• The submarine volcano Hunga Tonga awoke in December 2014, erupting between Hunga Ha'apai (left) and Hunga Tonga, part of the South Pacific island nation of Tonga. A new crater emerged, spewing enormous volumes of rock and volcanic ash. The debris eventually joined the new crater to Hunga Ha'apai, although the extended island is expected to erode back into the ocean in a matter of months.


    Use the slider to see the before (July 2014) and after (January 2015) images of the eruption. The remarkable image was created with the Pléiades satellite, operated by Airbus Defense and Space through the French space agency CNES. 

  • Term Part of Speech Definition Encyclopedic Entry
    crater Noun

    bowl-shaped depression formed by a volcanic eruption or impact of a meteorite.

    Encyclopedic Entry: crater
    debris Noun

    remains of something broken or destroyed; waste, or garbage.

    emerge Verb

    to develop or come into view.

    enormous Adjective

    very large.

    erode Verb

    to wear away.

    eruption Noun

    release of material from an opening in the Earth's crust.

    geologist Noun

    person who studies the physical formations of the Earth.

    Ring of Fire Noun

    horseshoe-shaped string of volcanoes and earthquake sites around edges of the Pacific Ocean.

    Encyclopedic Entry: Ring of Fire
    spew Verb

    to eject or discharge violently.

    submarine Adjective


    volcanic ash Noun

    fragments of lava less than 2 millimeters across.

    Encyclopedic Entry: volcanic ash
    volcano Noun

    an opening in the Earth's crust, through which lava, ash, and gases erupt, and also the cone built by eruptions.

    Encyclopedic Entry: volcano