List of foreshocks and aftershocks of the 2011 Tōhoku earthquake

This is a list of foreshocks and aftershocks of the 2011 Tōhoku earthquake. Japan had experienced 900 aftershocks after the M9.1 earthquake on March 11, 2011 with about 60 aftershocks being over magnitude 6.0 and three over magnitude 7.0. For conciseness, only earthquakes with magnitudes greater than 7.0 or an intensity greater than lower-6 on the shindo scale are listed here. Mw refers to the moment magnitude scale, while Mjma, Mjma, or Mj refer to the Japan Meteorological Agency seismic intensity scale.

Map of aftershocks until March 14 (first 4 days)
Visualization of intensity of aftershocks in the first few days

Foreshocks edit

Japan Time Magnitude Coordinates Depth Intensity (shindo)[1] Comment
2011-03-09 11:45 Mw 7.3, Mj 7.3[2] 38°25′26″N 142°50′10″E / 38.424°N 142.836°E / 38.424; 142.836 32 km[USGS 1] 5-

The source was estimated to have a length of 28.7 km and a width of 53.2 km with a slip of 1.25 m.[3] Caused a 55 cm tsunami.[4]

2011-03-10 06:23 Mw 6.4, Mj 6.8 38°10′16″N 143°02′35″E / 38.171°N 143.043°E / 38.171; 143.043 9 km 4 Caused 11 cm Tsunami.[5]

Main shock edit

Japan Time Magnitude Coordinates Depth Intensity (shindo)[1] Comment
2011-03-11 14:46 Mw 9.1, Mj 8.4[2] 38°19′19″N 142°22′08″E / 38.322°N 142.369°E / 38.322; 142.369 29 km[USGS 2] 7 19,759 deaths,[6] 2,553 people missing[7], tsunami, nuclear incidents.

Aftershocks edit

Japan Time Magnitude Coordinates Depth Intensity (shindo)[1] Comment
2011-03-11 15:08 Mj 7.4[1] 39°49′12″N 139°01′30″E / 39.82°N 139.025°E / 39.82; 139.025 32 km[1] 5-
2011-03-11 15:15 Mw 7.9, Mj 7.6[1] 36°16′N 141°08′E / 36.27°N 141.14°E / 36.27; 141.14 43 km[USGS 3] 6+
2011-03-11 15:25 Mw 7.7, Mj 7.5[1] 38°03′N 144°35′E / 38.05°N 144.59°E / 38.05; 144.59 19 km[USGS 4] 4
2011-04-07 23:32 Mw 7.1, Mj 7.2[1] 38°15′11″N 141°38′24″E / 38.253°N 141.640°E / 38.253; 141.640 42 km[USGS 5] 6+ 4 dead, 100+ injured, large scale power outage in Tōhoku region.[8][9]
2011-04-11 17:16 Mw 6.6, Mj 7.0[1] 37°00′25″N 140°28′37″E / 37.007°N 140.477°E / 37.007; 140.477 10 km[USGS 6] 6- 6 dead, several injured, localized power outage and landslides in Iwaki, Fukushima.[10]
2011-04-12 14:07 Mj 6.4[1] 37°03′07″N 140°38′35″E / 37.052°N 140.643°E / 37.052; 140.643 15 km[1] 6-
2011-07-10 09:57 Mw 7.0, Mj 7.3[1] 38°02′24″N 143°17′13″E / 38.040°N 143.287°E / 38.040; 143.287 23 km[USGS 7] 4 10 cm of tsunami in Sōma and Ōfunato.[11]
2012-12-07 17:18 Mw 7.3[1] 37°48′N 144°12′E / 37.8°N 144.2°E / 37.8; 144.2 49 km (JMA)[1]
36 km [USGS 8]
5- Tsunami under 1 meter. Considered an aftershock by the National Earthquake Information Center in Colorado, USA.[12]
2013-10-26 02:10 Mw 7.1 37°10′12″N 144°39′54″E / 37.170°N 144.665°E / 37.170; 144.665 10 km [USGS 9] 4 Tsunami[13]
2016-11-22 05:59 Mw 6.9 37°23′35″N 141°23′13″E / 37.393°N 141.387°E / 37.393; 141.387 9 km 5-
2021-02-13 23:07:49 Mw 7.1
MJMA 7.3
37°41′10″N 141°59′31″E / 37.686°N 141.992°E / 37.686; 141.992 35 km (USGS)
55 km (JMA)
6+ This earthquake resulted in at least 1 death and left at least 185 injured.[14] Serious damage was caused. There was no tsunami. It is believed that this was an aftershock of the earthquake almost 10 years to the exact date of the 2011 mainshock.[15]
2021-03-20 18:09:45 Mw 7.0
MJMA 6.9
38°28′30″N 141°36′25″E / 38.475°N 141.607°E / 38.475; 141.607 54 km (USGS)
60 km (JMA)
5+ 11 people injured.[16]

