Results 1 to 23 of 23

Thread: Krakatoa has erupted, looks like a VEI-6 (Larger the St Helens a little)

  1. #1
    Join Date
    Nov 2001
    Posts
    3,272

    Krakatoa has erupted, looks like a VEI-6 (Larger the St Helens a little)

    News is still coming in but like the original eruption Darwin witnessed, it caused a tsunami, and the death toll has been steadly rising the last few hours.

  2. #2
    Join Date
    Nov 2001
    Posts
    3,272
    vaac: Darwin
    volcano: Krakatau 262000
    psn: S0606 e10525
    area: Indonesia
    summit elev: 813m
    advisory nr: 2018/369
    info source: Himawari-8
    aviation colour code: Red

    eruption details: Eruption to fl550 obs ext sw at 23/0740z.
    obs va dtg: 23/0800z
    obs va cld: Sfc/fl550 s0605 e10534 - s0625 e10528 - s0757
    e10257 - s0716 e10208 - s0601 e10343 - s0540 e10524 mov sw
    30kt
    fcst va cld +6 hr: 23/1400z sfc/fl550 s0605 e10534 - s0638
    e10523 - s0809 e10252 - s0605 e10158 - s0540 e10523
    fcst va cld +12 hr: 23/2000z sfc/fl550 s0604 e10532 - s0541
    e10524 - s0552 e10156 - s0737 e10231 - s0637 e10523
    fcst va cld +18 hr: 24/0200z sfc/fl550 s0606 e10534 - s0637
    e10523 - s0737 e10232 - s0553 e10157 - s0541 e10524
    rmk: Continuous emission observed to fl550 extending
    southwest, awaiting confirmation of va at ground. So2
    observed on satellite imagery ext southwest at 23/0222z.
    nxt advisory: No later than 20181223/1100z

  3. #3
    Join Date
    Jun 2004
    Location
    The Great NorthWet
    Posts
    14,659
    News reports this morning are saying the tsunami was caused by an underwater landslide, not an earthquake. Not clear if it's connected to the eruption.
    Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.

  4. #4
    Join Date
    Nov 2001
    Posts
    3,272
    Eruption still ongoing, to 55,000 feet. A photographer there was caught in the tsunami, and caught the following photo (Link to his page) just before the tsunami hit.

    https://www.facebook.com/photo.php?f...type=3&theater


    It does appear to be an underwater land slide being the cause, probably related to the current large eruption.
    Last edited by dgavin; 2018-Dec-23 at 06:33 PM.

  5. #5
    Join Date
    Nov 2001
    Posts
    3,272
    The landslide confirmed, but appears to be very similar to the St. Helens event, in that about 1/3 of the western face of mountain slid into the sea. It was probably both under and above water.

    https://twitter.com/CATnewsDE/status...48305215324160

    Ash cloud is still topping 55,000 feet to SW and 25,000 to N. Spectral readings are showing it is mostly SO2/ICE and not very much ash at all. Not sure what is meant by ICE as the only place Sulfur Dioxide ice in our solar system is the planet Io.

  6. #6
    Join Date
    Jun 2004
    Location
    The Great NorthWet
    Posts
    14,659
    I'd suspect they mean it's SO2 and water ice. The latter was, of course, not frozen when it was erupted but it gets cold that far up.
    Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.

  7. #7
    Join Date
    Nov 2001
    Posts
    3,272
    Water ice makes sense, didn't have enough coffee before posting this morning.

    Image form the ISS Nasa released this morning, but it's actualy from September.

    https://www.instagram.com/p/BoHL-g5D..._web_copy_link

    It's still hard to tell how much of a collapse there was.

    I -think- from zooming in on the black and white satalite images, that the cone may have suffered a caldera collapse. It's hard to be certain but it looks like part of where the cone was might now be filled with water, and there is a new crater/cone forming in that water.
    Last edited by dgavin; 2018-Dec-24 at 04:03 AM. Reason: Correction on Photo info

  8. #8
    Join Date
    Oct 2001
    Location
    The Space Coast
    Posts
    4,472
    It would be ironic if this is a large enough and right kind of eruption to cool the planet temporarily, giving us some breathing room in reducing CO2 over a few years longer than we have. Desperate hope and not without potentially horrible trade-offs.

    CJSF
    "Flipping this one final switch I'm effectively ensuring that I will be
    Overcoming all resistance long after my remains have been
    Vaporized with extreme prejudice and shot into outer space.

    I'll be haunting you."

    -They Might Be Giants, "I'll Be Haunting You"


    lonelybirder.org

  9. #9
    Join Date
    Nov 2001
    Posts
    3,272
    It seems to be pumping out more S02 and Water, then ash right now. So2 is a reflective cooling gas.

    Darwin VAAC is calling it a anomalous eruption. I'm not sure it qualifies as a VEI-6 anymore, but the Tsunami reached the Ural's and parts of Australia, so the land slide was fairly significant.

    I suspect if the central cone had been larger, and more was above water, then there would of been a pyroclastic flow like with the 1883 eruption.

  10. #10
    Join Date
    Aug 2006
    Posts
    3,501
    Quote Originally Posted by dgavin View Post
    ... the Tsunami reached the Ural's and parts of Australia, so the land slide was fairly significant.
    Sorry, the only present day Urals I know of are a thousand miles East of Moscow.

    [ EDIT ] Oh. East coast of India?

