:April 2011 Fukushima earthquake

The magnitude 6.6 M_w Fukushima Hamadōri earthquake occurred inland on 11 April 2011 at 08:16 UTC at a focal depth of {{convert|13|km|mi|abbr=on}}, about {{convert|36|km|mi|abbr=on}} west of Iwaki, Fukushima, or {{convert|161|km|mi|abbr=on}} north-northeast of Tokyo. To the east of the epicentre, the oceanic Pacific plate is subducted beneath the continental Okhotsk microplate, on which much of Honshu's Tōhoku region is situated. Building stress near the resultant plate boundary has led to the development of shallow inland faults through crustal deformation and folding along the east coast of Tōhoku.{{cite news|url=http://www.yomiuri.co.jp/dy/features/science/T110906006251.htm|title=M-9 Tohoku quake cycle may be 260 years|newspaper=Yomiuri Shimbun|access-date=4 February 2012|date=8 September 2011|archive-date=7 September 2011|archive-url=https://web.archive.org/web/20110907225512/http://www.yomiuri.co.jp/dy/features/science/T110906006251.htm|url-status=live}}{{cite news|url=http://www.yomiuri.co.jp/science/news/20110416-OYT1T00503.htm|script-title=ja:先日のＭ７余震、予想外の井戸沢断層が原因|date=16 April 2011|access-date=4 February 2012|newspaper=Yomiuri Shimbun|language=ja|archive-date=18 April 2011|archive-url=https://web.archive.org/web/20110418013503/http://www.yomiuri.co.jp/science/news/20110416-OYT1T00503.htm|url-status=live}} This intraplate earthquake occurred in the vicinity of the Idosawa Fault – a shallow crustal fault in the Hamadōri region near Tabito town, Iwaki city, that had previously been inactive.{{cite web|url=http://www.asahi.com/national/update/0413/TKY201104130239.html|script-title=ja:いわき市の地表に７キロの断層 ４月１１日の余震でずれ|date=13 April 2011|access-date=2011-04-23|work=The Asahi Shimbun|language=ja|archive-date=2011-04-14|archive-url=https://web.archive.org/web/20110414154026/https://www.asahi.com/national/update/0413/TKY201104130239.html|url-status=live}}{{cite report|url=http://outreach.eri.u-tokyo.ac.jp/eqvolc/201103_tohoku/eng/hamadoori/ |title=第3報（9月7日掲載）: 2011年4月11日の福島県浜通りの地震に伴う地表地震断層のトレンチ掘削調査（速報） |series=2011年4月11日の福島県浜通りの地震に伴う地表地震断層について |year=2011 |access-date=31 January 2012 |publisher=Outreach and Public Relations Office |first1=Tatsuya |last1=Ishiyama |first2=Nobuhiko |last2=Sugito |first3=Tomoo |last3=Echigo |first4=Hiroshi |last4=Sato |url-status=dead |archive-url=https://web.archive.org/web/20120219213656/http://outreach.eri.u-tokyo.ac.jp/eqvolc/201103_tohoku/eng/hamadoori/ |archive-date=19 February 2012 }}

Surveys near the epicentre revealed a surface rupture of about {{convert|11|km|mi|abbr=on}} and numerous fault scarps, with general vertical displacements of {{convert|0.8|to|1.5|m|ft|abbr=on}}; a maximum displacement of {{convert|2.3|m|ft|abbr=on}} occurred at the small village of Shionohira. Localised right-lateral slip of {{convert|30|cm|in|abbr=on}} was observed at the subsiding west side of the rupture. The segments of the Idosawa Fault associated with this surface feature were classified as the "Shionohira Fault" in 2011.{{cite report|url=http://www.geerassociation.org/GEER_Post%20EQ%20Reports/Tohoku_Japan_2011/QR4_Preliminary%20Observations%20of%20Surface%20Fault%20Rupture_06.06.11.pdf |title=Preliminary Observations of Surface Fault Rupture from the April 11, 2011 Mw6.6 Hamadoori Earthquake, Japan (an aftershock of the March 11, 2011 Tohoku Offshore Earthquake, Japan) |publisher=Geotechnical Extreme Events Reconnaissance |first1=Keith I. |last1=Kelson | first2=Leslie F. Jr. | last2=Harder |first3=Tadahiro |last3=Kishida |first4=Isabelle |last4=Ryder |date=5 June 2011 |access-date=31 January 2012 |docket=GEER-025d |pages=1 6 |url-status=dead |archive-url=https://web.archive.org/web/20130516135608/http://www.geerassociation.org/GEER_Post%20EQ%20Reports/Tohoku_Japan_2011/QR4_Preliminary%20Observations%20of%20Surface%20Fault%20Rupture_06.06.11.pdf |archive-date=16 May 2013 }} The nearby Yunodake Fault, a normal dip-slip fault northeast of the Shionohira Fault that had been dormant for 120,000–130,000 years, also ruptured during the quake.{{cite report|url=http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_111121_03-e.pdf|title=Status of investigation on Yunotake Fault (quick report)|type=Pamphlet|date=21 November 2011|publisher=Tokyo Electric Power Company|series=Press Conference Handouts Archive: November 2011|access-date=1 February 2012|archive-date=13 December 2011|archive-url=https://web.archive.org/web/20111213225643/https://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_111121_03-e.pdf|url-status=live}} These observations indicated that the earthquake occurred as a result of normal dip-slip faulting with some strike-slip component.

