Talk:Lists of earthquakes/Archive 1

This is an archive of past discussions about Lists of earthquakes. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page.

Archive 1

Archive 2

Archive 3

Which earthquakes to include?

Los Angeles quake .. I think in 1971 was 6.1 ... should it be on this summary... EdMc

Approximately 120 earthquakes that size happen each year, it is not feasible to list all of them. Was there anything particulary noteable about that earthquake? Did it cause a lot of destruction? -- Popsracer 23:01, 27 Sep 2003 (UTC)

So what is the lower limit to the strength of an earthquake to merit addition to this list? If there is a specific limit then I would suggest removing those currently listed without magnitudes as they may be below that limit. SD6-Agent 17:29, 15 Oct 2003 (UTC)

There's no hard and fast number, but it needs to either be "major" in strength (somewhat subjective, but I'd put it in the high 6.x's), or be particularly notable in damage or other events. Basically, any earthquake that'd be interesting to read about five years from now. As for the ones without magnitudes, they're mostly historical ones, which should stay as they're clearly well-known enough to still be known about centuries later. --Delirium 19:50, Oct 15, 2003 (UTC)

It killed 14 people, which is more than the quakes of 29-Jun-1925 or 21-Jul-1952 which are on the list. It is the 10th deadliest earthquake in the US since 1900. It was magnitude 6.6. It was not terribly damaging but did cause the collapse of some modern highway bridges and the modern Olive View Hospital in Sylmar, causing considerable change in building codes. http://www.lafire.com/famous_fires/710209_SylmarEarthquake/1971-0500_SF-EqEdition_1971SFEarthquake.htm --Ttulinsky 00:01, 31 Dec 2004 (UTC)

Matthew White says in http://users.erols.com/mwhite28/quakes.htm : July 28, 1976 Tangshan, China. 242-800,000

He also says this earthquake was the worst single day in human history, and he's generally not wrong. So I think the 242 769 number is probably a severe understatement.

Some other site, http://www.geo.arizona.edu/K-12/azpepp/education/history/china/ says the number is closer to "half a million", which is similar to the half-way point of Matthe White's number. There are other pages quoting the 240 000 a lot and more giving upper ranges of 500 000. So I'll uhm... casually approximate the deaths of hundreds thousand of people and change the number to 400 000.

I think that all the 2003 earthquakes should be off the list as there is nothing major about any of them. Rmhermen 23:27, Dec 23, 2003 (UTC)

Note how the USGS lists earthquakes by magnitude (definition) as 'major' (7.0-7.9) and 'great' (>=8.0). This might be a good distinction to adopt here. Peter Ellis 14:20, 26 Dec 2004 (UTC)

Also the May 25-27 1980 Mammoth Lakes quakes should be removed, they are 6's and caused no deaths. They caused a lot of interest at the time because they are near a popular California ski area and with a dormant volcano. --Ttulinsky 00:10, 31 Dec 2004 (UTC)

GMT or local time?

It's a little odd to use GMT to list the earthquakes instead of local time. For instance the devastating Taiwan earthquake of 1999 happened on September 21 local time, and became known simply as "921" locally much as the terrorist attacks in the USA became known as 9/11. Yet it is listed as happening on 9/20, since that was GMT. So to know what time of day it happened you have to convert the timezones. Wouldn't it be better to go through this list and change all the times to local time with timezone attributions? 68.162.109.30 15:48, 5 Sep 2004 (UTC)

 Reply: I believe it would be appropriate for the local people to use their time, and for the rest of us to use GMT in response to this matter.  —Preceding unsigned comment added by 62.153.212.170 (talk) 19:16, 1 April 2008 (UTC)

A thirteen and a half year old question, but (just for closure) there is now a definite answer: use both. Use the new (as of yesterday) parameters 'local-date' and 'local-time' for local date-time (hopefully with a timezone), and 'timestamp', which is the UTC time in all-numeric 'yyyy-mm-dd hh:mm:ss' format used for identifying and indexing earthquakes (replacing the mis-used 'origintime'). ~ J. Johnson (JJ) (talk) 22:05, 17 March 2018 (UTC)

Major earthquakes

It'd be nice to have a list of earthquakes by intensity as well. When news sources were reporting that "this is the 4th largest earthquake this century", there was no source to turn to to verify that data.(unsigned)

Yes, see the USGS page about the 10 largest earthquakes since 1900, linked to from 2004 Indian Ocean earthquake. See USGS Past Earthquakes page, under "Top 10 lists". -- Curps 04:12, 28 Dec 2004 (UTC)

missing quake: Italy 23 Nov 1980 killed 4800

Seems to be missing from all lists on this page. It is listed in the Wikipedia for news of 1980 ( http://en.wikipedia.org/wiki/1980 ):

"November 23 - A series of earthquakes in southern Italy kills approximately 4,800 people."

This death toll makes it the second most deadly earthquake in a developed country since 1950 (after Kobe 1995), and the deadliest in Europe.

"Significant" Earthquakes-split into 3 objective lists

The list could be changed from a subjectivly chosen list of "Significant" earthquakes with unclear criteria, to a quantitative list, by splitting it into 3 lists:

Most Deadly Earthquakes-World
Most Deadly Earthquakes-Developed Countries
Largest Earthquakes by Magnitude

That would include most of the quakes on the Significant list. Making the list criteria quantitative is an improvement in my opinion.

This would also satisfies the desire of many readers to see the Loma Prieta earthquake of 1989 or the Northridge quake of 1994 in a list of major earthquakes when they do not make any list of major earthquakes by size or number of deaths.

--Ttulinsky 23:50, 30 Dec 2004 (UTC)

Positive and negative longitudes

I always thought it was standard to use negative numbers for EAST longitude and positive for WEST. That's the opposite of what this article does. Was I mistaken in what I thought was standard, or is there a reason to deviate? (I once hear the head of the math department at MIT (David Vogan, who has since been succeeded as department head), speaking before about 150 undergraduates, state that it's appropriate that longitudes in Europe are negative since Europe is a cultural cesspool. No one responded that east longitudes are positive and west negative. (Nor did anyone complain about that characterization of Europe.) So I'm not the only one to think that's standard.) Michael Hardy 01:10, 3 Jan 2005 (UTC)

This is pretty basic knowledge, but I'm glad you brought this up, because I was able to fix this glaring error in the longitude article. You don't have to believe me though:

—Cantus…☎ 07:24, Jan 3, 2005 (UTC)

While this may be a long dead issue I've always had a high view of MIT. However given the above charaterization of a former math department head and the undergraduates there, I wonder whether I should modify my opinion. Other then the glaring error and the rather silly characterization of Europe, the above also completely ignores the fact that in fact a significant part of the world is in West longitudes including Asia, most of Oceania, and a significant part of Africa. Of course, if the above characterization of David Vogan is true, perhaps he didn't even know Asia, Oceania or Africa existed or thought they didn't matter. It also ignores the issue as raised of east being right as on a cartesian coordinate system (I assume David didn't claim that south is positive). However most significantly perhaps, east being positive makes most sense considering the rotation of the earth (think of why timezones to the east of the GMT are +). However perhaps I'm being unfair to the students. Having been a student myself, I recognise they might have just decided to ignore the idiot rather then make a fuss about someone who was clearly wrong and seemingly a bit stupid. Nil Einne 17:46, 26 July 2006 (UTC)

Ashkhabad earthquake

Why Ashkhabad's (Turkmenistan now, than USSR) earthquake is not in the list? It happened in 1948, night 5-6 october. It caused 110,000 deaths by official sources (180,000 by other sourses: http://www.scgis.ru/russian/cp1251/dgggms/2-98/nikonov1.htm), magnitude 7.5 (up to 10.0 by other sources: http://geo.1september.ru/1998/geo41.htm). 98% of building in the city were distroyed.