  11. #11
    Join Date
    Feb 2009
    Posts
    2,213
    Quote Originally Posted by DaveC426913 View Post
    Sorry, the only present day Urals I know of are a thousand miles East of Moscow.
    And reach to the coast of Arctic Ocean. Novaya Zemlya are a continuation.

  12. #12
    Join Date
    Aug 2006
    Posts
    3,501
    Quote Originally Posted by chornedsnorkack View Post
    And reach to the coast of Arctic Ocean. Novaya Zemlya are a continuation.
    Sorry, are you saying the Tsunami reached all the way around the Asian continent - through the Bering Strait - to the Barents Sea?

  13. #13
    Join Date
    Nov 2001
    Posts
    3,272
    Quote Originally Posted by DaveC426913 View Post
    Sorry, the only present day Urals I know of are a thousand miles East of Moscow.

    [ EDIT ] Oh. East coast of India?
    I dug back through my source for that (National Geo) and after carful picking though it, I had missed a contextual point. SO need to correct myself.

    The (Seismic) waves form from the Krakatoa landslide were detected as far as the Ural's and to Western Australia. This is the text I misunderstood from their article. "But the waves didn't stop there—they traveled as far as Arti in the Russian Urals and Kambalda in Western Australia." Had to jump back a few paragraph's in the article to get to the proper context of a Seismic Wave form.

    Thanks for pointing out the inaccuracy with the information!

  14. #14
    Join Date
    Nov 2001
    Posts
    3,272
    Finnaly got enough information to determine that it does appear to have been a land slide combined with a lateral blast eruption. It also appears that the cone, and more like 1/2 of the island are gone.

    Sat. image from 22nd showing the differences, with the area to the bottom left a bit uncertain. Source Volcano Discovery, Public Domain.

    krakatau-comparisoin.jpg

    Arial image from yesterday, showing that generally it looks likes more then half the island, and probably all of the cone were lost. Source Reuters, copyright
    ANTARA FOTO / BISNIS INDONESIA / NURUL HIDAYAT / VIA REUTERS

    Krakatoa.jpg
    Last edited by dgavin; 2018-Dec-24 at 09:13 PM.

  15. #15
    Join Date
    Jun 2002
    Posts
    1,989
    BBC: Anak Krakatau: Indonesian volcano's dramatic collapse

    They say the volcano has lost more than two-thirds of its height and volume during the past week.

  16. #16
    Join Date
    Sep 2004
    Posts
    3,199
    https://www.newsweek.com/volcanoes-c...nology-1277215

    Update from Newsweek on Anak Krakatoa, with film. Region remains highly active, earthquakes and landslides reported in wide area around.

  17. #17
    Join Date
    Sep 2004
    Posts
    3,199
    WHOA - much better photographs, shocking results from cone collapse (now a bay):

    https://www.bbc.com/news/science-environment-46743362

  18. #18
    Join Date
    Feb 2005
    Posts
    11,594
    I wondered when we'd see the Sunda strait act up again

    Video here--interesting at 1:55
    https://www.youtube.com/watch?time_c...&v=pcwssxwy7CA

  19. #19
    Join Date
    Nov 2001
    Posts
    3,272
    Still showing signs of activity. I found out a film maker was actualy there, and caught the caldera collapse on camera. Unfortunately while he escaped the tsunami his equipment did not and was lost. They don't know if it washed out to sea, or is buried in debris some place.

  20. #20
    Join Date
    Nov 2001
    Posts
    3,272
    Updates finally, but not from my usual sources.


    Source - Volcano Discovery:
    The activity at the volcano continues at reduced rate. Steam explosions have been more intermittent and smaller during the past 2 days, generating plumes that rose a few hundred meters only.
    This trend corresponds to the seismic signals showing a marked decrease since the surge of supply of magma that led to the paroxysm during 21-22 Dec, which accumulated lots of new lava. This in turn might have been "the last straw that breaks the camel's back", i.e. the additional sudden weight on the slopes and/or the shaking induced by the continuous explosions could might have been the final trigger for the landslide to occur.
    The Indonesian Center for Volcanology and Geological Disaster Mitigation (PVMBG) published a first official estimate on the effects of the landslide:
    - The summit of Anak Krakatau originally 338 meters high is now reduced to only 110 meters, i.e. most of the summit cone has indeed disappeared.
    Source - Volcano Discovery:
    The northern coast of Rakata Island, facing Anak Krakatau, was hit by massive waves (up to approx 30 m high) during the catastrophic landslide and tsunami on the evening of 22 Dec.
    The entire beach and the slightly higher, up to 50 m wide forested platform behind it, separating it from the cliff, have been washed away and/or collapsed in landslides following the receding wave.
    Overall even with counting the landslide and steam with the eruption ejecta; I'd say my VEI-6 estimate was woefully far to high. All told it's looking like a VEI-2 maybe close to a 3.

  21. #21
    Join Date
    Nov 2001
    Posts
    3,272
    While my VEI estimate was incorrect, I did get the caldera collapse part right.

    Found a good before/after image.

    2019-01-12_the-anak-krakatau-volcano-before-and-after.jpg

  22. #22
    Join Date
    Feb 2005
    Posts
    11,594
    Oh, if only the equipment had not been lost.

  23. #23
    Join Date
    Nov 2001
    Posts
    3,272
    Quote Originally Posted by publiusr View Post
    Oh, if only the equipment had not been lost.
    I know. A lot of data was not gathered. This was probably the first Caldera Collapse type eruption in our life times, and that data could of been used to start models of seismic signals for monitoring our three super volcanoes, Yellowstone, Newberry and long valley.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •