Can you imagine a continent as big as the United States covered with ice more than four times as thick as the tallest building you have ever seen? If that is hard for you to picture, you are in the same boat as I was when I decided I was interested in glaciology. It was my curiosity as to how things as large as the massive ice sheets covering Greenland and Antarctica can move and rapidly change, that made me want to study glaciers. Knowing that through sea level rise these changes would affect people throughout the globe, perhaps even within our lifetimes, is the little bit of connection to something closer to home that continues to motivate my work.
One of the biggest surprises to me when I started in glaciology was the ease, using satellites, with which we can get information about the way the surfaces of the ice sheets are changing. On the other hand, there are very basic things that we understand fairly poorly about both the basic physics of how ice flows and about things which take place underneath the ice. For example, ice is pretty easy to look through if it is small, like an ice cube in a glass, but when it gets thick and full of bubbles you cannot see all the way through, like ice on many lakes in winter. We have some tools to overcome problems like these, but basic things like the height of the land underneath the ice sheets is something that is difficult to measure, and we do not know very finely.
My research tries to take advantage of the recent data that are available for one particular group of glaciers in Antarctica. I use these data to understand how these glaciers change and to try to gain insight into some of the processes in the ice which are not directly observable. I’m especially interested in how other earth systems – the ocean and atmosphere in particular – affect how the ice sheets evolve. Melting driven by the warm ocean causes rapid thinning where ice from the continent meets the ocean, and the flow of the ice is very sensitive to these changes. I try to better understand how small changes in melt will affect how things change on a larger scale. In some ways this is like coming down a waterslide into a pool. If there is more water, you will slide faster. If you arch your back so you scrape against the slide less, you will move more quickly. My research is like trying to figure out, depending on much water there is and what part of you is touching the slide, when you will splash into the pool and cause the water level to rise.
- David, University of Washington, Seattle, USA