Wednesday, January 20, 2010

Back to the wind farm

The evening sun is always incredible, somehow making everything look even more beautiful than it does during the day! Last night I spent a bit of time enjoying the scenery out and around Scott Base (by the way, today was the Scott Base's 53 birthday!). Scott Base is built on the tip of an island, known as the Ross Island. Around Ross Island is the ice shelf to the east and directly in front of the base (i.e. south) and to the west is the sea ice. Whilst the ice shelf is relatively permanent (and much thicker), the sea ice has become progressively thinner and weaker since I have been here. This is apparent by the number of holes that have appeared in the sea ice resulting in seals emerging to lounge around sunbathing on the ice. Although the sea ice can give you the illusion that you are surrounded by land, there is one phenomena that makes it very clear that something is going on out there in the great white sea in front of the base ... the Ross Sea beneath is, tidal (with just one tidal cycle per day, and holding no relationship with the moon phases) and therefore the water level rises and falls. Whilst we cannot see much of the Ross Sea there are two reminders to us that beneath the ice there is actually water. The first a permanent crack or tide crack that marks the boundary between the ice shelf and the sea ice. The second is this beautiful formation of pressure waves (see photo). As the tides change and the sea ice becomes thinner, the sea ice buckles forming a series of wave like features over the surface. Stunning!!!

Pressure waves out from Scott Base

Today Jana and I spent the whole day up at the wind turbine site working on the VSA. The site was broken into a number of zones and we assessed each zone based on a number of factors. For the first part of the morning we were fortunate enough to have Tanya helping us out, giving us tips on what to look out for. The following photos show a series of the features we were assessing.

Tania and I looking at the surface impressions on the ground as we worked through the VSA check list.

Evidence of vehicle tracks - they are much lighter in colour - grey-brown, compared to the darker grey-red scoria colouring of the surrounding, undisturbed terrain.

Fresh footprints at the site

Although there are a couple of snow patches, the white colouring in this photo is predominantly a salt, presumably calcium carbonate, that precipitates on the rocks. Extensive salt deposits (such as above)are typically an indicator of site disturbance.

Changes in the ground, or desert pavement, are evident throughout the turbine site. E.g. see the difference in the size of the larger cobbles in the foreground and the finer gravels marking increased disturbance in the middle of the photo. The size of the gravels, stones and cobbles in each zone also tend to illustrate different uses for each zone, with finer gravels representing increased disturbance.

Despite the common belief that there is no vegetation in Antarctica, this photo proves otherwise! There are many patches of lichens, as well as some mosses .. and the new cable way runs directly through them!

The field work for phase three of the Crater Hill wind turbine monitoring project is now complete, although I will hopefully have time before I leave to take a few more photos!

But for now my bed is calling!! As always, looking forward to another day in parad-ice!!!

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