Sunday, December 7, 2008

Cape Surprise

Hello everyone,

After two weeks in McMurdo, I finally made it out to the field. The outing was a day trip to Cape Surprise to service one of the seismic stations we had installed last year. To get to the station, we took a four hour (one way) flight in a twin otter along the Transantarctic Mountains (TAM). The TAM extend from the Ross Sea to the Weddell Sea along the entire length of Antarctica, and separate the continent into two halves, East and West Antarctica (see map below). The highest peaks rise over 14,000 feet above sea level. They are one of the worlds longest continental rift flank uplifts. This means the mountains were formed during extension and stretching of the continental lithosphere. The exact mechanism for their uplift involves thickened crust (similar to an ice cube in water, the thicker the ice cube, the higher it sits), and warm temperatures in the upper mantle that provide thermal buoyancy forces beneath the crest of the mountains. Rifting began in the late Jurassic or early Cretaceous (roughly 150 million years ago) with most of the uplift occurring in the Cenozoic (the last 67 million years or so). As you can imagine, the scenery was absolutely beautiful. Here are some pictures.



Transantarctic Mountains.


One of the many massive outlet glaciers that flows down through the TAM and onto the Ross ice shelf, draining the East Antarctic ice sheet .


Twin otter on the ground at our field site.


Some of the scenery at our field site.


A shot of us working on the station with the twin otter in the background.


Crevasse field.





It was a pretty long flight so we had to stop and refuel along the way. There are fuel caches placed throughout the continent each year for just such purposes. The pilots carry a pump in the airframe to transfer the fuel from the drums to the plane. Not unlike a stop at your local gas station!


Here's a shot of me in front of our station. The solar panels provide power for the instrumentation which is located in the big orange box (except for the actual sensor itself which is buried beneath the snow and ice). Also note the two small antennas located at the top of the frame. The small dome on the left is a GPS receiver that is used for timing of the seismographs, not location (it records a location as well, but we are only interested in the time). This is necessary so we know exactly when an event occurs, and can correlate that time with other seismic stations around the world. The cylindrical antenna on the right is an iridium satellite modem. This allows us to transmit information from our station to a webpage that can be accessed anywhere in the world. While we do not yet have the bandwidth to transmit the data itself, we can obtain state of health information such as voltages on the power supply, temperature in the box, and small snapshots of the data.


Another massive outlet glacier.



More shots of the TAM.



A good shot of the twin otter.






When we got to the station, we found it had tilted to one side from where we left it a year ago because the snow had been blow out from underneath of the frame. So we had to empty the box and dig down to some hard ice to make a level surface to prevent the whole thing from falling over. We never know what we're going to find when we arrive at a station to service it, but a typical service run involves digging out the station from the snow, replacing any equipment that is broken or malfunctioning, and retrieving the data that was collected over the last year.






Check back in a day or two for a special feature on life at McMurdo research station!

3 comments:

Mom said...

The scenery is beautiful! The explanations were very educational.
HOWEVER, the crevasse field is a mother's nightmare! Remember to always be safe and stay alert. I can't wait to get your next installment. Love, Mom

brian said...

Looks fun. I'm jealous. Keep the great pictures and explanations coming. By the way, I linked to your blog from a post in mine the other day - maybe you'll pickup a few more readers. Stay safe and enjoy yourself out there!
--Brian

Schoene said...

Great pictures Mitchell. Hope all is well and you are staying warm. Most importantly looking forward to taking you out in fantasy football this weekend.

Schoene