Talk:2004 Indian Ocean earthquake and tsunami/Archive 2

Page contents not supported in other languages.
From Wikipedia, the free encyclopedia

Magnitude clarification

Where it says "It was the largest earthquake" shouldn't we change it to "it was the STRONGEST earthquake" or may be combine the both... I understand it was large, but still, the correct classification when talking about the magnitute the word "strong" is more appropriate.

What magnitude scales are being used in the article? Particularly reffering to this paragraph:

"The quake was initially reported at magnitude 6.8 in the Richter scale but this was soon updated to 8.5 and then 8.9 on the moment magnitude scale. The largest recorded earthquake was the Great Chilean Earthquake of 1960, at magnitude 9.5."

It the 8.9 magnitude only for the moment magnitude scale? On all news sites that I've seen the scale used was the Richter scale. Is there a difference between 8.9 on the Richter scale and 8.9 on the moment magnitude scale? Also, which scale does the Chilean quake use?

The 9.5 on the Chilean quake is on the moment magnitude scale, as is the 8.9 for this one.
The Richter scale falls down for larger earthquakes, producing a number that does not relate well to the actual earthquake size. The moment scale does not have this flaw. Earthquake scales are scaled such that they correspond to the Richter scale in the Richter scale's accurate range.
The media is probably saying "Richter scale" because it's more widely known. The USGS Earthquake Magnitude Policy has some discussion of all of this. -- Cyrius|


-- I work for a large seismic network and our media always says we use the ricter scale even though our lab does not use it. For an earthquake this large the only Magnitude scale that will work is the Moment (Mw) Mag.

http://earthquake.usgs.gov/recenteqsww/glossary.htm#magnitude --

The Magnitude refers to an amount of energy released by an earthquake and really has nothing to do with felt intensity, so if the scale is applicable to the situation which one you use should not matter. With all of this being said, the ricter scale equates energy released by using a table to look up ground displacemnt at a distance.

-- If the 9.0 Indian Ocean Earthquake "was the largest earthquake in the world since the 9.2-magnitude Good Friday Earthquake", have the authors confused Richter with Moment Mag in the same sentence? If so, this should be clarified.--Westendgirl 18:32, 27 Dec 2004 (UTC)

The USGS says the 9.2 for the Good Friday Earthquake is moment magnitude. -- Cyrius| 22:03, 28 Dec 2004 (UTC)
Thanks. --24.64.223.203 05:27, 29 Dec 2004 (UTC)

I've seen some reports of 8.9 and 9.0 on the Richter scale elsewhere, and 9.0 on the moment magnitude scale here. This led me to conclude that it was actually 8.9 on the Richter scale and some people had confused the Richter and moment magnitude scales. There is no indication of what it is officially on the Richter scale in this article (only that it was initially 6.8). Brianjd 05:59, 2004 Dec 29 (UTC)

The Wikipedia articles on moment magnitude and Richter say that Richter saturates around 8.3 - 8.5, so a Richter magnitude for this quake sould not be meaningful. USGS says 9.0, and they do use moment magnitude for it, so that's what we should go with. -- Curps 06:02, 29 Dec 2004 (UTC)
As far as I can see, moment magnitude is better. However, despite the fact that that Richter scale saturates around that point, we can still give a reading, can't we? The news always mentions the Richter scale; people are going to look for that information. Brianjd 09:52, 2004 Dec 29 (UTC)

You guys are confusing method with scale. There's only ever been one scale for expressing the magnitude of an earthquake and that's the original scale devised by Richter. It was only Richter's original methodology that was innaccurate for large quakes; all subsequent methods of calculating magnitude give a Richter scale value, including Moment Magnitude [1]. It's pedantic and confusing for Wikipedia to insist on Moment Magnitude as this only refers to the calculations employed, which mean nothing to most people. For a common sense view, see this article [2] by a USGS geophysicist [3]. 144.138.194.202 13:08, 29 Dec 2004 (UTC)

