"Written" to the Core: A Core A Day

      Sediment coring from the bottom of the world's oceans includes miles of sediment and rock preserved at the USGS Repository here in Golden, CO, USA, as well as places like the Lamont-Doherty Core Repository.

     "Lamont has been actively collecting and archiving sediment from around the world . This is in large part due to Lamont's first director, Maurice Ewing, who instilled a philosophy of "A core a day" for all ocean research vessels. Ewing firmly believing that if we had the sediment we would be able to piece together patterns and stories about our planet, so every day at noon, or thereabouts, the ship would collect a core."

 The cores are used to reveal stories of earth systems, including those of climate cycles. Almost 40 years have passed since the groundbreaking work of the CLIMAP group that used the cores to connect the start of Earth's glacial cycles to changes in eccentricity, precession and tilt. (Hayes, Imbrie and Shackleton, 1976) . Collecting sediment on this Arctic GEOTRACES cruise will help scientists understand more of the stories locked in the oceans. 

    " The length of a core is dictated by the goal of the collection. Early Lamont cores were more about collecting just to gather the material because the ship was there. These early core were generally 6 to 9 meters long, although one incredibly long 28.2 meter core was collected from the Central Pacific. "

      For the sampling GEOTRACES is doing in the Arctic there is a specific goal of collecting just the top few dozen centimeters of sediment and the water just above it, yet at a depth of about 2200 meters. This will require a much different technique than what was used for the long Central Pacific core.

     "The sediment in this region is soft, so the plan was to drop a small general-purpose device called a Mono-corer over the side of the ship with a few small weights on top to help drive the core tube in straight."

     "The corer would hang below the bottom of the rosette of water samplers, far enough below that the rosette would remain 'mud-free' but still able to collect near bottom water samples. The mud in the mono-corer would be held in place by a spring-loaded door that snapped closed once the mud was inside and the tube began its return trip to the ship."

     You can read more about this technique, including the "Cone of Silence" here.

      I have two connections to these cores: a summer spent coring in the Mediterranean Sea on Duke University's Research Vessel Eastward and living in Lamont House (dorm) at Smith College, MA, USA.

       It was a fun summer.  What was your favorite educational summer?

Inspired to the core,
Steph