Although it was centred near a different fault zone, the earthquake was classified as an aftershock of the 11 March Tōhoku earthquake, which occurred offshore about {{convert|235|km|mi|abbr=on}} to its northeast.{{cite web|url=https://earthquake.usgs.gov/earthquakes/eqinthenews/2011/usc0001xgp/ |title=Magnitude 9.0 – near the East Coast of Honshu, Japan |date=11 March 2011 |access-date=2011-04-28 |publisher=United States Geological Survey |archive-url=https://web.archive.org/web/20110428005719/http://earthquake.usgs.gov/earthquakes/eqinthenews/2011/usc0001xgp/ |archive-date=28 April 2011 |url-status=dead }} The magnitude 9.0 M_w earthquake triggered widespread seismic activity,{{cite web |author=Choi, Charles Q |date=19 April 2011 |title=Japan earthquake triggered smaller quakes around the world |url=http://www.nbcnews.com/id/42662682 |access-date=2011-04-23 |publisher=NBC News |archive-date=2022-04-07 |archive-url=https://web.archive.org/web/20220407094943/https://www.nbcnews.com/id/wbna42662682 |url-status=live }} and its aftershock sequence includes well-over 67 earthquakes of magnitude 6.0 M_w or greater.{{cite report|url=https://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/usc0004sg6.php |title=Magnitude 7.0 – off the East Coast of Honshu, Japan |publisher=United States Geological Survey |date=10 July 2011 |access-date=31 January 2012 |at=[https://earthquake.usgs.gov/earthquakes/eqinthenews/2011/usc0004sg6/#summary Earthquake Summary] |url-status=dead |archive-url=https://web.archive.org/web/20111015132904/http://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/usc0004sg6.php |archive-date=15 October 2011 }} Apart from the Fukushima Hamadōri earthquake, four of the aftershocks measured magnitude 7.0 M_w or higher.{{cite web|url=https://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/usc0002ksa.php#summary |title=Magnitude 7.1 – near the East Coast of Honshu, Japan |publisher=United States Geological Survey |date=11 April 2011 |access-date=2011-04-23 |archive-url=https://web.archive.org/web/20110424225143/http://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/usc0002ksa.php |archive-date=24 April 2011 |url-status=dead }}{{cite web|url=https://earthquake.usgs.gov/earthquakes/eqinthenews/|title=2011 Significant Earthquake and News Headlines Archive|publisher=United States Geological Survey|year=2011|access-date=27 April 2011| archive-url= https://web.archive.org/web/20110426182123/http://earthquake.usgs.gov/earthquakes/eqinthenews/| archive-date= 26 April 2011 | url-status= live}} The Fukushima Hamadōri earthquake, however, was the strongest of the aftershocks to have its epicentre located inland. Early estimates placed the strength of the earthquake at a magnitude of 7.0–7.1, but the United States Geological Survey (USGS) lowered the magnitude to 6.6.{{cite web|url=http://www.theage.com.au/environment/japan-rattled-by-66-aftershock-20110411-1davj.html|title=Japan rattled by 6.6 aftershock|agency=Agence France-Presse|author-link=Agence France-Presse|work=The Age|date=11 April 2011|access-date=2011-04-23|archive-date=2011-04-13|archive-url=https://web.archive.org/web/20110413160532/https://www.theage.com.au/environment/japan-rattled-by-66-aftershock-20110411-1davj.html|url-status=live}}{{cite news|url=http://www.businessweek.com/news/2011-04-11/magnitude-6-6-quake-hits-japan-near-stricken-nuclear-plant.html|title=Magnitude-6.6 quake hits Japan near stricken nuclear power plant|date=23 April 2011|access-date=2011-03-23|first=Stuart|last=Biggs|newspaper=Bloomberg Businessweek| archive-url= https://web.archive.org/web/20110417012359/http://www.businessweek.com/news/2011-04-11/magnitude-6-6-quake-hits-japan-near-stricken-nuclear-plant.html| archive-date= 17 April 2011 | url-status= dead}} The Japan Meteorological Agency (JMA) assessed a magnitude of 7.0 M_j and a depth of {{convert|6.4|km|mi|abbr=on}}.{{cite web|url=http://www.jma-net.go.jp/sendai/jishin-kazan/j-kaiset/20110411hamadori.pdf|script-title=ja:福島県浜通りの地震について|work=jma-net.go.jp|publisher=Sendai District Meteorological Observatory|date=11 April 2011|access-date=2011-05-02| archive-url= https://web.archive.org/web/20110523092306/http://www.jma-net.go.jp/sendai/jishin-kazan/j-kaiset/20110411hamadori.pdf| archive-date= 23 May 2011 | url-status= live|language=ja}}

