100 days of summer

Farewell to the Davis summer expeditioners

This year’s summer crew arrived at Davis on the 6th November 2013 and we are scheduled to depart Davis on the 15th February 2014. By coincidence this gives us 100 days of summer. It is now a vastly different crew when compared to those that stepped off the Aurora Australis back in November. Back then we were basically strangers to each other but now many lifelong friendships have been formed and it will be a sad day when we sail, leaving some of our friends behind for the winter.

A lot has been achieved over the summer. The station has a different look about it with two newly constructed buildings. A fresh coat of paint on some other buildings and a lot of maintenance has also spruced up the station. A lot of science has been completed and there is a sense of overall achievement by those that are set to sail.

A formal dinner was held last Saturday night with the remaining winter crew being the waiters for the evening and giving their summer friends a farewell to remember.

Geoscience at Davis

Last year I managed a geotechnical investigation to assess the viability of a gravel landing area near Davis Station. A number of instruments were left out at the site about 3km north of the station to continue monitoring the physical environment, including an automatic weather station, subsurface soil temperature loggers, cameras, and open holes for manually measuring water table levels. This season opportunistic work has continued around these installations. In addition, a small-scale geological survey of boulder size and distribution has been conducted to understand the depositional history of the area (which provides clues to drainage patterns etc). Part of the investigation is also to assess the environmental impacts of the survey activities undertaken last season as well as investigations done as far back as the 1980s, so work has very much focused on collection of all relevant data (for example noting the presence/absence of birds and seals in the area).

The area in question is underlain by very old (PreCambrian) metamorphic bedrock called the Mossel Gneiss which has a network of almost equally old striking dolerite dykes intruded through it. The whole region is covered in glacially moved boulders, gravel and sand that were deposited out of the ice sheet that covered the area either during the last ice age (which ended about 20,000 years ago), or, as some believe, during earlier ice ages. The area was also under a few metres of sea only 6–7,000 years ago, so the glacial deposits show some evidence of marine reworking of gravel and sand, with  shell deposits amongst it. The soil in the area is very salty as a result, and you can see crusts of salt evaporating from the soil as well as from fresh sea spray throughout the region.

The work this season has been done with fantastic support from the wonderful Davis community. Anyone with technical ability or just an interest has willingly contributed to helping with these tasks, and I would like to express a huge thank you to everyone for their help.

The photos will give you an idea of what work has been done at Davis this summer.

Dr. Barbara Frankel, Antarctic Modernisation Program

Elephant Seals

Whilst the summer expeditioners are packing up to go home, there is another influx of visitors to Davis at this time of year. Juvenile male elephant seals come to several locations in and near Davis to moult. These young males stay at Davis for up to several months where they spend most of their days just wallowing on the beach and play fighting in preparation for real thing when they challenge for a harem. The two main areas at Davis where the seals come to are referred to as the “Wallow” and the “Old Wallow”. These young bulls can weigh up to 3 tonne with mature males weighing up to 4 tonne. It is easy to recognise the seals after a while as they all appear to have individual personalities.

Nick’s cartoon

This is Nick’s last contribution for the summer and again it is a cryptic cartoon. The only difference this week is I will supply the answer. The answer is “nunatak”.

A nunatak is a term widely used in Antarctica as it is an isolated mountain peak projecting through the surface of the surrounding glacial ice.