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"Concussive air waves from the explosions traveled seven times around the world, and were detectable for five days" - that's in the legacy section, Krakatoa#Legacy_of_the_1883_eruption, it has a reference but the reference doesn't mention anything like that. sbandrews (t) 20:15, 27 August 2007 (UTC)

The reference given is listed as simply washington post and does mention it toward the end. It's also a paid advertisement which makes me think it probably isn't fit for inclusion here. (The photo isn't even of Kraktau) Anynobody 06:14, 28 August 2007 (UTC)
ok, i missed that - however I deleted the 'were detectable for five days' as that was not in the ref. and seems unlikely, sbandrews (t) 09:02, 28 August 2007 (UTC)
I've restored it to the article, citing a better source (which was linked to in an earlier discussion above). -- Avenue (talk) 08:52, 29 December 2007 (UTC)

The Royal Society obtained the information from various locations around the world, scientists analysed, discussed and agreed that over a 5 day period the barographs registered an atmospheric disturbance which when all else was discounted could only be accounted for - allowing for time differences to the cataclysmic explosion at Krakatoa. The Royal Society report is available to download via Google in PDF format.The Geologist (talk) 12:13, 12 April 2012 (UTC)

Article could be visually improved.[edit]

I thought that there needed to be a few visual additions to this article, such as clear and scaled before and after maps of the islands. Also, a side on profile of the layers/magma chambers (labeled) inside the volcano before the eruption. If anyone could add these without infringing copyright it would improve the article greatly. —The preceding unsigned comment was added by (talkcontribs) .

There are no maps of the island prior to the eruption, nautical charts depicted (and still do) all land as uncharted except for features used for navigation. What the geological structure of the island was prior to the eruption can be inferred from the present exposures. If you want a profile of what the volcano looked like prior to eruption - any good text book will suffice providing you use the profile for a strato-volcano.The Geologist (talk) 16:48, 4 April 2012 (UTC)
Aside from nautical charts, which I agree are uninformative for detailed geological information, I would suggest several possibilities:
  • any of the pre-1883 shipboard sketches,
  • Verbeek's 1880 drawing from his survey,
  • either of the May 27th photos of Perbowatan erupting (the engraving used is from the most well-known photo),
  • the sketch of Perbowatan's crater from the May 27th excursion,
  • Capt. Ferzenaar's contour map of August 11th,
  • the 'pointed mountain' engraving from the Report of the Royal Society (which did use to be here),
  • any of Verbeek's illustrations.

-- CFLeon (talk) 01:07, 19 January 2013 (UTC)

loudest sound: true or false?[edit]

did krakatoa emit the loudest sound in recorded history? i heard this from two tv documentaries. the article called Krakatoa (explosive) also stated this. —Preceding unsigned comment added by (talk) 06:23, 15 March 2009 (UTC)

Simon Winchester's book on Krakatoa also backs this up. Dantès (talk) 03:21, 28 March 2010 (UTC)
EVERY book written about Krakatoa makes the statement. The explosions were heard 3000 miles away. (talk) 20:44, 14 August 2010 (UTC)

The sound was heard in Perth, Western Australia and at Rodrigues Island both over 4800 kilometres away. This was arrived at by the fact that reliable people reported sounds like canon fire, noted the time and reported it to the Royal Society, who then calculated that allowing for the time difference due to longitude the only source of the sound was Krakatau's cataclysmic final explosion. I don't have Simon Winchester's book to hand but if I recall he asserts that the sound was heard over approximately 1/4 of the Earth surface with the sound being heard in China. No nuclear detonation to date has ever been heard over such a distance.The Geologist (talk) 12:58, 9 April 2012 (UTC)

OK, to be really blunt, the LOUDEST sound would be unsurvivable. Period. As in ZERO persons inside of ground zero of the last two atomic bombs survived the event, even IF they were "shaded" by surviving structures. Organs do very ugly things at high shock wave values, as does skin. One can humbly suggest that both hearing organ systems AND central nervous systems cannot survive the "loudest" values of the consideration "index". Indeed, there is LESS than an absolute measurement of "loudest sound or even LOWEST sound"! Each value is variable upon surviving humans present. If a soldier today were to be holding an audiometer inside of an IED blast, is THAT the highest measurement of survivability? Or is that merely a measurement of the observed survivable at present?Wzrd1 (talk) 04:09, 16 June 2012 (UTC)
A circular area on the Earth's surface with a radius of about 3000 miles or 4800 km, is a long way short of "1/4 of the earth's surface". Eregli bob (talk) 08:32, 15 July 2012 (UTC)

