The most powerful quake ever recorded on Mars was produced by tectonic forces from within its crust, not a meteor impact, which suggests that the Red Planet might be much more seismically active than previously thought.
In 2022, NASA鈥檚 InSight lander detected a magnitude-4.7 marsquake, called S1222a, which was five times larger than the previous most powerful one on record. 快猫短视频s had found fresh meteor craters associated with the next two biggest marsquakes, so they thought it likely that S1222a was produced from an impact too.
Now, at the University of Oxford and his colleagues have concluded that S1222a was actually the result of activity within Mars. They conducted a comprehensive search for impact evidence, like a crater or dust cloud, across data from seven different Mars spacecraft, but found nothing.
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鈥淲e would expect this crater to be so large if it did form,鈥� says Fernando. 鈥淲e鈥檙e probably talking about a crater that鈥檚 between 300 and 500 metres in diameter, and a blast zone that鈥檚 probably 100 kilometres across. It would be really hard to hide something that big.鈥�
The marsquake is likely to have been the result of stresses that had built up in Mars鈥檚 crust over billions of years finally being released, says Fernando. S1222a had particularly strong surface waves, which are the components of quakes that tend to cause the most damage. Understanding how these surface waves travel across Mars might shed light on the very different crust profiles between its northern and southern hemispheres, says Fernando.
While the quake was small compared with Earth鈥檚 largest tremors, it will still be important to gauge how frequent these large events are for any future crewed Mars missions. 鈥淚t鈥檚 probably not going to bring your house down. But, equally, if your house had been near, it probably would have smashed windows. You might have ended up with stuff collapsing on the shelf,鈥� says Fernando. 鈥淚t鈥檚 big enough that I think you鈥檇 want to know about it if you were living there.鈥�
Geophysical Research Letters
