NASA’s InSight lander has detected a couple of sizable quakes on Mars, with magnitude 3.3 and 3.1 tremors last month offering further evidence that the location, Cerberus Fossae, is prone to seismic activity.
InSight has been on the Martian surface since 2018, and early on in its mission detected two other significant so-called “marsquakes” in the same area, with magnitudes of 3.6 and 3.5.
Our @NASAInSight is picking up good vibrations. Two marsquakes were detected in an area called Cerberus Fossae, where two strong quakes were felt earlier in the mission. These quakes add weight to the idea that the area is a center of seismic activity. https://t.co/AhHYuNVRR0 pic.twitter.com/BKRfHIkzDb
— NASA JPL (@NASAJPL) April 1, 2021
These aren’t the first tremors recorded by InSight. In fact, so far the lander has recorded more than 500 marsquakes, but the four referenced above are of particular interest to scientists because of their relatively large size.
Major quakes on Earth are caused by the sudden movement of the tectonic plates that make up its crust. Mars doesn’t have tectonic plates, with its tremors caused instead by volcanic activity. Analyzing Mars’ seismic activity can help the InSight scientists to gain a clearer understanding of the red planet’s mantle and core.
“Over the course of the mission, we’ve seen two different types of marsquakes: One that is more ‘moon-like’ and the other, more ‘Earth-like,’” said Taichi Kawamura of France’s Institut de Physique du Globe de Paris, which helped to create InSight’s seismometer.
“Moon-like” means that the seismic waves tend to be scattered, while “Earth-like” waves travel more directly through the planet. Marsquakes tend to fall somewhere in between, but Kawamura said that the four larger quakes were particularly interesting as they were more Earth-like
A couple of years ago scientists in Switzerland conducted a fascinating exercise where they recreated the experience of marsquakes in a so-called “shake room” usually used for simulating earthquakes.
In the video below, the scientists use data gathered from Earth, Mars, and the moon to demonstrate the different effects of seismic activity in all three locations.
InSight’s seismometer operates from beneath a dome that’s used to block out the sound of the wind and to protect it from the bitterly cold nights. But despite the protection, Martian winds occasionally cause seismometer vibrations that can obscure some marsquakes. For example, during the past northern winter season when winds are more prevalent, InSight was unable to detect any quakes.
Still, John Clinton, a seismologist who leads InSight’s Marsquake Service at ETH Zurich, is pleased with the recent seismic data. “It’s wonderful to once again observe marsquakes after a long period of recording wind noise,” Clinton said, adding, “One Martian year on, we are now much faster at characterizing seismic activity on the red planet.”