Komap 16:34, 3 Jan 2005 (UTC)

More missing major earthquakes-outside US

New one today: http://www.bom.gov.au/cgi-bin/wrap_fwo.pl?IDN23900.txt 61.88.76.4 01:01, 2 April 2007 (UTC)

What about the 1948 Turkmenistan (then USSR) quake? 7.3, killed 176,000 (according to Turkmenistan, 110k other sources) http://en.wikipedia.org/wiki/1948_Ashgabat_earthquake —Preceding unsigned comment added by Wreave (talk • contribs) 15:02, 10 April 2009 (UTC)

Empty fatalities column

If the fatalities column is empty, does that mean "0" or "Unknown" ? (unsigned)

It means 0 (unsigned)

Order of material

Having just looked at this page a number of things strike me as odd in how the material is ordered:

Most recent Earthquakes are way down the page.
Wouldn't the "records" (top 10 casualties, top 10 magnitude) be better near the top?
Wouldn't a reverse date order make more sense?

Having made these comments, here is the ordering I propose: Most recent (reverse date, newest 10? only), Top 10 Casualties, Top 10 Magnitude, All major earthquakes (if someone feels like taking the time to reverse date this, go right ahead, but it isn't for me), non-USGS listed. I'm willing to make the change, but I'd like feedback before doing it as to whether it's a good idea. --Random Chaos 22:52, 28 Mar 2005 (UTC)

The 1201 Syria Earthquake

I have just looked through the list of the deadliest earthquakes. I am appaled that the July 5, 1201 Upper Egypt or Syria earthquake that killed 1,100,000 is not in there!!

Was it in Upper Egypt or was it in Syria? Upper Egypt means the south of Egypt and is a long way away from Syria. Anthony Appleyard 06:05, 18 October 2005 (UTC)

The earthquake is indeed listed. However the above is a relevant point. Upper Egypt and Syria are not the same thing, not even close so calling it Upper Egypt or Syria is a bit confusing. Did it affect both Upper Egypt and Syria (and everything in between) or what? Nil Einne 17:57, 26 July 2006 (UTC)

Strange that such a huge earthquake is not mentioned anywhere else. It's not in the list of deadliest quakes, or in the list of largest earthquakes. It is not mentioned in the list of notable events for the year 1201. Even it's location is unsure by thousands of km. I'm starting to think perhaps it is a hoax/vandalism. Can anyone cite a source for this major historical event? Astronaut 20:02, 21 July 2007 (UTC)

I've done some research. A brief Google search revealed several mentions by trustwothy-looking sites including universities and geology journals. However, the USGS does not mention this earthquake; maybe due to a lack of detailed information from so long ago (or maybe I didn't look hard enough :-). To summarise: there was an earthquake in 1201 which affected the "eastern mediterranean" and killed around a million people in a wide area from Syria to Upper Egypt. Astronaut 06:28, 24 July 2007 (UTC)

I've created a page on the 1202 Syria earthquake, which may be the same event. A minority of sources have them as two separate earthquakes. Mikenorton (talk) 12:26, 16 April 2009 (UTC)

Anthony Appleyard's edits

# (cur) (last)  08:43, 21 October 2005 Cantus (return to established version)
# (cur) (last) 07:58, 21 October 2005 Anthony Appleyard (rev vandalism (someone added a pointer to a videogame))

In this part of this page's editing history, I can understand Cantus reverting to his version. But my reasons for my edits are:-

In a table with many columns and many rows, wide margins waste much space, and make the table sprawly, and make table entries fold onto another line of text when they need not fold, thus also creating a blank extra line in all other boxes in that row of boxes.
For the same reason I replaced United States by USA everywhere (which is the usual form used in a list of addresses), and "northwest" etc by the very well known useful abbreviations "NW" etc, since Wikipedia's editor has been moaning that this file is too big (40 kilobytes).
For the same reason I removed the line break in the frequent table entry "Turkey see NAFZ"

Anthony Appleyard 06:32, 23 October 2005 (UTC)

Where is "Sua-ho" Taiwan?

I LIVE in Taiwan and have never heard of Sua-ho. That's not even Chinese. Could someone actually confirm what the hell that's talking about so it can be changed to something not completely WRONG? (unsigned)

While the above poster could have been more polite, it appears he/she may have a point as the only mention of Sua ho I can find on Google appear to be from wikipedia and copiers/mirrors. Of course, it's possible it's just the name for a small place in Taiwan that is really hard of or spoken about. Nil Einne 17:31, 26 July 2006 (UTC)

chilean earthquakes

En la lista faltan algunos terremotos muy importante ocurridos en Chile, como por ejemplo el de 1985 en la zona central del pais, el cual destruyo muchas estructuras en Valparaiso y Santiago, y dejo mas de 1.000.000 de damnificados.

Tambien falta uno que ocurrio en Valdivia el dia 21 de Mayo de 1960, el dia anterior al famoso terremoto de Valdivia.

Sorry for say it in spanish, but my english is not very good. -(Anonymous author)

Here is a rough translation of the above Spanish:

The list lacks some very important earthquakes that happened in Chile, like for example one that occurred in 1985 in the central zone of the country, which destroyed many structures in Valparaiso and Santiago, and left 1,000,000 victims. The list also is missing one that occurred in Valdivia on the 21st of May of 1960, one day before the famous earthquake of Valdivia.

I hope I accurately translated what the above person was trying to say. --Cab88 17:47, 19 April 2006 (UTC)

You just missed Pais, which translates to English as "country".

Lack of links

Practically none of the tables in this article contain links to the earthquakes' articles. I added some for the deadliest-earthquakes table. Without these, the article is close to useless! Jdorje 23:10, 31 January 2006 (UTC)

1957 Daly City (San Francisco suburb) earthquake

How about the 5.3 earthquake in Daly City, California (just south of San Francisco) on March 22, 1957? At the time, I believe it was the biggest quake in the S.F. area since 1906. Richwales 19:49, 15 June 2006 (UTC)

2004 Indian Ocean earthquake

Why is the magnitude listed as 9.0-9.3? As far as I can tell from the 2004 Indian Ocean earthquake page, while the original magnitude was 9.0, all sources have since upgraded it to between 9.1-9.3. Is there any source that still lists it as 9.0? If not, surely we should list it as 9.1-9.3 NOT 9.0-9.3? Nil Einne 17:55, 26 July 2006 (UTC)

Lima, 1746

Lima, Peru was hit badly by an earthquake on October 28, 1746, and is mentioned on the 1746 page. Alpheus 06:04, 28 October 2006 (UTC)

Vandalism

Watch out for vandalism, I'm not registered, so I'm not gonna edit, but someone fix that unibrow thing in the table. Thank you. (unsigned)

26 Dec 2006 Taiwan Earthquake

The earthquake (on the 26 Dec 2006 which happens 91km SSE of Koahshiung, Taiwan) not only interrupted phone services but also interrupted internet services in many parts of Asia like Taiwan, Japan & Singapore. This is the source. Aranho 13:08, 27 December 2006 (UTC)

List needs cleaning up

The list of recent earthquakes contains far too many minor earthquakes. This list should be tidied up to focus on major earthquakes. A list of all earthquakes would be impossible to maintain. Carcharoth 13:45, 28 April 2007 (UTC)

