(ORDO NEWS) — An international team of scientists has discovered signs of recent volcanic activity on Mars.
Beneath the surface of the planet, in the region of the Cerberus Fossae faults, there is probably a clot of molten lava that causes marsquakes recorded by the seismometer installed on the InSight spacecraft.
Since 2018, when NASA’s InSight mission deployed the SEIS seismometer, more than 1,300 marsquakes have been recorded.
Their epicenters were located in the region of Cerberus, where there is a series of faults, or grabens, called Cerberus Fossae (Cerberus Furrows).
During the first year of operation of the probe, planetary scientists recorded low-frequency seismic waves, indicating the ongoing expansion of faults.
It is believed that the sources of these marsquakes are located in the lower part of the Martian crust or in the upper part of the mantle, at a depth of 15 to 50 kilometers.
However, the most common type of seismic activity is high-frequency marsquakes, the hypocenter of which is located at a relatively shallow depth.
Until December 31, 2021, 1150 events were recorded, but scientists could not connect them with a specific region of Mars and explain their origin.
In the new work, the scientists analyzed both low-frequency (LF) and high-frequency (HF) seismic waves. Most of the low-frequency events were associated with the central sulcus of Cerberus Fossae.
As for HF waves, the researchers first determined their relative distances to the source, and then studied their distribution, which corresponded to the entire length of the Cerberus Furrows region.
An assessment of the overall seismicity indicated that the central sulcus is the source of at least 50 percent of the total tremor strength recorded by SEIS.
For LF-marsquakes, the source of which is located in the region of Cerberus Fossae, is characterized by a reduced frequency compared to seismic waves coming from other regions.
The most likely explanation for this is that there is an elevated temperature zone below the furrows where the rocks are heated and softened.
At the same time, scientists did not find signs of volcanism in the seismic data, which is why the structure is probably dormant or inactive.
HF earthquakes are most likely due to breaks in the very structure of the central furrow above the volcanic fault.
Surrounding the furrow is also a dark patch of the Cerberus Mantling Unit (CMU), which is thought to be a sign of relatively recent volcanic activity around 53,000-210,000 years ago.
The researchers suggest that earthquakes may be either the last echoes of this process, or serve as a sign that magma is moving east, to the next eruption site.
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