We are a group of glacial geologists from the University of Maine, University of California Berkeley, and Dartmouth. Led by Gordon Bromley (UMaine), we will be collecting rock samples from moraines (see below) in the Transantarctic Mountains, which separate the East Antarctic Ice Sheet from the West Antarctic Ice Sheet. Follow us as we embark on a six-week field season in the Antarctic! Have questions about life in the field, or about our research? Email us at ancientmoraines@gmail.com, or comment on this blog! Our first three posts were written by UMaine undergraduate Holly Thomas during our 2015 field season. Check those out to get a feel for what life is like in Antarctica. Read on to find out more about our project:

Why is this blog called Ancient Moraines?

Moraines are ridges of rock and sand left behind by moving glaciers. Once the ice has melted away from a spot on the landscape, the moraines are still visible. Glacial geologists use moraines to determine where ice sat in the past. Our project will look at ancient moraines lain down by the East Antarctic Ice Sheet millions of years ago when the ice sheet was larger than it is today. Here are some pictures of moraines observed during our 2015 field season:

What is the goal of this project?

Did you know that an estimated 55 meters of sea level rise equivalent is locked up in the East Antarctic Ice Sheet (EAIS)? The melting of the EAIS would profoundly affect coastal communities across the globe, so we need to understand how this ice sheet will respond to warming temperatures in the future. In order to understand the future, we must look back to a period of time in the past when the earth was warmer than it is today. We will look to the Pliocene, a period of time ~5-2.5 million years ago when global temperatures were 2-3°C warmer than today, and atmospheric CO2 concentrations hovered around 400 ppm, a concentration similar to today. We aim to see if the East Antarctic Ice Sheet melted, grew, or was about the same size as it is now during the Pliocene using moraines. We will map the locations of these moraines, and will collect rock samples for surface exposure age dating. This dating technique allows us to figure out exactly when a moraine was lain down by the ice sheet so that we can compare the timing of moraine deposition to other climate records. Thus, we can see from the moraine record if the East Antarctic Ice Sheet was larger, smaller, or the same size as today during periods of past warmer-than-present climate.

Check out our field sites page to see where we’re working!