Ever had a yen to fly across the Antarctic ice? Or cruise the slopes of Mt. Erebus, maybe the coldest active volcano on the planet?

Me neither.


But scientists at NASA, the USGS, the National Science Foundation and the British Antarctic Survey can hardly contain themselves at the notion. They are hailing the completion of the Landsat Image Mosaic of Antarctica (LIMA), the biggest, most detailed photographic map of Antarctica ever assembled.

With a few clicks of a computer mouse, geologists, glaciologists, global warming researchers — in fact, anyone with a computer — can now float at will above the ice, zoom in on any region of the continent and see it all in the full light of day – no pesky clouds, no snowstorms no months-long darkness.

"I have had an absolute ball working with this data set," said Robert Bindschadler, chief scientist at the Goddard Space Flight Center's Hydrospheric and Biospheric Lab. He's been on the ice many times, he said, but LIMA has "changed my view of Antarctica. It has influenced the scientific questions I am asking."

LIMA is not just for scientists. The entire photo map is available free, online, to anyone with Internet access. Since its unveiling on Tuesday, servers for the site have been swamped by people dropping in to cruise the continent most of us will never see.

A sort of Google Earth for the empty wastes of the planet's remotest continent, LIMA allows anyone to explore the snowy plains and rugged, ice-choked sounds and coastlines. Users on NASA's LIMA website can choose to explore Antarctic mysteries, zip to specific sites by typing in one of 14,000 place names, or access classroom materials designed for teachers.

"The climate of the Earth is changing nowhere faster that at these polar regions," Bindschadler said. People must learn to care about the Antarctic "because it is part of our planet, and to understand what's happening, they have to understand what scientists are telling us" about change at the cold ends of the Earth.

To visit the USGS LIMA site, click here. For a more user-friendly experience, try the NASA LIMA site.

The LIMA photo map of Antarctica was assembled from among 10,000 images of the continent, all shot over a period of years by NASA's Landsat satellites.

Cartographers, photo experts and others from NASA, the USGS, BAS and NSF worked to select more than 1,000 of the best images – shot under the clearest, cloud-free lighting conditions.

Those digital photos were then stitched together and adjusted to match landmarks on the ground – accurate to within about 100 yards. They completed a photo mosaic of the entire continent – the first ever produced. Well, almost.

Only a small doughnut hole surrounding the South Pole remains unfilled by Landsat images, an artifact of the down-looking satellites' inability to fly directly over the pole. The missing data will be supplied in part by imagery from other satellites, and by less precise sidelong views to be gathered by more advanced Landsat missions in the coming years.

Until now, scientists have had to work with survey maps, aerial and satellite photos covering only portions of the continent with widely varying degrees of clarity, detail and accuracy.

The Landsat images provide impressive detail. One of the satellites passes 400 miles over nearly every point on the globe once every eight days, photographing a swath 100 miles wide. Over the years they have assembled a 35-year archive of global change.

The LIMA photo map of Antarctica is composed of more than 100 billion pixels, or data points, in all, compared with 8 million in images shot by a digital camera available in stores today.


Each LIMA pixel covers an area on the surface the size of half a basketball court, providing very sharp, high-resolution images of the surface. That allows viewers to zoom close to the surface before the picture breaks down into individual pixels.

The images can be viewed in true color, or users can adjust or "stretch" the contrast to reveal surface details hidden in the data. Geologists can see patterns in the rocks, while glacier experts can discern the movements in the shifting ice. Users can also switch to radar images of the same region they're viewing in true color.

"Antarctica is key to understanding the process of global climate change," said Andrew Fleming, director of the British Antarctic Survey, which is studying climate change on the Antarctic peninsula that juts out from the continent toward South America.

Average temperatures there have risen three degrees in the last 50 years, Fleming said. That's 10 times the global average, accompanied by the breakup of ice shelves, melting of snows and the retreat of glaciers.

LIMA, he said, provides "new information for planning and executing field work. Higher resolution [images] of the entire continent is helping scientists understand our planet." To explore the USGS LIMA photo map site, click here. Or, for a more user-friendly version from NASA, click here.