Revealed cause of three-month-old earthquake in Yellowstone

More than three months more than 2,500 earthquakes were recorded in the region, one of which was the longest seismic survey in the history of Yellowstone. Most of the earthquakes were very weak, but some were felt in the park, as in the case of the strongest, magnitude 4.4, felt on June 16, 2017.

The series of earthquakes Land was also captured in more detail than any other large swarm felt in Yellowstone, notes Shelley in his publication.

According to the seismologist, the schemas of this seismic chain, particularly the rapid migration and the absence of deformation near the surface, suggest what might have been caused by the diffusion of the earthquake. water through cracks in the subsoil of the Earth, and not by the movement of magma, which can also generate swarms of earthquakes on volcanoes

For the scientist, the l & # 39; water can explain in part why these swarms are so long. Its duration is long because the swarms "develop considerably over time" and also because the fault structures are "so complex".

"This may also explain why these swarms are common in volcanic regions, where water is a by-product released by magma more deeply when it cools", have explained the scientists.

As this water is under enormous pressure in the deep crust, it tends to rise and sometimes laterally. By interacting with colder and more fragile rocks, this water can trigger earthquakes, Shelley adds.

On the other hand, the seismologist believes that there is no other sign of volcanic activity – such as a rapid deformation of the surface or changes in gas emissions – the seismic swarms " probably do not indicate a growing risk " of an eruption