Mounting tension in the Himalaya
The Gorkha earthquake struck Nepal on April 25, 2015. It’s a part of the world that is prone to earthquakes, as the Indian plate makes its incremental, sticky descent beneath the Eurasian plate. The magnitude 7.8 jolt, which was very shallow (only 15 km underground), caused a tremendous amount of damage in Kathmandu. But it didn’t rupture the Earth’s surface, signifying that only part of the fault had slipped, below-ground.
In the following days, even the afterslip––post-earthquake movement––produced little surface evidence of continued movement. That meant only one of two things could be happening: either the part of the fault that hadn’t moved was experiencing a slow-slip event, a slow-motion earthquake, or it remained completely locked, accumulating further strain in that segment of the fault.
A new research paper, out online from Nature Geoscience, finds it is likely the latter.
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