Possibly related earthquakes edit

The following earthquakes are possibly related to the 2011 Tōhoku earthquake. However, agreement toward the relationships has not been reached among the researchers.[17]

Japan Time Magnitude Coordinates Depth Intensity (shindo)[1] Comment
2011-03-12 03:59 Mw 6.3, Mj 6.7[1] 37°01′N 138°22′E / 37.02°N 138.36°E / 37.02; 138.36 8 km[1]
2 km[USGS 10]
6+ Possibly a triggered earthquake.[18][19]
2011-03-12 04:31 Mj 5.9[1] 36°56′53″N 138°34′19″E / 36.948°N 138.572°E / 36.948; 138.572 1 km[1] 6- Possibly a triggered earthquake.[19]
2011-03-12 05:42 Mj 5.3[1] 36°58′19″N 138°35′24″E / 36.972°N 138.59°E / 36.972; 138.59 2 km[1] 6- Possibly a triggered earthquake.[19]
2011-03-15 22:31 Mw 6.0, Mj 6.4[2] 35°17′N 138°32′E / 35.29°N 138.54°E / 35.29; 138.54 9 km[USGS 11] 6+ 50 injured. Power outage.[20] Near presumed location of magma chamber of Mount Fuji.
Sinistral strike-slip fault.[21] Possibly a triggered earthquake.[22]
2021-05-01 10:27:27[23] Mw 6.8 38°13′48″N 141°39′54″E / 38.230°N 141.665°E / 38.230; 141.665 47 km 5+ Three people were injured by the strong shaking.[24]
2022-03-16 23:36:33 Mw 7.3
MJMA 7.4
37°42′07″N 141°35′13″E / 37.702°N 141.587°E / 37.702; 141.587 63.1 km (USGS)
57 km (JMA)
6+ A tsunami advisory was issued by the Japan Meteorological Agency for this earthquake. There was 4 dead and 225 injured.[25][26][27] An estimated 2.2 million households from 13 prefectures and one metropolitan area were left without power.[28]

