NASA Probe Insights: A peek beneath Mars’ surface with ambient noise

Since the unmanned NASA probe “InSight” landed on Mars in November 2018, the probe has been using a seismometer — the Marsquake Service — to evaluate the planet’s seismic activities to draw conclusions about the planet’s internal structure. .

In July, the ETH Zurich team, in collaboration with the Swiss Seismic Service (SED), provided roughly insight into the thickness of the Martian crust, the diameter of the Martian mantle and liquid core, for example.

Ambient noise instead of deep drilling

However, other than by drilling, formations close to the surface cannot be determined in this way. Meanwhile, researchers at ETH Zurich have taken a step forward: They used ambient noise (“ambient noise”) on Mars to determine the local geology. This technique is used on Earth, for example, to detect whether the subsurface is weakening or amplifying seismic waves. This allows for the determination of the seismic hazard of a location and the analysis of unstable landslide zones on mountains or lakes.

While there are many sources of noise available on earth, Wind was the only remaining source of ambient noise for researchers on Mars,

your geological results They have now published in Nature Communications the history of Mars at depths of a few dozen to two hundred meters.,

A detailed look beneath the surface of Mars

Unlike Earth, Mars never had any active plate tectonics. It was formed by the phases of an active volcano. Large areas were covered by basaltic lava plateaus. Analysis by ETH Zurich provides a detailed picture of the subsurface at the InSight landing site. The top layer consists of three meters of sand (regolith) and about 20 meters of loose rock, which has been broken by meteorite impacts. Below are layers of lava flows that the publication said covered the planet between 1.7 and 3.6 billion years ago.

These lava layers are divided by sediments that lie at depths of 30 to 75 metres. A seismic image of geological stratification has for the first time enabled researchers to understand the most important geological events that have occurred at the InSight landing site on Mars over the past three billion years.

(Mac)