Update #6
1-13 February 2003

Over the past two weeks, we have noticed a change in the weather and it is getting steadily colder as the summer ends.  The average daytime temperatures are now typically anywhere from -2 to -5º C.  This lower temperature actually makes it easier to get around on the snow--there are fewer melt pools and streams as the water refreezes, making it easier to cross snowy areas on foot or by vehicles.  Hopefully, no more Hagglunds will get bogged!
Our first snowfall in late summer.

We've spent this time completing more lab and field work.  We went on another trip to the hut at Robinson Ridge, the Robo''s Hut, where we sampled one more abandoned colony in this area.  After sampling one site here in January, and processed the sediments in the lab, we found that it contained lots of squid beaks, more so than any other site we had sampled this season.  I was curious as to why this was and wanted to sample one more site in this area to see if it was the same.  We traveled over to the hut by Hagglund one evening, about an hour drive, and had no trouble getting there. We spent the night at the hut, then excavated a new site the next day.  The weather held for us and we were done by noon and drove back to the station. The next day, we processed this sample and I was somewhat surprised to see that it contained hundreds of squid beaks, much more than I expected!  It also contained fish bones and otoliths, or ear bones that can be identified to the species of fish they are from based on their size and shape.  So, it was real interesting to find that the sites at Robo's are a little different from the rest.

How we sort the fine sediments for otoliths and squid beaks.
Close up of the fine sediments as they are sorted, little by little.

An otolith is found amongst the sand grains.
A squid beak found during sorting.

           Why these sites have so many squid beaks in them may be related to their age. I don't think squid beaks preserve well in the sediments over hundreds to thousands of years.  If the site is relatively young, less than 500 years old, then the squid beaks are still preserved while older sites probably no longer have them left in the sediments--they have disintegrated from the constant freeze/thaw in the soils.  To test this, we excavated two more sites that I knew were relatively young. These sites were on Peterson Island, about 10 miles to the south of the station. We had visited this island one day earlier in the season and learned that it had over 140 abandoned colonies on it. Now, we returned to sample a couple of these.

Using a zodiac at Casey Station.
View on Peterson Island looking south with Browning Peninsula in the back left.

To get to Peterson Island, we left by zodiac on 11 February.  Since there were two others going with us that wanted to do some other work on the island, and because of all of our field equipment and supplies, we had to take three zodiacs.  We left at 7:30 am and it was a cold morning with 10-15 knot winds. The ride out was long, cold, and wet, but we made it there by 10:30 am.  There is a small hut, called an 'Apple' (see photo in the photo album) where we could get out of the wind and cook our meals.  After warming up there, we went to work and excavated one site that afternoon. The next day, we dug one more site. Both are fairly young in age as you can see all the bones and even feathers still preserved in the sediments.  Between the two sites, we brought back 22 bags of sediments to wash and process in the lab.  These two sites also were the last abandoned colonies I will be excavating here and brings my total sample up to 17 sites, the most I've ever done in one season.

 

A large male Southern Elephant Seal rests on the island.
A penguin chick bone (a femur) from an abandoned colony.

Peterson Island has more to it than penguin colonies. There are lots of ventifacts here, carved by the nearly constant winds off the glaciers on the continent just to the south and east of the island.  In addition, there is an historic cairn that was placed here by the U.S. Navy in 1948. It's called the Proclamation Cairn as it was constructed to leave a canister with a note and a U.S. flag inside that claimed this region of Antarctica for the United States. Later, the U.S. turned over this claim to Australia.  The original proclamation document is no longer in the cairn, but preserved in the archives at Casey Station.  Instead, a copy of the document is in a metal canister under the cairn with the original flag and a visitor's log book inside.

A ventifact, honeycombed by the wind, on Peterson Island.
Steve and Rodney by the U.S. Proclamation Cairn.

We'll spend the next few days processing our samples from Peterson Island and then I can report to you our findings--will there be lots of squid beaks in these too, because they are so young, or will the Robo's sites remain unique in that respect?  I'm anxious to find out and will tell you the results in the next update.

Steve Emslie