Since the second list is not listed by the USGS I added a column in the table for the source of each particular item. (Such a column in the USGS list would be pointless since it is the source of each item on it). Anynobody 05:10, 29 April 2007 (UTC)

recent activity

I removed the addition of some statistics and commentary about current events such as a recent spate of major quakes seeming to have diminished since April - this page is a list of historical quakes; if that information belongs anywhere, it is not here - and I would argue that ths time period "since April" is inappropriate for an encyclopedia... Cheers Geologyguy 03:27, 29 May 2007 (UTC)

Coordinates & microformats

Merging the "latitude" and "longitude" columns as "coordinates" would allow use of the {{coord}} template, which has many benefits for users (end editors) including choice of display format and the emission of a geo microformat. See, for example List of impact craters in Canada, where this has been done. Would anyone object if I request a bot to do this? I'd also ask the bot owner (or be willing myself) to add hCard microformat mark-up to each table row. An example would be the table of features on Manchester Ship Canal. Andy Mabbett 13:22, 14 June 2007 (UTC)

The current list is a mess

Why not just have one single list with the most recent earthquakes at the top, and historic ones at the bottom? The USGS list of significant quakes has not been updated for more than 2 years, and plenty of significant quakes have happened, so it is surely pointless having it there? RapidR 11:07, 30 September 2007 (UTC)

2004 earthquake

With respect to the editor a representetive IS NOT the magnitude. The highest confirmed magnitude so far for the 2004 indian ocean earthquake is 9.31 so that makes it the 2nd largest earthquake in recorded history which means it will stay that way until evidence proves it's true magnitude.
I updated some information according to 2004 Indian Ocean earthquake. Although in my opinion, the number of fatalities and the magnitude of earthquake provided by United States Geological Survey is seemed to be not very reliable, I know that the 300,000 fatalities and the 9.31 magnitude are old numbers. Therefore, I decided to change the number and the rank for consistency. If anybody feels that my action is wrong, please say so here... QQ (talk) 19:32, 20 May 2008 (UTC)

What's the source for the 9.31? That's suspiciously precise for such a hard thing to measure. 2004 Indian Ocean earthquake lists 9.1-9.3, with 9.1 being the USGS number and 9.3 being a more recent number. Of course, the accuracy of the other 9.3 quake is even more in question. Bhudson (talk) 05:03, 22 May 2008 (UTC)

the chart needs major fixes

If you rank the quakes by date, they are listed alphabetically, starting with April 1 and ending September 4th. It should be ranked by date. The fatalities ranking doesn't seem to work well either. Kingturtle (talk) 21:06, 12 May 2008 (UTC)

Someone added colspan tags to a few of the entries which messed up the sorting. I have removed the colspans and added blanks columns back to fix the sorting; however the lat/long columns for a few of the entries are now blank... actually, I guess I'll go look up that info also. Aepryus (talk) 14:46, 15 May 2008 (UTC)

I couldn't find the lat/long data at the USGS site. Not, sure where to get info on the location of epicenters. Aepryus (talk) 14:56, 15 May 2008 (UTC)

USGS list contradictions

Hi. The source for the USGS list lists almost all the earthquakes listed in the section "not listed above", for 2008. Also, Sichuan earthquake is found in both sections. Please fix this problem, because the actual USGS list for 2008 is way more than the one listed in our list. Thanks. ~A H 1^(TCU) 20:37, 2 August 2008 (UTC)

Too long

This list is far too long. It would be better if it were split by country. For example, see lists of volcanoes. Black Tusk (talk) 19:40, 11 October 2008 (UTC)

Used WikiCleaner to fix broken links to other WP pages, since the article is long, had to run program twice, please don't reverse! Thanks--Funandtrvl (talk) 16:33, 23 October 2008 (UTC)
Perhaps we could have a page for 'list of earthquakes by magnitude' and 'list of earthquakes by country' and perhaps list by year as well? - AndrewJ

Skopje, Republic of Macedonia - 1963 earthquake

I have noticed that most locations are followed by present-day country names, for example Turkey, Greece, etc., although those countries didn't exist by those names at the time of the listed events. This approach seems reasonable, as it would be inconvenient to a present-day reader to use historical names for the locations/countries. Following this analogy, I have changed Skopje, Yugoslavia to Skopje, Republic of Macedonia. Crnorizec (talk) 08:15, 26 January 2009 (UTC)

For cases where it'd be anachronistic, most of the other entries try to use a formulation like "former location (now present location)". For example, the 1428 Catalonia earthquake says "Catalonia (now Spain)", and the 1797 Sumatra earthquake says "Sumatra, East Indies (now Indonesia)". That seems like a more sensible approach to me than using modern state names in anachronistic contexts, e.g. claiming that something from the 1600s happened in "the United States" or something from 1963 happened in "the Republic of Macedonia". --Delirium (talk) 08:32, 26 January 2009 (UTC)

Puerto Rico quake the deadliest?

Could someone check the deadliest quake's list? I highly doubt that over 200.000 people died in Puerto Rico (213.22.144.70 (talk) 02:34, 20 March 2009 (UTC))

suggestion to prune recent quakes

The 2009 list has far more earthquakes than really belong on a list of "significant" earthquakes, including many of quite low magnitudes. I'd recommend, as a first cut, to remove those with magnitudes under 5.0, except any that are significant enough to have their own Wikipedia article. Thoughts? --Delirium (talk) 23:15, 26 March 2009 (UTC)

Improve article

The List of earthquakes is way too long. So I moved "Recent earthquakes not listed above" to List of 2004-2009 earthquakes. It looks better now. But if you don’t like it, you can change it back and delete the sub-article. At least, I try to improve this article. Do you like what I have done so far on this article?--Michael (talk) 21:43, 28 March 2009 (UTC)

It is a lot better, but I think the name of the new article needs to be changed to something a bit more persistent that wouldn't need changing every year (e.g. List of 21st century earthquakes), or perhaps split it by year, List of earthquakes in 2009 etc. RapidR (talk) 17:32, 29 March 2009 (UTC)

Public Notice

Done –Michael (talk) 06:16, 7 April 2009 (UTC)

Moved: Other earthquakes not listed by the USGS to Historical Earthquakes

Moved: Recent earthquakes not listed above TO List of 2004-2009 earthquakes

Removed: cleanup and too long TAGS

If you have eny questions, Please Send your comments to my talk page--Michael (talk) 06:16, 7 April 2009 (UTC)

Agreed that this list had become too big, but I don't think that moving just the 'earthquakes not listed by the USGS' to Historical Earthquakes was the best solution. Ideally there should be one list of historical earthquakes that includes the USGS list as well. Also the recent earthquakes should be named 'List of earthquakes from 2004' or similar, so it doesn't need to be renamed in 8 months time and it should include those from the USGS list. Mikenorton (talk) 11:22, 7 April 2009 (UTC)

Does it look better now?--Michael (talk) 01:07, 8 April 2009 (UTC)

The main problem that I have is that the USGS list fails to include several very large earthquakes such as the M 7.8 2001 Kunlun earthquake and the M 8.0 1855 Wairarapa earthquake. We need a single list IMO containing all significant earthquakes. If we're going to split it, to keep the size within bounds, perhaps we should have a list for 'earthquakes before 1901' another for '20th century earthquakes' and finally recent earthquakes. Earthquakes before 1900 are in almost all cases not recorded instrumentally and the level of data that we have for them is less, in many cases we're guessing about the size, location and cause. Most of those in the 20th century are, in contrast, well located with good records of the damage caused and were in many cases recorded instrumentally. I am also unconvinced about 2004 as the start date for recent earthquakes rather than 2001, it looks more like 'earthquakes since the start of wikipedia'. I am aware that combining the existing USGS and 'historical earthquake' lists will be time consuming but I feel that the result would be a lot more useful. Mikenorton (talk) 07:15, 8 April 2009 (UTC)

