Dynamically triggered slip on a splay fault in the Mw 7.8, 2016
Geophysical Research Letters
Supporting Information for
Dynamically triggered slip on a splay fault in the Mw 7.8, 2016 Kaikoura (New Zealand)
James Hollinsworth a,b, Lingling Yec, Jean-Philippe Avouacc
aUniversité Grenoble Alpes,
ISTerre, 38058 Grenoble, France
ISTerre, UMR 5275, 38058 Grenoble, France
Laboratory, California Institute of Technology, Pasadena, CA 91125, USA
Contents of this file
Figures S1, S2, S4 and S5
Additional Supporting Information (Files uploaded separately)
Supplementary Movie S3
The following Supplementary Figures provide additional supporting information on: (S1) postseismic deformation field for the month following the 2016 Kaikoura earthquake, obtained
from the correlation of Landsat8 imagery (see main text for further details), (S2) Co-seismic
deformation field for the southwest end of the rupture, obtained from the correlation of
Landsat8 imagery, (S3) an animation showing the results from our P-wave back projection (see
also Figure 2), (S4) a kinematic slip solution for our one-fault model, with accompanying fits to
the P-wave and SH-waveforms, and (S5) a comparison of our two-fault kinematic slip model to
the raw P-wave and SH-wave waveforms.
Figure S1. (a) EW and (b) NS displacement fields for the Kekerengu, Jordan Thrust and Papatea
Faults, spanning the post-seismic period 13th November to 15th December 2016 (by subtracting
“2015.12.13>2016.11.13” from the “2015.12.13>2016.12.15” correlation). De-correlated areas are
shown by sun-shaded SRTM topography, and indicate the presence of cloud in the 13th
November 2016 images.
Figure S2. (a) EW and (b) NS displacement fields for the southwest of the Kaikoura rupture,
including the Kekerengu, Jordan Thrust, Papatea, Hundalee, and Humps Fault Zone, spanning
the co-seismic period (from correlation of Landsat8 images from 13th Dec 2015 and 15th Dec
2016). Fault ruptures are shown in red. Mainshock gCMT solution (dark orange), and the Mw 6.4
aftershock from the 14th November (light orange) are shown at their epicentral locations. (c) to
(e) Displacement profiles across the Papatea, Hundalee and Humps Fault Zone. Location of
each swath profile is shown by dashed black boxes in (a). Blue line indicates fault parallel
displacement (left-lateral for Papatea Fault, and right-lateral for Hundalee and Humps Fult
Zone); the red dashed line indicates fault normal displacements (thrust slip in all cases).
Movie S3. Animation showing the time evolution of source radiation during the 2016 Kaikoura
mainshock (see Figure 3 and main text for further details).
Figure S4. (a) Coseismic slip distribution on a single thrust fault, corresponding to the best
double-couple fault geometry of the gCMT moment tensor solution (red beach ball). The red
star shows the initiation of rupture on the fault (same as USGS-NEIC epicenter). Circles colored
for depth show aftershock and mainshock epicenters from the GNS catalogue
(http://info.geonet.org.nz/display/appdata/Earthquake+Catalogue). (b) Vectors show
horizontal surface displacements predicted by our source model. The color coding shows
amplitude of vertical surface deformation. Blue arrows show coseismic horizontal
displacements produced by the Nevada Geodetic Laboratory (http://geodesy.unr.edu).
Comparison of observed (black lines) and computed (red lines) broadband (c) P-wave and (d)
SH-wave ground velocity waveforms for the one-fault slip model.
Figure S5. Comparison of observed (black lines) and computed (red lines) broadband (left) Pwave and (right) SH-wave ground velocity waveforms for the two-fault slip model
(corresponding to Fig. 4 in main text).