William B. Curry
Woods Hole Oceanographic Institution
|When:||Friday, Oct. 21, 2011, 10:30 a.m. to 11:30 a.m.
Join us for coffee beginning at 10:00 a.m.
|Where:||Seminar Conference Room, 10100 Burnet Road, Bldg 196-ROC, Austin, Texas 78758|
|Host:||Jamie Austin, UTIG|
Following sea trials in 2007, the long coring system on RV Knorr began scientific operations in 2009 with two cruises to the equatorial Pacific, followed in 2010 with four cruises in the equatorial and North Atlantic. In total (including the sea trials cruise), sixty seven piston cores have been recovered. Of these, three were greater than 40 m in length, fifteen were between 35 and 40 m, thirteen were between 30 and 35 m, twenty eight were between 25 and 30 m, and eight were shorter than 25 m. The longest cores recovered were in Pacific Ocean oozes far from the continents and in sedimentary drift deposits at the Bermuda Rise and Corner Rise in the Atlantic Ocean. Nearer to the continents, core lengths were 25 to 32 m, limited for the most part by poorer penetration into coarse-grained continental margin sediments. The core recoveries are comparable to core lengths of the original Giant Piston Core on Knorr in the 1970s (Hollister et al., 1973), shorter than the longest Calypso cores recovered by France's Marion Dufresne, but comparable to typical recovery for the Calypso core (~30 to 40 m). The Knorr piston core recoveries are about two to three times longer than standard UNOLS piston coring systems and thus represent a significant enhancement to coring capabilities for U.S. researchers.
Preliminary results from two expeditions to the North Atlantic provide some insights into the changes in Atlantic overturning circulation since the last glacial maximum 21,000 years ago.