Slow Seismic Waves

14 Nov 2021

At ... subduction zones are central to Plate Tectonics theory. One plate is thought to slide under another in order to compensate for new growth on the sea floor [and avoid earth expansion]. Apparently, it has been found that at least one subduction zone the seismic waves are slower than anticipated. Various theories why are on offer.

Robert sent in the link ... with the comment that according to the consensus model of the earth's interior, earthquakes should not occur at depths where rocks supposedly become plastic. Unfortunately for the consensus, it appears they do. He offers another link ...

The said earthquake occurred on the remote Bonin [Ogasawara] Islands off mainland Japan, back in 2015. It was an aftershock following a 7.9 magnitude earthquake in the region. The tremor could not actually be felt at the surface but was captured by sensitive recording instruments that trapped the source - 467 miles underground.