R/V Pelican sets sail, data collection begins
Researchers are mapping the seafloor and the seabed between Haiti and Jamaica to assess the likelihood of earthquakes.
R/V pelican. Photo: Cecilia McHugh
R/V pelican Departing Ocho Rios on January 8 and arriving at our first location along the Jamaican Seaway on January 9.
During the day, we run the CHIRP subsea profiler, which allows us to see acoustic images of the seafloor and about 10 meters below the surface, plus multi-channel seismic surveys, which in this case go deep into the ground (~100 m). We collect sediment core and heat flow measurements at night.
The multi-channel seismic survey and seafloor profiling were slow to start due to 15-knot winds, rough seas with waves up to 8 feet, and some minor technical issues. But the coring was so successful that we recovered three gravity corings in water depths ranging from 2500 to 2700 meters.
Gravity core is a metal tube with a very heavy weight (core head) that lowers the core to the seafloor by gravity. It penetrates the sediment beneath the seafloor and restores layers of sediment, like a layer cake, revealing the history of a site, with the oldest layer at the bottom and the youngest at the top.
Together, these measurements and the data we collect in the coming weeks will help us assess the potential seismic hazard along the Enriqueillo-Plantain Gardens fault, which lies between Haiti and Jamaica.
As of January 13th, all systems are fully operational and we are collecting a lot of data.
The coring system we used was the “Big Bertha” with a coring head weight of 3500 lbs. It can recover up to six meters of sediment from the seafloor.Photo: Cecilia McHugh