What you said is in conflict with the Moment magnitude scale article. Reading that article (as well as the extrernal "common sense" view you give), I find the impression that while the moment magnitude method has been defined to align as well as possible with Richter, it does not align perfectly, even in the lower ranges. Further, the external article you reference has the sound of a scientist who is arguing against convention, which means it's probably inappropriate to make what he says the convention of an encyclopedia entry. --Zawersh 08:02, 30 Dec 2004 (UTC)

I moved the following from Template talk:In the news#2004 Indian Ocean Earthquake. Note that this was moved after this was archived.

This had a magnitude of 9.0 on the moment magnitude scale. Yes, people could click on the "magnitude" link, but how many will? I think many people are going to interpret this as "9.0 on the Richter scale". Brianjd 06:59, 2004 Dec 29 (UTC)

Great, now people are going to wonder "What's that on the Richter scale?" -- Cyrius| 08:10, 29 Dec 2004 (UTC)
Well, I suppose if they're curious, they'll click on this newfangled "moment magnitude" thing and get educated about the limitations of the Richter scale. Win-win. -- Curps 08:13, 29 Dec 2004 (UTC)
I clarified it, and it got changed back - I still don't understand how we can put this confusing thing on the main page. Most people only know about the Richter scale and this is going to mislead them. Brianjd 06:14, 2005 Jan 2 (UTC)
Actually, I have been wondering that myself. Wikipedians seem to have no interest in including it, or stating that it officialy was never determined. Brianjd 07:39, 2005 Jan 5 (UTC)

Good job

It's been ... at this point, almost exactly (if my time zone converstion is dead on) 26 hours since the earthquake struck, and we have a very nice article with local aspects, historical reference (The Bam earthquake, in particular) and already an illustration made by a user, not made by a news organization. I have got to say, I am god damned proud to be a wikipedian at this moment, if this is what y'all can come up with in 26 hours. --Golbez 03:07, Dec 27, 2004 (UTC)

Bear in mind that somebody working for a newspaper would have to produce something like this - with photographs and interviews - in much less than twenty-six hours. -Ashley Pomeroy 10:46, 27 Dec 2004 (UTC)
While being paid for it, with professional tools at their disposal. --Golbez 11:02, Dec 27, 2004 (UTC)
And an Associated Press license. -- Cyrius| 22:04, 28 Dec 2004 (UTC)
Yes, being an Indian and from the state of Tamil Nadu, the worst affected in mainland India, I feel really thankful to see how so many people are working to keep this article up-to-date and of good use to its readers. A good and useful article has been formed in just a couple of days. Thank you all once again for your care. Jam2k 19:51, Dec 27, 2004 (UTC)

As a German living in the U.S. to see the pulling together of care and interest from so many different people across the world to contribute to this article is amazing. I decided to become a contributor because I was so impressed and moved. Thanks to everybody who has contributed. Wikipedia appears to be just an amazing resource and not just mushy 'oh, isn't it awful what happened.' Way to go! oh, yeah, and well, journalists do this professionally, while, and I may be assuming much here, many of the contributors here may just be concerned cosmopolitans doing this on their own time... --HolyFool 22:49, Dec 29, 2004 (UTC)

Aid call

Good work on that section. I remember reading somewhere that the government of Pakistan is sending Rupees 10 million in aid on Monday, mostly in the form of tents, medicines and the like.

Name?

