S1222a, the most powerful earthquake ever recorded on Mars!
As the activity of the InSight probe on Mars draws to a close, the data recorded over the last few months continues to provide new insights into the dynamics and structure of the Red Planet. In a study published this December 14th in the journal Geophysical Research Letters, the international SEIS seismometer team unveils the detailed analysis of the recording of the strongest earthquake detected by the instrument, an exceptional signal.
Polarized signals and location (blue ellipse) of event S1222a (© GRL - AGU)
Publication date: 17/12/2022
Observatories, Press, Research
Related observatories : InSight Observatory
On the night of May 4th this year, or Sol 1222 on Mars, the seismometer on NASA’s InSight Mars lander detected an earthquake on the Red Planet, which reverberated for several hours.
This Martian earthquake was at least five times more powerful than the last largest tremor recorded on the planet, according to new research published on 14 December in Geophysical Research Letters, an AGU journal, which will be publishing a collection of articles on this earthquake (two articles published on 14 December in Geophysical Research Letters, and two others soon to be published, to which IPGP scientists also contributed).
“This is undoubtedly the largest Mars quake we have detected,” said Taichi Kawamura, lead author and planetary seismologist at the Institut de Physique du Globe de Paris and Université Paris Cité. Together with seismologist John Clinton from the Swiss Federal Institute of Technology in Zurich, T. Kawamura is co-director of the Marsquake Service (MQS), an international team that monitors and evaluates the seismological data recorded by NASA’s InSight Mars probe.
The biggest Martian earthquake previously recorded, in August 2021 (Sol 976 on Mars), was of magnitude 4.2, while the one in May had a magnitude of 4.7 (the magnitudes of Martian earthquakes are comparable to those of earthquakes on Earth).
“We were able to observe long-period energy from this event that had never been observed on Mars before, which we can identify as Love waves and multi-orbit Rayleigh waves, perhaps explaining why this makes the amplitude larger by a factor of 5”, explains J. Clinton.
The earthquake waves lasted between four and five hours, much longer than most previous Mars quakes, which had lasted only one or two hours at most.
The study also notes that the epicentre was close to, but outside, the Cerberus Fossae region, which happens to be the most seismically active region on the Red Planet. The epicentre did not appear to be obviously linked to any known geological features, although a deep epicentre could be linked to hidden features lower down in the crust.
Mars tremors are often divided into two different types: high-frequency tremors, characterised by rapid but shorter vibrations, and low-frequency tremors, when the surface moves more slowly but with greater amplitude. This latter event is unique in that it appears to have characteristics of both high and low frequency earthquakes. Further research may reveal that the low-frequency and high-frequency earthquakes recorded previously are just two aspects of the same thing,” proposes T. Kawamura.
These initial studies have been carried out by analysing the data from this major earthquake, published by the Mars SEIS data service, hosted by the Institut de Physique du Globe de Paris data centre, and relayed to the NASA and IRIS data centres; while the Insight probe is nearing its operational end, due to the dust that has gradually covered its solar panels and reduced its power in the four years since it landed in November 2018.
“For all the members of the InSight National Observing Service team, the detection of this earthquake by our very broadband seismometer, almost at the end of the mission, was an extraordinary moment” adds T. Kawamura. On the basis of the data collected during this earthquake, “I would say that this mission has been an extraordinary success”, he concludes.
About InSight and SEIS:
JPL manages the InSight mission on behalf of NASA's Science Mission Directorate. InSight is part of NASA's Discovery program, managed by the Marshall Space Flight Center (MSFC), a NASA facility in Huntsville, Alabama.
Lockheed Martin Space in Denver built the InSight probe, including its cruise stage and lander, and supports spacecraft operations for the mission. CNES is the prime contractor for SEIS and the Institut de Physique du Globe de Paris (Université Paris Cité/IPGP/CNRS) has scientific responsibility for it. CNES is financing the French contributions, coordinating the international consortium (*) and has been responsible for the integration, testing and supply of the complete instrument to NASA. IPGP designed the VBB (Very Broad Band) sensors, tested them before delivery to CNES and is contributing to the operation of the VBBs on Mars.
SEIS and APSS operations are led by CNES within the FOCSE-SISMOC, with support from the Centro de Astrobiologia (Spain). SEIS data is formatted and distributed by the Mars SEIS Data Service of the IPG Paris, as part of the InSight National Observation Service, to which the LPG also contributes and, for Sismo activities at the School, GéoAzur. Daily identification of earthquakes is carried out by InSight's Mars Quake Service, a collaborative operational service led by ETH Zurich to which seismologists from IPG Paris, the University of Bristol (UK) and Imperial College London (UK) also contribute.
Several other CNRS laboratories, including the LMD (CNRS/ENS Paris/Ecole polytechnique/Sorbonne Université), the LPG (CNRS/Nantes Université/Le Mans Université/Université d'Angers), the IRAP (CNRS/Université de Toulouse/CNES) and the LGL-TPE (CNRS/Ecole normale supérieure de Lyon/Université Claude Bernard Lyon 1), IMPMC (Sorbonne Université/Muséum national d'Histoire naturelle/CNRS) and LAGRANGE (CNRS/Université Côte d'Azur/Observatoire de la Côte d'Azur) are working with IPGP and ISAE-SUPAERO to analyse data from the InSight mission. These analyses are supported by CNES and the French National Research Agency as part of the ANR MArs Geophysical InSight (MAGIS) project.
(*) In collaboration with SODERN for the production of the VBBs, JPL, the Swiss Federal Institute of Technology Zurich (ETH, Zürich, Switzerland), the Max Planck Institute for Solar System Research (MPS, Göttingen, Germany), Imperial College London and Oxford University have supplied the SEIS subsystems and are participating in the scientific exploitation of SEIS.
Find out more : press release on the AGU website
Ref: Kawamura T, Clinton J., Zenhäusern G., Ceylan S., Horleston A., Dahmen N., Duran C., Kim D., Plasman M., Stähler S., Euchner F.,Charalambous, C., Giardini D., Davis P., Sainton G.,Lognonné, P., Panning M.,Banerdt W.B. (2022), S1222a – the largest Marsquake detected by InSight, Geophys. Res. Let. doi: 10.1029/2022GL101543
