Mini Tremors detected on Mars for first time:

[beecee]

https://www.sciencemag.org/news/2019/03/mini-tremors-detected-mars-first-time

THE WOODLANDS, TEXAS—After months of delicate maneuvering, NASA’s InSight lander has finished placing its hypersensitive seismometer on the surface of Mars. The instrument is designed to solve mysteries about the planet’s interior by detecting the booming thunder of “marsquakes.” But just a few weeks into its run, the car-size lander has already heard something else: the minute tremors that continually rock our red neighbor. If marsquakes are the drum solo, these microseisms, as they’re known, are the bass line.

The signal first became apparent in early February, as soon as the lander placed a protective shield over the seismometer, said Philippe Lognonné, a planetary seismologist at Paris Diderot University who heads the team that runs the instrument, in a talk here today at the annual Lunar and Planetary Science Conference. “We do believe that these signals are waves coming from Mars.” This is the first time, he said, that such microseisms have been detected on another planet.

On Earth, microseisms are ubiquitous, caused largely by the sloshing of the ocean by storms and tides. Mars, despite the dreams of science fiction writers, has no present-day oceans. Instead, this newly discovered noise is likely caused by low-frequency pressure waves from atmospheric winds that rattle the surface, inducing shallow, longer-period waves in the surface, called Rayleigh waves, Lognonné said.

more at https://www.sciencemag.org/news/2019/03/mini-tremors-detected-mars-first-time

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Interesting article and find I must say...a few questions...[1] Do these microquakes indicate or confirm plate tetonics? or as suggested pressure waves known as Rayleigh waves? [2] If not, would the expected fully blown Mars quakes indicate or confirm plate tetonics? [3] If and when they are able to unstick the probe that has only achieved .3 meter before becoming stuck, then re-probe and get to the original 5 meters, allow for more accurate confirmation of what causes these microquakes or as defined in the article, microseisms? [4]  And finally, with regards to these microseisms on Earth, could they affect the search for gravitational radiation? Although the confirmation of GW170817 observed with EMR and light would indicate that aLIGO and the other detectors are achieving what they set out to do.

Any discovery/detection of Mars quakes would need to be accurately confirmed and assessed as distinct from quakes caused by meteorites and/or landslides...are they capable of accurately discerning those possibilities?

[beecee]

a few questions...[1] Could these microquakes indicate or confirm plate tetonics? or as suggested pressure waves known as Rayleigh waves? [2] If not, would the expected fully blown Mars quakes indicate or confirm plate tetonics? [3] If and when they are able to unstick the probe that has only achieved .3 meter before becoming stuck, then re-probe and get to the original 5 meters, allow for more accurate confirmation of what causes these microquakes or as defined in the article, microseisms? [4]  And finally, with regards to these microseisms on Earth, could they affect the search for gravitational radiation? Although the confirmation of GW170817 observed with EMR and light would indicate that aLIGO and the other detectors are achieving what they set out to do.

Any discovery/detection of Mars quakes would need to be accurately confirmed and assessed as distinct from quakes caused by meteorites and/or landslides...are they capable of accurately discerning those possibilities?

[Intrigued]

On 3/19/2019 at 8:16 PM, beecee said:

Interesting article and find I must say...a few questions...[1] Do these microquakes indicate or confirm plate tetonics? or as suggested pressure waves known as Rayleigh waves? [2] If not, would the expected fully blown Mars quakes indicate or confirm plate tetonics? [3] If and when they are able to unstick the probe that has only achieved .3 meter before becoming stuck, then re-probe and get to the original 5 meters, allow for more accurate confirmation of what causes these microquakes or as defined in the article, microseisms? [4]  And finally, with regards to these microseisms on Earth, could they affect the search for gravitational radiation? Although the confirmation of GW170817 observed with EMR and light would indicate that aLIGO and the other detectors are achieving what they set out to do.

Any discovery/detection of Mars quakes would need to be accurately confirmed and assessed as distinct from quakes caused by meteorites and/or landslides...are they capable of accurately discerning those possibilities?

Re your questions, or at any rate, some of them.

1) Why would such microquakes indicate plate tectonics? I don't know of any such association, but that may well be ignorance on my part. Perhaps you have read of such a connection, or have inferred a logical relationship. Yes?

2) "Full blown Mars quakes" would simply demonstrate that Mars is seismically active. Such quakes could originate from events like isostatic adjustment, caldera collapse, asteroid impact and probably other sources. Sure, plate tectonics could be another source, but the consensus view as I understand it is that plate tectonics is not active on Mars, and most experts do not believe it ever has been.

