Quakes on Mars as seen by InSight
After completing its first full Martian year on the surface of the Red Planet, the scientists for the lander InSight today gave a report [pdf] of their results at this year’s annual 52nd Lunar and Planetary Science Conference, normally held in Texas but being done virtually this year out of terror of the coronavirus.
All told the lander’s seismometer has, as of just a few days ago, detected just over 500 quakes. The map to the right, showing the most distinct quakes and their locations, was adapted from a different presentation [pdf] at the conference. The numbers indicate the sols after landing when these quakes were detected.
This is essentially the region on Mars that I call volcano country. Some of the lava flood plains here are the youngest on Mars. To the east just beyond the edge of the map is the Tharsis Bulge, which holds Olympus Mons and the string of three giant volcanoes to its east. South of Cereberus Fossae but north of the yellow-colored cratered highlands is the vast Medusae Fossae Formation, the largest volcanic ash deposit on Mars.
The quakes suggest they are occurring as large blocks shift along faults, creating fissures and cracks that geologists call grabens. The long fissures of Cereberus Fossae are considered an example of grabens, so this activity suggests that shifting is still going on in the region.
In addition to outlining the location of the detected volcanoes, the presentation today summarized these other discoveries made by InSight about Mars’ interior structure:
- The crust of Mars has likely two or three layers either 12 or 24 miles thick, with a total thickness no more than 45 miles. This is much thinner than most scientists had expected.
- The mantle layer below the crust is estimated at about 250 to 375 miles thick, with a temperature between 1,600 to 1,700 degrees Kelvin. While quite hot, this is a cooler mantle than expected.
- The core of Mars is somewhere between 1,100 to 1,300 miles in diameter, with a outer layer made of liquid. These results are at the high end of pre-mission expectations.
As already admitted, it was noted that the heat sensor experiment will not be able to provide the interior temperature of Mars, as its digging mole was unable to dig into the ground the 9 to 15 feet planned.
Readers!
Please consider supporting my work here at Behind the Black. Your support allows me the freedom and ability to analyze objectively the ongoing renaissance in space, as well as the cultural changes -- for good or ill -- that are happening across America. Fourteen years ago I wrote that SLS and Orion were a bad ideas, a waste of money, would be years behind schedule, and better replaced by commercial private enterprise. Only now does it appear that Washington might finally recognize this reality.
In 2020 when the world panicked over COVID I wrote that the panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Only in the past year have some of our so-called experts in the health field have begun to recognize these facts.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
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4. Donate by check, payable to Robert Zimmerman and mailed to
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You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
After completing its first full Martian year on the surface of the Red Planet, the scientists for the lander InSight today gave a report [pdf] of their results at this year’s annual 52nd Lunar and Planetary Science Conference, normally held in Texas but being done virtually this year out of terror of the coronavirus.
All told the lander’s seismometer has, as of just a few days ago, detected just over 500 quakes. The map to the right, showing the most distinct quakes and their locations, was adapted from a different presentation [pdf] at the conference. The numbers indicate the sols after landing when these quakes were detected.
This is essentially the region on Mars that I call volcano country. Some of the lava flood plains here are the youngest on Mars. To the east just beyond the edge of the map is the Tharsis Bulge, which holds Olympus Mons and the string of three giant volcanoes to its east. South of Cereberus Fossae but north of the yellow-colored cratered highlands is the vast Medusae Fossae Formation, the largest volcanic ash deposit on Mars.
The quakes suggest they are occurring as large blocks shift along faults, creating fissures and cracks that geologists call grabens. The long fissures of Cereberus Fossae are considered an example of grabens, so this activity suggests that shifting is still going on in the region.
In addition to outlining the location of the detected volcanoes, the presentation today summarized these other discoveries made by InSight about Mars’ interior structure:
- The crust of Mars has likely two or three layers either 12 or 24 miles thick, with a total thickness no more than 45 miles. This is much thinner than most scientists had expected.
- The mantle layer below the crust is estimated at about 250 to 375 miles thick, with a temperature between 1,600 to 1,700 degrees Kelvin. While quite hot, this is a cooler mantle than expected.
