News & Events

Grad student talk - West Greenland Cruise JR175: Reconstructing the Quaternary retreat of...

Thursday, October 08, 2009, 4:30PM - 5:30PM

Speaker

Mariah Walton

INSTAAR

Location:

RL-1 269

Full title: "West Greenland Cruise JR175: Reconstructing the Quaternary retreat of the Greenland Ice Sheet."

August and September of this summer saw me aboard the British Antarctic Survey’s RRS James Clark Ross off the West Coast of Greenland. The objective of this JR175 scientific cruise was to obtain geological and geophysical data to characterize the past behavior, extent, and retreat of the Jakobshavns Isbrae—the largest ice stream on Greenland’s West coast. The primary areas of study were Disko Bay and the Vaigat, into which Jakobshavn directly drains, the continental shelf and slope, and the neighboring Umanak fjord system. Swath bathymetry and seismic profile data were collected in tandem with ocean sediment cores (vibro, box, and gravity cores) to provide a comprehensive physical and paleoceanographic data set. Foraminiferal assemblages will be counted at INSTAAR using samples taken from 28 of the 55 cores taken to constrain the retreat and possible re-advance of ice in the Disko and Umanak systems and to correlate changes in ice with changes in Atlantic and Arctic currents. This talk will summarize how bathymetry and seismics relate to core site selection and the cores themselves, how cores are collected and processed, and how forams will be used as paleoceanographic indicators, as well as providing insight into the role of a lowly grad student at sea.