segmentation at continental rupture in the 2005 Afar dyking episode, Nature, Vol 442, 291-294
P37
Magnetotellurics at the Central American Margin in Costa Rica and Nicaragua
Mütschard, L., Brasse, H.
P38
A permanent array of magnetotelluric stations located at the South American subduction zone in
Northern Chile
Dirk Brändlein1, Oliver Ritter1, Thomas Krings2, Ute Weckmann1,3
1
GFZ German Research Centre for Geosciences, Potsdam, Germany
2
University of Bremen, IUP, Bremen, Germany
3
University of Potsdam, Institute of Geosciences, Potsdam, Germany
In order to monitor the dynamic behavior of an active deep subduction system, the GFZ Potsdam operates
since 2006 a permanent array of combined geophysical and geodetic stations in Northern Chile called the
Integrated Plate Boundary Observatory Chile (IPOC). Magnetotelluric data is recorded at seven out of
eleven sites. The MT measurements are covered by three component long period fluxgate magnetometers
and Ag/AgCl electrodes measuring the two horizontal components of the electric field. EDL dataloggers
are used to record data with a sampling rate of 20 Hz. The objective of the project is to continuously
analyze electromagnetic data to decipher possible changes in the subsurface resistivity distribution, e.g.
as a consequence of large scale fluid relocation.
All seven MT stations are located in the Atacama Desert between the cities of Antofagasta and Iquique in
Northern Chile. The extreme dry ground in this area causes huge problems to record the electric field
continuously with sufficient data quality. Contact resistances in the order of several hundreds of kΩ up to
more than one MΩ and electrodes with leaking electrolyte produce unstable time series of the electric
field and thus scattered MT transfer functions. As the electrodes must be left in the ground unattended for
several months, regular refilling is not possible. One year after the first deployment, dry electrodes were
replaced by new ones which were coated in aluminum foil to prevent the electrolyte from leaking. Some
months later these coated electrodes ran dry again because the reactive foil oxidized. In June 2009 the
electrodes were replaced again, now with a modified coat. Within this presentation the new treble-coated
electrodes are compared to the one-coated ones in terms of their data quality.
The magnetic field data is of good quality. We show time series of vertical magnetic transfer functions
over a time span of nearly two years from different sites and periods. These vertical magnetic field
transfer function time series reveal interesting ultra long period variations which appear to be consistent
over the array of sites.
P39
Evolution of the crust and upper mantle structure beneath the Kunlun Shan in Northern Tibet
from INDEPTH magnetotelluric data.
Florian Le Pape1, Alan G. Jones 1, Jan Vozar 1 and the INDEPTH MT Team
1Dublin Institute for Advanced Studies, Dublin, Ireland
During the INDEPTH (International Deep Profiling of Tibet and Himalaya) project Phase III surveys in
1999, broadband and long period magnetotelluric (MT) data were collected in Northern Tibet across the
Kunlun Fault. The MT stations, placed along the northern part of the Lhasa to Golmud highway, defined
the so-called 600-line profile extending from the middle of the Qiangtang Terrane to the southern edge of
the Qaidam Basin. Previous inversions of the data from the 600-line, used the MT TE-mode, TM-mode
and vertical magnetic field data to derive minimally smooth models. The final model obtained is
characterized by a uniform mid-crustal conductor extending from the Kunlun Shan to the south end of the
600 profile and ending abruptly at the Kunlun Fault. North of the Kunlun Shan, the middle and lower
crust, as well as the upper mantle, appear more resistive. As part of the new INDEPTH Phase IV, a new
MT profile crossing again the Kunlun Shan, east of the 600-line, is planned to complement seismic data
being acquired in the area. To introduce this coming survey, the 600-line data were re-analysed and remodelled centring on the Kunlun Shan to focus on the shape of the resistivity changes beneath the Kunlun
system in the crust and upper mantle. As an alternative to the previous studies, the models generated are
more complex and exhibit greater lateral variability. The preliminary results, using all responses,
highlight the changes in resistivity for the middle to lower crust, from conductive structures south to the
Kunlun fault to resistive structures north to the fault. These lateral changes are representative of changing
physical conditions, such as temperature or water content variability.
P40
Magnetotelluric data from the Tien Shan and Pamir continental collision zones, Central Asia.