- The core of Mars is somewhere between 1,100 to 1,300 miles in diameter, with a outer layer made of liquid. These results are at the high end of pre-mission expectations.
As already admitted, it was noted that the heat sensor experiment will not be able to provide the interior temperature of Mars, as its digging mole was unable to dig into the ground the 9 to 15 feet planned.
Readers!
Please consider supporting my work here at Behind the Black. Your support allows me the freedom and ability to analyze objectively the ongoing renaissance in space, as well as the cultural changes -- for good or ill -- that are happening across America. Fourteen years ago I wrote that SLS and Orion were a bad ideas, a waste of money, would be years behind schedule, and better replaced by commercial private enterprise. Only now does it appear that Washington might finally recognize this reality.
In 2020 when the world panicked over COVID I wrote that the panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Only in the past year have some of our so-called experts in the health field have begun to recognize these facts.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation or subscription:
4. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
I’m not a seismologist but I would think triangulation (3 dimensional) is one of the fundamental tools required to start to understand anything going on on a sphere. As such I would have expected a requirement of all future probes to be a Mars-quake sensor. This would of course would start slow but with every new probe a new point would be established. After enough the math and other analysis can help provide the answers – or at least good guesses.
Chris: Your idea has merit, but it is likely not practical. A close look at the technical requirements needed to make this seismometer sensitive enough to provide worthwhile data, outlined in today’s talk, makes it clear that the cost to produce a similar instrument on all other landers would likely conflict too much with their other purposes.
Ok. If not practical- then not prectical
OK, nice to attempt to figure out the martian interior structures and stuff. I get it. (almost)
How does all of this translate into me shaking on the ground if I where there ?
I know the shake, and following shake/shudders, of Loma Prieta quake of ’89 – M6.9. I was on my commute – S.J. > Santa Cruz at that time.
What does the current Mars InSight info tell me in that regard ?
Beside that their are no commuter lanes on Mars.
Chris, I agree.
A small detachable independent seismograph/ weather station with its own roll out solar panel should be sent with every lander. The descent rocket that lowers the lander could have this package attached to it? It has enough weight to be an excellent base if they landed it, instead of crash it.
Didn’t we discuss dropping such probes, that collect heat measurements and seismic activity, “from space” so they can impell themselves at desired locations? A ribbon of flexible solar panel can keep the metal stake vertical until impact. Or maybe they should use feathers like an arrow and just protect the solar panel/broadcast instruments inside the hollow tube for protection and perform extraction after impact.
Sensitive equipment like temperature, barometer, fish eye lenses, communication capabilities can fit in a wrist watch. A small light unit in a helium mylar balloon with a solar panel top could drift around mars for years collecting data. In fact, the parachute, If it’s double layered, could be filled with helium after detachment, for this purpose. (I wonder if they filled it before detachment if it would have enough “lift” to slow the descent more effectively?)
It would not take much volume from the helium tank, because of the low atmospheric pressure. The canister and the ascent/descend pump would last for year’s before the tank was empty and could be dropped like ballast.
Amazing what they can do with seismology. Maybe not every lander, but I wonder if they’d get a serious improvement with just one more seismometer?
But these numbers don’t add up: crust at 45 miles, mantle at 375 miles and core of 1300 miles diameter. All packed together you get “2 ( 45 + 375 ) + 1300” = 1720 miles across, coming up short of the real Mars at 4212 miles. My guess, the mantle is considerably thicker at about 1400 miles thick.
But, but, but they told me there would be no maths! Good catch, David.
Is there another component that gets what’s leftover? That is, are crust, mantle, and core the only three layers? I see “inner” and “outer” broken out of “core” in some places.
David Telford: I suspect what Bob reports as mantle thickness is more precisely “upper mantle”. So your missing layer is “lower mantle”.
As they acquire more data, they will come up with a more exact model for Mars interior structure. Of course it would really help if we had more stations, and maybe people there to maintain and operate them :-)
But then you’d have WAY more human-created seismic noise!
Huh. I thought we’d believed that Mars lacked magnetosphere from its core being frozen.
So much for simple explanations, I guess.