Link Between Earthquakes and Tropical Cyclones: New Study May Help Scientists Identify Regions at High Risk for Earthquakes

Scientists expect global warming to cause earthquakes because of the melting of ice causing a redistribution of the weight on the earth, but that will be on a longer time frame.

http://www.sciencedaily.com/releases/2011/12/111208121016.htm

ScienceDaily (Dec. 8, 2011) — A groundbreaking study led by University of Miami (UM) scientist Shimon Wdowinski shows that earthquakes, including the recent 2010 temblors in Haiti and Taiwan, may be triggered by tropical cyclones (hurricanes and typhoons), according to a presentation of the findings at the 2011 AGU Fall Meeting in San Francisco.

See Also:
Earth & Climate

Earthquakes
Natural Disasters
Hurricanes and Cyclones
Severe Weather
Rainforests
Earth Science

Reference

North Anatolian Fault
Alpine Fault
Typhoon Tip
1997 Pacific typhoon season

"Very wet rain events are the trigger," said Wdowinski, associate research professor of marine geology and geophysics at the UM Rosenstiel School of Marine and Atmospheric Science. "The heavy rain induces thousands of landslides and severe erosion, which removes ground material from the Earth's surface, releasing the stress load and encouraging movement along faults."

Wdowinski and a colleague from Florida International University analyzed data from quakes magnitude-6 and above in Taiwan and Haiti and found a strong temporal relationship between the two natural hazards, where large earthquakes occurred within four years after a very wet tropical cyclone season.

[...]

The researchers suggest that rain-induced landslides and excess rain carries eroded material downstream. As a result the surface load above the fault is lessened.

"The reduced load unclamp the faults, which can promote an earthquake," said Wdowinski.

Fractures in Earth's bedrock from the movement of tectonic plates, known as faults, build up stress as they attempt to slide past each other, periodically releasing the stress in the form of an earthquake.

According to the scientists, this earthquake-triggering mechanism is only viable on inclined faults, where the rupture by these faults has a significant vertical movement.

Wdowinski also shows a trend in the tropical cyclone-earthquake pattern exists in M-5 and above earthquakes. The researchers plan to analyze patterns in other seismically active mountainous regions -- such as the Philippines and Japan -- that are subjected to tropical cyclones activity.

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