References edit

USGS edit

  1. ^ Magnitude 7.2 – NEAR THE EAST COAST OF HONSHU, JAPAN Archived 2011-03-10 at the Wayback Machine. Earthquake.usgs.gov. Retrieved on 2011-04-12.
  2. ^ https://earthquake.usgs.gov/earthquakes/eventpage/official20110311054624120_30/executive Archived 2011-03-13 at the Wayback Machine. Earthquake.usgs.gov (2011-03-14). Retrieved on 2011-04-12.
  3. ^ : Preliminary Earthquake Report: NEAR THE EAST COAST OF HONSHU, JAPAN Archived 2011-04-12 at the Wayback Machine, USGS Earthquake Hazards Program (2011-03-11). Retrieved on 2011-04-12.
  4. ^ USGS Earthquake Hazards Program: Preliminary Earthquake Report: OFF THE EAST COAST OF HONSHU, JAPAN Archived 2011-04-12 at the Wayback Machine. Neic.usgs.gov (2011-03-11). Retrieved on 2011-04-12.
  5. ^ Magnitude 7.1 – NEAR THE EAST COAST OF HONSHU, JAPAN Archived 2011-04-14 at the Wayback Machine. Earthquake.usgs.gov. Retrieved on 2011-04-12.
  6. ^ Magnitude 6.6 – EASTERN HONSHU, JAPAN Archived 2011-04-16 at the Wayback Machine. Earthquake.usgs.gov. Retrieved on 2011-04-12.
  7. ^ "Magnitude 7.0 - Off the East Coast of Honshu, Japan 2011 July 10 00:57:12 UTC". Archived from the original on 2011-10-15. Retrieved 2017-07-23.
  8. ^ "undefined". Archived from the original on 2019-02-04. Retrieved 2017-09-03.
  9. ^ "undefined". Archived from the original on 2013-10-27. Retrieved 2017-09-03.
  10. ^ USGS Earthquake Hazards Program: Preliminary Earthquake Report: NEAR THE WEST COAST OF HONSHU, JAPAN [permanent dead link]. Neic.usgs.gov. Retrieved on 2011-04-12.
  11. ^ USGS Earthquake Hazards Program: Preliminary Earthquake Report: EASTERN HONSHU, JAPAN [permanent dead link]. Neic.usgs.gov (2011-03-15). Retrieved on 2011-04-12.

