Coseismic slip model

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2 Figure 3 - Preliminary highly smoothed model of coseismic slip for the 11 March UCL Institute for Risk & Disaster Reduction Magnitude 9.0 (JMA scale) earthquake Occurred at 02:46:23 pm local time near the east coast of Honshu, Japan Subduction zone megathrust earthquake Five minutes in duration, It triggered a tsunami more than 10 m high Causing immense damage along the northeast coast of Japan Coseismic slip model It rupture crust 500 km long by 200 km wide in 3 sub events. It is the largest known event in and around Japan

3 Was the 11 th March 2011 Tohoku earthquake forecasted? Earthquakes expected in the source region had much smaller magnitude M 7.4 to 8.2 From 6 smaller fault segments based on historical seismicity The March 11 earthquake ruptured all 6 segments in a single earthquake.

4 Was the 11 th March 2011 Tohoku earthquake forecasted? Within 10 minutes of the first tsunami reached the coast as minor backwash 10s cm high mins after the earthquake huge 4-7 m high run up attacked the coastal lowlands. The Sanriku coast have suffered repeated tsunami in 1896, 1933 and 1960 (Chilean) earthquakes In Iwate prefecture run-up heights exceeded 10m but in Miyagi and Fukushima prefectures less than 4m So nobody had expected such high tsunami But tsunami in 869 and m high had devastated the Sendai plain Koji Okumura, Hiroshima University

5 Could the Tohoku earthquake be forecast? Magnitude yes! Ignore coloured dots Slip deficit from modelled GPS (Igarashi 2003 JGR). Similar to the slip patch last Friday? Earthquakes aftershocks

6 (DART)warning tsunami buoys work. Here are some good resources that will help you learn more about both systems. UCL Institute for Risk & Disaster Reduction SXSW: Tablets will Become Ubiquitous when the Xoo Becomes Obsolete SXSW: How Smart Gadgets Let Us Down Did the warning systems work? Credit: Japan Meteorological Agency. SXSW: Building Human Rights Into Social Sites MOR Yes and saved lives This image shows the location of detected seismic activity, and its severity (Japan uses a different scale for measuring the intensity of earthquakes). Further information here. conference gadgets social networks BLOG TOPI game dynamics SXSW television gaming video gam Credit: NOAA The image above shows the location of tsunami buoys across the Pacific, and which buoys have been triggered (the larger yellow diamonds). Live information can be found in this page at the National Oceanic and Atmospheric Administrations National Data Buoy Center. Updated 14:30 EST: NOAA has published a page dedicated to the tsunami event. How Japan's Earthquake and Tsunami Warning Systems Work - Technology Review 22/03/ :46 The graphic above shows how the Deep-ocean Assessment and Reporting of Tsunami (DART) tsunami buoys work. Credit: Japan Meteorological Agency The graphic above shows the stages involved with triggered Japan's earthquake warning system. Further information can be found at this page of the Japan Meteorological Agency. Credit: NOAA Credit: NOAA. Credit: NOAA The image above shows the location of tsunami buoys across the Pacific, and which buoys The image above was generated using the method of splitting tsunami (MOST) model. It uses data collected by tsunami buoys to estimate the wave arrival time and the wave height of the tsunami. FACEBO

7 Is this the Big One? Great Kanto Earthquake 1923 No JMA Intensities

8 Great Kanto Earthquake 1923 Great Kanto earthquake (Mw = 7.9; M s = 8.2) Occurred along the Sagami Trough in the Sagami Bay on 1 September 1923 One of the most disastrous earthquakes in Japanese history Refugees Imperial Palace Saiten Tamura Earthquake claimed 99,331 dead, 43,746 missing, and left 3.4 million homeless Major social consequences - systematic massacres & political assassinations