Geological factors combined to make Nepal earthquake particularly deadly

New York Times : Saturday a magnitude 7.8 earthquake struck to the northwest of Kathmandu, the capital and largest city of Nepal. Thousands of people are known to have died and many more have been reported injured. The quake was particularly devastating because of the tectonics of that region, the local geology, and poor building construction, according to geologists. Nepal lies near the subduction zone between two major tectonic plates. The colliding continental crust created the Himalayas, where 9 of the 10 highest peaks on Earth are located, including the highest—Mount Everest. Because the two land masses are still colliding, the area is prone to earthquakes: In 1934 a magnitude 8.1 quake killed more than 10 000 people. Saturday’s quake occurred at a relatively shallow depth of about nine miles, so it caused greater surface shaking than the 1934 quake. In addition, Kathmandu sits on an ancient lake bed with very soft soil, which further amplified the shaking. Because of the city’s high population density and tall, flimsy buildings, the region was more vulnerable than many others that sit near major tectonic faults.