Submitted by Anonymous on Sat, 08/04/2012 - 16:39
Forums
High Arctic Change 2012

I noticed in several of the images that you posted that the length of the lake sediment cores seem to be smaller than what I see with typical marine pulls (depending on the area and the purpose of the core, as we do get small ones as well). I was wondering if there is a general size that is retrieved from specific regions in the lake? Are you using a gravity core retrieval?

Tue, 08/07/2012 - 11:05

Dan Frost

Hello,The cores we are taking are quite a bit smaller than the average marine core though they vary in size depending on the situation. For the most part, our cores this year are on average about 40 cm in length (~8 cm diameter) and being used mainly to determine sediment origin rather than the long term record. The long term record may be anywhere up to 5 meters or so reaching back to the last glacial maximum and those cores are typically taken with a wider diameter tubing not made of polycarbonate. As for coring type, we use a universal corer in that it can be used simply as a gravity corer but also has a percussion head that can be added or not depending on the sediment type. For just about all the lakes we've cored here we've needed to use the percussion head to get into the stiff silt/clay sediments.
Thanks for the coring question!
-Dan

Thu, 08/09/2012 - 11:37

Anonymous

Perfect response, thatnks!