I've now created a list of twentieth century earthquakes, I'm currently combining the USGS and other lists for a revised Historical earthquakes page. You should find that all the earthquakes in the new list have either a link to a specific article about the earthquake or to a source. I would appreciate other views on this. I'm rather hoping that people will like what they see, which would encourage me to finish the job. Mikenorton (talk) 16:04, 19 May 2009 (UTC)

Historical earthquakes page now combined with USGS significant earthquakes list, As above, all events now have either a source or a link to the relevant earthquake's article. Next task is to add the post 2000 earthquakes from the two old lists into the List of 2004-2009 earthquakes and rename it 'List of recent earthquakes'. No-one seems to be objecting to what I'm doing, so I'm ploughing ahead. Mikenorton (talk) 12:20, 23 May 2009 (UTC)

I think the List of 2004-2009 earthquakes page should be renamed 'List of 21st Century earthquakes', consistent with the List of twentieth century earthquakes, which itself in my opinion should be renamed 'List of 20th century earthquakes'. Also, the 21st century list is missing events from 2001-2003. RapidR (talk) 00:34, 25 May 2009 (UTC)

I'd be happy to see the twentieth century list renamed as you suggest, it looks better, ditto the recent earthquakes for consistency, although the current name seems fine to me as well. Mikenorton (talk) 14:36, 1 June 2009 (UTC)

chart cosmetics AND what is criteria for earthquake to be included?

i'm clearly not an expert on editing charts on wikipedia (just make 1st changes (minor) to charts in last few days). if i could figure how to i would, for easier readbility, etc. -

make "date" column wider (such that "september 30, 2009" (for example) would fit on one line)
make "fatalities" much narrower (only 1 line has extended text - which, if needed, could be thrown to a footnote)
put, at a minimum, the "country" in a separate column (so that chart can be sorted by country) (ideally, the u.s. state would be a separate column (for further sorting) but that may be too much to fathom)

anyone that could help?

also, what is criteria for being on this list? a minimum magnitude? of what? i would expect language explaining that before the chart.--71.183.238.134 (talk) 00:30, 10 April 2009 (UTC)

Magnitude of Tangshan Earthquake

Please check for consistency. The magnitude of the 1976 Tangshan earthquake should be 7.8 according to many sources including the "Tangshan earthquake" page in Wikipedia.

According to this USGS page, 7.8 was the initial estimate, later reduced to 7.5. Magnitude estimates often show considerable variation. The article may need to be updated, but that would need some checking around in the scientific literature. Mikenorton (talk) 16:15, 27 February 2010 (UTC)

List not correct

According to the U.S.G.S there are other earthquakes and some listed here are not as strong as the list claims. [1] Seeing as the U.S.G.S are the experts on the matter I would refer to the list. - Knowledgekid87 (talk) 16:00, 27 February 2010 (UTC)

They are not the only experts in the world. The USGS generally does an early estimate of the magnitude and then sticks with that. Further analysis may refine the numbers, up or down. Is there a specific earthquake that you think is incorrect, and are you only referring to the list by magnitude? Mikenorton (talk) 16:07, 27 February 2010 (UTC)

Just to clarify matters: there are multiple magnitude scales in use (see Seismic magnitude scales), which measure different aspects of a quake, or do so in different ways or with different data, so having different magnitudes (according to different scales) is neither unusual, nor invalid. Initial reports are also subject to large errors, and are subsequently refined. The Advanced National Seismic System, a partnership of the USGS (including the NEIC) and other regional seismic networks which was just getting organized then this discussion opened, is the premier source for early reports. ~ J. Johnson (JJ) (talk) 22:23, 17 March 2018 (UTC)

I spotted some errors

I once did an analysis of earthquakes to see if they were more numerous/greater since 1914. It was demonstrated conclusively that they were - http://www.webspawner.com/users/cauthonmattpage8/

Anyway I note that the Wiki list has some apparent errors.

Missed earthquakes

1896 Japan M8.5
1868 Chili M9.0
1730 Chili M8.7
1687 Peru M8.5

I would also suggest you check and double check these as i have never heard of them:

1920 China M8.6
1737 Kamachaka M8.3
1575 Chili M8.5

You need to find reference for these last three as their were no record of these when i investigated these a few years ago

Matt Cauthon —Preceding unsigned comment added by 94.0.116.31 (talk) 19:38, 27 February 2010 (UTC)

Yeah, I immediately noticed that the 1868 quake was missing. I can't even find a reference to this quake anywhere on Wikipedia. Very strange. — RockMFR 15:10, 28 February 2010 (UTC)

I've created 1868 Arica earthquake for the 1868 one. — RockMFR 15:41, 28 February 2010 (UTC)

(ec)Well, the Arica quake is listed on the Historical earthquakes page, but it won't have an article until someone writes it (hah I see you have). ~~I'll add it to my 'to do' list~~ but there are lots of notable earthquakes out there without articles, anyone can join in. Answering Matt, the best estimate for the 1896 Meiji-Sanriku earthquake is a surface wave magnitude of 7.2. The 1575 Valdivia earthquake has an article, as does the 1737 Kamchatka although very little info is included, also the 1920 Haiyuan earthquake. The 1687 Peru and 1730 Chile events don't appear to be in any of our articles as yet, I'll check these out. Mikenorton (talk) 15:57, 28 February 2010 (UTC)

I've added the 1687 Peru event to Historical earthquakes, I've found references to the 1730 Chile event, but that will take me longer to add as I try to find a location (it's not in my favourite global catalogue). Mikenorton (talk) 21:41, 28 February 2010 (UTC)

OK, found that one too and added it. Mikenorton (talk) 22:01, 28 February 2010 (UTC)

Articles now exist for both the 1687 Peru earthquake and the 1730 Valparaiso earthquake. Mikenorton (talk) 18:03, 6 March 2010 (UTC)

Many thanks for checking and reviewing. I just happened to be talking about earthquakes with someone and reviewed this list again. I have noticed that a number of historic earthquakes have appeared in this list that i was not aware of. Double checking against my list i realise that some have crept from the lower magnitude into this higher magnitude. So for example i had the 1877 Chili down as an 8.3 but on this list it is down as 8.5 i.e. just above the threshold for the larger earthquakes. I am pretty sure various authorities have this down as 8.3 and can only suggest unless there are secular authorities who say it is 8.5 i would recommend that wikipedia simply follow the experts and put 8.3. Mat Cauthon. — Preceding unsigned comment added by 95.131.110.104 (talk) 08:15, 6 September 2012 (UTC)

Actually various seismologists have estimated it as up to Magnitude 9 (Mw). Peyrat et al. in 2006 give Mw ~ 9.0 [2], Bejar-Pizarro et al. 2010 give Mw=8.8 [3], Peyrat et al. 2010 give Mw=8.9 [4], so 8.5 is probably at the lower end of the estimated range (note that all these sources involve the same group of seismologists). Zamudio et al. 2005 give Mw=8.6 [5] & Bilek 2009 gives Mw=8.8 [6], so M>8.6 is actually the consensus as far as I can make out. Mikenorton (talk) 17:47, 6 September 2012 (UTC)

Minor re-name of page

I think that this page should be renamed "Lists of Earthquakes", i.e. that the word List should be plural as there is more than one list accessed through this page. Any thoughts? OLEF641 (talk) 09:07, 14 March 2010 (UTC)

Strictly speaking it should be 'List of earthquake lists'. I don't think that the current title is a problem personally. Mikenorton (talk) 23:52, 3 March 2010 (UTC)

USGS list of earthquakes by magnitude

I reverted the recent edit to the 'List of earthquakes by magnitude', that essentially copied the USGS list sorted by magnitude. The problem with that list is that the magnitudes given aren't necessarily those most generally accepted and some earthquakes are missing entirely, such as the 8.8-9.2 1833 Sumatra earthquake. Mikenorton (talk) 21:10, 12 March 2010 (UTC)

Ranking for 1138 Aleppo earthquake ?

