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Volcanoes on Venus May Still Be Active

Recent infrared data from an instrument on the Venus Express spacecraft indicate there could be active volcanism on Venus. “We are pretty sure that Venus still has volcanic activity,” said Joern Helbert and Nils Mueller from the DLR Institute of Planetary Research, members of the Visible and Infrared Thermal Imaging Spectrometer(VIRTIS) team. Nine ‘hotspots’ on Venus’ southern hemisphere have been identified as possibly active, according to a paper published in Science by an international team.

Focusing on areas that showed a lack of surface weathering – which indicates a young surface — the scientists looked at variations in surface thermal emissions to identify compositional differences in lava flows at three specific hotspots. They found that lava flows at the those areas emit abnormally high amounts of heat when compared with their surroundings. That the temperatures are higher does not indicate “heat” as such from volcanism, but means that not much rock degradation by exposure to the harsh Venusian weather took place.

For planetary scientists, that indicates recent active volcanos. How recent?

“Based on a wide range of estimates for rates of volcanism on the surface, we find an upper bound of 250 years to 2.5 million years,” lead author Suzanne Smrekar from JPL told Universe Today in an email. “From predictions about how fast rocks weather on the surface of Venus, we think they are likely on the young side of these estimates. However, there is nothing to preclude them from happening today – but we don’t have any data that demonstrates that.”

The colored overlay shows the emissivity derived from VIRTIS surface brightness data, acquired by ESA¹s Venus Express mission. The high emissivity area (shown in red and yellow) is centered on the summit and the bright flows that originate there. Image courtesy NASA/JPL-Caltech/ESA; image created by Ryan Ollerenshaw and Eric DeJong of the Solar System Visualization Group, JPL.

The areas are analogous to Hawaii with volcanism, broad topographic rises, and large positive gravity anomalies suggesting mantle plumes – which are rising masses of hot molten rock.

Smrekar said the temperature variations aren’t huge. “Only a degree or two above the background temperature,” she said. “‘Hot spot’ refers to the geologic environment. On Earth, places like Hawaii where there is hot material coming up from deep inside the Earth to produce volcanism, are referred to as ‘hot spots’.”

Like on Earth, Venus’s valleys are warmer than its mountains. But the venusian atmosphere is so dense that it completely determines the temperature of the planet’s surface. This enabled the scientists to predict surface temperatures with computer models. Data obtained from VIRTIS last year shows that certain areas deviate from the predictions by as much as two or three degrees, and that was the focus of the team’s study.

Smrekar said the team was surprised at the findings. “Although we suspected that these areas could be volcanically active on geologic time scales from past data sets, this is the first data to confirm very recent volcanism, geologically speaking.”

Sources: Science, email exchange with Suzanne Smrekar, DLR

About 

Nancy Atkinson is Universe Today's Senior Editor. She also works with Astronomy Cast, and is a NASA/JPL Solar System Ambassador.

Comments on this entry are closed.

  • William928 April 8, 2010, 3:52 PM

    If this study is inferring active volcanism strictly from a change in temperature from the ambient temperature of 2 to 3 degrees, the findings seem a bit questionable. With the dense atmosphere and severe temperatures present on Venus, how can this temperature variance be measured accurately? It would seem measuring rock degradation levels would lead to a better conclusion, as the article mentions.

  • Kevin April 8, 2010, 4:17 PM

    We need to drop another probe on Venus. I’m sure we could cook up something that wouldn’t “cook” that quickly. We know annoyingly little about the surface of the closest planet.

  • Lawrence B. Crowell April 8, 2010, 5:58 PM

    Wow, I was unaware a spacecraft was in orbit around Venus.

    Severe weather on Venus is mentioned above. I have been under the impression that with the lack of latent heat activity, such as with water and clouds, that the winds on Venus were very mild. The H_2SO_4 latent heat driven weather takes place in the upper atmosphere. Does this drive violent weather at lower altitudes?

    Getting a probe or robot on Venus is a tough problem. Electronics and the rest are not very tolerant of such heat. To keep the interior cool would require some mighty heat pumps! This is not to mention a nuclear power plant is needed to run them.

    LC

  • IVAN3MAN_AT_LARGE April 8, 2010, 6:53 PM

    Lawrence B. Crowell:

    Wow, I was unaware a spacecraft was in orbit around Venus.

    Like, err… where have you been, man? :-)

    See: ESA — Venus Express.

