Earth X-rays possible thanks to storms

Using a network of detectors in Japan, scientists have detected a rare type of tremor from deep within the Earth known as a "weather bomb" emanating from a storm far away in the North Atlantic.

The discovery marks the first time scientists have observed this particular type of shock, known as a super seismic wave.

The Atlantic “weather bomb” was a fast-growing, powerful storm that sent waves offshore sending small, deep shockwaves into the ocean crust. These silent waves penetrated the Earth and could be detected as far away as Japan, where instruments were first used to measure the amplitude of storm surges from P and S waves, called the “Hi-net” method.

Model of S wave capture from ocean storm.

Peter Gerstoft and Peter D. Bromirski say the team's findings give seismologists a new tool for studying the Earth's deeper structures. It will contribute to a clearer picture of the Earth's movements, even those originating in the atmosphere-ocean system.

These small tremors are called microseismic waves. They are caused by the ocean waves crashing over the solid earth during a storm. Detectable anywhere in the world, microseismic waves can take many different forms as they travel through the Earth’s surface and interior.

P and S waves are Body waves that travel through the interior of the Earth.

Until now, scientists have only analyzed small earthquake activity up to the P wave line (which animals can sense before an earthquake occurs). And S waves (the type of waves that humans feel during an earthquake) are very difficult to observe.

Here, using 202 Hi-net stations operated by the National Institute for Earth Science and Disaster Prevention in Japan's Chugoku region, researchers Kiwamu Nishida and Ryota Takagi detected not only P waves but also extremely small-amplitude S waves generated by a North Atlantic storm, known as a weather bomb.

The Earth's internal structure remains a mystery.

Furthermore, the authors determined both the distance and the origin of the waves that provide information and the structures the storm passed through. In this way, the seismic energy travels from this shock through the Earth. Nishida and Takagi's findings not only provide a new means to explore the internal structure of the Earth, but may also contribute to more accurate detection of earthquakes and storms./.

According to Khoahoc.tv