The Template:Deadliest earthquakes ranks the Aleppo quake 5th, the USGS source currently quoted in 1138 Aleppo earthquake ranks it 3rd. How would you resolve this discrepancy for the article on the Aleppo quake. -- KlausFoehl (talk) 13:52, 11 October 2010 (UTC)

Deadliest earthquakes list

A couple of problems with the deadliest earthquakes list.

The notes for the 1138 Aleppo earthquake seem to be saying that 230,000 people didn't actually die in that quake because the 230,000 number represents the total deaths from the Aleppo quake and another one. So, surely, the more than 230,000 deaths in the 2004 Indian Ocean earthquake should rank above the not-really-230,000 deaths at Aleppo?

The notes for the 1703 Genroku earthquake appear to be copy-pasted from the article text but change the death toll from the tsunami from the 10,000 quoted in the article to 100,000. The earthquake's article cites two sources, one of which claims 10,000 deaths; the other, 100,000. So which is it?

Dricherby (talk) 01:30, 23 February 2011 (UTC)

There are real problems with this list. I have started to assemble a spreadsheet of death tolls and their supporting references, but I've run out of steam for the moment. Taking the 1703 Genroku earthquake as an example, I can find estimates in reliable sources for the following death tolls - 5233, 10000, 37000+, 100000, 150000, 226000, 270000 - so which number should we use? It's difficult enough getting a definitive figure for the 2010 Haiti earthquake, which happened last year. The 1138 Aleppo earthquake is a little simpler in that there is a very good source saying that the figure of 230,000 actually includes the deaths from three separate earthquakes, but the same source does not provide an alternative number. My aim is to find some sort of rationale for handling all these different estimates. Part of me says - just get rid of the list ordered by death toll and replace it with a chronological list of earthquakes with estimated death tolls of over 50,000 (or whatever). Mikenorton (talk) 23:14, 23 February 2011 (UTC)

There is a discrepency with the indian ocean earthquake magnitude

I noticed in the "largest earthquakes by magnitude" section it says this earthquake was 9.2 magnitude, whereas in the "deadliest earthquakes on record" section it says that this earthquake was 9.1 magnitude. I do not know which one is correct, but I thought that I would just bring it to attention. 76.88.196.198 (talk) 16:46, 11 March 2011 (UTC)

Various sources give estimates in the range 9.1 to 9.3 and to quote our article on this earthquake "Dr. Hiroo Kanamori of the California Institute of Technology believes that M_w 9.2 is a good representative value for the size of this great earthquake." Mikenorton (talk) 21:14, 11 March 2011 (UTC)

While 9.2 is a good representative value, a similar assessment of the Prince William Sound earthquake seems to be lacking. From my reading of the USGS analyses, the wikipedia articles on the two quakes, and what little I remember from Hiroo's class (which I took in Spring 2005), the use of 9.2 for this event in any ranking would require a similar reevaluation of the other large events. Most lists seem to consider the 1964 Alaska Earthquake (Prince William Sound) to be slightly stronger than the 2004 Indian Ocean event, but a lack of instrumentation then/there has limited further analysis. So for consistency sake, I would advocate listing the 2004 Indian Ocean Earthquake as a 9.1-9.3, but ranking it like a 9.1. If others disagree, I will bow to further research. Elriana (talk) 19:01, 8 April 2015 (UTC)

If you look towards the bottom of this page (USGS update), you will see a discussion on the various magnitudes being quoted by the USGS these days. For the 2004 quake, they give two estimates at M9.0 and one at M9.2 - if we take the ISC-GEM catalogue that also gives a M9.0. As stated in that section, I think that the aim should be to use the most recently recalculated numbers (using the ISC-GEM for most of them, now that the USGS seems to be using them for earthquakes before 2000). For the 1964 Alaska earthquake that catalogue gives M9.3±0.2. Mikenorton (talk) 20:17, 8 April 2015 (UTC)

Fair enough. I'll add some comments there regarding opinions on the magnitudes listed. But the point I wished to make was that the listing of magnitudes, particularly for the largest few events, should be consistent enough to preserve the common ranking. Regardless of the magnitude listed, most resources rank the top 4 in the same order. Elriana (talk) 18:03, 10 April 2015 (UTC)

"Recorded History" Bit

According to sources the recent earthquake was the 5th NOT THE 7th most intense earthquake ever recorded, so my question is why does Wikipedia have earthquakes here dating from the 1700's if records did not start to be kept since about 1900? - Knowledgekid87 (talk) 19:57, 11 March 2011 (UTC)

Before 1900 very few earthquakes were recorded instrumentally with seismographs. However, there are a number of ways in which magnitudes can be estimated from isoseismal maps, from uplift patterns (e.g. the 365 Crete earthquake data taken from raised shorelines or the 1833 Sumatra earthquake where the data were taken from coral microatolls), from the lengths of surface ruptures and from modelling the records of associated tsunamis, as in the 1707 Hōei earthquake or the 1700 Cascadia earthquake. All these earthquakes were recorded in contemporary documents and have sourced magnitude estimates which are then reported in the list. Mikenorton (talk) 21:09, 11 March 2011 (UTC)

Largest vs Strongest

Shouldn't this listing be titled the "Strongest measured Earthquakes"? Earthquake energy is measured in magnitude and strong or weak would be the right descriptor. Its not a tree so its not a question of height, and its not a Mountain (volume) or landmass (area).

A recent edit made this change but I have reverted it because 'largest' is the more commonly used term as in Largest Earthquakes in the World Since 1900, this is also backed up by an analysis of hits on GoogleScholar and GoogleBooks. Mikenorton (talk) 11:04, 13 May 2011 (UTC)

Largest earthquake list ranking

Someone seems to have edited the ranking on the list. Instead of earthquakes with equal magnitudes tying for the same rank, the list now goes from 1 to 24, with quakes of equal magnitude having been ranked possibly arbitrarily. Is there a reason for this particular ranking, or is there a Wikipedia policy that says that items with tied rankings aren't allowed? Please enlighten me. Sang'gre Habagat (talk) 21:30, 11 March 2011 (UTC)

Yeah, that looks stupid.

But, another thing, how should the earthquakes which have 8.7–9.2 (#9), 8.7-9.0 (#12), 8.5–9.0 (#16). They are now listed with the lower bound of estimation. Should/could they be listed with the upper limit? 85.217.34.63 (talk) 18:13, 12 March 2011 (UTC)

I reordered the list without noticing this talk page entry; sorry if this has been a point of contention. I put my ranking criteria in a comment in the page source: first by magnitude, second by upper magnitude if it's listed, then finally by date. Also added back in ties, the list doesn't make sense without them. I agree quakes with a range are a bit of an issue, but I think ranking them primarily by their lower magnitude is more appropriate; though they ARE listed like described above (e.g., an 9.0–9.5 would come before a 9.0–9.3, which would come before any 9.0s without a range, but their rank # would still be listed as a tie.) –flodded ☃ (gripe) 06:45, 13 March 2011 (UTC)

I think there are two options here:

Create a shorter list to cover recorded earthquakes and a second to list estimated earthquakes.
Keep the combined list, but rank them as they are ranked by a reliable source (like the USGS).