The USGS seems to be calling this the "Nicobar Islands Earthquake of 2004". Should this be mentioned anywhere? --Golbez 04:37, Dec 27, 2004 (UTC)

Do you have a link? The biggest aftershock (7.3) was in the Nicobar Islands, but not the big 9.0 quake itself. -- Curps 04:41, 27 Dec 2004 (UTC)
See this. The name "Nicobar Islands Earthquake of 16 December 2004" is on the map a little down the page. (I would not want to be on the island just south of the star.) Googling "Nicobar Islands Earthquake" turns up one page, to a 7.9 magnitude in 1881. No hits on Google News. I would wait to see if this becomes the "geologist name" for the earthquake or gets picked up by the media before putting it in the article. BanyanTree 05:00, 27 Dec 2004 (UTC)
As a temporary measure, I created a redirect for "Nicobar Islands earthquake". Others may want to create redirects for other names/references. 30 Dec

It is amazing that you have so much about the earthquake and tsumanis on this site so quickly. I've been trying to find exactly where the epicentre was, and can't. (The Myanmar discussion is a bit pedantic, isn't it?)

BBC World has been calling it the Bay of Bengal earthquake. [maestro] 05:27, 27 Dec 2004 (UTC)

It's not pedantic to the people of Burma, let me assure you. When the regime there is overthrown they will remember who their friends were. And the epicentre was not in the Bay of Bengal. Adam 05:56, 27 Dec 2004 (UTC)
I rather doubt that Wikipedia or any of its editors will be the first against the wall when the revolution comes, or that the use of "Myanmar" on a map of this disaster is anywhere near the top of the Burmese people's concerns right now. By all means, do advocate for regime change... but not here; Wikipedia is supposed to remain neutral. Tverbeek 14:11, 27 Dec 2004 (UTC)

We can always move the page later once a name settles in. The other languages seem to be largely using similar names, and it seems to be well-linked from places where people would be looking for it. -- Cyrius| 18:10, 27 Dec 2004 (UTC)

The earthquake did originate in Indonesia, around the Sumatra islands to be precise... the Great Indonesian Quake, maybe? Jam2k 20:00, Dec 27, 2004 (UTC)

I think it's fine as it is, tbh. violet/riga (t) 20:13, 27 Dec 2004 (UTC)

-- Earhtquakes often get names on accident, such as what ever the media first calls it also the name often comes from a prelim location computed by a computer. Often the location of the quake changes slightly after more data comes in and it is reviewed by a seismologist.

I'm hearing it called "The Sumatra Earthquake [and Tsunami]" more frequently in various broadcasts. -- Zosodada

I would suggest "Indian Ocean Tsunami Disaster" as a new name, as I've seen this in use in the media quite a bit. However, the "Sumatra Earthquake" might be good alternative. -- Gavin

Indian Ocean tsunami disaster now redirects here. --David Iberri | Talk 23:33, Dec 30, 2004 (UTC)

Sumatra moved 100 feet?

Drudge is reporting that the ENTIRE ISLAND of Sumatra has moved 100 feet to the southwest. www.drudgereport.com , can this be true. I can't find supporting documentation anywhere. Has anybody else found the documentation for this. if it's true that's an entire island a little larger than California moving 1/3 of a US football field, WOW!!!

Sounds like BS.
The US National Earthquake Information Center is cited by the NYT as saying that hundreds of miles of seabed shot 50 feet upward. This is the sort of motion that causes tsunami. This is also consistent with the subduction faults off Sumatra's west coast. -- Cyrius| 06:36, 27 Dec 2004 (UTC)
The shift was 15m (50ft). [4]. It would have been mostly vertical as the Indian Plate shifted down under the Burma Plate. 600 miles of fault line jumps 500ft, and all the water over hit starts flowing downhill... BanyanTree 10:39, 27 Dec 2004 (UTC)

In today's The West Australian paper it had the story about Sumatra moving 30m to the southwest. - Mark 10:02, 28 Dec 2004 (UTC)

As far as I can tell, the 100 ft. number originated with the LA Times and was immediately propagated by the Chicago Tribune, Xinhua, and countless other papers worldwide. I would be very surprised if this turned out to be accurate. ADH (t&m) 14:54, Dec 28, 2004 (UTC)

