Low Pressure from Typhoons Affects Seismic Pressure

Joined
Jan 7, 2008
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537
Location
Bryan, TX
Interesting study here:

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http://www.breitbart.com/article.php?id=CNG.0e72e8e889357fc5b4c54b72f3332e06.1a1&show_article=1
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A typhoon causes a fall in atmospheric pressure -- and the researchers suggest that this in turn reduces pressure on the land over the fault.

As a result, one side of the fault lifts slightly, causing the pressure that has been building up inside to be released.

"This fault [in Taiwan] experiences more or less constant strain and stress buildup," Linde said in a press release.

"If it's close to failure, the small perturbation due to the low pressure of the typhoon can push it over the failure limit.

"If there is no typhoon, stress will continue to accumulate until it fails without the need for a trigger."

The typhoon does not work as a seismic trigger on faults that lie on the seabed because water moves into the area, dampening out any difference in pressure, they theorise.

Often considered a curse, typhoons -- for Taiwan -- could in fact could be a blessing.

A storm could act as a pressure valve, preventing strain from building up to the point where the fault ruptures devastatingly.
 
My point of contention is that the terra firma has much more mass than the atmosphere. So even a 5% drop in air pressure is going to be even more negligible when the weight of all of the sand, soil, rock, and water table above the stress points are taken into account. I would also guess that the difference in the water table level between monsoon season and the dry season would make a much greater difference than air pressure would.
 
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