Remnants of a violent past

By Phil Plait | November 24, 2010 7:00 am

Will I ever get tired of these satellite images of volcanoes?

No. No, I won’t.


That’s Krakatau, or Krakatoa, an active volcano in Indonesia (click the pic to pyroclastinate). If the name is familiar, then you may remember that this particular hill decided to throw something of a hissy fit in 1883. In fact in four separate monstrous explosions the volcano detonated with the energetic yield of about 200 megatons of TNT — several times the energy of the most powerful nuclear weapon ever tested. The explosions tore the island apart, and killed tens of thousands of people. It threw so much ash in the atmosphere that the global average temperature dropped over a degree.

As a solution to global warming it leaves something to be desired.

NASA, understandably, keeps an eye on Krakatau, and in this image by the Earth Observing-1 satellite you can see the ash plume blowing to the north (I rotated the image 90° to make it fit better here). The volcanic island you see here is new; it’s been building up since the 1883 event, and is roughly 2 km (1.2 miles) across. It’s hard to imagine that this beautiful and serene island was the epicenter of one of the most massive explosions in modern history, but there you go. But then, we don’t need to imagine it, when we have the science to hand us the data.

NASA Earth Observatory image created by Jesse Allen, using EO-1 ALI data provided courtesy of the NASA EO-1 team.

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CATEGORIZED UNDER: Pretty pictures

Comments (36)

  1. Bob

    Oh boy – just had visions of the mega cauldron in the USA blowing up….

  2. Gary Ansorge

    I wonder how much life has reestablished its self around the island. I recall watching a documentary about life recovery around Chernobyl and THAT was impressive, critters both great and small seemed not at all bothered by the elevated local radiation.

    Life is really amazing.

    Gary 7

  3. Interesting stuff going on in the water in the enlarged image. What caused the line to the NE, a boat? What’s the grey stuff in the water to the NW, ash? And what are the striated areas off the beaches to the NW? At first I though wind streaks, but the volcanic plume disagrees.

    Sure wish they had a live 24/7 HD camera feed from the ISS. Get all the cable operators to dedicate one channel to it. Hell, I’d pay for it. Put it on TV as moving wallpaper, great for a party…or just sit and look spellbound. It would bring a whole new meaning to “just watching the world go by.”

  4. Don’t you mean Anak Krakatoa translated as, I think, “child of Krakatoa” there? 😉

    Unless I’m very much mistaken (&, ok, yeah I might be!) the original Krakatoa was kinda vapourised in its 1883 hyper-eruption and the subsequent volcano that grew out of its shattered caldera bears that new name representing the very much changed geography.

    Neat image – I love the volcanoes & can never get enough of them too. 8)

    @1. Bob : I presume you’re referring to the Yellowstone supervolcano there, yes?

  5. mike

    Phil, you seriously need to get a volcano lair. I think it’ll suit you well :)

  6. See Wikipedia :

    & also worth checking out is :

    & specifically from whence :

    A new island volcano, named Anak Krakatau or Child of Krakatoa rose above the waterline a few days later. The eruptions were initially of pumice and ash, and that island and the two islands that followed were quickly eroded away by the sea. Eventually a fourth island named Anak Krakatau broke water in August 1930, and produced lava flows faster than the waves could erode them. Of considerable interest to volcanologists, this has been the subject of extensive study.

    So I got the spelling a bit wrong but otherwise..

  7. Dan

    “It’s hard to imagine that this beautiful and serene island was the epicenter of the most massive explosion in modern history”

    Well actually… it wasn’t. Look up Mt. Tambora’s 1815 eruption, and the year without a summer.

    But it still is a pretty cool picture.

  8. IanS

    This comment may or may not apply depending on when you choose to define Modern History as beginning (and lets face it.. its your blog so any lines in the sand are yours to draw!)

    The 1815 explosion of Tambora was bigger by every measure:
    Krakatoa had a Volcanic Explosive Index of 6, Tambora scored 7
    Krakatoa produced an ash column of 25km, Tambora 43km
    Krakatoa caused a 0.3 degree C drop in temp in the northern hemisphere, Tambora 0.5
    Krakatoa killed approx 36000 people, Tambora 71000

    There is even a school of thought that the change in weather in Europe caused by Tambora lead to conditions favourable to the British army at the battle of Waterloo thus changing the course of European history!