Yeah, I added info on movement to the "Quake characteristics" section last night but am leery of it. The numbers are based on a computer model of possible movement and I don't think anyone has actually taken a tape measure out to see yet. Since Sumatra is on two different plates I would be surprised if they had identical movement (though I'm not a geologist by any means). So there's also the issue of relative movement: was it 30m southwest versus a point on the India plate, which was going under the Burma Plate, so there's no relative movement between, for example, Jakarta and Banda Aceh? Or did the Burma plate move 30m southwest versus all the other plates in the world? BanyanTree 17:35, 28 Dec 2004 (UTC)

New data will have to be collected and correlated to existing data. There hasn't been time for this. There has been, according to best theory and previous history, movement both upward and out, but the numbers we've seen are all theoretical (and often from unattributed sources). This paragraph that addresses the issue of earth's rotation has become overly geeky and in the process is confusing increasing and decreasing of the rotation. The cited article clearly states that the earth slows down over time, but the Wiki is now confused on this matter. -- Zosodada

Not "Tidal waves"

As with the case of "injured" vs "wounded" above, I note repeated use of the term "tidal wave" in the article. This wasn't a tidal wave. Quite the opposite - it was a tsunami. Tsunamis have nothing to do with tides. Grutness|hello? 23:57, 27 Dec 2004 (UTC)

Some news sources are calling them "sea surges", perhaps this terminology could be used instead? -- Michael Warren | Talk 00:02, 28 Dec 2004 (UTC)
Perhaps you might want to let Sky News know: they're still using "tidal wave": [5] -- Graham ☺ | Talk 00:12, 28 Dec 2004 (UTC)
...and, of course, mass media use of language is always impeccable. The same mass media that report people being seriously ill after car crashes. Just because Sky News is wrong doesn't mean that we should be. Grutness|hello?
Er I think you misunderstand me. I wasn't making a snide remark or anything, if I thought you were wrong I'd tell you outright, I don't believe in beating about the bush. It was sarcasm. -- Graham ☺ | Talk 01:34, 28 Dec 2004 (UTC)
Sorry :). My reponse was a bit harsh too, probably. Still a bit shaken about this and my humour indicators are probably turned off (I live right next to a beach close to one of the world's most active faults, so I'm a little thoughtful about this, shall we say). Grutness|hello? 06:40, 29 Dec 2004 (UTC)
No problem at all, we've been a little stressed too however fortunately my uncle and aunt contacted us from Phuket today and are on their way home tomorrow. -- Graham ☺ | Talk 02:02, 30 Dec 2004 (UTC)
I've gone through and reworded all the "tidal wave"s in the article. BanyanTree 01:14, 28 Dec 2004 (UTC)
Is the use of Freak Wave correct at the end of the article? The linked page makes a clear distinction betwen freak wave and tsunami. --RayNixon 10:29, 29 Dec 2004 (UTC)
It looked wrong so I went ahead and changed it to "ocean surge". Good catch. BanyanTree 10:48, 29 Dec 2004 (UTC)
The use of freak wave was incorrect. Freak or rogue waves are a distinct phenomenon from tsunami. A freak wave can generate a huge wall of water even in the open ocean, whereas a tsunami will pass a ship miles from shore without it noticing. -- Cyrius| 21:07, 29 Dec 2004 (UTC)

-- Also, freak waves are thought to be caused in an entirely different way than tsunamis.

Unreal

I've seen the first people talk about >100,000 dead.. [6], unfortunately it's German-only. Interestingly, news.yahoo.de seems much more up-to-date that news.yahoo.com. -- Nils 17:55, 28 Dec 2004 (UTC)

Indonesian Local Media ( detik.com ) said, According to Indonesian Healthy Department ( Departemen Kesehatan ) The latest death toll from Aceh and North Sumatera tsunamis has increased to more than 32.800 and 1200 still missing, as relief workers and supplies begin to reach some of the most devastated areas such as Meulaboh.. This number can be increased... ( sorry my english not very good.. )