ERS-2 helps detect massive rivers under Antarctica   A photograph of the Dry Valleys in coastal East Antarctica. This is a region where, today, too little snow falls to form ice, yet it is so cold that no erosion takes place. In fact, the surface is reckoned to be at least 8 million years old. So what is exposed is the bed of an earlier, long-gone, ice sheet. The photograph shows channels eroded by a sub-glacial water flow, giving some idea of the complexity of the drainage system that may connect the lakes.   An ERS-2 SAR interferogram of the drop in elevation of the ice sheet above the emptying lake. The drop in elevation determined by ERS-2’s radar altimeter has been superimposed on it. The estimated extent of the lake is outlined as a white dashed line.   The follow-on from ERS-1, ESA's ERS-2 Earth Observation satellite remains operational more than a decade after its 1995 launch. Its payload includes a unique C-band scatterometer that can measure wind fields at the heart of storms of hurricanes, even through clouds and heavy rain. Release date: 20 April 2006