Either way, if there is a tie of N entries, the next rank is increased by N. If there are 3 ties for #6, the next entry is #9. -- ☑ SamuelWantman 07:02, 13 March 2011 (UTC)

First off, the list looks a lot better now, thanks to flodded for that. As to the two options listed above

Magnitudes for instrumentally recorded earthquakes may still vary depending on source. If you look at the moment magnitude scale and seismic moment articles you will see that the estimated magnitude (and they are all estimates) is based on knowledge of the size of the rupture area and the displacement. Initial estimates may then be changed as more data becomes available e.g. when the aftershocks have defined the full extent of the rupture area. It's wrong to give the impression that magnitude estimates area necessarily more unreliable for historical earthquake before seismographs became commonly used, estimates for the 2004 Indian Ocean earthquake range between 9.1 and 9.3.
If you keep the combined list (which I prefer) then you are stuck with how to rank them — the USGS does not include all the events listed here, such as the 1833 Sumatra earthquake. I think that flodded's approach is the best that we're going to get. Mikenorton (talk) 08:54, 13 March 2011 (UTC)

I'd go with the 2nd/current format as well, keep the combined list. It's not as useful a list if it's split up, even if it's technically more accurate. –flodded ☃ (gripe) 11:59, 13 March 2011 (UTC)

I made a change which got reverted pending this discussion's resolution, which I still think is a good one: sort by lower magnitude (insurance against overenthusiastic ratings), but I broke ties using the upper estimate. This reduced the number of 3+-way ties and generally made the list more readable. I also like flodded's ordering criteria. 71.41.210.146 (talk) 13:35, 13 March 2011 (UTC)

My rationale behind calling those ones ties is that they're older quakes with estimated ratings, thus I though I'd err on the side of caution and pay more attention to the lower bound. Perhaps we should look for information on whether these estimated quakes tend to fall more along the average of their range? If that was the case, then I'd see a clear case for moving them up. I do agree that the list would like nicer that way (I don't like that we have those huge clumps like at 16th place and nothing but ties after the top 3.) However, accuracy is more important than appearance. Opinions? –flodded ☃ (gripe) 16:11, 13 March 2011 (UTC)

I'm glad the ranking is gone, but there seems to be no consistency in how the list is ordered. For example, the 2011 Sendai earthquake is listed above the 1952 Kamchatka earthquake, despite the fact that both were magnitude 9; on the other hand, the 1906 Ecuador-Colombia earthquake is listed above the 2010 Chile earthquake, and both of these are 8.8.

When we have two earthquakes of equal magnitude, do we list the most recent one above the earlier one? Or the other way around? Thoughts? -- 78.129.222.39 (talk) 06:06, 16 March 2011 (UTC)

Removed pie chart

I've removed this pie chart from the article because it does not seem to make sense. I.e. It fails to take into account logarithmic nature of the values: an 8 should be ~~10×~~ ~32 times the size of a 7. Also it's a poor way of displaying this kind of information. —Pengo 05:10, 14 March 2011 (UTC)

Actually, it does take the logarithmic nature into account. For example, the slice for the 2004 Sumatra earthquake (M9.3) appears to be about half the size of the 1960 Chile earthquake (M9.5), consistent with a full unit of magnitude difference being 32x more powerful and, therefore, 0.2 of a unit being twice as powerful. Perhaps you're confused because the brown, orange, yellow and green slices represent the total of all earthquakes of a given range of magnitude, not a single earthquake (compare the tiny slice for the 1906 San Francisco quake). The pie chart conveys useful information — for example that the three most powerful earthquakes in the period 1906-2005 were responsible for very nearly half of the total energy release in that century. I'm not sure the pie chart really belongs in this article but I think it ought to be included somewhere. Dricherby (talk) 17:54, 14 March 2011 (UTC)

I see. Some of the values are totals, while others are single earthquakes. Well the description is poor, and the data used is not given (the total number of quakes would be a start). I also don't really see the value in comparing the total energy released by a large number of recorded earthquakes over a long period of time with another energy total over of a large number of recorded earthquakes over the same lengthy time. What is this chart meant to be illustrating exactly? What meaning is there in displaying earthquake energies in this way? It also seems it has selection bias as well, as minor offshore quakes would go unreported, while large ones would be, making the type of comparison it makes fairly meaningless. Surely a logarithmic bar graph would make more sense for comparing scale of quakes, and a separate chart could be used to compare the total count of different sized quakes reported? I might have a go at making a new chart (or charts) if no one else does. —Pengo 22:55, 17 March 2011 (UTC)

The purpose of this chart is to show the relative contributions of a few very powerful earthquakes to the seismic moment release compared to all earthquakes of other magnitudes recorded during the same time period. I really don't see the problem with the chart, although the caption could certainly be clearer. Mikenorton (talk) 23:20, 17 March 2011 (UTC)

The main problem is that it's a pie chart. —Pengo 05:08, 19 March 2011 (UTC)

I don't understand why, pie charts are used to compare relative proportions - which is the case here. Mikenorton (talk) 10:26, 19 March 2011 (UTC)

I've expanded the caption above in an attempt to be clearer about what the pie chart shows. Mikenorton (talk) 11:55, 19 March 2011 (UTC)

Does anyone object to the pie chart with the revised caption being added back into the article? Mikenorton (talk) 13:51, 24 March 2011 (UTC)

There being no response, I'm adding it back. Mikenorton (talk) 11:08, 13 May 2011 (UTC)

Tangshan?

The USGS says that the Tangshan earthquake of 1976 was likely the deadliest in 400 years, second only to the 1556 quake in all of recorded history, and yet it's not even listed here. The official death toll was 255,000, and the USGS estimates the actual toll was 655,000. Even the official toll is high enough to warrant inclusion on the deadliest quake list. What gives? Phiwum (talk) 02:16, 15 March 2011 (UTC)

Just old-fashioned vandalism of the template - fixed, thanks for pointing it out. Mikenorton (talk) 08:07, 15 March 2011 (UTC)

Duplication

The 1755 Lisbon, Portugal quake is listed twice with two different magnitude estimates. It's referring to the same quake, so which one is correct? CFLeon (talk) 01:39, 28 August 2011 (UTC)

Updating "Deadliest earthquakes on record" section

In addition to changing some numbers and therefore the order of the earthquakes, shouldn't the publisher be the USGS instead of "Earthquake.usgs.gov"? If no one objects, I will change the publisher named in that section. Mauri96 (talk) 22:11, 7 February 2012 (UTC)

Sorry not respond earlier - I've filled in that ref a bit. What were the changes to be made to numbers and order? Mikenorton (talk) 22:43, 11 March 2012 (UTC)

Earthquakes by magnitude

I've reverted the recent addition of three earthquakes with magnitudes higher than the 1960 Valdivia quake, because the NOAA list only one greater than 9.4 [7]- the 1960 Valdivia earthquake. Mikenorton (talk) 13:06, 20 March 2012 (UTC)

