Seamounts and the muffling of earthquakes

[Omar Ahmed7]

New research shows that a seamount that was analysed led to the lubrication between 2 plates in a subduction zone. The researchers found that when a seamount gets subducted, the water is released, lubricates the plate boundary, and leads to slow slip. It is described in a lot of detail here:

https://physicstoday.scitation.org/do/10.1063/PT.6.1.20210811a/full/#:~:text=When%20extinct%20undersea%20volcanoes%20are,carry%20trapped%20seawater%20with%20them.

There is also older research describing how seamounts muffle earthquakes, by leaving behind wet material and weakened rock after its subduction, but the full article is only available by purchase or through institutions.

https://www.sciencedaily.com/releases/2020/03/200302113353.htm

[Omar Ahmed7]

This is a part of the full research in the second article

"It was earlier hypothesized that
subducting seamounts act as interseismically locked asperities
where earthquakes nucleate, but more recent studies argue that
they appear to act as barriers, thus stopping earthquake rupture.
Analyses of global seismic and geodetic datasets suggest that basement roughness tends to limit earthquake size and that geometrically rugged megathrusts are often dominated by fault creep
resulting from both severe damage of wall rocks and heterogeneity
in stress and pore fluid pressure1. Modern high-precision monitoring provides a detailed view of this creep, manifested by an abundance of small earthquakes and (or) slow slip events