© NASAMore than 7,000 kilometers (4,400 miles) long and more than 500 kilometers (300 miles) wide in places, the Andes Mountains encompass a wide range of climates and habitats, from snow-capped mountain peaks to rainforests to high deserts. This picture, acquired by NASA’s Landsat 7 satellite, shows a dramatic change in landscape about 250 kilometers southeast of la Paz, the capital of Bolivia.
Millions of people living near the Andes Mountains face a significantly higher risk of a giant earthquake than previously thought, and such a temblor could be more than 10 times stronger than anything the region has expected in the past.
Scientists investigated the Subandean margin along the eastern flank of the
Andes Mountains, an area that includes Bolivia. A recent hazard assessment estimated a maximum earthquake there of magnitude 7.5.
Now, however, researchers unexpectedly find that a
giant quake of up to magnitude 8.9 is possible, threatening more than 2 million people living in the area, where the infrastructure is not designed for a temblor that big.
"If the entire fault below the Subandes were to rupture, you can get a lot of damage," researcher Benjamin Brooks, a geodesist at the University of Hawaii in Honolulu, told OurAmazingPlanet. "It could be like a combination of the
2010 earthquake in Chile, which was very powerful, with the
2010 earthquake in Haiti, which hit a place with inadequate building standards."
The scientists used global positioning satellite data to map movement of the Earth's surface in the Subandean margin. They discovered that west-to-east surface movements measure 2 to 10 millimeters less per year over a stretch up to about 60 miles long (100 kilometers) than in the area's surroundings.