“Little” ANDRILL is about to leave us—probably as early as Monday, October 22, 2007, depending on weather. ANDRILL (ANtarctic geologic DRILLing) this year has two projects on the Ice, and they both have teachers involved in research immersion experiences. “Little” ANDRILL is actually the Mackay Sea Valley Seismic Survey (MSV) and “Big” ANDRILL is the Southern McMurdo Sound drilling project (SMS). Eight ARISE (ANDRILL Research Immersion for Science Educators) participants have become close friends as we have traveled and worked together over the past few weeks.
The ARISE Team 2007 - from left: Joanna Hubbard, Louise Huffman, Kate Pound, Bob Williams, Julia Dooley, Rainer Lehmann, Ken Mankoff, Robin Frisch-Gleason
(Graziano Scotto di Clemente, not pictured)
We will miss the MSV teachers as they set off on their traverse of the sea ice, to set up camp near the Mackay Sea Valley. Half of their team will use piston bullies to move their seismic equipment across the sea ice to the camp the carpenters have set up for them. The other half of the team will be flown by helicopter to meet up with the traverse team.
Seismic surveys are the first step in planning for a drilling project. The MSV Project is looking for more information to locate the next place to drill sediment cores which hopefully will provide new, but related information to the sediment cores being drilled by the SMS this season. The seismic team drills a hole and then uses an air gun to generate a loud noise through the hole beneath the sea ice. The “thunder sled” pulls sound receptors behind it, which pick up the reflected sound energy from the layers of sediment below the sea floor. For millions of years, the sediments of the Ross Sea have been building up and wearing down. Because the sediments are made up of different materials, each layer has unique properties, and sound is reflected and refracted differently because of those properties. By reading the returning sound waves, the scientists are able to generate a computer profile of what the ocean floor sediments probably look like. The next step is to interpret the profiles and decide where the next drilling project should take place.
Big ANDRILL, SMS, is “drilling back to the future.” SMS is projected to reach sediments from the late Miocene period, which is expected to provide information about past advances and retreats of the Antarctic ice sheet. With each new meter of core recovered, the scientists are working to unlock the climate secrets stored there. By understanding past climates, they hope to fill in missing pieces of the climate puzzle that will help us explain the rapid changes around the globe we are experiencing today and also help predict what may happen in the future.
BREAKING NEWS: Just as I was going to post this blog, we found out that the weather in McMurdo had been deemed too dangerous to travel, so MSV must stay in town at least one more day. Even though we are glad to spend another night with Robin and Julia, we know they are disappointed to not be able to get going on the next leg of their adventure.
Dr. Greg Browne, leads a "Core Tour" to tell the whole ANDRILL Team what the loggers observed the night before.