Because no one in 1883 had a means of measuring how loud was loud we have to rely upon peoples observations. The loudest sound I have heard was the double sonic boom that Concorde made - I was about 10 miles below the flight path and about 2 miles east of it as it flew down the Scottish coast during tests in the summer of 1983. I was working in the Andes helping install monitoring equipment on a volcano when Chaiten exploded, the supersonic pressure wave expanded from Chaiten, hit us with a force that knocked several people over and a few seconds later we heard the ear throbbing noise. Go to any disco or whatever name they have now and listen to the thump of noise. Yet in 1883 Krakatau caused the loudest noise that had been recorded and the reason it ws heard over such a vast distance is due to physics - low frequency is long wave and travels furthest. Oh and soldiers have been centimetres away from blasts and can still hear albeit with reduced frequency range.The Geologist (talk) 17:13, 24 January 2013 (UTC)

Sound deafens - it is the pressure wave that kills by concussion. There was no-one that we know of on the island, people were on land several kilometres away or on ships nearby. Read the accounts in the various publications about the ships.

The circumference of the Earth is approximately 40010 kilometres, which using Pi as equal to 22/7 = 3/142857 gives a diameter of 12730 kilometres, which means the radius of the Earth equals 6365 kilometres. Therefore using the formula 4Pi x r2 = 509364883 square kilometres and 1/4 of this is 127341221 square kilometres. The radius from Krakatau to Pert Western Australia is approximately 3082 kilometres. This gives an area of 29853133 square kilometres. Dividing the whole Earth surface area of 509364883 square kilometres by the area of the radius to Perth 29853133 square kilometres gives a result of 1/16th of the Earth's surface. To prevent anyone with out the correct source and jumping to their own conclusions without the mathematics to back them up is the reason why I have written out the mathematics involved. Eregli bob is correct in his or her assertion of 15th July 2012. As for the origin of the claim that it was heard over about 1/4 of the Earth's surface further investigation is needed.The Geologist (talk) 15:38, 10 November 2013 (UTC)

Celsius and Fahrenheit[edit]

Is it possible to add the Fahrenheit to the Celsius listing about the temperature drop of 1.2 degrees celsius and add on 2.16 degrees fahrenheit? For those who do not speak Celsius. It might make things more clearer. Thanks. Light keeper (talk) 15:08, 8 July 2010 (UTC)

Well since almost ALL the nations in the world now use Celsius why revert back to an obsolete temperature scale.? If you don't know how to convert between the two temperature scales here is how: Fahrenheit to Celsius = Farenheit MINUS 32, then divide by 9 and multiply by 5. Celsius to Fahrenheit = Celsius divided by 5, multiply by 9 and then add 32.
Example 212 F to Celsius, = 212-32 = 180, 180/9 = 20, 20x5 = 100 Celsius. Similarly 100 C to Fahrenheit = 100/5 = 20, 20x9 = 180, 180+32 = 212.The Geologist (talk) 13:06, 9 April 2012 (UTC)

Krakatoa in fiction[edit]

AFD recently decided that Krakatoa in media and popular culture should be deleted. However, many of the mentions were properly referenced and quite well known in their own right. Merging here seemed appropriate. I have only copied the material from there. Please feel free to change as needed.  The Steve  07:18, 10 January 2012 (UTC)

These seem to have been deleted, so I added the relevant ones to Krakatoa (disambiguation). HairyWombat 23:47, 18 November 2012 (UTC)
Should add a link to 21 Balloons as Krakatoa is featured prominently and this is discussed on the 21 Balloons page.

--Whystopnow (talk) 02:30, 5 October 2013 (UTC)


Infobox image failure. Suddenadultdeathsyndrome (talk) 10:55, 15 February 2012 (UTC)

Looks like the image has vanished from Commons (it still appears on some pages there, but the image file is missing). I'll chase it up. --McGeddon (talk) 11:10, 15 February 2012 (UTC)
Took a while for the log to appear for me, for some reason, but it was apparently deleted as lacking a source, last week: "9 February 2012 Fastily (talk | contribs) deleted "File:Krakatoa 01.JPG" ‎ (No source since 1 February 2012)". I'll bump the lithograph up to the top. --McGeddon (talk) 11:21, 15 February 2012 (UTC)
Thanks for that. Is paying attention to the dead links we create when deleting images not required? Suddenadultdeathsyndrome (talk) 12:00, 15 February 2012 (UTC)
Usually not, as there are bots (eg. User:CommonsNotificationBot) that run around taking care of this sort of minor legwork. It must just have overlooked this particular file - the slight oddity of its deletion log (when I first looked at the commons page, it was as if the file had never existed) may have confused it in this case. --McGeddon (talk) 12:12, 15 February 2012 (UTC)

