March 28, 2023

Return of the R/V Pelican to Ocho Rios, Jamaica

As we approached Ocho Rios, Jamaica and completion of our exploration, the science team got together and summarized our brand-new and interesting findings. We mapped the northern border of the Caribbean plate in between Haiti and Jamaica throughout the Jamaica Passage. Here the immersed portion of the plate limit is the Enriquillo-Plantain-Garden Fault. The fault is manifested by a deep trough. This trough includes 3 2.5- to 3-kilometer-deep basins– the Motley, Navassa, and Moran basins– which were the focus of our research study. We collected 50 seismic sub-bottom profiles and 47 sediment cores in the basins.The Enriquillo-Plantain-Garden Fault is plainly “transpressional,” meaning it accommodates lateral and compressional motions. Evidence of compressional movements are typically manifested as folded sediment layers that increase in frequency and amplitude from south to north. This compression is moving a 50-meter-high ridge from north to south. This ridge is the surface area expression of the fault and recommends that interaction in between compression and reducing along the fault is shifting the plate border to the south.Seismic sub-bottom profile line throughout Motley Basin showing folded strata– evidence of compression and shortening along the plate boundary.We prepare for that big earthquakes along the Enriquillo-Plantain-Garden Fault remobilized sediment and formed occasion deposits. The really different sediment types composed of calcareous microfossils and iron-rich mineral grains will assist to recognize the deposits and their sources– microfossils raining from the water column and minerals obtained from exposed basalt outcrops. The ages of the event deposits will yield a record of pre-historic and historic earthquakes along the plate border and assistance to comprehend the geohazards for the populations that inhabit Jamaica and Haiti.The night coring group and the day seismic employee got together upon arrival of the R/V Pelican to Ocho Rios, Jamaica on January 26, 2022. From right to left: Benjamin Freiberg, Cecilia McHugh, Justin Kersh, Victor Cabiativa, Brian Agee, Vashan Wright, Chris Fanshier, Jhardel Dasent, Leonardo Seeber, Richard Kilburn, Matthew Hornbach. Picture: Cecilia McHugh