I see that the NOAA mention a value of 9.7 from one source for the 1827 Bogota earthquake, although they use 7.0 themselves and other sources give values under 8. For the 1868 Arica earthquake, there are estimates up to 9.0 and the 1812 Caracas earthquake, there is one estimate of 9.6, with all other being less than 8. I note that the very high numbers come from the same source - Ocola 1984. These numbers do not appear to have been picked up by any other seismologists as representative. Mikenorton (talk) 22:31, 20 March 2012 (UTC)

April 11 2012 Earthquake

There is a duplicate entry for the April 11 2012 Sumatra Earthquake. The Sumatra name seems more widely used, but the Ace name already has an article. TSawala (talk) 09:40, 11 April 2012 (UTC)

I've removed the duplicate, thanks for pointing it out. Mikenorton (talk) 12:12, 11 April 2012 (UTC)

2012 Indian Ocean Earthquake

For some reason everyone says this is a 8.6 earthquake when it is really an 8.7 earthquake. Don't know why........ JoJaEpp (talk) 04:09, 12 April 2012 (UTC)

As far as I know, we're using 8.6 because that is the magnitude given by the USGS. If there are other equally good sources (seismological observatories rather than newspaper stories) we can include them if we have a source. Mikenorton (talk) 12:38, 12 April 2012 (UTC)

List of Earthquakes by Magnitude

It seems like it would be helpful to have a separate unified "List of earthquakes by magnitude" article that would be long and have something like 7.5 as the minimum requirement. Sfoske70 (talk) 18:18, 18 January 2013 (UTC)

With a minimum of 7.5 it would be very long (the NOAA database gives 928 earthquakes of that magnitude range). I would suggest a minimum of 8.0, although that would still be over 200 potentially. Mikenorton (talk) 18:33, 18 January 2013 (UTC)

Magnitude of 1960 Chile Earthquake

USGS says it is 9.6? Pubserv (talk) 20:04, 10 July 2013 (UTC)

They give it as 9.5 [8]. Mikenorton (talk) 20:52, 10 July 2013 (UTC)

http://comcat.cr.usgs.gov/earthquakes/eventpage/centennial19600522191117#summary Pubserv (talk) 08:36, 11 July 2013 (UTC)

OK, thanks for the link. It appears that there are range of estimates from about 9.4 to 9.6, depending on the method used to derive the magnitude. The 9.6 was first reported by Pacheco & Sykes, based on the seismic moment estimated by Cifuentes & Silver 1989. This was then used in the Centennial catalogue of Engdahl & Villasenor in 2002. Bufe & Perkins (2005), describe these different estimates, choosing to use the 9.5 value originally estimated by Kanamori (1977) for their own purposes. Satake and Atwater (2007) report the 9.4-9.6 range that I mentioned above, but quote 9.5 as being the " widely accepted number". So I don't think that there's anything wrong with using the 9.5 value here, but we should probably have the full range in the earthquake article itself. Mikenorton (talk) 20:53, 11 July 2013 (UTC)

Jordan

Why isn't there a list for Jordan's eartquakes? — Preceding unsigned comment added by 211.225.34.163 (talk) 06:15, 10 January 2015 (UTC)

Because Jordan is a country with few significant earthquakes the NGDC list just five in the last 4,000 years. Mikenorton (talk) 08:31, 10 January 2015 (UTC)

We lack list articles for earthquakes in all of the countries of the Middle East, but that's because no-one has created them yet. Mikenorton (talk) 08:40, 10 January 2015 (UTC)

USGS update

USGS recently updated their website to a new design, and they also updated all the earthquakes.

The earthquake updates include:

The 1960 Concepcion foreshocks were updated to 8.1, 7.1 and 8.6: http://earthquake.usgs.gov/earthquakes/eventpage/iscgem879106#general_summary http://earthquake.usgs.gov/earthquakes/eventpage/iscgem879127#general_summary http://earthquake.usgs.gov/earthquakes/eventpage/iscgem879134#general_summary — Preceding unsigned comment added by 194.169.217.224 (talk) 03:37, 27 January 2015 (UTC)

After looking at a few of these, I noticed that the USGS is now using magnitudes, locations etc. from the ISC-GEM catalogue, replacing their own estimates, except for the 2004 Indian Ocean event, where the details still come from the USGS catalogue, although the ISC-GEM also has it as a 9.0. I think that the magnitudes used in this list article should be the same as those in the individual earthquake articles, so that's where the updating should take place. ISC-GEM is the latest recalculations for all these events, so that probably gives them precedence over other sources. That's a lot of earthquake articles to check out, but something that I had in mind to do. That the USGS is using the ISC-GEM results routinely for historical events will probably make it easier to convince others that this is the way forward. Thanks for mentioning it. Mikenorton (talk) 20:16, 27 January 2015 (UTC)

And now, the USGS has three entries for the 2004 Indian Ocean earthquake from multiple sources:
http://earthquake.usgs.gov/earthquakes/eventpage/duputel122604a#general_summary 9.2 mww
http://earthquake.usgs.gov/earthquakes/eventpage/usp000dbed#general_summary 9.0 mw/mwc
http://earthquake.usgs.gov/earthquakes/eventpage/atlas20041226005853#general_summary 9.0 m?

These are for the 2005 Sumatran earthquake:
http://earthquake.usgs.gov/earthquakes/eventpage/usp000dk85#general_summary 8.6 mw/mwc
http://earthquake.usgs.gov/earthquakes/eventpage/duputel200503281609a#general_summary 8.5 mww

And the 2010 Chile earthquake also got two entries, both M8.8
http://earthquake.usgs.gov/earthquakes/eventpage/gcmt20100227063415#general_summary
http://earthquake.usgs.gov/earthquakes/eventpage/usp000h7rf#general_summary

The 1952 Kamchatka earthquake is not listed anymore.

Which of these could be the most trusted source? 194.169.217.124 (talk) 09:45, 7 February 2015 (UTC)

They're all reliable sources, but that's the problem with magnitudes, depths and locations for earthquakes, there's rarely just one estimate of all these parameters. As to the 1952 Kamchatka earthquake, it's still listed, but the page doesn't display for some reason [9]. For the 2004 Indian Ocean event, the USGS are reporting three separate estimates, based on information from seismologist Zacharie Duputel, Harvard and ATLAS (possibly Cornell?). The other two earthquakes have one estimate from the USGS and another from another catalogue, Duputel for the Sumatra event and GCMT (global centroid moment tensor catalogue) for the Chile event. So these are not necessarily USGS estimates, but also them reporting other's estimates. None of this helps us to come up with a single number for the purposes of either our individual earthquake articles, or this list article - the best we can do is to report the ranges for which we have sources. Mikenorton (talk) 12:13, 7 February 2015 (UTC)

Nepal

Someone has changed Nepal's largest earthquake to the recent one, but I'm not sure this is quite right. The 1934 Nepal–Bihar earthquake has Mw=8.0 while the 2015 Nepal earthquake is currently listed at Mw=7.8. However, there's an estimate of Ms=8.2 for 2015, and Ms=8.1 for 1934. So after the USGS (or other agencies) have stabilized their estimates, someone should evaluate if the recent earthquake is larger than the 1934 one. Or perhaps we should consider making it possible to have more than one "largest" per country when there are two earthquakes that are pretty close in size. Argyriou (talk) 15:55, 30 April 2015 (UTC)

Thanks for pointing that out, all the estimates for the 1934 earthquake are larger - the most up to date recalculation in the ISC-GEM catalogue is Mw=8.0, so I've changed it back. The list of largest by country is getting bigger as more countries are included, giving two would in my view make it completely unwieldy. Mikenorton (talk) 21:15, 30 April 2015 (UTC)

