New research has revealed that the record-breaking massive earthquake that rocked Mars in May this year was at least five times larger than the previous record.
It is not clear what the source of the quake was, but it was certainly strange. In addition to being the strongest earthquake ever recorded on Mars, it was also the longest by quite a bit, shaking the Red Planet for regarding 10 hours.
“The energy released from this single quagmire is equivalent to the cumulative energy of all the other earthquakes we’ve seen so far,” says seismologist John Clinton of the Swiss Federal Institute of Technology in Switzerland. Although the event was more than 2,000 kilometers (1,200 miles) away, the waves were The intensity recorded in InSight is so large that it almost saturates our seismometer.” The new analysis of the quake, published in Geophysical Research Letters, put its intensity at 4.7. The previous record was held by a magnitude 4.2 earthquake detected in August 2021.
This may not sound like a major earthquake by Earth’s standards, as the strongest quake ever recorded measured around 9.5 magnitude. But this for a planet that was thought to be seismically inactive until NASA’s InSight probe began recording its interior in early 2019 is surprising.
Although Mars and Earth have a lot in common, there are some really major differences. Mars does not have tectonic plates; It also does not have a coherent global magnetic field, which is often interpreted as a sign that not much is going on in the interior of Mars, where the Earth’s magnetic field is supposed to be caused by internal convection.
InSight revealed that Mars is not as seismically calm as previously assumed. It’s shaking, hinting at volcanic activity beneath the Cerberus Fossae region where the InSight probe is, observing the planet’s hidden bowels.
But determining the state of activity inside Mars is not the only reason to monitor earthquakes. The way seismic waves propagate across the planet’s surface might help reveal density changes in its interior. In other words, they can be used to plot the structure of the planet.
“For the first time we have been able to identify surface waves, which move along the crust and upper mantle, and which have traveled around the planet many times,” Clinton says.
In two other separate Geophysical Research Letters papers, teams of scientists analyzed these waves to try to understand the structure of the crust on Mars, and to identify areas of sedimentary rock and possible volcanic activity within the crust.
But there is more to be done regarding the earthquake itself. First, it originated near, but not from, the Cerberus Fossae, and we cannot trace it to any obvious surface features.
Earthquakes usually have a high or low frequency, the former being characterized by quick, short tremors, and the latter by longer, deeper waves of greater amplitude. This earthquake combined these two frequency bands, and researchers aren’t quite sure why.
However, it is possible that previously recorded high and low frequency earthquakes that were analyzed separately might be part of the same seismic event.
This may mean that scientists need to rethink how they understand and analyze swamps, and uncover more secrets hiding beneath Mars’ deceptively placid surface.