    The eruption of Krakatoa is so much better known for one reason only, it happened within a few miles of a British telegraph station and news of the eruption was transmitted, as it was happening, accross the Empire. It was the first media frenzy around a natural disaster, a notable first in its own right, but not the biggest explosion.

  9. Messier Tidy Upper

    @ ^ Dan :

    “It’s hard to imagine ..

    Well *that’s* always going to depend on how good your individual imagination is isn’t it? 😉


    Luke Skywalker : “She’s rich. Rescue the Princess and the reward will be .. ”

    Han Solo : “Will be what?”

    LS : “Well, more than you can imagine!”

    HS : “I don’t know kid, I can imagine quite a bit!”

    Star Wars : Episode V – A New Hope / The Original (& still the best. 😉 ) George Lucas, 1977.

  10. amphiox

    I think Messier is correct in #4 regarding Anak Krakatoa. On the other hand, since it is the same volcano that just rebuilt its peak until it went above water and could be seen again, you could say that Anak Krakatoa is Krakatoa, and the name change is a historical error made due to incomplete understanding of what was really happening at the time.

  11. IanS

    @ Tailspin
    Krakatoa sits in the middle of the Sunda straits between Java and Sumatra, there are some very strong currents following through there, where those currents meet you get lines like those to the NE in this image. THe grey stuff in the water is a seamount, a secondary caldera that hasn’t broken the surface (it looks to be very close to the surface) the striations of the beach to the NW are water waves. the reason they look a little odd is that they are interferance waves caused by the swell running between the island and the seamount, there is probably an element of tidal or current flow influence there as well. If you look in the SW corner of the image you can see lines of oceanic swell running SE to NW (propogating NE) around the islands thes swell lines are disrupted and interference patterns are generated all over in between the islands.

  12. MadScientist

    We didn’t need any science to know about Krakatau – there were numerous witnesses and much written about it at the time. Seismography was a very young field though and there were numerous issues regarding the calibration of seismographs from that era. Most were an “inverted pendulum” design which drove a mechanical amplifier (levers) and a recording pen. As large an explosion as Krakatau was, it was a little firecracker compared to the eruption of Tambora in 1815 – the largest known historic (recorded) volcanic eruption to date. Now if you want to see a decent supervolcano caldera, have a look at images of Mt. Taal in the Philippines. That lake (~16x30km) is the ancient crater of one hell of a volcano. Most historic activity has occurred on Volcano Island (which many people mistakenly believe constitutes Taal). For a nice short collection of descriptions of a volcanic eruption try:

  13. I decided to add the words “one of” to “the most massive explosions” to make this more accurate. :)

  14. Shoeshine Boy

    Which way to Java?

  15. There is a well done, in my opinion at least, documentary/dramatization. I think it’s just called Krakatoa: Volcano of Destruction? It was on Discovery so Phil should know about it. 😉

    Even though I’m sure the actual events were different it did well at depicting the tension. We all know what was going to happen but many in the area didn’t. I really liked the part with the boat going out to sea rather than staying in port. Face the wave head on and increase your odds of surviving. That actually happened and is documented.

    The part I liked the most was when the biggest explosion hit and how loud it was. They did something clever with that. Instead of a roaring boom that you’d expect, we got it from the perspective of the people nearby. The sound was so loud it was deafening and that’s what we hear: nothing.

    Slowly the ringing fades and hearing returns. Imagine that everything is normal and wham you’re deaf and feel like you got knocked right over. That’s powerful stuff and it was several miles away at that. Ouch!

    That’s a very fascinating bit of history there. We’d be wise to keep an eye on that one. :)

  16. Bob

    @4. Messier Tidy Upper – ayup

  17. mike burkhart

    How about volcanos on Venus,Mars and Io? In fact one on Mars (Olympus mons )is the bigest in the solar system, and on Io , they just keep eurpting . hears another line form Star Wars I now understand since the prequels : Darth Varder: I’ve been wating for you Obi Wan we meet again at last, the circle is now compleet , when I left you I was the learner , now I am the master. Obi wan : Only a master of evel Darth. Darth Vader blames Obi wan for what happen to him even thro according to ep3 it was his fault , If he had not jumped to attack Obi wan he would not have had his other arm and legs chopted off and he would not have caught on fire. Also he still upset that the Jedi councel did not make him a master.

