Sunday, January 10, 2010

Hola, Amigos!

People are very friendly at sea. Still, Ted Scambos spends an awful lot of time talking about his amigos. But it turns out that these are no ordinary friends - they're Automated Meteorology-Ice-Geophysics Observing Stations.

The area that we'll be visiting used to be a huge ice shelf, called Larsen B. It collapsed 2002, losing 3320 square kilometers (1,282 square miles) of ice. One of the goals of this research cruise is to figure out how that happened and what it means for the rest of the area. Only a small piece of Larsen B, the Scar Inlet Shelf, remains.

Before this cruise, Ted and his team tested the hypothesis that when there is a lot of water sitting on an ice shelf, it works its way down into cracks in the ice and causes the ice shelf to break apart. Normally, the pressure of the ice is enough to keep small cracks from growing. But this time, there was so much water that the cracks were pushed all the way open and the ice sheet broke apart.

How did he test this hypothesis? With AMIGOS! AMIGOS are machines that keep track of their location, the temperature of the air around them, and the thickness of the ice underneath them. They even take photos and send all of this information back to Ted. Ted put AMIGOS out on icebergs and saw that there was a lot of melted water on the icebergs right before they came apart. Their temperature was near the freezing point of water, which is very warm for an iceberg. These results were consistent with the hypothesis that water on the ice causes them to break apart.

But to get stronger proof, Ted is putting newer, better AMIGOS on the Scar Inlet shelf to see exactly what happens. If the hypothesis is correct, they should see more and more melted water on the surface of the ice before it breaks apart. Here is a picture of an AMIGOS on an iceberg, and one of Ted working on a thermometer for one of the new AMIGOS. Just so you know, he isn't only interested in how icebergs and ice shelves break apart. He's also monitoring what happens to glaciers after the ice shelves around them are gone, but we'll cover that in another post.

(Photo originally published in Journal of Glaciology, reproduced with
permission of the author)

1 comment:

  1. A few more questions for you, from Noam:
    - who drives the boat? How? Can you post a picture of the driver?
    - I know you study the ocean, but how do you get to study the water if you're on a big boat and the water is down below?
    - Where do you sleep?