January 25, 2006

Today I gave the weekly science lecture at the Station.  I spent most of the day preparing my talk.  I gave  some general background on DMS and DMSP and then talked a bit about our Biocomplexity project.  I tried to make the talk very general because quite a few folks in the audience were not scientists. But they are all knowledgeable and eager to learn about what we are doing here.  It was fun. 

After the lecture Ray, Maria and I decided to go for a little walk in the “backyard”. It was too late for a full glacier hike, so we just wanted to walk up to the base of the glacier and back. Its about a half a mile, over some very rough, rocky terrain.  It was great to get outside in the fresh air after being in all day.  It was also great to get away from the hum of the station.  Each of the buildings has a certain sound to it, from wither the ventilation systems, or in the case of the building where I sleep, the diesel generator.  Its kind of like being on a ship. 

While we were hiking we crossed a little gully with a melt water stream. In the gully the rocks looked like all the other rocks, but these were embedded in some soft mud.  Ray and Maria got their shoes dirty first, but I was going to be more careful.  I cautiously planned a route across but after about two steps, my chosen rocks sank into the mud, and my shoes were covered.  We all had a laugh over that.   Maria wanted my camera and she took a picture of all three of our legs and feet. 

By far the highlight of this hike was listening and watching the glacier.  The glacier was busy tonight, releasing lots of big chunks of ice into Arthur Harbor.    The sounds of the glacier are incredible.  It varies from something like a gunshot, to low rumbles of thunder.  If you watched, you could see pieces of the glacier face start to fall and then the sound would come a few seconds later.  This was because light travels faster than sound and we were probably 2000 feet from the glacier itself. Every once in a while a big chunk would fall into the water and set up a big wave of water that would crash on the shore.

Glaciers are made up of layer, upon layer of snow, which eventually get compressed by its own weight.  In a mere few thousand years you can build up quite a lot of ice in a place that gets a lot of snow.  Yesterday as we were motoring through the brash ice in the harbor, I got a good picture of a big blue ice chunk that revealed the strata (layers) in the ice rather nicely.    Researchers can drill into glacial ice and get a history of what conditions were like when different layers were put down.  There is even a record of DMS emissions in glacial ice – in the form of MSA, a unique degradation product of DMS in the atmosphere.