AsianScientist (Aug. 29, 2016) – Using a detection network based in Japan, scientists have uncovered a rare type of deep-earth tremor that they attribute to a distant North Atlantic storm called a ‘weather bomb.’ Their findings were published in Science.
Faint tremors called microseisms are phenomena caused by the sloshing of the ocean’s waves on the solid Earth floor during storms. Detectable anywhere in the world, microseisms can be various waveforms that move through the Earth’s surface and interior, respectively.
So far, however, scientists analyzing microseismic activity in the Earth have only been able to chart P waves, which animals can feel before an earthquake, and not their more elusive S wave counterpart, those that humans feel during earthquakes.
In the present study, Drs. Kiwamu Nishida and Ryota Takagi from University of Tokyo used 202 Hi-net seismic stations operated by the National Research Institute for Earth Science and Disaster Prevention in Japan’s Chugoku district. They successfully detected not only P wave microseisms triggered by a severe and distant North Atlantic storm, known as a weather bomb, but also S wave microseisms.
What’s more, the authors determined both the direction and distance to these waves’ origins, providing insight into their paths as well as the earthly structures through which they traveled.
The research findings not only offer a new means by which to explore the Earth’s internal structure, but may also contribute to more accurate detection of earthquakes and oceanic storms.
The article can be found at: Nishida et al. (2016) Teleseismic S wave microseisms.
Source: Science; Photo: P K/Flickr/CC.
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