Marie-Helene Cormier1, Ruth Elaine Blake2, Dwight F. Coleman1

OS33A-1039
Windward Passage and Jamaica Channel: New Insights About two Tectonic Gateways of the Northern Caribbean
Marie-Helene Cormier , Ruth Elaine Blake , Dwight F. Coleman , Kelly Guerrier , Nicole Raineault , Nixon Saintilus , Sharon L Walker , Steven Auscavitch and Jamie Wagner
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(1) U. Rhode Island, Graduate School of Oceanography, Narragansett, RI, USA;
(2) Yale U., Dept. Geology and Geophysics, New Haven, CT, USA;
(3) U. d’Etat de Haiti, URGeo-FDS, Port-au-Prince, Haiti,;
(4) Ocean Exploration Trust, Graduate School of Oceanography - U. Rhode Island, Narragansett, RI, USA,
(5) SEMANAH (Haiti maritime and Navigation Service), Delmas, Haiti,
(6)NOAA/PMEL, Seattle, WA, USA,
(7) U. Maine, Orono, ME, USA, (8)Duke U., Durham, NC, USA
In August 2014, The E/V NAUTILUS of the OCEAN EXPLORATION TRUST explored the region delimited by
two deep straits of the northern Caribbean, the Windward passage and the Jamaica Channel. The morphology
of these straits is controlled by two transform faults: The
Septentrional fault, which stretches between Cuba and
Haiti (slip rate: ~13 mm/yr), and the Enriquillo-Plantain
Garden Fault (EPGF), which stretches between Jamaica
and Haiti (slip rate: ~9 mm/yr). Together, these faults
bound the Gonave microplate, an elongated platelet
caught between the North America plate and Caribbean
plates. The Septentrional fault ruptured in 1842, devastating the town of Cap Haitien. The EPGF ruptured catastrophically in 2010 near Port-au-Prince (death toll >
100,000). Tsunamis were associated with both earthquakes. Oblique slip on these two faults is presumably
controlling the history of uplift and subsidence of the seafloor, and has therefore also been regulating the water exchanges between the north central Atlantic and the Caribbean Sea. Multibeam bathymetric data acquired with the
E/V NAUTILUS and direct observation made with the
ROV HERCULES provide new information about the
physiography of the plate boundary.
This project was funded by the Ocean Exploration Trust.
We gratefully acknowledge the crew and the entire team that
sailed aboard the E/V Nautilus during cruise NA050.
C - Thrust fold
Windward passage
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pla
Gonave micro
CUBA
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Septent
Cap Haitien
HAITI
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Eric Calais, http://www.nsf.gov/news/mmg/media/images/haiti5_h.jpg
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JAMAICA
Red lines: Ship tracks
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Port-au-Prince
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Enriq den Fault
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Jamaica Channel
ROV Hercules
A - Navassa Island
Seafloor is jointed near the fold
axis, and beds are upturned on
south side.
B - Windward passage
Lobated
lava flows?
Tortue Island
Septentrional
Fault
Lava flow exposed
at base of Navassa Island ?
Septen
trional
Fault
Rifted
volcanics?
Landslide
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En
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P
illo
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nta
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Gar
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Fa
A tectonized seafloor characterizes the central section of the Septentrional fault. South of Tortue Island, the fault trace is heavily sedmented, but near the top of the northern fault escarpment, the steep wall displays a fractured surface.
A landslide 7 km-wide and 10 km-long has cut into the lower terrace that surrounds Navassa Island. It is unclear how
young this landslide is, and whether it may have been triggered by an earthquake on the nearby Enriquillo-Plantain Garden
fault. Volcanics may be exposed at the base of the north side of Navassa island, which may have been emplaced as part
of the Caribbean Oceanic plateau, or be relict from the volcanic arc that migrated eastward through the area.