• Evidence that Venus is volcanically acti

    From ScienceDaily@1:317/3 to All on Wed Mar 15 22:30:34 2023
    Evidence that Venus is volcanically active

    Date:
    March 15, 2023
    Source:
    University of Alaska Fairbanks
    Summary:
    Venus appears to have volcanic activity, according to a new research
    paper that offers strong evidence to answer the lingering question
    about whether Earth's sister planet currently has eruptions and
    lava flows.

    Venus, although similar to Earth in size and mass, differs
    markedly in that it does not have plate tectonics. The boundaries
    of Earth's moving surface plates are the primary locations of
    volcanic activity. New research has revealed a nearly 1-square-mile
    volcanic vent that changed in shape and grew over eight months in
    1991. Changes on such a scale on Earth are associated with volcanic
    activity, whether through an eruption at the vent or movement of
    magma beneath the vent that causes the vent walls to collapse and
    the vent to expand.


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    FULL STORY ========================================================================== Venus appears to have volcanic activity, according to a new research
    paper that offers strong evidence to answer the lingering question about whether Earth's sister planet currently has eruptions and lava flows.


    ========================================================================== Venus, although similar to Earth in size and mass, differs markedly in
    that it does not have plate tectonics. The boundaries of Earth's moving
    surface plates are the primary locations of volcanic activity.

    New research by University of Alaska Fairbanks Geophysical Institute
    research professor Robert Herrick revealed a nearly 1-square-mile volcanic
    vent that changed in shape and grew over eight months in 1991. Changes
    on such a scale on Earth are associated with volcanic activity, whether
    through an eruption at the vent or movement of magma beneath the vent
    that causes the vent walls to collapse and the vent to expand.

    The research was published today in the journal Science.

    Herrick studied images taken in the early 1990s during the first
    two imaging cycles of NASA's Magellan space probe. Until recently,
    comparing digital images to find new lava flows took too much time,
    the paper notes. As a result, few scientists have searched Magellan data
    for feature formation.

    "It is really only in the last decade or so that the Magellan data has
    been available at full resolution, mosaicked and easily manipulable by
    an investigator with a typical personal workstation," Herrick said.

    The new research focused on an area containing two of Venus' largest
    volcanoes, Ozza and Maat Mons.

    "Ozza and Maat Mons are comparable in volume to Earth's largest volcanoes
    but have lower slopes and thus are more spread out," Herrick said.

    Maat Mons contains the expanded vent that indicates volcanic activity.

    Herrick compared a Magellan image from mid-February 1991 with a
    mid-October 1991 image and noticed a change to a vent on the north side
    of a domed shield volcano that is part of the Maat Mons volcano.

    The vent had grown from a circular formation of just under 1 square mile
    to an irregular shape of about 1.5 square miles.

    The later image indicates that the vent's walls became shorter, perhaps
    only a few hundred feet high, and that the vent was nearly filled to
    its rim. The researchers speculate that a lava lake formed in the vent
    during the eight months between the images, though whether the contents
    were liquid or cooled and solidified isn't known.

    The researchers offer one caveat: a nonvolcanic, earthquake-triggered
    collapse of the vent's walls might have caused the expansion. They note, however, that vent collapses of this scale on Earth's volcanoes have
    always been accompanied by nearby volcanic eruptions; magma withdraws
    from beneath the vent because it is going somewhere else.

    The surface of Venus is geologically young, especially compared to all
    the other rocky bodies except Earth and Jupiter's moon Io, Herrick said.

    "However, the estimates of how often eruptions might occur on Venus have
    been speculative, ranging from several large eruptions per year to one
    such eruption every several or even tens of years," he said.

    Herrick contrasts the lack of information about Venusian volcanism with
    what is known about Jupiter's moon Io and about Mars.

    "Io is so active that multiple ongoing eruptions have been imaged every
    time we've observed it," he said.

    On a geological time scale, relatively young lava flows indicate Mars
    remains volcanically active, Herrick said.

    "However, nothing has occurred in the 45 years that we have been observing Mars, and most scientists would say that you'd probably need to watch
    the surface for a few million years to have a reasonable chance of seeing
    a new lava flow," he said.

    Herrick's research adds Venus to the small pool of volcanically active
    bodies in our solar system.

    "We can now say that Venus is presently volcanically active in the sense
    that there are at least a few eruptions per year," he said. "We can
    expect that the upcoming Venus missions will observe new volcanic flows
    that have occurred since the Magellan mission ended three decades ago,
    and we should see some activity occurring while the two upcoming orbital missions are collecting images." Co-author Scott Hensley of NASA's Jet Propulsion Laboratory performed the modeling for the research.

    * RELATED_TOPICS
    o Space_&_Time
    # Solar_System # Venus # Space_Missions #
    Space_Exploration # NASA # Astronomy # Moon # Space_Probes
    * RELATED_TERMS
    o Venus o Volcano o Transit_of_Venus o Jupiter o Planet o Moon
    o Neptune o Solar_eclipse

    ========================================================================== Story Source: Materials provided by University_of_Alaska_Fairbanks. Note: Content may be edited for style and length.


    ========================================================================== Journal Reference:
    1. Robert R. Herrick, Scott Hensley. Surface changes observed on
    a Venusian
    volcano during the Magellan mission. Science, 2023; DOI: 10.1126/
    science.abm7735 ==========================================================================

    Link to news story: https://www.sciencedaily.com/releases/2023/03/230315143900.htm

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