The Fukushima Hamadōri earthquake was succeeded by a number of smaller tremors; that same day, at least 11 earthquakes of magnitude 3.5 M_j or higher were recorded near its epicentre.{{cite web|url=http://www.fnet.bosai.go.jp/event/joho.php?tm=201104&all=&LANG=en|title=Earthquake Information 2011/04 (UT)|work=fnet.bosai.go.jp|publisher=National Research Institute for Earth Science and Disaster Resilience|date=April 2011|access-date=2011-04-23|archive-date=2012-03-22|archive-url=https://web.archive.org/web/20120322190623/https://www.fnet.bosai.go.jp/event/joho.php?tm=201104&all=&LANG=en|url-status=live}} Of the series, the strongest registered at a magnitude of 5.5 M_j and occurred within 3.5 hours after the initial quake.{{cite web|url=http://www.fnet.bosai.go.jp/event/tdmt/2011/20110411114100/update2/cmt.gif|title=Event – 36.9N 140.6E, 8 km Mw5.5|work=fnet.bosai.go.jp|publisher=National Research Institute for Earth Science and Disaster Resilience|date=11 April 2011|access-date=2011-04-23|archive-date=2012-03-22|archive-url=https://web.archive.org/web/20120322190712/https://www.fnet.bosai.go.jp/event/tdmt/2011/20110411114100/update2/cmt.gif|url-status=live}} A shallow magnitude 6.0 M_w (6.4 M_j) earthquake and several smaller tremors struck the region on 12 April.{{cite report|url=http://www.jishin.go.jp/main/chousa/11apr_fukushima/index-e.htm|title=Earthquake in Hamadori, Fukushima Prefecture on April 11, 2011|publisher=Headquarters for Earthquake Research Promotion|date=12 April 2011|access-date=31 January 2012|archive-date=3 March 2016|archive-url=https://web.archive.org/web/20160303221959/http://www.jishin.go.jp/main/chousa/11apr_fukushima/index-e.htm|url-status=live}}{{cite web|work=平成23年４月 地震・火山月報（防災編）|url=http://www.seisvol.kishou.go.jp/eq/gaikyo/monthly201104/201104_tohoku_3.pdf|title=（３）平成23 年４月11 日の福島県浜通りの地震・平成23 年４月12 日の福島県中通りの地震|year=2011|publisher=Japan Meteorological Agency|access-date=2012-02-01|archive-url=https://web.archive.org/web/20120420053222/http://www.seisvol.kishou.go.jp/eq/gaikyo/monthly201104/201104_tohoku_3.pdf|archive-date=2012-04-20|url-status=dead}}