  18. Pete Jackson

    It has actually been mentioned as a possible solution for global warming – add sulphur to jet fuel so that every airliner spews out an aerosol that, after reacting with the atmosphere, creates a global high-level haze much as Tambora and Krakatoa did.

    One obvious problem with that idea is that the sulphur would also get spewed out at low elevations as the airplane takes off and climbs, contributing to air pollution. Maybe they would propose that the planes switch between clean and ‘dirty’ fuel tanks depending on the altitude.

  19. amphiox

    @17. mike burkhart;

    Olympus Mons is one huge volcano of course, but the type of earth volcano it most resembles tend not to erupt that violently but rather do a slow, constant, lava ooze sort of thing.

    Of course to really find out one would have to do some extensive geology on mars, looking for the ash layers and pyroclastic flows and such. The kind of thing that would probably take a geologist, and not a rover (at least not right now).

  20. MAC

    Would could forget Krakatoa: East of Java? Never mind that it’s actually west of Java. The important thing is that at least there was java, so those poor people didn’t have to die without their caffeine fix.

  21. MAC

    As for Olympus Mons, you can thank Mars’ lack of plate tectonics for that one. Here on Earth, volcanic “hot spots” move with the continental plates, forming chains of moderately-sized volcanoes in their wake. Without that constant movement, you’d get gigantic volcanoes like OM, sitting over one magma column for eons, getting bigger and bigger. So volcano-wise, it could be worse.

  22. Menyambal

    I was watching a TV show about Krakatoa one night in a hotel room, and it slowly dawned on me that I had just flown over it a few hours before–I was in Jakarta. I don’t remember seeing anything below the plane, but yes, Krakatoa is in the Sunda Strait between Sumatra and Java. Java is to the west, which Phil says is up in the photo.

    I read one old Indonesian account that implied that an eruption of Krakatoa back in the tenth century actually made Sunda Strait–before that Sumatra and Java were one island. I don’t give that much credit.

    “Anak” does mean child in Indonesian.

    If you want a big volcano, go to Lake Toba on Sumatra. That’s the one that nearly killed off all humans about 70 thousand years back.

  23. From Phil’s post:

    As a solution to global warming it leaves something to be desired.

    Indeed! Particularly since the cooling effects from volcanism are relatively short-lived compared to their warming effects from ejected greenhouse gasses.

    If memory serves, mass volcanism (Siberian Traps, Deccan Traps, that sort of thing) were responsible for large increases of CO2 and hence global warming in the geological record.

    I’ll settle for rather more banal solutions. :)

  24. Menyambal

    “Don’t you mean Anak Krakatoa translated as, I think, “child of Krakatoa” there?”

    That is the popular understanding of the translation, yes. But, based on my dim recall of Indonesian, I’m saying that the translation should be closer to “Baby Krakatoa”. The adjective follows the noun in Indonesian. “Anak perempuan” means a girl child, while “anak laki-laki” means a boy child. “Child girl” and “child boy”, literally by word order.

    So, to me, “Anak Krakatoa” (or Krakatua) literally is “Child Krakatua”, in word order, meaning something like “Krakatua Child” or “the Krakatua which is a little one”. It sure isn’t a possessive or a parent in meaning. Not “of”, but an implied “which is”.

    “The Krakatua Kid”, maybe?

  25. Menyambal

    “child which is Krakatua” is probably what I should say.

  26. MadScientist

    @Pete#18: Another problem with that is that aviation fuel is processed so that it has pretty low sulfur content. Sulfur is not good for those turbine engines, it sure accelerates the degradation of parts. Yet another problem: you’ll generate more CO2 mining and transporting the sulfur than what you’ll “offset” with the cooling effect. Still another problem: the planet is huge – can you even mine that much sulfur, much less transport it into the air? And still one more problem: the sulfate aerosol will settle out due to gravity so it needs to be replenished at a very high rate (~2 months, assuming favorable conditions in the stratosphere), and of course it doesn’t help the problem of acid rain either.

    Geoengineering: making the horrible stuff we do now look relatively harmless.

  27. It’s weird, but in that picture it strangely resembles MYST island.

  28. Woo Fighter

    Why pyroclastinate today, when you can pyroclastinate tomorrow?

