Sub-EIS-Obs II – Studies and geoscientific observations beneath the Ekström Ice Shelf
Report of the project:
The geophysical-geoscientific expedition „Sub-EIS-Ob II“ was the follow-up campaign of “Sub-EIS-Obs I” and took place on the Ekström Ice Shelf from end of November 2017 to January 2018. The eight expedition members were from AWI, BGR, Polar Research Center (Jilin, China) and Laeisz.
Working area Sub-EIS-Obs
Source: BGR
Transport of the hot water and drilling sledge to the first drilling location. AWI station „Neumayer III“ in background
Source: BGR
During the first part of the campaign, the existing net of reflection seismic profiles was condensed and further extended. Using explosion seismics, the vibroseismic data of season 2016/2017 were condensed and improved at some selected locations. The second part of the expedition was used to conduct shallow drillings to recover samples of the uppermost sediment layers beneath the ice shelf. For this purpose, a 30-40 cm wide whole was drilled into the at this location approximately 200 m thick ice shelf using a hot water drilling system. To recover the samples, different devices were used: Wippermann grabber, gravity corer, UWITEC percussion driller and a vibro corer, which was provided by the Chinese colleagues. To use the time before refreezing and closure of the open hole, these devices were used continuously for about 14 hours. In total, two drilling localities could be finished.
During the first drilling campaign, several short cores could be recovered but also disturbed sediment sampled directly from the seafloor. Additionally, the new samples gave first information about the manifold fauna beneath the ice shelf but also about pebbles in the cores, which derived from the hinterland and/or the underlying bedrock. All samples are stored at AWI in Bremerhaven and will be jointly analysed by AWI and BGR.