7 weeks 2 days
Third Time’s A Charm?
Submitted by Dena Rosenberger on Wed, 11/21/2012 - 21:33
Where are we now?
Hole U1412C, off the western coast of Costa Rica, in the Pacific Ocean. Our coordinates have changed slightly to 8°29’ N, 84°8’ W. Some rain this morning. Air temperature is 28 °C (82 °F) and the water temperature staying steady at 33 °C (91 °F).
Scientists at Work
So, yesterday we had trouble completing the downhole logging, so we pulled out, followed environmental guidelines for leaving a drill hole, and moved the JR about 20 meters (66 feet) N/NE and started setting up the drill string for the new hole. Today, we will start preparing to core and wash the hole down to about 300 meters below sea floor (mbsf). Keep your fingers crossed.
If you have ever been driving along a road and noticed in a roadcut that there were layers of rocks with different colors, and they might have been all wiggly or pushed together, you are looking at the job of a structural geologist. Based on clues they find in the rocks, they interpret what has happened to those rocks since the time that they were first deposited in flat layers at the bottom of a lake or sea.
Sedimentologist Steffen Kutterolf is a teacher and researcher at the University of Kiel and also works at GEOMAR in Germany. He grew up in Weinsberg, and studied at the University of Stuttgart. His specialty is volcanic ash, called “tephra,” found in layers in the ocean floor sediments. Cristina Millan is a Ph.D student at Ohio State University. Her specialty is Structural Geology and Sedimentology, and she has worked in Antarctica studying sediment cores there in the mountains and in the ocean floor.
By studying sediment cores from the land and from the sea, these scientists can transfer the processes that they see on a microscopic scale in the sediment cores into the large-scale processes that might have formed these sediments.
They can also use things like volcanic eruptions to find out the date of specific layers found in sediment cores brought up from the ocean floor. As the volcano spews out ash during an eruption, the ash can be carried by wind over the ocean, where it sinks through the water to the ocean floor and eventually gets buried (See light colored ash layer in core sample above). Some elements found in this ash can change in very specific ways over time. Knowing this, and using the ash layers that we find in the ocean-bottom cores, they can figure out the date of that layer of the core.
Life on Board
Aye, Matey, pirates were indeed spotted onboard the JR today (during a drill). They gave me a rousing “Aaaaaaarrrrrg!” with cutlasses and all! With Ian Alparaque, Bong Cruz, Chris Gavino, Tony Ricardos, and Edgar Bebis.
Who would have thought that ordering a simple quesadilla for lunch would produce this visual and gastronomical delight? Hats off again to our wonderful kitchen staff!
Selling shells at the seashore...West of Costa Rica