Washington, US: Scientists have found out the mechanism that produces earthquakes that happen away from tectonic plate boundaries. Researchers have discovered while earthquakes situated at tectonic plate boundaries are due to movement between the plates, earthquakes at distances from fault lines are mainly caused by a movement below the plates.
Even though intraplate quakes account for a tiny amount of overall earthquakes (around 98% of earthquakes happen at the tectonic plates’ boundaries), they have been measured with strengths up to 7 magnitude. Also, they are dangerous as well as destructive because of their unexpected nature.
For instance, human habitats affected by intraplate earthquakes may lack earthquake-prepared infrastructure compared to the habitats that are located on plate boundaries.
Just below our planet’s crust exists a layer of hot, semi-fluid rock that is constantly flowing, getting heated and rising followed by cooling and sinking.
Convective activity causes intraplate seismicity, interacting with the perennially changing movement of the plates at the surface. The activity also determines the occurrence of the earthquakes to a large degree. As per their models, the crust structure above also affects the location to a lesser degree.
Lead author and professor of Earth sciences, Thorsten Becker opined that presently all is not known about how strange earthquakes happen. However, their work demonstrates that how imaging advances in the area of seismology along with mantle flow modeling can discover the connections between mantle convection and seismicity.
Earthquakes at plate boundaries take place when plates shift horizontally, dashing into each other, shifting away from each other or sliding past each other. However, earthquakes in the middle of plates, look to happen when the mantle pushes up or down on the surface from below.
Becker with his team harnessed an updated mantle flow model to examine the movement below the mountain belt that is situated north to the south in the interior of the Western US. The area is known to be active seismically. As Yellowstone is situated above a volcanic hotspot, it has geysers. Earlier scientists had speculated that the plate’s varying density was the primary reason.
However, the team discovered that the small-scale convective currents below the plate correlated with seismic events up in a predictable manner.
They also attempted utilizing the varying plate density to forecast seismic events and discovered a much lesser correlation.
Mountains can supply clues regarding past earthquakes, both in the middle of tectonic plates and at plate boundaries. Scientists want to find out if a link exists between mantle convection and mountains.