Ain’t no mountain high enough for Mother NatureIn the aftermath of the devastating Nepal earth
Ain’t no mountain high enough for Mother NatureIn the aftermath of the devastating Nepal earthquake, scientists from the German Aerospace Center observed that part of the Himalayas had dropped by up to 1.5 meters relative its elevation prior to the earthquake. This image is a composite of before-and-after images captured by the European Space Agency’s Sentinel-1A radar satellite; the blue areas mark regions that were uplifted by up to 2 m, while the Langtang range, located northwest of Kathmandu and represented by areas in yellow, experienced the most subsidence. Known for its scenic hiking and mountain-climbing trails, the Langtang range was heavily ravaged by avalanches and landslides triggered by the 7.8-magnitude earthquake and is still an active search-and-rehabilitation region.The subsiding Himalayas seems like an impossible phenomenon that doesn’t obey the known rules of geology. After all, the Himalayas are the product of two actively colliding tectonic plates — the Indian plate from the south and the Eurasian plate from the north. The constant compressional forces between the two plates causes folding in the Eurasian plate that created the peaks and valleys of the Himalayas. When two tectonic plates meet, the denser plate is always pushed downward by the less dense plate, but since the Indian and Eurasian plates are almost similar in density, only a part of the Indian plate is pulled under the Eurasian plate, while the rest collides head-on with the Eurasian plate itself.Minor earthquakes are very common in the Himalayan plateau, which are mainly caused by frictional forces between the Indian plate and the overriding Eurasian plate. The circumstances surrounding the Nepal earthquake, however, were slightly different. The immense forces pulling and squishing the Indian plate eventually caused the plate to break along its weak points, like a rubber band that snapped after being stretched too hard. The sudden release of pent-up energy caused the Indian plate to snap back toward the surface, creating uplift as shown by the blue regions in the image. Meanwhile, the Himalayan plate sunk downward to compensate for the space left by the rebounded plate.In the long run, however, as tectonic forces are still pushing the Indian and Eurasian plates toward each other, the Indian plate will eventually be pulled back under the Eurasian plate, returning the Himalayan plateau to its original elevation. Meanwhile, observations of the earthquakes’s aftermath are still in its early stages, and scientists are still unsure how other areas were affected by the earthquake. For scientists, obtaining seismic information from difficult-to-access sites remains a daunting task in the wake of the massive structural damage dealt by the earthquake.-DCPhoto credit: http://bit.ly/1JbrRlUMore reading: http://bit.ly/1F41Gg0http://on.wsj.com/1R3rZbAhttp://bbc.in/1InlZsBhttp://bit.ly/1EjyxtoOur previous write-ups on the Nepal Earthquake: http://on.fb.me/1R3skekhttp://on.fb.me/1LlwJX2http://on.fb.me/1OSPUaVhttp://bit.ly/1HnikplMore on continental collision and plate tectonics: http://bit.ly/1hN4WR3http://bit.ly/1JA2mNz -- source link
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