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RRS James Clark Ross JR20090804 (JR175)

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS James Clark Ross (74JC)
Cruise identifierJR20090804 (JR175)
Cruise period2009-08-04 — 2009-09-11
StatusCompleted
Port of departureFalmouth, United Kingdom
Port of returnImmingham, United Kingdom
PurposeResearch
ObjectivesMarine geophysical and geological investigations of past flow and stability of a major Greenland ice stream in the late Quaternary

The aim of cruise JR175 to the West Greenland continental margin and Baffin Bay was to collect blocks of marine geophysical data using EM120 multibeam swath bathymetry and subbottom profiling, as well as transects of sediment cores using vibro-, box, and gravity coring from the continental shelf, slope and adjoining deep-sea basin offshore of Jakobshavns Isbrae in order to answer a number of scientific questions including:
- How long has this ice stream been in existence, what were its dimensions during past glaciations and particularly the LGM?
- When and how rapidly did it last retreat from the continental shelf of Greenland?
- What are the processes responsible for the high flow velocities of this ice stream and what are the major controls on its location?
- What is the nature of sedimentation associated with Jakobshavns Isbrae and has it undergone large-scale collapse prior to modern times?
Chief scientistColm O'Cofaigh (University of Durham Department of Geography)
Cruise reportRRS James Clark Ross JR20090804 (JR175) cruise report jr175.pdf (1.06 MB) 
Ocean/sea areas 
GeneralThe Northwestern Passages - Baffin Bay
SpecificWest Greenland and Baffin Bay
Track chartsRRS James Clark Ross JR20090804 (JR175) cruise track — jr175trk.pdf (0.19 MB) 
Measurements 
Physical oceanography 
BathythermographQuantity: number of profiles = 33
Description: XBTs collected for underway correction of EM120 multibeam swath bathymetry data
CTD stationsQuantity: number of stations = 7
Description: CTD stations.
Geology and geophysics 
Core - soft bottomQuantity: number of cores = 55
Description: 46 vibrocores (up to 6 m in length), 3 gravity cores (up to 6 m in length), 6 box cores (up to 0.49 m long)
Multi-beam echosoundingQuantity: activity duration in days = 28
Description: EM120 multibeam swath bathymetry data collection
Other geological/geophysical measurementsQuantity: activity duration in days = 28
Description: TOPAS sub-bottom profiler data collection