  29. Messier Tidy Upper

    @24. Menyambal : Thanks for elaborating on that – interesting. :-)

    @19. amphiox :

    @17. mike burkhart; Olympus Mons is one huge volcano of course, but the type of earth volcano it most resembles tend not to erupt that violently but rather do a slow, constant, lava ooze sort of thing.

    Yup, Sheild volcano like they have in Hawaii (among other places natch) with very gentle slopes and very fluid lava.

    Its not just Olymus Mons with Mars either as you have the whole Tharsis Bulge complex with three huge shield volcanoes – Arsia Mons, Pavonis Mons and Ascraeus Mons – plus the separate Elysium plateau region with its massive supervolcano too.

    Walking on most parts of these colossal martian shield volcanoes you wouldn’t realise how high you are or that what you’re on is mor ethan a very gently sloping plain but they poke out above most of the thin Martian atmosphere or so I understand.

    Of course to really find out one would have to do some extensive geology on mars, looking for the ash layers and pyroclastic flows and such. The kind of thing that would probably take a geologist, and not a rover (at least not right now).

    Well, yes, although I’m fairly sure that they’ve done some amazing studies and come up with quite a lot of astounding knowledge with orbiters imaging them from above at varying ever improving resolutions.

    I’d love to see a rover land somewhere on the middle of one of those Tharsis volcanoes (or the Elysium one too) and explore its way both up and down – or better yet a human crew. :-)

    I have always really hoped to see that happen in my lifetime but the way its looking now, well, lets just say its a lot less certain than I thought it was going to be. :-(

  30. Messier Tidy Upper

    See :

    For the wiki-page on Tharsis &

    For brief one on the Elysium one.

    Plus :

    For shield volcanoes generally.

  31. Messier Tidy Upper

    @26. MadScientist :

    Geoengineering: making the horrible stuff we do now look relatively harmless.

    Well I hope not – because I think we’re going to *have* to use geoengineering techniques as our future last best hope for slowing and mitigating our Anthropogenic Global Over-Heating problem.

    The sad reality is that it looks very much like we are just NOT going to do anything near enough, anytime soon enough to slow Global Broiling otherwise. :-(

    With the Republicans having their added power now and Obama lacking the ability &/or really the political will to force any serious climate change measures through the USA; with international treaties and talkfests producing nothing but hot air and bickering; with overpopulated dirtily industrialising China and India ever-rising and ever-growing and also not doing anything near enough, soon enough either – and with personal lifestyle tokenism being far too little too late, really we’re stuffed. Afraid, I am very pessimistic about us Humans getting our act together to fight this until its far too late. :-(

    Especially when you take the time lag factor and natural feedbacks (eg. albedo FXTS and permafrost melt releasing methane, desertification, deforestation, via climate change factors, etc..) into account as well. :-(

    I think we simply have to face future geoengineering projects and adapting (incl. most likely abandoning some doomed cities and even entire nations) as the best we can realistically, plausibly hope to do.

  32. Shoikan

    I was reading the site where this was linked from… And as a bit of a ‘putergeek, I couldn’t help but be interested in how the satellite that shot these pictures has been ‘reused’. By adding some new software, they made (in their words) more ‘customer driven’. Is there any way you can shed some light on that, for ‘the informationally challenged’ such as myself? :)

  33. JB of Brisbane

    @Pete Jackson #18 – I wonder what the chemtrails crowd would have to say about that?

  34. Radwaste

    Well, that’s an interesting idea, volcano growth on Mars with no plate movement. Are you sure Olympus Mons wasn’t the result of a hundred-ton rock delivered on purpose, at a significant faction of lightspeed?

  35. Just last night after Thanksgiving I brought a new plant from my parents’ place to my apartment. When Anak Krakatau (the new island, ‘child of krakatoa’) showed up, scientists were given a unique chance to study how ecosystems colonize pristine territory. Turns out my new potted tree is a Casuarina equisetifolia, which (or a closely related species) was found to the be the first major plant to colonize the island (IIRC some grasses came before it, or concurrently). It’s a weird one too. It has needle-shaped leaves that are segmented like horsetail plants. It’s also a nitrogen-fixer, which might be one reason it’s the first big plant to show up. It puts yummy nitrogen into the soil for other plants to use later.

  36. Chas, PE SE

    In one of James Cobb’s books, he has Capt. Amanda Garrett describing the explosion to her Marine force commander. When he asks, horrified, where the calamity took place, she calmly points over the port bow and says “See that island over there…”


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