3) I don't know enough about the specific instrumentation to give an assured answer, but common sense suggests that if they designed the probe to take readings from a greater depth that's because they felt it would give superior results. I guess the question you are really asking is, how much of a difference would it make? I don't know.

4) No idea. Sorry.

?) The signature of quakes generated by internal stresses should be sufficiently distinct from those initiated by impact.

[beecee]

11 hours ago, Intrigued said:

Re your questions, or at any rate, some of them.

1) Why would such microquakes indicate plate tectonics? I don't know of any such association, but that may well be ignorance on my part. Perhaps you have read of such a connection, or have inferred a logical relationship. Yes?

2) "Full blown Mars quakes" would simply demonstrate that Mars is seismically active. Such quakes could originate from events like isostatic adjustment, caldera collapse, asteroid impact and probably other sources. Sure, plate tectonics could be another source, but the consensus view as I understand it is that plate tectonics is not active on Mars, and most experts do not believe it ever has been.

Thanks for the answers. I have been under the impression that Earthquakes are a result of the tectonic plates geography on Earth as well as being seismically active. With regards to Mars, I was under the impression that it is seismically inactive at this time, although certainly has been active in the past. The article suggest that they are waiting for the inevitable Marsquake, which to me suggests tectonic plates. Although tectonic plates on Mars has not yet been fully confirmed, one could point towards huge geographical faults such as the "Valley Marineras" as well as the extinct volcano "Olympic Mons"

I did find the following......https://en.wikipedia.org/wiki/Marsquake

https://en.wikipedia.org/wiki/Geology_of_Mars extract: "The origin and age of the hemispheric dichotomy are still debated. Hypotheses of origin generally fall into two categories: one, the dichotomy was produced by a mega-impact event or several large impacts early in the planet’s history (exogenic theories)[13][14][15] or two, the dichotomy was produced by crustal thinning in the northern hemisphere by mantle convection, overturning, or other chemical and thermal processes in the planet’s interior (endogenic theories).[16][17] One endogenic model proposes an early episode of plate tectonics producing a thinner crust in the north, similar to what is occurring at spreading plate boundaries on Earth.[18] Whatever its origin, the Martian dichotomy appears to be extremely old. A new theory based on the Southern Polar Giant Impact[19] and validated by the discovery of twelve hemispherical alignments[20] shows that exogenic theories appear to be stronger than endogenic theories and that Mars never had plate tectonics[21][22] that could modify the dichotomy." 

then I found this.......https://www.spaceanswers.com/deep-space/how-did-we-first-measure-the-speed-of-light/ extract: "While Mars no longer appears to be geologically active, we see from surface features that it once was very Earth-like in its geological processes.  The surface of Mars plays host to the largest volcano in the Solar System, Olympus Mons, and a huge rift valley called Valles Marineris.

And it is this rift valley that indicates that Mars does in fact have tectonic plates. When analysing this ‘crack’ in the surface of Mars, scientists have found that the ‘matching sides’ are separated by a horizontal distance of 150 kilometres (93 miles). This suggests that the surface of Mars is effectively two large tectonic plates that were rubbing by each other.

However, since Mars cooled down much more rapidly than Earth, and therefore the molten rock beneath the plates has solidified, the process of tectonic plate formation appears to have ground to a halt" 

Another..... https://en.wikipedia.org/wiki/Tectonics_of_Mars extract: "Like the Earth, the crustal properties and structure of the surface of Mars are thought to have evolved through time; in other words, as on Earth, tectonic processes have shaped the planet. However, both the ways this change has happened and the properties of the planet's lithosphere are both very different when compared to the Earth. Today, Mars is believed to be largely tectonically quiescent. However, observational evidence and its interpretation suggests that this was not the case further back in Mars' geological history".

another......http://newsroom.ucla.edu/releases/ucla-scientist-discovers-plate-237303 extract: "For years, many scientists had thought that plate tectonics existed nowhere in our solar system but on Earth. Now, a UCLA scientist has discovered that the geological phenomenon, which involves the movement of huge crustal plates beneath a planet's surface, also exists on Mars.

"Mars is at a primitive stage of plate tectonics. It gives us a glimpse of how the early Earth may have looked and may help us understand how plate tectonics began on Earth," said An Yin, a UCLA professor of Earth and space sciences and the sole author of the new research."

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I would also say that my question re microseisms on Earth, and the gravitational wave detectors, would certainly have been taken into account considering the incredible accuracy and precision of these detectors. I was interested in getting the views of any online geologists re the article and my questions in general, but again thanks for your interests and answers. 

 

 

 

Edited March 21, 2019 by beecee