Can storms prevent nasty earthquakes? That鈥檚 the suggestion of study showing that typhoons can trigger benign, 鈥渟low鈥� quakes that ease the stress between tectonic plates.
Beneath Taiwan, a tectonic plate is diving under its neighbouring plate at one of the world鈥檚 fastest rates. 鈥淵ou can almost watch them,鈥� says study co-author of the Carnegie Institution in Washington DC. Yet the island has had fewer big rumbles than you鈥檇 expect from such movement.
One explanation is that Taiwan undergoes slow earthquakes, in which crustal faults slip over hours or days, rather than seconds, creating no seismic judders.
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Now a team led by Chichung Liu of the in Taipei says these slow earthquakes can be triggered by typhoons. Using strain meters, they identified 20 slow quakes over five years, 11 of which occurred during typhoons (Nature, ).
The chances of this being a coincidence are vanishingly small, so they suggest that typhoons are triggering slow quakes via low atmospheric pressure, which makes it easier for the land to slip over the descending plate. This is the first 鈥渢otally unequivocal鈥� evidence that atmospheric changes can trigger fault slip, says Linde.
鈥淭hese are quite impressive results,鈥� says Lars Ottemoller of the British Geological Survey. 鈥淚 am fairly convinced that the link between the slow earthquakes and the typhoons is real.鈥�
