The rock and ice mechanics lab at Lamont-Doherty is led by PIs Heather Savage, Christine McCarthy and Ben Holtzman. We are in the process of growing our lab and building our experimental program. Along with a team of postdocs, undergrads, grads, and longtime staff engineer Ted, we are rehabilitating and revamping some of the old equipment and building new rigs for exciting new experiments on both rock and ice. You can follow along with our progress here.

Saturday, 25 October 2014

Open House 2014

On October 11th, Lamont held its annual Open House, during which our doors were open to the public. Most labs or research group put together a booth or presentation to highlight what they do as well as entertain/educate our guests. Despite the rain, we had a huge turn out this year. In the Rock Mechanics lab we had a constant stream of excited kids and adults come enjoy our presentation called "Bending, Sliding, Cracking, Squeezing Rocks". 
 A slider block pulled along by a motor demonstrated stick-slip events that were monitored by a transducer and displayed in real time on a computer screen.
Heather demonstrated reaction driven cracking with a piece of calcium oxide submerged in water.

Hannah discussed similar cracking occurring over longer time scales in expanding mortar within cored sandstone...
…and in naturally occurring peridotite samples.

 I used a rock that Ted had rigged up with strain gages to demonstrate how to squeeze rocks and watch the dial on the analog meter move. 

Saturday, 18 October 2014

Visitor in the cold room

Early this month Tess Caswell a graduate student from Brown University came to visit us and image ice samples with our brand new, cold room-designated microscope and microtome. She risked strange stares from fellow passengers as she lugged a dewar of liquid nitrogen onto the Amtrak train, through Grand Central, and out to Queens via subway.
In the outer refrigerated room at Lamont, she developed a protocol for breaking off bits of sample and affixing them to thin section slides. She used tweezers and razor blades and worked on top of a metal platform that sat in a small cooler filled with liquid nitrogen
Then she braved the cold (-29degC!!) to spend time microtoming the samples. She first tried transmitted light mode on the microscope and thus needed to shave the samples until they were very thin. Later she tried reflected light and was able to keep the samples relatively thick.

Ultimately the thick samples in reflected light proved to be the best for imaging grain and sub-grain boundaries in her previously deformed samples. Great images, Tess!
She plans to come out again soon and try to also determine orientation of the grains.