Into an Ancient Glacial Lake
Scientists have located the ideal drill site for the first ever exploration of an Antarctic sub-glacial lake, a development that it likely to facilitate a revolution in climate change research and which may lead to the discovery of life forms cut off from the main line of evolution for millions of years. Far below in the isolated dark strange life forms may have evolved isolated form the mainstream. Also down there are frozen relics of bygone ages and climates.
Lake Ellsworth is a subglacial lake located in West Antarctica under approximately 2 miles of ice. It is approximately 6 miles long and is estimated to be hundreds of feet in depth
Since the 1970’s scientists have used radar, seismic and satellite technologies to discover over 150 lakes locked beneath Antarctica’s vast ice sheets. The water beneath the ice remains liquid because of small levels of heat from the Earth’s core coming up through bedrock and from the insulating effect of several kilometers of ice above. The temperature of the subglacial water is below the normal freezing point of water. The largest and most well known of these strange lakes is Lake Vostok in East Antarctica which may be the size of Lake Ontario.
Some of these lakes may be as old as the ice sheet has been in existence, possibly 15 million years in East Antarctica. The age of the water within the lakes will be as old as the ice which melts into them, which in East Antarctic is around 1 million years. Lake Ellsworth has been isolated from the surface for hundreds of thousands of years.
These strange lakes have a very extreme yet viable environment for unusual lifeforms that may have evolved in the dark and cold. The environment is extreme enough so as to more similar to the extraterrestrial potential environment of Europa (the moon of Jupiter than it is to Earth normal.
Deep down in the sediment of the lake bottom, lie undisturbed records of what types of life once was and the the climate that was once there.
The optimal drilling site into the lake has to avoid possible areas of in-coming water that would disturb the sediment, as well as areas of so-called basal freezing — where lake water freezes to the underside of the ice. It also has to avoid any concentrations of trapped gases which could rush up the bore hole to cause a potentially dangerous blowout at the surface.
To locate the optimal drill site, the team had to conduct the first detailed characterization of the physiography of a sub-glacial lake. Between 2007—2009, the lake was subject to a ground based geophysics campaign involving an ice penetrating radar to investigate ice thickness, seismic surveys to calculate lake water depths and flow measurements to calculate how the ice sheet flows over the underlying lake.
The climactic stage in the project will take place in the 2012—13 Antarctic summer when the the actual drilling will be done.
For further information: http://www.antarctica.ac.uk/press/press_releases/press_release.php?id=1212