Under Hawaii found 1,200-kilometer long anomaly

Hot lava pours into the sea from the hardened crust on the Big Island of Hawaii. (Photo by Patrick McFeeley, National Geographic.)


Hawaii — volcanic island. They are believed to exist due to the flow of hot rock rising out of the kernel.

Explanation — the most obvious, and in the absence of good-quality seismic data, there is nothing stopping him to take. And analysis of information on earthquakes in the last twenty years, finally allowed to find convincing evidence of a huge mass (waist width — 1 300 km) hot stone under the seabed. However, he does not go out of the core to the surface and also is in the hundreds of kilometers to the west of the archipelago. And under the Big Island — the youngest and traditionally assumed to be located on the expected plume of magma — nothing.

Despite this, the scientists do not exclude the presence of a narrow plume beneath the island, said study co-author Robert van der Hilst of MIT (USA)

Education volcano begins where a thick layer of the planet's mantle meets the molten outer core — at a depth of about 2900 km. The outer core heats the lower mantle rocks, and then they go up to the cortex. A few kilometers from the bark of species undergoing decompression, resulting in an eruption. Seismic tomography is able to detect such "hot spots" on the waves, which spread after the earthquake on the planet. Hawaii are far from seysmooborudovaniya networks, so the study's authors had to work deciphering the signals.

According to them, obtained clear evidence of the existence of a huge anomaly at a depth of 660 km in the form of disc-shaped segment, which is about 300-400? C hotter surrounding rock. It is located in the 600-1 600 km from the Big Island.

Scientists suspect that the magma directly from the core reaches the boundary between the upper and lower mantle, then passes through the winding to the crust beneath the archipelago, and then rises, keeping Hawaii.

The study is published in the journal Science.

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