8 comments on “Antarctica 2 – The Deception Island Caldera

  1. Wonderful article Agimarc. Really good read. Looks like the place has just about everything a sailor needs! No wonder it was so popular. Probably the only place like it in the entire Southern Ocean.
    Pretty interested to hear that such slow subduction can power volcanism, maybe there are some residual anomalies in the upper mantle/lower crust from the zone was more active that assist magma genesis or something. Does seem like a long time gap though between the old volcanics and the new stuff.

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    • Howdy Bruce – thank you for the kind words. One of the things that stuck me about Antarctica is how sloooowly things take place. And for a place where things move slowly, there is a lot (at least to me) of volcanic activity and the tectonics appear complex.

      As I think about the South Shetlands, the subduction driven volcanism is obvious, though it appears to now be concentrated in the line to the east of the main island chain. The subduction kind of disappears to the south of Deception. I wonder how much magma generation is due to decompression melting due to the slow spreading of the Bransfield strait? Wouldn’t be surprised that number is “some”, but what percentage of the melt is produced by that process is anyone’s guess.

      And how the heck do you get a spreading center without new sea floor being created? My guess would be that this is sufficiently new that there hasn’t been enough time for the uplift and decompression melt to start that process. Expect the slow speed of tectonic activity is a cause.

      So much neat stuff. So many questions. Fascinating region that we don’t know a lot about. Best to you and yours. Cheers –

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  2. La Cumbra volcano on Ferdinandina (Galapagos Islds.) is erupting big after 8 years!
    Mirova: http://www.mirovaweb.it/?action=volcanoDetails&volcano_id=353010
    IGEPN: http://www.igepn.edu.ec/servicios/noticias/1511-informe-especial-volcan-fernandina-n-1-2017

    Satellite 04/09/2017 (Worldview):

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  3. If you like to read posts of Erik Klemetti, it seems he writes now on a blog of Discover Magazine – Rocky Planet. I don’t know if exclusively and permanently or just occasionally; here is Erik’s latest: Who Owns the Rocks?.

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    • Very beautiful photo. It gives an impression like the hand-colored images in an old book.

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      • A writer on one of the blogs I follow was at totality in eastern Oregon. He said right before the sun was covered completely, the shadows got very fine and precise. His words:

        The unexpected oddity was that as totality approached, the shadows all got sharper and sharper. There were a number of small plants growing by the side of the road. Near totality, even the tiniest branches cast a precise, finely delineated shadow that made a most beautifully detailed lace-like tracery on the pavement.

        After some thought, it was obvious that it is the width of the sun that washes out shadows of fine stalks and stems. The light from one side of the sun erases the shadow cast by the light from the other side of the sun. But just before totality, the light is coming from only a sliver of the sun, and as a result, we got the loveliest elegant finely delineated shadows.

        https://wattsupwiththat.com/2017/08/27/northern-journeys/

        I think I’m going to Dallas in 7 years (assuming I’m still around), and see the next one with one of my brothers. Cheers –

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