Other edit

  1. ^ a b c d e f g h i j k l m n o p q r s t u 震度データベース検索 Archived 2013-02-13 at the Wayback Machine. Japan Meteorological Agency. Retrieved on 2013-02-18.
  2. ^ a b c 「平成23 年(2011 年)東北地方太平洋沖地震」について(第28 報) Archived 2011-04-09 at the Wayback Machine(Press Release), 25 March 2011. Published by Japan Meteorological Agency.
  3. ^ "2011年3月11日 東北地方太平洋沖地震(M9.0)の特集 — 東北大学 地震・噴火予知研究観測センター". Archived from the original on 2012-01-19. Retrieved 2011-12-02.
  4. ^ 日本付近で発生した主な被害地震(平成8年以降) Archived 2017-07-29 at the Wayback Machine」JMA, Access date March 5, 2017
  5. ^ 平成23年3月10日(06時23分)の三陸沖の地震で発表した津波注意報について Archived 2018-06-21 at the Wayback Machine JMA
  6. ^ "平成23年(2011年)東北地方太平洋沖地震(東日本大震災)について(第162報)(令和4年3月8日)" [Press release no. 162 of the 2011 Tohuku earthquake] (PDF). 総務省消防庁災害対策本部 [Fire and Disaster Management Agency]. Archived from the original (PDF) on 2022-08-27. Retrieved 2022-09-23. Page 31 of the PDF file.
  7. ^ "平成23年(2011年)東北地方太平洋沖地震(東日本大震災)について(第162報)(令和4年3月8日)" [Press release no. 162 of the 2011 Tohuku earthquake] (PDF). 総務省消防庁災害対策本部 [Fire and Disaster Management Agency]. Archived from the original (PDF) on 2022-08-27. Retrieved 2022-09-23. Page 31 of the PDF file.
  8. ^ asahi.com(朝日新聞社):東北の広域停電、完全復旧めどたたず 余震死者2人 – 東日本大震災 Archived 2011-04-14 at the Wayback Machine. Asahi.com (2011-04-08). Retrieved on 2011-04-12.
  9. ^ 7日の地震 4人死亡141人けが NHKニュース Archived 2011-04-11 at the Wayback Machine. .nhk.or.jp. Retrieved on 2011-04-12.
  10. ^ CNN Wire Staff (11 April 2011). "At least 6 killed in new Japan earthquake". articles.cnn.com. CNN World News. Archived from the original on 2 June 2011. Retrieved 2011-04-23. {{cite web}}: |author= has generic name (help)
  11. ^ "Archived copy". Archived from the original on 2011-07-11. Retrieved 2011-07-10.{{cite web}}: CS1 maint: archived copy as title (link)
  12. ^ Japanese Quake Stirs On-Air Alarm, but No Damage to Nuclear Plants Is Reported Archived 2018-02-03 at the Wayback Machine, New York Times
  13. ^ "津波注意報、岩手・宮城は地震40分後「精査に時間」:朝日新聞デジタル". Archived from the original on 2013-10-29. Retrieved 2013-10-26.
  14. ^ "1st death confirmed in Feb. 13 northeastern Japan earthquake". Kyodo News. Kyodo News. 25 February 2021. Archived from the original on 25 February 2021. Retrieved 25 February 2021.
  15. ^ "Large earthquake was an aftershock of 3/11 killer quake, expert says". The Japan Times. Archived from the original on 14 February 2021. Retrieved 14 February 2021.
  16. ^ "宮城県沖を震源とする地震による被害及び 消防機関等の対応状況(第6報" (PDF). Fire and Disaster Management Agency Disaster Countermeasures Headquarters (in Japanese). 22 March 2021. Archived (PDF) from the original on 23 March 2021. Retrieved 22 March 2021.
  17. ^ 静岡東部の震度6強、東海地震誘発せず…専門家 : 科学 : YOMIURI ONLINE(読売新聞) Archived 2011-03-19 at the Wayback Machine. Yomiuri.co.jp. Retrieved on 2011-04-12.
  18. ^ 2011年3月 東北地方太平洋沖地震 | 広報アウトリーチ室 Archived 2011-04-21 at the Wayback Machine. Outreach.eri.u-tokyo.ac.jp. Retrieved on 2011-04-12.
  19. ^ a b c 「平成23年(2011年)東北地方太平洋沖地震」について(第38報) Archived 2018-03-23 at the Wayback Machine(Press Release), 12 April 2011. Published by Japan Meteorological Agency. Retrieved on 2013-02-17.
  20. ^ "3月15日静岡県東部の地震に関する被害情報(第5 報)" (PDF). Archived from the original (PDF) on 27 September 2011. Retrieved 9 September 2022. "Archived copy" (PDF). Archived from the original on 2011-09-27. Retrieved 2011-04-23.{{cite web}}: CS1 maint: archived copy as title (link) CS1 maint: bot: original URL status unknown (link)
  21. ^ 2011年3月15日静岡県東部の地震の評価 Archived 2011-04-25 at the Wayback Machine. Jishin.go.jp. Retrieved on 2011-04-17.
  22. ^ 東日本沖巨大地震 Archived 2011-03-24 at the Wayback Machine. Sk01.ed.shizuoka.ac.jp. Retrieved on 2011-04-12.
  23. ^ "M 6.8 - 38 km ESE of Ishinomaki, Japan". United States Geological Survey. May 1, 2021. Archived from the original on 2021-05-01. Retrieved 2021-05-01.
  24. ^ "6.8-Magnitude Quake Rattles Northeast Japan, No Tsunami Risk". Channels Television. Archived from the original on 2021-05-01. Retrieved 2021-05-01.
  25. ^ "地震による原発の異常なし、4人死亡・97人負傷…参院予算委で首相" [No abnormalities in the nuclear power plant due to the earthquake, 4 people died, 97 people injured ... Prime Minister at the House of Councilors Budget Committee]. Yahoo News Japan (in Japanese). 17 March 2022. Archived from the original on 17 March 2022. Retrieved 17 March 2022.
  26. ^ "地震【随時更新】宮城・福島で震度6強 被害状況は" [Earthquake [Updated from time to time] Seismic intensity 6 strong in Miyagi and Fukushima]. NHK (in Japanese). 17 March 2022. Archived from the original on 16 March 2022. Retrieved 17 March 2022.
  27. ^ "地震 宮城 福島で震度6強 3人死亡 225人けが(19:00)". NHK. 16 March 2022. Archived from the original on 17 March 2022. Retrieved 17 March 2022.
  28. ^ "宮城、福島で震度6強 けが人、搬送相次ぐ" [Injured people with seismic intensity 6 or higher in Miyagi and Fukushima, one after another]. Kyodo News (in Japanese). Okinawa Times. 17 March 2022. Archived from the original on 16 March 2022. Retrieved 16 March 2022.

External links edit