I agree with Mikenorton on this one. If the recent event is consistently upgraded in the future, the entry can be changed. Until then, we should stick with the 1934 earthquake, since most sources seem to agree it had a slightly higher magnitude. Elriana (talk) 20:45, 19 May 2015 (UTC)

On another note, why has the 2015 Nepal event been added as an 11th entry on the list of property damage by earthquake? The damage ($5 billion) is ~half that estimated for the entry above it. I find it hard to believe there are no other earthquakes with estimated damages between these two numbers. Is this list meant to be a top 10 list? If the recent Nepal event is included, it is only fair to include others, such as the 2004 Chūetsu earthquake (damage estimates range up to $32 billion), the 2001 Gujarat earthquake (>$5.5 billion), the 1990 Luzon Earthquake (~$7 billion), etc.. Elriana (talk) 20:45, 19 May 2015 (UTC)

Elriana - if you have a good source for the damage for Chūetsu, please add it into the list in the appropriate place. I'm not certain we want to expand the property damage list beyond 10 (or 11), but if we do, we should definitely include those. Argyriou (talk) 21:51, 19 May 2015 (UTC)

A number of landslides were triggered by the 2004 Chuetsu earthquake and its aftershocks. Sorting out which damage estimates include landslide damage and which slides were triggered by the main quake is a non-trivial undertaking (especially since I do not read Japanese). Should the damage from landslides be included in the total used in this list? We seem to have been inconsistent with how damage caused by tsunamis is handled as well. The property damage for 2011 Tohoku includes the tsunami, but the 2004 Indian Ocean earthquake and tsunami is not mentioned at all. I know that the estimates for the Indian Ocean event(s) are more difficult to handle because of how widespread the effects were. But not listing it at all seems inconsistent.Elriana (talk) 19:33, 20 May 2015 (UTC)

FYI: Some sources now list the damages from the recent Nepal earthquake at ~$10 billion. I'm not changing the entry yet because the accepted value is likely to take some time to stabilize.Elriana (talk) 20:42, 20 May 2015 (UTC)

The Philippines and which scale to use for 'strongest' earthquake

The Philippines entry has changed a couple of times since I started following this list. But each new entry is no more justifiable than the last, not because they are wrong, but because they are all right in some way. The variety of magnitude scales used in evaluating historic earthquakes (and, to a lesser extent, the disagreement of different catalogs) makes comparisons between similarly sized events problematic no matter the country.

For example, the current entry (1948 Lady Caycay earthquake) is listed as 8.2 Ms, which is supportable. But the NGDC lists this event as the 5th largest Philippines earthquake, and the USGS has it as the 5th largest since 1900 (and listed at only 7.8, presumably Mw). Both sources list the 1918 and 1924 Mindanao events as larger, but the strongest two events differ between the catalogs (NGDC lists two 1897 events, while USGS excludes pre-1900 and lists 1972 and 1976 Mindanao).

Event	NGDC Rank	USGS Rank	M_s	M_w
1948 Lady Caycay earthquake	5	5 (tied with 3 others)	8.2	7.8
1976 Moro Gulf earthquake	10	4	7.9	7.9-8.0
1918 Celebes Sea (Mindanao:Cotabato)	3	1	8.3	8.3?
1924 Davao Gulf (Mindanao)	4	2 (tied)	8.3	8.0
1972 Mindanao (Davao)	42	2 (tied)	7.4	8.0
1897 Mindanao	1	-	8.7	-
1897 NW Mindanao (Dapitan)	2	-	8.6	-

Most of these do not have event pages, nor are they in the List of earthquakes in the Philippines, which should also be dealt with at some point. But for the purposes of this page, how should we handle such ambiguity? Are we listing only the strongest event with a wiki page? or should we stick to the M_w scale, ignoring events for which no M_w estimate exists? Or is there some clever way we could annotate our list to account for discrepancies between scales? Or would it be reasonable to put in multiple entries, presuming we can strictly define when such listings are appropriate?Elriana (talk) 15:42, 8 June 2015 (UTC)

To answer the last question, if there's a possibility that there are two different earthquakes which could be the "largest", I think it would be fair to put in both earthquakes, with a note explaining the issue. In the particular case, the Lady Caycay earthquake should not be the listed one, because even using M_s, it's not the largest. But since it's likely but not certain that one of the Mindanao earthquakes of 1897 was larger, we should list the 1918 earthquake and the larger of the 1897 ones, until someone finds an M_w estimate for the 1897 quakes. Definitely, we should not limit the entries to those earthquakes which have no separate article. Argyriou (talk) 17:37, 8 June 2015 (UTC)

For earthquakes after 1900 we have the ICS-GEM catalogue, which gives recalculated Mw values. In this case we have (with uncertainties):

1948 Lady Caycay 7.8 0.2
1924 Davao Gulf 8.01 0.34
1918 Mindano 8.3 0.4
1972 Davao 7.45 0.47
1976 Moro Gulf 7.96 0.1

For the Ms 8.7 1897 event on 21/9 Abe (1994), quoted in Hough 2013 [10], recalculated the event as 7.5 Ms. Overall I would go with the 1918 earthquake. Mikenorton (talk) 21:10, 8 June 2015 (UTC)

Thanks, Mikenorton, for the additional information. I agree that the 1918 event is the one list, particularly since the editors of this article/list use the Mw scale whenever possible (as we should). What little I can find on the 1897 events also seems to indicate lower Mw (7-8), despite higher surface wave magnitudes (Ms). Elriana (talk) 13:26, 26 June 2015 (UTC)

Have you found anything better than Abe (1994)? I'm somewhat suspicious of that conversion because a) that's a big change in estimate b) Hough's paper is mostly about how a similar earlier Mw estimate is wrong, and c) Abe's estimate seems to be based primarily on instrumental data from 1897. So long as that's the only source for an Mw estimate, I don't think we should change it, but it seems not a very good estimate to me. Argyriou (talk) 20:20, 26 June 2015 (UTC)

I'm still looking, but this abstract of a paper by Abe & Noguchi provides some explanation of why the magnitudes estimates were reduced. Mikenorton (talk) 10:48, 27 June 2015 (UTC)

Ye et al 2012 use Abe's redeterminations of the 1897 events - see Figure 1. My feeling is that, if Hiroo Kanamori is happy with them, we should probably be so too. Mikenorton (talk) 11:16, 27 June 2015 (UTC)

Finally, quoting Bautista & Bautista (from the Philippines Institute of Volcanology and Seismology) in 2004 "The various works of Abe (1981, 1984, 1994) and Abe and Noguchi (1983) especially their redetermination of the magnitudes by Gutenberg and Richter covering the early 20th century period helped to improve the earthquake data in the Philippines including those during the 1892 to 1900 period." Mikenorton (talk) 11:34, 27 June 2015 (UTC)

I've started 1897 Mindanao earthquakes. I've mentioned the change in estimated magnitudes using the Ye et al 2012 source. As I expand the article, I'll discuss the reasoning for the redetermination, as set out in the various Abe papers. BTW, I noticed that I stated several posts up in this thread that the Abe redetermination for the 21/9 event gave 7.5 Mw - that was wrong, it's 7.5 Ms - I misunderstood the Hough paper, but Ye et al make it clear. Mikenorton (talk) 15:21, 27 June 2015 (UTC)

I've also started 1918 Celebes Sea earthquake, so that anyone can check the sources of the magnitudes for the two earthquakes. Mikenorton (talk) 17:28, 27 June 2015 (UTC)