Pensacola Mountains, West Antarctica: Scheduled Blog Post

Who we are and what we're doing!

Welcome to our project site! We are six National Science Foundation-funded researchers from Pacific Lutheran University, Berkeley Geochronology Center, University of Washington, and the University of Maine who are studying the glacial history of the Pensacola Mountains in West Antarctica.

Our 2011-2012 field season is almost underway! We will spend about two weeks in McMurdo equipping ourselves for another month in the Pensacola Mountains. We spent December 16th, 2010 through January 17th, 2011 in the Pensacola Mountains, where we mapped and sampled glacial deposits along the Foundation Ice Stream. This year, we will revisit last year's field sites, and map new regions of the mountain range.

Our work will track the thinning history of the Weddell Sea Sector of the West Antarctic Ice Sheet, and will also provide insights into ice sheet dynamics, and the history of sea level contribution from this sector of the ice sheet.

In the coming weeks and months, we will use this site to show you our preparations for the 2011-2012 field season, and to share our initial results as they emerge. Please check back to catch up with our progress. Thanks for finding us!

Saturday, January 7, 2012

Scheduled Blog Post - Glacial Geologic Research!

Hi Friends,

This blog entry was written before we left McMurdo! We do not have internet access in the field!

We will typically work in two teams of three. One team used snowmobiles to drag an ice-penetrating radar unit across the ice surface. The second team (usually Greg, Matt, and myself) will climbing the mountains above the ice surface in search of glacial deposits.

Previous studies in Antarctica have shown that the ice sheet used to be thicker and more extensive. This thicker ice sheet would have flowed over the top of most of the mountains in our research area. When glacier ice flows across the earth's surface, it erodes the rock beneath the ice, breaking off portions of this rock and transporting it within the ice. When the ice thins and retreats, these glacially-transported pieces of rock are left behind on rock surfaces. We use these rocks to track past ice thinning and retreat (more on this later!).

Thus, most days, Greg, Matt and I will climb above the current ice surface looking for rocks that are glacially-transported. These rocks will have rounded edges, and flat smooth faces that formed as the rock was transported in flowing ice. We are also looking for rocks that are "erratic," or a different composition than the rock surface beneath it or nearby.

Here are some shots from our work days to give you an idea of what a typical day entails:

We will typically set out from our camp via snowmobile a little after 9:00 AM.

We will always carry a sled with our survival bags on it, in the event that weather stranded us away from camp.

We often walked across rock and snow to access our sampling locations.

We're always looking for evidence that ice used to flow over our sampling locations. In this picture, Greg is pointing out glacial striations, or scratches formed when ice flows over rock surfaces.

When we find these scratches on mountainsides and mountain tops, it tells us that ice used to be much thicker than it is today!

This photograph and the photograph below are great examples of "glacial erratics." They are distinct from the rock surface beneath them and they have rounded edges that are typical of rocks that have been transported by ice.

Last season, Michael kept track of striations and sample locations on maps he made from satellite imagery.

Sometimes the rock is too big to carry home, so we have to hammer a piece off of it!

We always take a lunch break:

Looks like bagel (in Michael's hand) and soup (in Kat's hand) are on the menu. We carry a liter of hot water in a thermos to make soup and hot drinks for lunch.