File:April11 2011 Fukushima earthquake shake map.jpg

The earthquake struck in the late afternoon near a moderately populated region of the Fukushima Prefecture, although most structures around the epicentre were resistant to earthquake shaking. Focussed at an unusually shallow depth, the earthquake generated significant shaking throughout many adjacent prefectures. The strongest ground motion registered at severe (MM VIII) in Ishikawa town on the Mercalli intensity scale.{{cite web|url=https://earthquake.usgs.gov/earthquakes/pager/events/us/c0002n9v/onepager.pdf|title=Pager Version 4 – M 6.6, Eastern Honshu, Japan|publisher=United States Geological Survey|date=11 April 2011|access-date=2011-04-22|archive-date=2011-04-19|archive-url=https://web.archive.org/web/20110419173638/https://earthquake.usgs.gov/earthquakes/pager/events/us/c0002n9v/onepager.pdf|url-status=live}} Strong shaking (MM VI) spread through Iwaki, Sukawaga, Kuroiso, Ōtawara and Kitaibaraki, with light tremors (MM IV) felt in areas up to several hundred kilometres from the epicentre, including Tokyo and Yokohama.{{cite web|url=https://earthquake.usgs.gov/earthquakes/pager/events/us/c0002n9v/index.html|title=Pager – M 6.6 – Eastern Honshu, Japan|publisher=United States Geological Survey|date=11 April 2011|access-date=2011-04-22|archive-date=2011-04-14|archive-url=https://web.archive.org/web/20110414124420/https://earthquake.usgs.gov/earthquakes/pager/events/us/c0002n9v/index.html|url-status=live}} The earthquake cut electricity to about 220,000 households, with most of the cuts reported in Iwaki city. Workers at the Fukushima Daiichi power plant – distanced {{convert|70|km|mi|abbr=on}} from the epicentre{{cite web|url=http://www.tageo.com/index-e-ja-v-08-d-m33711602.htm|title=Fukushima Daiichi Nuclear Power Plant – 1–4 unites – Japan|work=tageo.com|access-date=2011-04-28|archive-date=2011-03-21|archive-url=https://web.archive.org/web/20110321023558/http://www.tageo.com/index-e-ja-v-08-d-m33711602.htm|url-status=live}} – evacuated to safety, and external power to the plant was cut. The outage briefly disrupted cooling water injections into three of the reactors, but services to the plant were restored by 18:05 JST. Authorities at Tokyo International Airport closed all runways momentarily,{{cite web|url=http://www.abcactionnews.com/dpp/news/world/7.1-magnitude-earthquake-shakes-northeast-japan|title=7.1 magnitude earthquake shakes northeast Japan|work=abcactionnews.com|publisher=ABC Action News|agency=Associated Press|date=11 April 2011|access-date=2011-04-26|archive-url=https://web.archive.org/web/20120307174833/http://www.abcactionnews.com/dpp/news/world/7.1-magnitude-earthquake-shakes-northeast-japan|archive-date=7 March 2012|url-status=dead}} while NTT DoCoMo restricted voice calls in 14 prefectures following the quake. East Japan Railway Company temporarily suspended its services to restart four of five bullet-train lines; other Shinkansen bullet trains in the region were also halted.{{cite web|url=https://spectrum.ieee.org/quake-and-tsunami-warning-halt-work-at-fukushima-plant|title=Quake and tsunami warning halt work at Fukushima Plant|date=11 April 2011|access-date=2011-04-27|author=Boyd, John|work=IEEE|publisher=IEEE Spectrum|archive-date=2022-08-11|archive-url=https://web.archive.org/web/20220811205019/https://spectrum.ieee.org/quake-and-tsunami-warning-halt-work-at-fukushima-plant|url-status=live}}

