The Largest Marsquakes to Date Have Been Detected in The 'Shadow Zone'

One of the most intriguing features of Mars is the presence of earthquakes.

planetary scientists have been logging thesemarsquakes with a seismometer built into the InSight lander The two largest marsquakes ever put on record have been detected.

There were two earthquakes that happened in 24 days, one was a magnitude 4.1 and the other was a magnitude 4.2. They are five times stronger than any previous marsquakes.

The shadow zone is the opposite side of the planet from where InSight is located. It is the first time that the lander and its sensors have recorded a marsquake across such a large distance.

There is a relief map on Mars showing the location of InSight. The seismic record was written by Horelston et al.

Anna Horleston is a planetary seismologist from the University of Bristol in the UK.

They are remarkable events in the Martian catalog.

The team described S1000a as a clear outlier in the earthquakes that have been recorded so far, because of the broad spectrum of the energy it produced. It lasted 94 minutes and is the longest- lasting event InSight has monitored.

The waves known as PP waves and SS waves were used to detect. These are waves that do not follow a direct path but are reflected at the surface, which is how InSight was able to measure them.

Small waves that pass through the core-mantle boundary were picked up. It is the first time that InSight has recorded P diff waves, and there are signs that the S 1000a earthquake happened closer to the surface.

Horleston says that the event may have occurred near the surface because it has a frequency spectrum much more like a family of events that have been modeled as shallow, crustal earthquakes.

Many of the events we have located to the area of extensive faulting that has been modeled to be around 50 kilometers deep are likely to be in S0976a.

The marsquakes happened in the core shadow zone, a part of Mars where InSight cannot track the P wave and S wave seismic activity directly. The team was able to place it within the canyon network.

This is the first time that recordings have been made in these canyons, which have previously been identified as places where earthquakes could happen. Scientists know where S 1000a happened, even though the precise location has not been established.

Most of the activity on Mars prior to these two events came from a distance, but the latest data gives scientists an opportunity to sample new parts of the red planet.

Recording events within the core shadow zone is a real stepping stone for our understanding of Mars.

The majority of the earthquakes were within 40 degrees of InSight. The energy traverses parts of Mars we have never been able to sample before.

The research has been published.