Talk:Japan Meteorological Agency seismic intensity scale

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my source for the ground accelleration [1] doesnt separate the 5 and 6 upper and lower levels, so I have estimated with a geometric mean Zeimusu

Why does japan have their own scale? How come they developed it from the beginning? Moberg (talk) 21:08, 27 May 2008 (UTC)[reply]

JSA <--> Seismic scale Conversion[edit]

It is possible someone can update that chart to include the Equivalent Seismic scale numbers? I'd do it but I can not find the information. Mkrupnic (talk) 15:59, 23 July 2008 (UTC)[reply]

It seems to me that the JMA scale is one for measuring the damage, not necessarily the actual power of an earthquake, unlike the seismic scales. I believe that a good analogue would be the Fujita scale used to rank tornados in comparison to the actual ind-speed inside the tornado itself. There is a distinct difference between a JMA 7 that has a richter scale of 8 and a JMA 7 that has a richter scale of 9. Anyone? Jtodsen (talk) 16:26, 11 March 2011 (UTC)[reply]
If you go to the JMA Website, and look at daily records of earthquakes, you will see that while it is likely that a stronger earthquake, will have more intense results over a wider area, there is no direct correlation between the two types of scale. One deals with the actual intensity of the earthquake, the other deals with its consequences in areas where it has been felt. To bring the problem home further, there are (as here) situations where the intensity of shaking is stronger at some stations further away from the epicentre of the earthquake. In this case, when you zoom in, while close to the epicentre, you are finding stations recording 2s and 3s, further away there are three stations recording 4s. There are too many factors involved to make any direct correlation easy. You see something similar, here. Kuitan (talk) 18:32, 5 February 2016 (UTC)[reply]

　Official term?[edit]

Is "Shindo" the ACTUAL, OFFICIAL name used for the scale in English?　Because in Japanese it's used as a generic term for magnitude or intensity, in fact the JMA　page linked to as a source seems to translate 震度 directly into "intensity". And if you look at the Japanese wiki page for 震度, it contains the JMA　scale, the Mercalli scale, MSK scale, EMS scale, Rossi-Forel scale, all of them using 震度. All signs seem to point to "intensity" as a measure in the JMA scale, with no special "shindo" term necessary in English. Identity0 (talk) 03:47, 15 August 2008 (UTC) Italic text — Preceding unsigned comment added by 182.179.64.8 (talk) 04:40, 25 September 2012 (UTC)[reply]

On their English language site, the Japanese Meteorological Association when measuring seismic intensity talk of JMA Seismic Intensity. They have produced a PDF download in English that is available on their website [2] . Kuitan (talk) 18:38, 5 February 2016 (UTC)[reply]
震度 shindo as, used by the JMA to qualify the local shaking of earthquakes (it has other technical meanings, too), means (seismic) intensity; so No, it is not the (or even an) official English term. As Kuitan says, in its own English documents, the JMA uses “JMA Seismic Intensity” and “seismic intensity” interchangably; so I see no reason to overburden English readers with the Japanese term. Mentioning it once should be enough to satisfy readers who want to know what it’s called in Japanese. Jim_Lockhart (talk) 11:03, 22 January 2019 (UTC)[reply]

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Proper noun[edit]

I have capitalized Japan Meteorological Agency (JMA) Seismic Intensity Scale as the full, in the first paragraph because it is a proper noun. Jim_Lockhart (talk) 14:39, 18 January 2019 (UTC)[reply]

No comment on the proper noun, but I do have a question for you. What did my edit summary say? Dawnseeker2000 15:03, 18 January 2019 (UTC)[reply]
OK, gotcha. I hadn’t realized the significance of the WP:BOLDAVOID reference. Mea culpa, so I will go back and fix that. Thanks! Jim_Lockhart (talk) 07:33, 19 January 2019 (UTC)[reply]

Evidence that this is a proper noun: http://www.jma.go.jp/jma/en/Activities/inttable.html Jim_Lockhart (talk) 08:32, 19 January 2019 (UTC)[reply]

Heavy copyedit, but article's wikitable based on poor translation[edit]

I have done a fairly heavy copyedit of the whole article, especially with regard to potentially confusing wording (e.g., earthquakes are not assigned an intensity; each gets assigned several).

However, I more or less gave up on the table—especially after discovering that the JMA provides a viable English version of it at http://www.jma.go.jp/jma/en/Activities/inttable.html. I think the wikitable should be removed in favor of a direct link to the JMA's page, but I'm not sure whether that would be a breach of Wikipedia procedure or etiquette; please advise.

Also, I think the article's title should be revised to Japan Meteorological Agency Seismic Intensity Scale (note capitalization: if the JMA's English website is anything to go by, this is the scale’s official name, making it a proper noun); but I don’t know how to make this change myself. Please advise. Jim_Lockhart (talk) 07:37, 20 January 2019 (UTC)[reply]

Rationale for edits (reversion) of 21 January 2019[edit]

  • The name Japan Meteorological Agency Seismic Intensity Scale (shortform: JMA Seismic Intensity Scale) is obviously a proper noun and should be capitalized like one; cf: http://www.jma.go.jp/jma/en/Activities/earthquake.html and http://www.jma.go.jp/jma/en/Activities/inttable.html
  • An earthquake does not "have an" intensity, each quake has several of them, as my rewording of the prose makes clear.
  • 震度 (shindo), the Japanese term, is a term of art; it maps to "seismic intensity" (not "shake intensity") in English.
  • Other changes I’ve made in the past few days are explained in my previous postings to this page, above.
  • I think the rationale for the rest of my edits ought to be self-evident. Most are for clarity and readability. If they are substantively mistaken, I will be glad to see the mistakes clarified and corrected.