O. Ritter(1), A. Rybin(2), G. Muñoz(1), V. Batalev(2)
(1) Helmholtz Centre Potsdam – GFZ, German Research Centre for Geosciences
(2)Research Station of the Russian Academy of Sciences, Bishkek, Kyrgyzstan
We present magnetotelluic (MT) data obtained within the framework of the multi-disciplinary Tien Shan
– Pamir Geodynamic program (TIPAGE). The dynamics of the Tien Shan and Pamir orogenic belts are
dominated by the collision of the Indian and Eurasian continental plates. With the geophysical
components, we intend to image the deepest active intra-continental subduction zones on Earth (the Ndipping Hindu Kush and the S-dipping Pamir zones) and to establish how the highest strain over the
shortest distance that is manifested in the India–Asia collision zone is accommodated structurally.
The MT data were recorded in summer 2008 at 80 stations in the Pamir mountain ranges in Tajikistan and
in summer 2009 at 98 stations the southern Tien Shan in Kyrgyzstan. A typical spacing was
approximately 2 km between BB-only sites and 14 km for the combined BB+LMT sites. The stations
form an approximately 340 km long profile from Osh in Kyrgyzstan via Sarytash, the Kyrgyz-Tajik
border, Karakul and Murgab to Zorkul in southern Tajikistan. We present examples of the MT data, which
is of exceptionally high quality in this very remote area, and show preliminary 2D inversion results.
Dienstag 29.9. – Diskussionsbeiträge (19:30 – 21:00)
PW1
Hanstein, T.
PW2
28 Jahre mit Peter Weidelt: Von der Betreuung der Diplomarbeit bis zu gemeinsamen
Forschungsaufenthalten in Indien
Tezkan, B.
PW3
Konjugierte Gradienten
Spitzer, K.
PW4
Peter Weidelt’s Anisotropy Studies
Pek, J.
PW5
A direct inversion? Application of Propagation Number Analysis - in remembrance of Peter
Weidelt
Weckmann, U.
Mittwoch 30.9. – Diskussionsbeiträge (19:30 – 21:00)
D1
Geophysikalischer Gerätepool Potsdam: Bedarf der Arbeitsgruppe ?
Tezkan, B.
D2
Permanente Remote Referenzstationen in Deutschland – eine konzertierte Aktion des AK EMTF?
Ritter, O.
Donnerstag 1.10. – Diskussionsbeiträge (19:30 – 21:00)
D3
Interpretation der magnetotellurischen Anisotropie: Ansätze nach Ulrich Schmucker
Tezkan, B.
D4
What I always wanted to know...
Weckmann, U.
D5
Geothermal exploration using MT and gravity techniques at Szentlırinc area in Hungary
T. Hanstein*1, Z. X He3, I. M. Þorbergsdóttir2, K.-M. Strack1, and H. Tulinius2, and G. Yu1
KMS Technolog.ies, Houston, TX, USA, 2Mannvit, Reykjavík, Iceland, and 3BGP, Hebei, Chin
1
2-D AMT/MT and gravity surveys were completed in 12 survey areas in Hungary during 2008. The main
objective of this project was to locate potential geothermal targets for alternative energy development in
Hungary. We selected here the Szentlırinc survey area because the first geothermal drilling project just
completed.
The main geothermal reservoir systems found in Hungary are the Mesozoic carbonate–karstic basement
rocks and the Pliocene-Upper Pannonian porous sedimentary formations. The interpretation of 2-D
AMT/MT and gravity focuses on locating potential geothermal areas of the geothermal reservoir system
within Mesozoic fractured carbonate–karstic basement rock for drilling locations.
We estimated that the faults within the north-south strike in the Szentlörinc survey area were developed in
the deep basement. In addition, dense fractures have also been widely developed in the top basement
(limestone) of the survey areas. Thermal energy, which was transported up along the fault systems from
the deep Earth, seems to be the heat source of geothermal formation. A set of thick tertiary deposits, are
located above the formation. Fractured karst limestone and dolomite deeply buried in the Mesozoic
system contain the targeted geothermal reservoirs. Based on the cooperative constrained inversion of
magnetotelluric (MT) and gravity data, we surmise that the geothermal aquifer is characterized by a
relatively low apparent resistivity and low density, while the higher porosity and permeability formations
are unique for faults and fractured zones.
The distribution characteristics of the fault zones with relatively low resistivity and with boundaries
outlined by cooperative constrained inversion of MT and gravity data indicate that the prospective zones
for potential geothermal reservoirs in the Szentlörinc survey area indicate that the mid-northern part of
AMT/MT line 1 and the middle part of AMT/MT line 2 are potential areas for geothermal power plants or
space heating.
The client has successfully drilled a well in Szentlörinc, Hungary using our exploration technology. Hot
water of 80°C, estimated to have a peak heating capacity of 4 MW, was found at depths of 1,620 to 1,790
meters. This discovery was possible by utilizing different geophysical and geological information to
determine the well location. The drilling was targeted by integrating electromagnetic and gravity methods
with seismic and stratigraphic information.