. The Astrobiology Web: Your Online Guide to the Living Universe TM
An Antarctic Photo Album, Volume 1
by Dale Andersen

 About these images
Text and Photographs ©copyright 1996 Dale T. Andersen. All Rights Reserved. Reproduced with permission.

Last update: 20 December 1996

Note: click on thumbnail image to view a full screen version of an image. [Image number, size, and format] are contained to the right of each thumbnail within the caption.

[028, 47K, jpeg] Taylor Glacier and the West Lobe of Lake Bonney, Taylor Valley, Antarctica.

Scott, Evans and Lashley discovered the "Dry Valley" after descending the Taylor Glacier during explorations of the Western McMurdo Sound Region in 1903.

[052, 50K, jpeg] Remote field camp on Lake Vida, Victoria Valley, Antarctica.

The drilling rig to the right of the screen was used to drill through the thick (approximately 17 meters) ice-cover of this lake. Once thought to be frozen to the base, this lake appears to have a saline layer beneath the ice. Samples of the water and bottom sediments will provide information regarding the history of the lake and whether or not life exists beneath the thick ice-cover.

[161, 69K, jpeg] Field camp at Lake Hoare, Taylor Valley, Antarctica.

This is one of several remote field camps in the McMurdo Dry Valleys. The buildings provide shelter and a place to work, eat and relax. Individual tents are used for sleeping giving each person a small amount of personal space.

[179, 48K, jpeg] Underwater beneath the 4.5 meter thick ice-cover of Lake Hoare, looking back at the dive hole.

The tether allows the diver to remain in contact with the surface via a communications system and prevents the diver from getting lost beneath the ice.

[207, 48K, jpeg] Benthic microbial mat community in Lake Hoare.

This mat is composed of an assemblage of organisms including cyanobacteria and diatoms which trap and bind the sediment. Microbial communities similar to the benthic communities found in the McMurdo Dry Valley lakes were the dominate life forms on Earth until about 600 million years ago. These ancient microbial communities left evidence of their existance in the fossil record in the form of structures known to geologists as stromatolites. The earliest stromatolite fossils have been dated to about 3.5 billion years ago. In the McMurdo Dry Valley lakes there are no higher organisms such as vertebrates; all life found in these very unique lakes is microbial.

[209, 65K, jpeg] Dale Andersen collecting samples and making observations of the microbial mat community in Lake Hoare.

[214, 50K, jpeg] Another view of the benthic microbial mats.

These lakes are supersaturated with gases mainly as a result of the thick ice-cover. Above 11 meters, bubble formation occurs. This, in turn, causes large amounts of the microbial mat to tear lose from the bottom of the lake. Some of this material then floats to the underneath side of the ice-cover, is incorporated into the ice, and then is transported to the surface of the ice over a period of about 10 years. The now dry, frozen, mat may be transported via the wind to other locations. If the mat should happen to land in liquid water (during the summer months) the cells will rehydrate and begin to grow again if the necessary nutrients required for growth are available.