Thanks, Jim_Lockhart (talk) 08:45, 21 January 2019 (UTC)[reply]

Saying that an earthquake has "several" levels of shaking is incorrect, as that implies discrete and distinct levels of shaking, whereas the shaking actually varies over a range. Discreteness comes from the scale, which (like all seismic intensity scales) is arranged into categories. The intensity of shaking by which an earthquake is characterized is that of its epicentral intensity, or I0. Note that this is not, as the text states, a quantification of "how much ground-surface shaking takes place at measurement sites distributed throughout an affected area." (Emphasis in the original.) I0 is the maximum intensity of shaking, and applies at (generally) only the epicenter. It is to be expected that a maximal intensity of shaking implies all lesser intensities.
The areal extent of shaking, seen as either the total "felt area" of the quake, or as isoseismal maps of the extent of various levels of shaking, depend on observations across, and even beyond, the affected area. But the Shindo scale/number does NOT quantify any of that. It is simply a categorization of shaking intensity at a specific location.
As to "measurement sites": JMA does have sites equipped with strong-motion accelerometers, which can measure the velocity and/or acceleration of ground shaking. (And indeed, I see you have just added content about that.) However, the Shindo scale is not based on those. Like all intensity scales, the Shindo is based on perciptible or observed effects, not any kind of instrumentally measured phenomenon. The measurements JMA takes with the instruments are expressed in terms of Shindo, just like the USGS "Did You Feel It?" results are expressed in equivalent Modified Mercalli scale categories. But the concept and formulation of the Shindo scale is non-instrumental.
I don't know on what basis you "map" shindo to seismic intensity. For sure, as "seismic" it is distinguished from other intensity scales, such as for wind speeds, hurricanes, tornadoes, etc. But I yet have to see any cases where that was not clear from the context. The more common problem (ask any seismologist that has worked with the public) is the frequent confusion between intensity of seismic shaking versus intensity of seismic rupture. Qualifying "intensity" with "seismic" clarifies nothing, adds no information. "Intensity" needs to be qualified with "shaking", as that is how seismologists restrict the term, a usage not generally well known.
Enough for today. ♦ J. Johnson (JJ) (talk) 23:44, 22 January 2019 (UTC)[reply]
Well, a little more. First: There is material about the Shindo scale in the scientific literature. Look for Bormann and Saul 2009, Musson 2012 (Ch. 12, "Intensity and Intensity scales" in NMSOP-2), Katasumta 1996, and Doi 2012; full citations at Seismic magnitude scales#Sources.
Second: the bit in the article that "Japan experiences some 400[5] earthquakes daily" (besides being unverifiable) is bullshit, lacking some stated criterion of how far down the scale one goes. That needs qualification, and with a more accessible source. ♦ J. Johnson (JJ) (talk) 00:11, 23 January 2019 (UTC)[reply]
Sorry, but I've read the material on the JMA's website, and several of your comments above are wrong, including the one to the effect the JMA seismic intensities are not based on instrument reading: they are, with each category mapped to specific ranges of acceleration. I map shindo to seimic intensity on the basis of two things: my 35 years as a Japanese-to-English translator (including material on seismic issues for the AE&C industry), and the JMA's own characterization of the terms; “map” is a lingustic term of art, fwiw. But I'm not going to fight with you. I wanted first to improve the article well enough so that it was at least readable, then move on to correcting the numerous mistakes it’s riddled with. I'm not going to bother looking at what changes you made, since I imagive you've merely just reverted everything again rather than made any constructive changes.
I can see that my input is not welcome here and that trying to improve this article will be futile, so I’m out of here. Jim_Lockhart (talk) 12:10, 23 January 2019 (UTC)[reply]
And I have read the technical descriptions (in English) of the JMA system. Please note that I did not say that "JMA seismic intensities are not based on instrument reading". What I said is that "the Shindo scale is not based on those." What you seem to have missed is the distinction between "JMA seismic intensities" and "Shindo scale". Which I explained, but apparently you didn't bother to read, so I wonder why I should invest any more time in you.
You are also incorrect in what you imagine, but we can continue that discussion on my Talk page. ♦ J. Johnson (JJ) (talk) 21:52, 23 January 2019 (UTC)[reply]

Edit of 22 January[edit]

The content and rationale for my edits tpday ought to be self-evident. For the time being, I worked from Japanese sources (including the Japanese Wikipedia article) because I haven’t been able to track down English ones.

In the course of today’s session, I noticed that a lot of the source-reference links are dead or outdated. I’ll try to rectify them over the coming weeks.

Best regards, Jim_Lockhart (talk) 11:09, 22 January 2019 (UTC)[reply]

Utilities column descriptions not properly ascending from Shind 3 to 9?[edit]

The entries in the Utilities column don't seem properly sequenced to me, but I'm no expert on this scale:
3. Unaffected
 4. Interruptions (esp. electricity)
 5. Automatic valves cut residential gas. Some water supply interruptions. Blackouts.
 6. Gas pipes and water mains are damaged. (Gas service and/or water service are interrupted in some regions.)
 7. Gas pipes and/or water mains will be damaged. Gas, water and electricity are interrupted.
 8. Occasionally, gas and water mains are damaged. (Electrical service is interrupted. Occasionally, gas and water service are interrupted over a large area.)
 9. Electrical, gas and water service are interrupted.
 For example, the "Occasionally" at beginning of Shindo 8 makes it sound less severe than 6 and 7, though the parenthetical statements at the end of 8 suggest to me that it's meant to apply to how widespread the outage is likely to be. — soupvector (talk) 12:43, 22 March 2022 (UTC)[reply]

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