The earthquake sparked several fires in Iwaki, with one fire breaking out in Asakawa town. Fire engines extinguished a blaze in a liquefied natural gas tank at Daiichi Sankyo's Onahama Plant. Most of the structural damage was due to scattered rock- and landslides along hillsides in the vicinity of Iwaki. A landslide crushed two vehicles and buried three homes in the city, trapping a number of the inhabitants.{{cite web|url=http://www.cnn.com/2011/WORLD/asiapcf/04/11/japan.quake/index.html |title=At least 6 killed in new Japan earthquake |publisher=CNN|date=11 April 2011 |access-date=2011-04-23 |archive-url=https://web.archive.org/web/20110602012159/http://articles.cnn.com/2011-04-11/world/japan.quake_1_fukushima-daiichi-nuclear-plant-tsunami-quake |archive-date=2 June 2011 |url-status=live }} The incident resulted in two immediate deaths. Four people were critically injured and taken to hospital; one of them was later pronounced dead.{{cite news|url=https://www.telegraph.co.uk/news/worldnews/asia/japan/8445069/Japan-earthquake-three-killed-in-powerful-aftershock.html|title=Japan earthquake: three killed in powerful aftershock|work=The Daily Telegraph|date=12 April 2011|access-date=2011-05-15| archive-url= https://web.archive.org/web/20110426071000/http://www.telegraph.co.uk/news/worldnews/asia/japan/8445069/Japan-earthquake-three-killed-in-powerful-aftershock.html| archive-date= 26 April 2011 | url-status= live}}{{cite web|url=http://www.fdma.go.jp/bn/data/%E7%A6%8F%E5%B3%B6%E7%9C%8C%E6%B5%9C%E9%80%9A%E3%82%8A%E3%82%92%E9%9C%87%E6%BA%90%E3%81%A8%E3%81%99%E3%82%8B%E5%9C%B0%E9%9C%87%EF%BC%88%E7%AC%AC11%E5%A0%B1%EF%BC%89.pdf|script-title=ja:福島県浜通りを震源とする地震（第１１報）|publisher=Fire and Disaster Management Agency|date=13 April 2011|access-date=2011-05-16|language=ja|archive-url=https://web.archive.org/web/20110721015759/http://www.fdma.go.jp/bn/data/%E7%A6%8F%E5%B3%B6%E7%9C%8C%E6%B5%9C%E9%80%9A%E3%82%8A%E3%82%92%E9%9C%87%E6%BA%90%E3%81%A8%E3%81%99%E3%82%8B%E5%9C%B0%E9%9C%87%EF%BC%88%E7%AC%AC11%E5%A0%B1%EF%BC%89.pdf|archive-date=21 July 2011|url-status=dead}} The Iwaki Ibaraki Route 14 interchange of the Jōban Expressway, which runs from Misato, Saitama, to Tomiya, Miyagi, was cut off to traffic by a large landslide of {{convert|120|x|100|m|ft|abbr=on}}.{{cite report|url=http://www.geerassociation.org/GEER_Post%20EQ%20Reports/Tohoku_Japan_2011/QR4_Preliminary%20Observations%20of%20Surface%20Fault%20Rupture_06.06.11.pdf |title=Sediment-related disasters and sabo-related facilities |publisher=Public Works Research Institute |series=Reconnaissance Survey on Damage to Infrastructures |year=2011 |access-date=31 January 2012 |pages=10–13 |url-status=dead |archive-url=https://web.archive.org/web/20130516135608/http://www.geerassociation.org/GEER_Post%20EQ%20Reports/Tohoku_Japan_2011/QR4_Preliminary%20Observations%20of%20Surface%20Fault%20Rupture_06.06.11.pdf |archive-date=16 May 2013 }} In Tabito town, very close to the epicentre, a {{convert|170|x|50|m|ft|abbr=on}} landslide resulted in the formation of a quake lake – a natural damming of a river by mass wasting – with a water level of {{convert|15|m|ft|abbr=on}} and a storage volume of 1,000–2,500 m³ (35,000–90,000 cu ft). Significant land deformation with traces of uplift was observed in and around town, affecting local roads but largely sparing its structures.

A total of seven people from other regions near the epicentre, including southern Ibaraki, Tochigi and Kanagawa prefectures, suffered minor injuries. Another person was injured during the magnitude 6.0 (M_w) aftershock of 12 April. In a report from July 2011, the Fire and Disaster Management Agency confirmed a death toll of four from the earthquake.{{cite report|url=http://www.jishin.go.jp/main/chousa/11sep/p13-e.htm|title=Seismic Activities from Hamadori, Fukushima Prefecture to Northern Ibaraki Prefecture|publisher=Japan Meteorological Agency|date=20 September 2011|access-date=31 January 2012|archive-date=4 March 2016|archive-url=https://web.archive.org/web/20160304042957/http://www.jishin.go.jp/main/chousa/11sep/p13-e.htm|url-status=live}}

