Japan Meteorological Agency seismic intensity scale

Japan Meteorological Agency seismic intensity scale

The Japan Meteorological Agency seismic intensity scale is a measure used in Japan and Taiwan to indicate the strength of earthquakes. It is measured in units of . Unlike the Richter magnitude scale (which measures the total magnitude of the earthquake, and represents the size of the earthquake with a single number) the JMA scale describes the degree of shaking at a point on the Earth's surface. As a result, the measure of the earthquake varies from place to place, and a given quake may be described as "shindo 4 in Tokyo, shindo 3 in Yokohama, shindo 2 in Shizuoka".

The JMA operates a network of 180 seismographs and 600 seismic intensity meters [ [http://www.seisvol.kishou.go.jp/eq/intens_st/index.html 気象庁 | 震度観測点(全国) ] ] and provides real-time earthquake reports to the media and on the internet. [ [http://www.jma.go.jp/en/quake/ Japan Meteorological Agency | Earthquake Information ] ]

History

Japan experiences approximately 400 [http://www.hinet.bosai.go.jp/about_earthquake/part1.htm Japanese web site; official data of Shindo 1-7 in 1997 to 2006 is 32,244 times, and Shindo 1-3 is 4 to 5 times in a day. Web site of 防災科学技術研究所;National Research Institute for Earth Science and Disaster Prevention=NIED/ Although none of web site is available for basis of 400 times in a day, but 400 times is well told and well assumable number with this data. ] earthquakes every day, although the vast majority are "shindo scale" "0" or less and detectable only using specialist apparatus.

The Japan Meteorological Agency (JMA) first assigned a four stage "Shindo" in 1884, with the levels: 微 (faint), 弱 (weak), 強 (strong), and 烈 (violent).

In 1898 this scale was changed to a numerical system, assigning earthquakes levels 0-7.

In 1908, the levels on this scale were given descriptions, and earthquakes were assigned levels based on their perceived effect on people. This scale was widely used during the Meiji period, and revised during the Shōwa period with the descriptions seeing an overhaul.

Following the Great Hanshin earthquake in 1995, "Shindo" was further expanded to a total of 10 levels of earthquake: 0-4, lower/upper 5 (5弱、5強), lower/upper 6 (6弱、6強) and 7.

The "Shindo" scale has been used in Japan from 1996 without change. [ [http://www.e-pisco.jp/equake/shindo/old/oldshindo2.html 気象庁震度階級(明治17年~昭和23年)] in Japanese] [ [http://wwweprc.eri.u-tokyo.ac.jp/CSS/shindo.html 震度] in Japanese]

JMA scale explanation

The JMA Scale runs from 0 to 7, with 7 being the strongest. The Mercalli intensity scale is sometimes used together with the "Shindo"; however this is not usual practice in Japan. Real-time earthquake reports are calculated automatically from measurements of ground acceleration. The JMA reports the earthquake level based on the ground acceleration, measured automatically with seismic intensity meters. There is no simple and linear relationship between Shindo Number and peak ground acceleration, [ [http://www.jma.go.jp/jma/kishou/know/shindo/keisoku.html Calculation method of seismic intensity (Japanese)] ] , [ [http://www.seisvol.kishou.go.jp/eq/kyoshin/kaisetsu/comp.htm Seismic intensity and acceleration (Japanese)] ] so the values of the table below should only be regarded as an approximate orientation.

See also

* Seismic scale
* List of earthquakes

References

External links

* [http://weathernews.jp/quake/ Up dating information of earth earthquakes in Japan in last 7 days] , Japanese language. Circled number is "Shindo"(震度) Number. Format is Hypocenter of earthquakes, location, north latitude, east longitude and depth.
* [http://www.jma.go.jp/jma/kishou/know/shindo/shindokai.html JMA Seismic Intensity Scale] in both Japanese and English language.


Wikimedia Foundation. 2010.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • Mercalli intensity scale — Part of a series on earthquakes Types Foreshock • Aftershock • Blind thrust Doublet • Interplate • …   Wikipedia

  • Intensity (disambiguation) — Intensity is a widely used term, which can refer to:In colloquial use: *Strength *Amplitude *Level *MagnitudeIn physics: *Intensity (physics), power per unit area (W/m2) *Field strength of electric, magnetic, or electromagnetic fields (V/m, T,… …   Wikipedia

  • Richter magnitude scale — Part of a series on earthquakes Types Foreshock • Aftershock • Blind thrust Doublet • Interplate • …   Wikipedia

  • 2011 Tōhoku earthquake and tsunami — 2011 Miyagi earthquake redirects here. For the aftershock that occurred on 7 April, see April 2011 Miyagi earthquake. 2011 Tōhoku earthquake and tsunami 東日本大震災 An aerial view of damage in the Tōhoku region with black smoke coming from the Nippon… …   Wikipedia

  • Peak ground acceleration — (PGA) is a measure of earthquake acceleration on the ground and an important input parameter for earthquake engineering, also known as the design basis earthquake ground motion (DBEGM)[1] Unlike the Richter and moment magnitude scales, it is not… …   Wikipedia

  • Portal:Earthquakes — Wikipedia portals: Culture Geography Health History Mathematics Natural sciences People Philosophy Religion Society Technology …   Wikipedia

  • 1948 Fukui earthquake — Earthquake title=1948 Fukui earthquake date= June 28 1948 magnitude = 7.1 Mw depth= 0 km location=coord|36.10|N|136.17|E countries affected = flag|Japan tsunami = No casualties = 3,769 dead, 22,203 injuredThe nihongo|1948 Fukui… …   Wikipedia

  • Munakata, Fukuoka — Munakata 宗像市   City   …   Wikipedia

  • Shindo — refers to:* The Japanese family name Shindō (進藤). This can refer to the following people: ** Kaneto Shindō, Japanese film director xx ** Kokoro Shindō ** Naomi Shindō, Japanese voice actress * And the following fictional characters: ** Hikaru… …   Wikipedia

  • Earth Sciences — ▪ 2009 Introduction Geology and Geochemistry       The theme of the 33rd International Geological Congress, which was held in Norway in August 2008, was “Earth System Science: Foundation for Sustainable Development.” It was attended by nearly… …   Universalium

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”