First summary of the findings of the MARS INSIGHT spacecraft on Mars
One of the interesting subjects in the study of Mars, which can testify a lot about the face of the planet, is earthquakes. A growing database of earthquakes on our planet has revealed many of the secrets of the Earth's interior. This allowed a deep recognition of the crust, the mantle and the core of the world we live on, a kind of geological EKG. The Insight spacecraft that landed on Mars was equipped with a seismograph for the same purpose: getting to know the interior of Mars.
One of the areas measured is the separation zone between the crust and the mantle at a depth of 35 km below the landing site of the Insight. Another place that was measured is the transition zone inside the mantle, where there are silicates of iron and magnesium undergoing geochemical change. Above this area these elements form a mineral called olivine, and below it the heat and pressure compresses them and a mineral called Wadsleyite is formed. For this reason this region was named Wadsleyite Olivin. This region will be at a depth of 1170-1110 km below the lander, and information about it can help in the development of thermal models of Mars. A third transition zone is found deep inside Mars 1600 - 1520 km below the lander (1).
The seismic measurements showed that the earthquakes on Mars are different from those on Earth. Their strength is weaker. The strongest intensity measured was 3.6 on the Richter scale. The Red Earthquakes are easy to measure because the shaking created by the ocean waves on Earth does not exist on the Red Planet, and in addition the atmosphere is quieter between sunset and the wee hours of the night.
Two types of earthquakes were observed: low-frequency earthquakes that create waves that propagate at different depths in the mantle, and higher-frequency earthquakes that create waves that travel through the crust. The low frequency tremors are similar to terrestrial earthquakes and the high frequency tremors are similar to lunar earthquakes. Most earthquakes are of high frequency and occur hundreds of kilometers from the lander. The frequency changes throughout the lunar year, a phenomenon not known on Earth.
One of the epicenters of the earthquakes is Cerberus Fossae 1800 km from the landing site. This is one of the youngest geological structures on Mars, its age is estimated at 20 million years and it was created as a result of tensile forces that created fault lines or ground subsidence due to the movement of dykes(2).
So far (April 2022) 47 new earthquakes have been measured at this location. It is believed that the magma is still active in the mantle. Mars appears to be geologically more seismically active than previously thought(3).
Based on an examination of rocks on the ground and measurements from spacecraft orbiting Mars, they came to the conclusion that in the core, 1800 km below the ground, there are small amounts of sulfur, oxygen and hydrogen. The mass of the nucleus is 1/6 of the mass of Mars, and this corresponds to the estimate that Mars has more oxygen atoms than the Earth, its nucleus is small, its surface is rusty and the explosiveness of the volatile elements is greater than that on Earth(4)
1. "Rice researches use InSight for deep measurements"
2. "Seismicity on Mars Full of surprises, in first continuous year of data" 24.4.2021/XNUMX/XNUMX
https://www.marsdaily.com/reports/Seismicity_On_Mars_ Full _of_ Surprises_ In_ First_ Continuous _Year _Of_ Data_999.html
3."Magma makes Marsquakes rock red planet" 4.4.2022
4. "Journey to the center of Mars: new compositional model for the red planet"
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