Japan's Earthquake Early Warning system was activated upon the detection of primary waves – seismic waves that forego an earthquake's perceivable ground motions – giving residents 6.8 seconds to seek cover before the main shock. At the risk of a tsunami – which reach their destructive wave heights near shallow coastal waters{{cite web|url=http://walrus.wr.usgs.gov/tsunami/basics.html|title=Life of a Tsunami|date=22 October 2008|work=Western Coastal & Marine Geology|publisher=United States Geological Survey|access-date=2011-04-27|archive-date=2014-10-21|archive-url=https://web.archive.org/web/20141021072112/http://walrus.wr.usgs.gov/tsunami/basics.html|url-status=live}} – local fishing boats along coastlines were shown heading out to sea on national news broadcasts. A warning for a localised tsunami of up to {{convert|2.0|m|ft|abbr=on}} was issued by the Japan Meteorological Agency; however, no significant waves were recorded, and the warning was cancelled soon thereafter.{{cite web|url=http://www.rte.ie/news/2011/0411/japan.html|title=Japan hit by 6.6 magnitude earthquake|publisher=RTÉ|date=11 April 2011|access-date=2011-03-23|archive-date=2011-04-12|archive-url=https://web.archive.org/web/20110412194852/http://www.rte.ie/news/2011/0411/japan.html|url-status=live}} In response to the earthquake, the fire department dispatched search and rescue teams and emergency crews for relief efforts and damage assessments throughout the affected area. Six medical crews in pairs of two were also sent to Kanagawa, Chiba and Gunma prefectures. Former Prime Minister Naoto Kan postponed a press conference scheduled for 17:50 JST marking the one-month anniversary of the catastrophic Tōhoku earthquake and tsunami.

The Fukushima Hamadōri earthquake occurred in a region with historically low levels of seismicity; studies showed that the recent activity near the fault zone had been triggered by the Tōhoku earthquake.{{cite web|url=http://outreach.eri.u-tokyo.ac.jp/eqvolc/201103_tohoku/fukushimahamadoori/ |script-title=ja:2011年4月11日の福島県浜通りの地震に伴う地表地震断層について |work=outreach.eri.u-tokyo.ac.jp |publisher=Outreach and Public Relations Office |date=13 April 2011 |access-date=2011-04-23 |archive-url=https://web.archive.org/web/20110428185218/http://outreach.eri.u-tokyo.ac.jp/eqvolc/201103_tohoku/fukushimahamadoori/ |archive-date=28 April 2011 |url-status=dead |language=ja }} Ever since the earthquake triggered their reactivation, the Shionohira and Yunodake faults have provided essential data for local geological surveys on regional land deformation, sedimentary rock distribution and landslide vulnerability.{{cite web|url=http://iisee.kenken.go.jp/syndb/?action=abstr&id=MEE10510&est=S&year=2011|title=Implication of recent case histories of earthquake-inflicted mass movement; a case studies at Ojiya City aftermaths the 2004 Mid Niigata Prefecture Earthquake and at Iwaki City aftermaths the 2011 Fukushima Prefecture Hamadori earthquake (docket=MEE10510)|first1=Cigdem|last1=Tetik|publisher=International Institute of Seismology and Earthquake Engineering|date=11 September 2011|access-date=1 February 2012|archive-date=13 July 2012|archive-url=https://web.archive.org/web/20120713180511/http://iisee.kenken.go.jp/syndb/?action=abstr&id=MEE10510&est=S&year=2011|url-status=live}} In the earthquake's aftermath, Professor Yagi Hiroshi from the Faculty of Education, Art and Science noted that "a possibility exists for widespread aftershocks of the same size to occur in the near future."

• List of earthquakes in 2011
• List of earthquakes in Japan
• 2016 Fukushima earthquake
• 2021 Fukushima earthquake

{{Reflist}}

• [http://www.cbsnews.com/video/watch/?id=7362425n Japan hit with 6.6 aftershock] – CBS News
• [https://earthquake.usgs.gov/earthquakes/eventpage/usp000hzq8#general_summary Earthquake M6.6 – eastern Honshu, Japan] – United States Geological Survey

{{2011 Tōhoku earthquake and tsunami}}

{{Earthquakes in 2011}}

{{Earthquakes in Japan}}

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Category:Earthquakes of the Heisei era

Category:2011 earthquakes

Category:April 2011 in Japan

Category:Landslides in Japan

Category:Earthquakes in Fukushima Prefecture

Category:2011 disasters in Japan