Envisat GMM mosaic of Antarctica - April 2004

The Antarctica Continent as imaged by ASAR in the Global Monitoring Mode. The mosaic was obtained from a time series of data collected from 1st to 30 April 2004. The 200 ASAR GMM products used to process the mosaic individually cover a 400 km-wide swath at 1 km resolution. Antarctica is the coldest, most windy and on average the highest continent on Earth. It contains 90% of all ice and 70% of all fresh water on Earth.

Ice monitoring can hardly be performed over the area using optical data due to constant cloud cover, whilst radar sensors can easily overcome such constraints and provide useful information. In fact, radar's capability to work day and night regardless of weather conditions ensures an optimal continuous monitoring of the ice sheet status. In the image centre, to the right, the underground Lake Vostok can be observed. Around the continent, the mosaic shows several ice shelves, namely Amery, Shackleton, Ross and Ronne, as well as highlands and plateaus and active volcanoes such as Erebus and Berlin Mounts. Being able to create mosaics like this one on a regular represents a valuable tool for the tracking of icebergs and monitoring of sea ice.