Second Author

Michael Studinger and his colleagues have discovered four subglacial lakes in East Antarctica (page 904), to add to the two they found last year. Located two miles beneath the ice surface in the catchment area of the Recovery Glacier, the new lakes are comparable in total size to Lake Vostok, a 15,690 km2 lake buried in Antarctica's interior. But it is their location that makes the lakes noteworthy. Subglacial lakes can drain catastrophically, and the newly discovered lakes are positioned precariously near fast-flowing ice streams on the eastern coast. Studinger, a researcher at the Lamont-Doherty Earth Observatory of Columbia University in Palisades, New York, explains why the Recovery lakes could be a potential hazard.

Why haven't they been found before?

The Recovery lakes region has remained virtually terra incognita because it's out of range of research aircraft. Essentially all we had were data collected on a ground expedition in 1964. Most satellite maps have gaps around the poles because satellite orbits are typically inclined below 80° north and south. The new Ice, Cloud and Land Elevation Satellite orbits have been pushed to 86°, enabling us to determine the elevation of ice surface in this area for the first time.

How can subglacial lakes pose a threat?

These lakes are located at the onset of fast-flowing ice streams. If they drained rapidly this could trigger a faster flow of ice and eventually affect the stability of a significant part of the East Antarctic ice sheet. We have to think about the impacts that such a large influx of fresh water would have on ocean circulation and climate.

What is the most impressive documented lake drain?

Multiple floods have come from subglacial lakes the size of Lake Vostok. These occurred between 12 million and 14 million years ago.

Can you tell whether a catastrophic flooding event is likely soon?

We have only just discovered these lakes and their location. To answer this question we need a more detailed understanding of them. Our current analyses are based on ice-surface data collected from satellites that provide virtually no information on what's underneath. We need to map these new lakes from aircraft equipped with ice-penetrating radar systems. Such data should allow us to understand their dynamic history, their hydrological setting, and their potential for catastrophic change.