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Laser reveals hidden earthquake “time bombs”
Nov. 8, 2006
Courtesy University of Leicester
and World Science staff
Using a laser mounted on an aircraft, scientists say they’ve
found earthquake-prone fault lines
previously hidden by forest—“time bombs” whose danger can only now be recognized and studied. Courtesy University of
Leicester
A fault is a crack in the Earth’s crust accompanied
by a shift in the ground on either side. Sudden movements like this
can produce earthquakes.
“Locating earthquake-prone faults in forested mountainous regions… has always been a problem to geoscientists,” said Dickson Cunningham of the University of
Leicester, U.K., one of the researchers.
A 2005 earthquake in the Kashmir region of Pakistan, he added, was an example of
the horrifying surprises these concealed faults can spring.
“Many regions of the world have undiscovered seismically active faults hidden by dense forests,” including Indonesia, India, northwestern North America, all Andean nations and Europe’s alpine countries, Cunningham said.
A team of geologists and geographers from the university said
the laser technique—called LiDAR, for light detection and ranging—“virtually deforests” the landscape to reveal these details.
Using it, they said, they mapped recently active, earthquake-prone faults in the southeastern Alps in Slovenia.
The results appear in the current issue of the journal
Geophysical Research Letters. The topographic images of two major Slovenian faults, known as the Idrija and Ravne strike-slip faults, shed light on both systems’ structure and history, the study found.
“For the first time, we are able to see how the faults connect at the surface and cut the landscape. This allows us to assess whether the faults are likely to produce large earthquakes or small events,” he said, and provides a framework for more detailed analyses to help predict the next big quake.
A excursion on-site last August verified the sky observations, the university’s Kevin
Tansey said. “As we trekked through the forest we found overwhelming evidence for previous fault activity, never before seen by earth scientists. We are now building on our initial results with followup research.”
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Using a laser mounted on an aircraft, scientists say they’ve revealed earthquake fault lines that until now were hidden by forest—ticking time bombs whose danger can only now be recognized and studied. “Locating earthquake-prone faults in forested mountainous regions and understanding the potential seismic hazard they pose… has always been a problem to geoscientists,” said Dickson Cunningham of the University of Leicester, U.K., one of the researchers. A 2005 earthquake in the Kashmir region of Pakistan and India, he added, was a terrifying example of how hidden faults can pose serious and unrecognized hazards. A team of geologists and geographers from the university said their laser technique—called LiDAR, for light detection and ranging—”virtually deforests” the landscape to reveal these details. Using it, they mapped recently active, earthquake-prone faults in the southeastern Alps in Slovenia. Their results appear in the current issue of the journal Geophysical Research Letters. “Many regions of the world have undiscovered seismically active faults hidden by dense forests,” including Indonesia, India, northwestern North America, all Andean nations and Europ’e’s alpine countries, Cunningham said. The topographic images of two major Slovenian plate boundary faults, known as the Idrija and Ravne strike-slip faults, shed light on both systems’ structure and history, the study found. “For the first time, we are able to see how the faults connect at the surface and cut the landscape. This allows us to assess whether the faults are likely to produce large earthquakes or small events,” he said, and provides a framework for more detailed analyses to help predict the next big quake. A excursion on-site last August verified the sky observations, the university’s Kevin Tansey said. “As we trekked through the forest we found overwhelming evidence for previous fault activity, never before seen by earth scientists. We are now building on our initial results with follow-up research.”