Giant mantle plume reveals Mars is more active than previously thought

On Earth, shifting tectonic plates reshuffle the planet’s surface and make for a dynamic interior, so the absence of such processes on Mars led many to think of it as a dead planet, where not much happened in the past 3 billion years.

more…

Tau.Neutrino said:

Giant mantle plume reveals Mars is more active than previously thought

On Earth, shifting tectonic plates reshuffle the planet’s surface and make for a dynamic interior, so the absence of such processes on Mars led many to think of it as a dead planet, where not much happened in the past 3 billion years.

more…

> In the current issue of Nature Astronomy, scientists from the University of Arizona challenge current views of Martian geodynamic evolution with a report on the discovery of an active mantle plume pushing the surface upward and causing earthquakes and volcanic eruptions. The finding suggests that the planet’s deceptively quiet surface may hide a more tumultuous interior than previously thought.

Isn’t this in direct contradiction of the results from the InSight lander?

No marsquakes were found, other than those caused by wind and meteorite impact.

> The researchers were drawn to a surprising amount of activity in an otherwise nondescript region of Mars called Elysium Planitia, a plain within Mars’ northern lowlands close to the equator. Unlike other volcanic regions on Mars, which haven’t seen major activity for billions of years, Elysium Planitia experienced large eruptions over the past 200 million years. Previous work by our group found evidence in Elysium Planitia for the youngest volcanic eruption known on Mars. It created a small explosion of volcanic ash around 53,000 years ago, which in geologic time is essentially yesterday.

Oh, OK.

So is this claim just based on the absence of impact craters in Elysium Planitia?

mollwollfumble said:

Tau.Neutrino said:

Giant mantle plume reveals Mars is more active than previously thought

On Earth, shifting tectonic plates reshuffle the planet’s surface and make for a dynamic interior, so the absence of such processes on Mars led many to think of it as a dead planet, where not much happened in the past 3 billion years.

more…

> In the current issue of Nature Astronomy, scientists from the University of Arizona challenge current views of Martian geodynamic evolution with a report on the discovery of an active mantle plume pushing the surface upward and causing earthquakes and volcanic eruptions. The finding suggests that the planet’s deceptively quiet surface may hide a more tumultuous interior than previously thought.

Isn’t this in direct contradiction of the results from the InSight lander?

No marsquakes were found, other than those caused by wind and meteorite impact.

> The researchers were drawn to a surprising amount of activity in an otherwise nondescript region of Mars called Elysium Planitia, a plain within Mars’ northern lowlands close to the equator. Unlike other volcanic regions on Mars, which haven’t seen major activity for billions of years, Elysium Planitia experienced large eruptions over the past 200 million years. Previous work by our group found evidence in Elysium Planitia for the youngest volcanic eruption known on Mars. It created a small explosion of volcanic ash around 53,000 years ago, which in geologic time is essentially yesterday.

Oh, OK.

So is this claim just based on the absence of impact craters in Elysium Planitia?

Lava Against an Impact Crater in Elysium Planitia

https://mars.nasa.gov/resources/6094/lava-against-an-impact-crater-in-elysium-planitia/?site=msl

This image shows lava crumpled against the upstream side of an impact crater. In places where we see smaller ridges in the lava, they have steep faces that retain less dust and look rocky. Because of the lesser amount of dust, we might be able to see better details of the topography.

The crater itself is extremely old, having long been filled in with dust and its rim severely eroded. Note also the flat surrounding terrain.

from

https://phys.org/news/2022-12-giant-mantle-plume-reveals-mars.html

Volcanism at Elysium Planitia originates from the Cerberus Fossae, a set of young fissures that stretch for more than 800 miles across the Martian surface. Recently, NASA’s InSight team found that nearly all Martian quakes, or marsquakes, emanate from this one region. Although this young volcanic and tectonic activity had been documented, the underlying cause remained unknown.

When the team studied the features of Elysium Planitia, they found evidence of the same sequence of events on Mars. The surface has been uplifted by more than a mile, making it one of the highest regions in Mars’ vast northern lowlands. Analyses of subtle variations in the gravity field indicated that this uplift is supported from deep within the planet, consistent with the presence of a mantle plume.

Other measurements showed that the floor of impact craters is tilted in the direction of the plume, further supporting the idea that something pushed the surface up after the craters formed.

Finally, when researchers applied a tectonic model to the area, they found that the presence of a giant plume, 2,500 miles wide, was the only way to explain the extension responsible for forming the Cerberus Fossae.

NASA spacecraft records epic ‘marsquakes’ as it prepares to die

Are there Marsquakes?

In August and September 2021, the spacecraft detected marsquakes on the other side of the planet for the first time6. And on 4 May this year, InSight detected a magnitude 4.7 quake — the biggest by far (most of InSight’s detections are in the magnitude 2–3 range).

The findings add to InSight’s rich legacy of discovery. Since arriving on Mars in November 2018, it has gathered information on more than 1,300 ‘marsquakes’3. This has allowed researchers to calculate, among other things, the long-sought size of Mars’s core and the thickness of its crust. Just last month, researchers used data from five marsquakes to determine that Mars’s mantle is richer in iron than is Earth’s4. All of this information on Mars’s internal layers will help scientists to understand how the planet formed and evolved over billions of years.