UNITED STATES: NASA’s InSight lander has detected the strongest and longest quake on Mars so far. The event was five times more powerful than any previous marsquake, unleashing as much energy as all others combined, and with the lander failing the record is unlikely to topple.
The study, conducted by UCLA planetary scientists and reported in two papers published in Geophysical Research Letters, suggests that the Earth’s surface consists of alternating layers of volcanic and sedimentary materials.
Five times more energy was released during the May 2022 marsquake, with a magnitude of 4.7 that lasted for over four hours.
However small by Earthly standards, the quake was nonetheless strong enough to send seismic surface waves all the way around the planet—the first time this phenomenon has been recorded on Mars.
The findings came from InSight, a spacecraft that touched down on Mars in 2018. The “inner space” of Mars, including its crust, mantle, and core, is being thoroughly studied by InSight, the first seismometer in orbit.
It took more than three years after landing for the seismometer on board the InSight lander to capture a marsquake of this size, according to corresponding author Caroline Beghein, a professor of Earth, planetary, and space sciences.
“Two waves, in particular, were confined close to the surface due to this earthquake. After two impact events, but never during a marsquake, just one of the two has ever been seen on Mars previously”, she said.
Future expeditions to the red planet will benefit from mapping the seismic activity, the position and frequency of impacts on Mars, and the internal structure because it will show scientists and engineers where and how to put up structures to protect human explorers in the future.
Like Earth, analysing the path that seismic waves take through rocks can provide scientists with information on the temperature and makeup of the planet’s interior, which aids in the search for subterranean water or magma.
Additionally, it aids in the understanding of the historical processes that shaped the globe.
Beghein’s team integrated measurements from two different types of surface waves, known as Love and Rayleigh waves, to estimate the speed of subsurface shear waves, which move rocks perpendicular to the direction of wave propagation and travel horizontally.
This is the first time Love and Rayleigh’s waves have been seen together on Mars.
The measurements revealed that, in contrast to when rocks between 10 and 25 kilometres down vibrate vertically, the shear waves in the crust travel more quickly when the rocks oscillate in a direction that is nearly parallel to the planet’s surface.
According to Beghein, “this wave speed information is related to deformations inside the crust.” The seismic data we saw is most likely explained by alternating ancient volcanic rocks and sedimentary layers or by a massive impact like a meteoroid.