Glacial lakes with ancient micro-organisms

As a result of geophysical data acquisition over several decades by the international research community, one of the largest (10,000 km2) freshwater bodies in the world has been identified lying beneath the 4 km thick ice sheet of Eastern Antarctica in the vicinity of the Russian Vostok Station.

Lake Vostok is around 230 km long by 50 km wide, has a maximum water depth of over 500 m and contains a sediment record up to hundreds of metres thick. A further 70+ smaller sub-glacial lakes are now known to occur beneath the ice sheet in various parts of the continent, including several in the vicinity of the South Pole.

The lake has generated enormous interest and speculation both within the scientific community and the media. We still know very little as to the origin and nature of this novel environment but data collected over the past five years have significantly increased the scope of the lakes potential scientific relevance. The glaciological and geological setting of the lake has already generated novel information that is contributing to our understanding of the structure and movement of large ice sheets.

The recently completed multi-national ice coring project at Vostok Station has provided further information on the nature of the ice cover overlying the lake and demonstrated the presence of ancient viable micro-organisms in the ice core that could feasibly be a source of propagules to the underlying water body. Recent Russian research has raised the possibility that Lake Vostok may have a rift valley setting similar to Lake Baikal. Establishing an origin from extensional tectonics would clearly have considerable relevance to the debate on the geological evolution of Antarctica. A rift valley origin would also raise the possibility of elevated heat flow and even hydrothermal vents. Both of these features could have profound consequences for biodiversity in the lake and the broader evolution of life debate, which has already been stimulated by findings from the marine abyssal environment. The presence of gas hydrates in the overlying ice sheet suggests that clathrates may exist within the lake, which could have considerable significance for both microbial diversity and biogeochemistry.

Even without such features, the permanently cold, dark, pressurised environment would clearly offer serious challenges to survival, which could again result in novel organisms and processes. It is also proposed that Lake Vostok may have similarities with the sub-glacial oceans that are thought to exist on the Jovian moon, Europa. Lake Vostok could therefore provide a unique technology test-bed and provide an opportunity for NASA to apply its undoubted technical expertise to investigate a novel environment here on Earth.

Following the success of the NSF-sponsored workshop on Lake Vostok held in Washington DC on Nov 7-8, 1998, the Scientific Committee for Antarctic Research (SCAR) announced that a further workshop would be convened in Europe during 1999. It has now been agreed that the British Antarctic Survey will host this workshop in Cambridge between Sept 25-28. The workshop is being convened under the auspices of SCAR with further financial support, reflecting the multi-national emphasis of this meeting, being provided by BAS, National Science Foundation (NSF), the European Science Foundation (ESF) and the National Agency for Space and Aeronautics (NASA).