Pre-eruption photo(s)?[edit]

Did anyone manage to take a photograph of Krakatoa before the 1883 eruption? It seems reasonable to think that someone would have, but I haven't seen any. If anyone else has seen such a picture, it would be a useful addition to this page and the page dealing with the 1883 eruption.-- (talk) 07:26, 2 April 2012 (UTC)

There are no photographs of the volcano pre-eruption. The best are wood cuts and engravings and even they are dubious! The best images from the few weeks between the initial eruption (May 1883 and the final cataclysmic phase August 1883) are the few field sketches made by the scientists who visited. The Geologist (talk) 16:42, 4 April 2012 (UTC)
Photography was still in its infancy, hence the lack of photographs. Think no film, only glass plates that were the practice and reality of the time, the technology was lacking upon TODAY'S consideration. Photography advanced far later.Wzrd1 (talk) 04:17, 16 June 2012 (UTC)
Actually several photos were taken by the May 27th excursion, all of Perbowatan erupting. I don't know how many total were made, but there are at least two different views from the ship and some were taken once the group had landed. The woodcuts (at least 2 different ones including the one used in the article, although it has been reversed) are taken from the photos, which are reprinted in the centenuary book (albeit they have been retouched). These are the ONLY photos that I know of the islands pre-cataclysm, although there are several sketches at various distances from ships, and Verbeek's sketch from his 1880 survey. The only good surveys made on the islands themselves are Verbeek's and Capt. Ferzenaar's August 11th which made a good contour map, and both were limited to the northern part of the main island and under a time constraint. Where the 'pointed mountain' drawing came from, I don't know, although it was used in the 1884 report of the Royal Society. In addition, there are only a few photos frrom the period after the eruption. Since the southerly part of Rakata remained pretty much intact, any photos from that view would be much the same as before. I've never seen good photos of Verlaten or Lang, either before or after 1883, and I've looked for them for over 40 years- even most modern views are from a distance or on the ground viewing eruptions at Anak. Again, find the centenuary book, it reprints most of the sketches, drawings and photos known, including the navigation charts. CFLeon (talk) 00:51, 19 January 2013 (UTC)

I would like to see them as I and other volcanologists have been lead to believe that none existed - hence my earlier assertion. If they prove to be true then that would be fantastic.The Geologist (talk) 13:06, 24 October 2013 (UTC)

Have you even LOOKED at the centennary book (published in 1983 and available in most major libraries- I'd think it would be one of your major sources, since you claim to be an expert)? It reproduces 3 of the photos and that was more than 30 years ago. They are NOT new discoveries- even the 1964 Furneaux book reproduces the best one of Perboewatan erupting. I'm not located in a major city with a world-class library like New York or London, but I've known about them for almost 50 years- where have YOU been?. CFLeon (talk) 21:01, 18 August 2015 (UTC)

Yes I have and those images were taken BEFORE the eruption that occurred in August - to which the original post refers. There are NONE whatsoever of the August eruption - and that is what I was referring to. As to where have I been - where would you like me to start? Mount St Helens, Katmai, Unzen, Galeras, Ruiz, Pinatubo, Geographical South Pole - would you like me to go on? Fifty years - you are still wet behind the ears I have been involved with geology and volcanolgy for almost 60 years!The Geologist (talk) 15:19, 9 September 2015 (UTC)

Geologist, please go back to my comments and ACTUALLY read what I 'said': "Actually several photos were taken by the May 27th excursion..." (Jan 19, 2013). I NEVER claimed that any photos were taken in AUGUST. YOU claimed "There are no photographs of the volcano pre-eruption." (Apr 04, 2012). The 1883 eruption began on May 20, with the paroximal phase August 26-27; but that doesn't matter since you make the absolute blanket statement that NO pre-eruption photos exist AT ALL, no matter what the date. In order to 'save your theory', you're putting words in my mouth (so to speak) that I did NOT 'say'. As for the "original post", the original question was "Did anyone manage to take a photograph of Krakatoa before the 1883 eruption?" (Apr 02, 2012), no date specified in the entire post. The answer is: photos were taken of Perboewatan in eruption on May 27, during the early stage of the 1883 eruptions. As far as I know, there are no other photos of the islands known before May, 1883 (or after: there certainly are no pictures of the island's destruction since the whole Sunda Strait area was ash-darkened as night after noon on August 26) or of any other view (west, east, or south). It's POSSIBLE that there might have been something taken earlier, or other photos in 1883 (the respose time during June-early July is most likely for that)- but it's extremely unlikely. As complicated and involved as photography was at the time, there really was no reason to do so until the island started erupting in May. Unfortunate- I'd really would like a better view of Danan, and Polish Hat (or any of the other islands) isn't in view in any of the extant photos.
Oh, and as to your accusation: I live about 60 miles from St. Helens and was on the mountain the week before it blew and saw LIVE each of its eruptions. (At the time, I lived about as close to the volcano as one could on the south side of the river (Columbia). I could see it out my living room window except for a Ponderosa Pine in the way- had to go outside to watch it.) Just a piece of information, since you brought it up and Experience seems to be what's important to you. Actually, the question that I have is: How did Irwin Allen's people get such an accurate animation for the island at the beginning of The Time Tunnel episode; "The Crack of Doom" in 1966? CFLeon (talk) 20:36, 11 September 2015 (UTC)

