More Antarctica impressions


Following up on the first Landsat 8 images from Antarctica here are a few more impressions of early spring in the far south. You can see the areas these are from in the map below.

First i assembled a more extensive image of the Transantarctic Mountains. You can see the whole mosaic below. The area covered here is about 400 × 700 km. The bow of the Transantarctic Mountains stretches across the upper part of the image separating the East Antarctic plateau on the right from the Ross ice shelf on the left. The Byrd Glacier is prominently visible in the center. At the bottom of the image you can see the open ocean at McMurdo Sound with Ross island on the center left and the McMurdo dry valleys further to the right. Since it is early spring even the ice free areas of those valleys are partly covered with thin layers of snow carried there by the wind making the contrasts between ice covered and ice free parts somewhat fuzzy.

Transantarctic Mountains

Assembling this kind of image with low sun position like here is usually difficult since small changes in the sun elevation lead to large differences in the appearance making combining different landsat scenes seamlessly next to impossible. A sufficient number of images has been collected within just a few days here to allow such assembly with just a few clouds in the north (that’s on the bottom end here) around Mount Erebus and at the south end of McMurdo Sound.

There are a lot of interesting details in this image, i will just show a few below.

The amount of ice carried by the Byrd Glacier to the Ross ice shelf for example is so large that the stresses induced lead to large fractures in the ice shelf which is more than 100 meter thick at this point. This can be seen in the crop below (with the glacier at the lower right end).

Byrd Glacier Ice breakup

The already mentioned McMurdo Dry Valleys are free of ice due to the extremely low precipitation. From the surrounding areas which receive more showfall glaciers reach into the valleys as shown in the following crop. These glaciers essentially evaporate in the dry climate of the valley. There is also some summer melting creating various small streams and several saltwater lakes in the valleys.

McMurdo Dry valley glaciers

The island in the lower part of the image, Ross Island, features the southmost active volcano on earth, Mount Erebus. The following crop shows its summit. There is a thin vane of clouds hanging on the summit on the upper left.

Mount Erebus summit

At the end of Ross Island you can see the edge of the Ross Ice Shelf. The ice shelf is on the upper left breaking into large icebergs. At the lower right you can see a larger area of land fast sea ice attached to the coast of Ross Island. This ice is much thinner than the ice shelf (at maximum a few meters) and will vanish during summer. On the lower edge of the crop you can see the Ocean partly covered by more mobile pack ice.

Ross ice shelf edge

The next mosaic is from the Ellsworth Mountains, the highest mountain range of the continent.

Ellsworth Mountains

The highest part of the mountain range is the Vinson Massif which can be seen in larger in the following crop.

Vinson Massif

Finally there is another smaller area i would like to show. This is the Davis Valley – an area free of ice due to very low precipitation like the McMurdo Dry Valleys and one of the most remote ecosystems of the planet with some minimal plant life that is separated from the rest of the world by several hundred kilometers of ice on all sides.

Davis Valley

I put the mosaics of the Transantarctic Mountains and the Ellsworth Mountains into the catalog – if you are interested in obtaining a print drop me a note.

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