A man surveys the wreckage in the wake of the 2015 Nepal earthquake that killed more than 8,000 people and injured thousands more. Photo by Roger Bilham/CIRES
BOULDER, Colo., June 13 (UPI) -- The 2015 Nepal earthquake that killed more than 8,000 people didn't break the surface. In the days following the quake, there was little evidence of afterslip movement.
A new study suggests the Gorkha earthquake was incomplete and much tension remains in the region's system of faults.
In the wake of the deadly earthquake, an international team of scientists used GPS and radar to monitor post-quake movements. The afterslip was small. Researchers measured surface movement of 2.75 inches to the north of the fault rupture and 1 inch to the south.
"There was a clear lack of afterslip," David Mencin, a geologist with the University of Colorado Boulder, said in a news release. "That has implications for future great earthquakes, which can tap into this stored strain."
Mencin and his colleagues believe more than 11 feet of strain remains locked in the segment of the fault running beneath Nepal.
The Himalayas are especially prone to severe earthquakes. As the Indian plate slowly slips under the Eurasian plate, pieces of the crustal plates grab at each other and form fault lines. An analysis of prior earthquakes show major fault slips in 1803, 1833, 1905 and 1947 also failed to rupture the surface or produce significant afterslip.
The findings, detailed in the journal Nature Geoscience, suggest a significant amount of strain is built up within the region's fault system.
"There's no evidence that it will spontaneously rupture in another damaging earthquake," said Roger Bilham, a professor of geological sciences at Boulder. "But the strain may fuel a future earthquake starting nearby."
"The entire Himalayan arc may host dozens of pockets of strain energy awaiting release in future great earthquakes," Billham added.