Distance to Perth[edit]

There's inconsistency in the distance: the "Historical significance" section mentions 1930 miles and 3110 km — but the "1883 eruption" section mentions 2200 miles and 3500 km! That's an eastward move (for Perth) of 270 miles or 390 km!! — Preceding unsigned comment added by (talk) 10:31, 26 August 2012 (UTC)

  • Fixed Someone had messed with the conversion templates. GenQuest (talk) 06:30, 21 November 2012 (UTC)

Not sure the megatonnage is right[edit]

The explosion is described as "equivalent to 200 megatons of TNT (840 PJ)". If you're using a UK ton (1.01 metric tonnes) or a metric tonne, 200 mega of them, of TNT, would indeed come out at about 840 PJ. However, my understanding was that the usual usage of "megaton-equivalent of TNT" units used the USAish ton, 0.907 metric tonne. Am I just confused about the usual meaning of megatonnage, or has someone done a misguided conversion here ? Eddy (talk) 20:47, 27 January 2013 (UTC)

Ever since the dropping of the bombs on Hiroshima and Nagasaki in 1945 scientists (mostly American) have used the term megatons to describe large explosions. However, the scientific community uses the term megaton to mean 1 million metric tons or 1000000000 kilograms in scientific notation 1 megaton is expressed as 1 x 109 kgs. However I suspect that since the person who wrote the item is probably American, they will have used the non-standard mass for the ton - 907 kilogrammes as against the IS 1000 kilogrammes.The Geologist (talk) 13:04, 24 October 2013 (UTC)

E. Munch's 'The Scream'[edit]

Was the painting "The Scream" by Edward Munch influenced in any way by the ash left behind from the August 27, 1883 Krakatoa volcanic eruption? The wiki page on Krakatoa displays a non-documented image of "The Scream" and claims that the back drop was reportedly influenced by ash [left over from the Krakatoa eruption] in the atmosphere that made the sky unusually colorful. However, there is no creditable documented source to support the claim. If there is a documented source that does exist it would be greatly appreciated if someone could post it into wiki. Also, I'm not an English major so my apologies for any grammatical errors, spelling errors, etc. — Preceding unsigned comment added by (talk) 22:33, 9 February 2013 (UTC)

etymology - Cacatoua?[edit]

Simon Winchester in his book Krakatoa (2003) says that Guy Tachard wrote "we made many Tacks to double the island of Cacatoua, so called because of the white Parrots that are upon that Isle, and which incessantly repeat the name" (p. 27). This would have been in the 1680s. Winchester dismisses it as improbable that he is referring to our island and unfortunately doesn't give a reference for Tachard. --Richardson mcphillips (talk) 00:32, 9 December 2013 (UTC)

It's one of the theories for the name (the "white parrots" are what are called "cockatoos" nowadays), but dismissed for reasons originally given in the article. (Cockatoos are NOT known from the Sunda Strait region) CFLeon (talk) 21:05, 18 August 2015 (UTC)

Semi-protected edit request on 6 May 2015[edit]

can i edit the type of volcano please? Kikitata87 (talk) 15:51, 6 May 2015 (UTC)

Not done This is not the place to request additional rights, try Wikipedia:Requests for permissions instead. Also, any proposed changes would need to be supported by reliable sources. Joseph2302 (talk) 15:56, 6 May 2015 (UTC)

Semi-protected edit request on 25 October 2015[edit]

Requesting that one sentence be slightly changed for better readability and consistency with the rest of the article.

ORIGINAL: 416 AD eruption may formed the outer caldera, which is 7-km wide.

SUGGESTED: The 416 AD eruption may have formed the outer caldera, which is 7 km wide. Masonmouse (talk) 04:43, 25 October 2015 (UTC)

 Done GenQuest "Talk to Me" 06:29, 25 October 2015 (UTC)