  • IVAN3MAN_AT_LARGE April 8, 2010, 7:30 PM

    Lawrence B. Crowell:

    Getting a probe or robot on Venus is a tough problem. Electronics and the rest are not very tolerant of such heat. To keep the interior cool would require some mighty heat pumps! This is not to mention a nuclear power plant is needed to run them.

    As a matter of fact, according to Wikipedia — Observations and explorations of Venus:

    [A] team led by Geoffrey Landis of NASA’s Glenn Research Center in Ohio has proposed a Venus Rover mission that includes a tough surface rover in communication with a solar-powered aircraft. The aircraft would carry the mission’s sensitive electronics in the relatively mild temperatures of Venus’ upper atmosphere. Another more recent rover design proposal by Landis uses a Stirling cooler powered by a nuclear power source to keep an electronics package at a relatively comfortable 200 °C (392 °F). [Emphasis mine.]

    Abstract from “Venus surface power and cooling systems“:

    A mission to the surface of Venus would have high scientific value, but most electronic devices and sensors cannot operate at the 450 °C ambient surface temperature of Venus. Power and cooling systems were analyzed for Venus surface operation. A radioisotope power and cooling system was designed to provide electrical power for a probe operating on the surface of Venus. For a mission duration of substantial length, the use of thermal mass to maintain an operable temperature range is likely impractical, and active refrigeration may be required to keep components at a temperature below ambient. Due to the high thermal convection of the high-density atmosphere, the heat rejection temperature was assumed to be at a 500 °C radiator temperature, 50 °C above ambient. The radioisotope Stirling power converter designed produces a thermodynamic power output capacity of 478.1 W, with a cooling power of 100 W. The overall efficiency is calculated to be 23.36%. The mass of the power converter is estimated at approximately 21.6 kg.

    COOL!

  • Lawrence B. Crowell April 8, 2010, 7:42 PM

    Cool? You mean hot! This strikes me as expensive and still difficult.

    LC

  • IVAN3MAN_AT_LARGE April 8, 2010, 8:23 PM

    Lawrence B. Crowell:

    This strikes me as expensive and still difficult.

    Maybe, but… “To boldly go where no [robot] has gone before…”

  • Torbjorn Larsson OM April 9, 2010, 2:31 PM

    It would seem measuring rock degradation levels would lead to a better conclusion,

    I’m not sure I understand. The temperature measurement is used as a proxy for the degradation. And the certainty would surely come from connected areas (i.e. it is not spotty, see the images) as well as correlation with several hotspots and no other features.

    Unfortunately I hit a pay wall for the paper, but here is more discussion meanwhile.

  • Torbjorn Larsson OM April 9, 2010, 2:54 PM

    Electronics and the rest are not very tolerant of such heat.

    Standard electronics, that is. Already 2007 SiC devices operated > 2500 h at 500 degC, and they promise to operate at 600 degC:

    “Active silicon transistors reach their normal operational temperature limits at approximately 125 °C, typically have a switching limit in the range of a few GHz, and are highly susceptible to harsh environments (most notably, intense radiation and thermal environments). SiC devices have the potential to operate at temperatures up to 600 °C at switching frequencies in the 10s to 100s GHz range and at increased power densities, thus improving upon many of the limitations associated with silicon electronics. [From MSCAD white paper]”

    [For one, SiC devices doesn't suffer from the thermal runaway problem that troubles Si devices. For another, higher bandgap extend operation at the higher temperatures.]

    For comparison, Venus is a balmy 460 degC.

    The temperature range, the radiation hardness and the possibility of high frequency operation, is no doubt why NASA is researching SiC electronics.

  • IVAN3MAN_AT_LARGE April 9, 2010, 7:17 PM

    @ Torbjörn Larsson OM,

    Thanks for that link. Just to let you know that someone is still reading this thread! :-)

  • Kevin April 10, 2010, 7:46 AM

    Cool? You mean hot! This strikes me as expensive and still difficult.

    “We don’t do these things because they are easy, but because they are hard!” -John F. Kennedy

  • Paul Eaton-Jones April 20, 2010, 3:13 AM

    Is there ANYTHING that LBC doesn’t find too expensive, a waste of time or a waste of resources or pointless????

  • Owain55 April 20, 2010, 11:25 AM

    Damn well said Kevin! Is there anything that LBC doesn’t find too expensive, too much of a waste of time, too difficult or a complete waste of resources?

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