Commonwealth Journal

Community News Network

October 7, 2013

Scientists find evidence of Martian supervolcanoes

We've known for a long time that Mars has volcanoes; after all, Olympus Mons on the Martian Tharsis shield is the largest volcano in the solar system.

But there may have been a more powerful menace lurking just below the red planet's surface eons ago. A paper published last week in Nature (though the authors first reported about it in March at 44th Lunar and Planetary Science Conference) claims to have found evidence of supervolcanoes on Mars.

On Earth, a supervolcano is far larger than a regular volcano; they have huge chambers of magma that can be dozens of kilometers across (like under Yellowstone). They build slowly over hundreds of thousands of years, and erupt catastrophically, and can change the landscape and climate of nearly the entire planet.

In the northern hemisphere of Mars is a series of craters that have been thought to be from impacts. Mars is littered with impact craters, since it has little atmosphere and no running water to erode away ancient features. But the craters in question, most notably Eden Patera (85 by 55 kilometers in size, or 53 by 34 miles), are a bit odd. The entire area is actually lower than average, literally sunken, which is consistent with a supervolcano; once the magma under the surface erupts out, the ground around it collapses to fill the empty space.

Other features make it suspiciously un-impact-like. The crater isn't round, it has no rim, no ejecta (material blasted out from impact), and no central peak (which are common in large craters, like Tycho on the Moon). There are substantial flows of lava around the area, and more evidence of ancient volcanism. Also, benches, or flattened rings around the inside of the crater, are present, and these are common in volcanoes as lava lakes subside.

If Eden Patera (and several other craters seen in the Arabia Terra region of Mars) are in fact supervolcanoes, this changes how we see ancient Mars. Olympus Mons, for example, probably built itself up over eons with big eruptions, but not catastrophic enough that it blew itself apart. That's why it grew to such enormous size; 600 kilometers (370 miles) wide and 22 kilometers (14 miles) tall- Mars also lacks plate tectonics, so a single volcano can just sit in one spot and grow ever larger.

But supervolcanoes explode. Gas dissolved in the magma is pressurized underground, but once it hits the surface it expands violently, creating a massive explosion. This would have distributed volcanic output like ash for thousands of kilometers across the planet. In fact, fine-grained volcanic deposits have been found across the equatorial regions of Mars that are most likely from volcanoes, but no source volcano has ever been found. Moreover, the deposits are layered, which is expected as well from episodic supervolcano explosions. Similar features are seen on Earth.

It's not certain that these craters are in fact supervolcanoes, but it would explain a lot. As we investigate more of Mars we're sure to find features that were previously unknown, and our view of the red planet will no doubt continually evolve. Perhaps we'll find evidence to support this idea of supervolcanoes; perhaps we'll find contradictory data. Either way, the only way we'll know is to keep exploring, keep looking around, and keep learning.

          

1
Text Only
Community News Network
  • To sleep well, you may need to adjust what you eat and when

    Sleep.  Oh, to sleep.  A good night's sleep is often a struggle for more than half of American adults.  And for occasional insomnia, there are good reasons to avoid using medications, whether over-the-counter or prescription.

    April 16, 2014

  • Doctors to rate cost effectiveness of expensive cancer drugs

    The world's largest organization of cancer doctors plans to rate the cost effectiveness of expensive oncology drugs, and will urge physicians to use the ratings to discuss the costs with their patients.

    April 16, 2014

  • Low blood-sugar levels make for grousing spouses

    Husbands and wives reported being most unhappy with their spouses when their blood-sugar levels were lowest, usually at night, according to research released this week in the Proceedings of the National Academy of Sciences. Missing a meal, dieting or just being hungry may be the reason, researchers said.

    April 16, 2014

  • Screen Shot 2014-04-16 at 12.51.22 PM.png VIDEO: Toddler climbs into vending machine

    A child is safe after climbing into and getting stuck inside a claw crane machine at a Lincoln, Neb., bowling alley Monday.

    April 16, 2014 1 Photo

  • portraitoflotte.jpg VIDEO: From infant to teen in four minutes

    Dutch filmmaker Frans Hofmeester’s time lapse video of his daughter, Lotte — created by filming her every week from her birth until she turned 14 — has become a viral sensation.

    April 16, 2014 1 Photo

  • Victimized by the 'marriage penalty'

    In a few short months, I'll pass the milestone that every little girl dreams of: the day she swears - before family and God, in sickness and in health, all in the name of love - that she's willing to pay a much higher tax rate.

    April 15, 2014

  • Allergies are the real midlife crisis

    One of the biggest mysteries is why the disease comes and goes, and then comes and goes again. People tend to experience intense allergies between the ages of 5 and 16, then get a couple of decades off before the symptoms return in the 30s, only to diminish around retirement age.

    April 15, 2014

  • treadmill-very-fast.jpg Tax deduction for a gym membership?

    April marks another tax season when millions of Americans will deduct expenses related to home ownership, children and education from their annual tax bill. These deductions exist because of their perceived value to society; they encourage behaviors that keep the wheels of the economy turning. So why shouldn't the tax code be revised to reward preventive health?

    April 15, 2014 1 Photo

  • bomb1 VIDEO: A year after marathon bombing, Boston remains strong

    The City of Boston came together Tuesday to honor those who were injured and lost their lives at the Boston Marathon on the one-year anniversary of the bombing. While the day was sure to be emotional, those affected by last year's race are showing they won't let the tragedy keep them down.

    April 15, 2014 1 Photo

  • Google acquires drone maker Titan Aerospace to spread Internet

    Google is adding drones to its fleets of robots and driverless cars.
    The Internet search company said it acquired Titan Aerospace, the maker of high-altitude, solar-powered satellites that provides customer access to data services around the world. Terms of the deal weren't disclosed.

    April 14, 2014

News Live
AP Video
Hyperlocal Search
Premier Guide
Find a business

Walking Fingers
Maps, Menus, Store hours, Coupons, and more...
Premier Guide
Stocks