Japan Tsunami Urgency Response
Lead Research Organisation:
British Geological Survey
Department Name: Environmental Modelling
Abstract
At 1446 (local time Japan) on the 11th March 2011, off the east coast of Honshu Island, Japan, an earthquake of Magnitude 9.0 generated a tsunami that inundated a 400 kilometre length of the adjacent coastline. The tsunami was up to 17 metres high, it surmounted many of the protective walls constructed to protect the coastal areas and at least 27,000 people died and over 350,000 people were made homeless. This is on a scale similar to that of the 2004 Indian Ocean event.
Small tsunamis in this earthquake-prone /tectonically active region are not unusual, but ones of this magnitude are rare, the last event of significant size was in 1896, when 27,000 people perished. After relief operations, it is essential for scientists to visit the affected area to acquire data on the tsunami impact including inundation, runup, flow depth and erosion. Much of the evidence on the tsunami is fragile and quickly eroded or removed. The orientation of a tsunami may be identified by the orientations of grass, tsunami height may be seen from water marks on buildings or building damage; debris caught in trees or bushes is common. After a tsunami, survivors are anxious to clean up, to wash the evidence away and to get their lives back to normal. Natural processes-rain, wind, surf-also degrade the evidence of a tsunami. Since much evidence is ephemeral, not only are scientists eager to make observations quickly, too many rapid response and preliminary surveys end up being the only surveys conducted. The surveys objectives are to better understand the tsunami, its relationship to the source mechanisms (in this case the earthquake) and prepare improved mitigation strategies for use in the future.
Now, for the first time, tsunami scientists have been invited into the devastated areas and the task they face is enormous. There are limited numbers of appropriately skilled people and the scale of the devastation huge - probably thousands of square kilometres in area. To acquire data over this area is going to be challenging at best, thus international scientists from outside Japan have been invited into the country to research the tsunami; there has been a significant delay to allow relief operations to proceed, so it is essential now to respond immediately, the PI of the proposal Professor David Tappin is one of the invited scientists. In addition, new methodologies are required to better cope with the scale of the event.
To address the need, here we propose to visit the area of tsunami inundation to collect data on tsunami deposits and tsunami impact. In addition we will develop an integrated methodology with desk-based mapping of the inundated area prior to acquiring the field data that will be followed by fieldwork. Thus the field work will be a validation of prior interpretations. Significantly, for the first time after a tsunami, high resolution satellite imagery has been released on humanitarian grounds to assist relief workers and scientists working on mitigation. Not only will the interpretation of the satellite images guide the field operations, but the images and interpretations will be uploaded onto field mapping computers. The desk-based interpretations will then be amended and improved by the digital acquisition of field data on tsunami inundation, flow directions, the location of areas of erosion and sedimentation, together with various aspects of the coast that will allow a better understanding of how the tsunami inundation took place. Downstream these data will be uploaded onto a GIS modelled with digital terrain models to allow the identification of areas of safety where people can escape to in future events. Mapping areas of inundation will also lead to better models of tsunami run up. Investigations of the tsunami sediments will result in better discrimination of past tsunami events and improved risk strategies.
Small tsunamis in this earthquake-prone /tectonically active region are not unusual, but ones of this magnitude are rare, the last event of significant size was in 1896, when 27,000 people perished. After relief operations, it is essential for scientists to visit the affected area to acquire data on the tsunami impact including inundation, runup, flow depth and erosion. Much of the evidence on the tsunami is fragile and quickly eroded or removed. The orientation of a tsunami may be identified by the orientations of grass, tsunami height may be seen from water marks on buildings or building damage; debris caught in trees or bushes is common. After a tsunami, survivors are anxious to clean up, to wash the evidence away and to get their lives back to normal. Natural processes-rain, wind, surf-also degrade the evidence of a tsunami. Since much evidence is ephemeral, not only are scientists eager to make observations quickly, too many rapid response and preliminary surveys end up being the only surveys conducted. The surveys objectives are to better understand the tsunami, its relationship to the source mechanisms (in this case the earthquake) and prepare improved mitigation strategies for use in the future.
Now, for the first time, tsunami scientists have been invited into the devastated areas and the task they face is enormous. There are limited numbers of appropriately skilled people and the scale of the devastation huge - probably thousands of square kilometres in area. To acquire data over this area is going to be challenging at best, thus international scientists from outside Japan have been invited into the country to research the tsunami; there has been a significant delay to allow relief operations to proceed, so it is essential now to respond immediately, the PI of the proposal Professor David Tappin is one of the invited scientists. In addition, new methodologies are required to better cope with the scale of the event.
To address the need, here we propose to visit the area of tsunami inundation to collect data on tsunami deposits and tsunami impact. In addition we will develop an integrated methodology with desk-based mapping of the inundated area prior to acquiring the field data that will be followed by fieldwork. Thus the field work will be a validation of prior interpretations. Significantly, for the first time after a tsunami, high resolution satellite imagery has been released on humanitarian grounds to assist relief workers and scientists working on mitigation. Not only will the interpretation of the satellite images guide the field operations, but the images and interpretations will be uploaded onto field mapping computers. The desk-based interpretations will then be amended and improved by the digital acquisition of field data on tsunami inundation, flow directions, the location of areas of erosion and sedimentation, together with various aspects of the coast that will allow a better understanding of how the tsunami inundation took place. Downstream these data will be uploaded onto a GIS modelled with digital terrain models to allow the identification of areas of safety where people can escape to in future events. Mapping areas of inundation will also lead to better models of tsunami run up. Investigations of the tsunami sediments will result in better discrimination of past tsunami events and improved risk strategies.
Planned Impact
Initially, the results will be of use to tsunami scientists studying tsunami impact in relation to tsunami source and levels of impact inundation. The research improves our understanding of the tsunami in relationship to the source mechanisms (in this case the earthquake) and in improving and developing future mitigation strategies.
The results will be used by government hazard managers in Japan, for developing new mitigation strategies. Following major tsunami events in 1923, 1933, 1960, 1983, and 1993, Japanese society progressively implemented more sophisticated responses to tsunami hazard, including relocating houses and employing forecasting methods. There is no doubt that after the 11th March event major changes in mitigation will take place, involving improved defence structures, tsunami-resistant town development and evacuation procedures based on better forecast warning and that these changes need to be based on a solid foundation of observational evidence on the impact of the tsunami. The data acquired during the forthcoming surveys will thus be essential for use by government hazard managers in developing these new strategies. The result will be major new coastal construction works and the saving of lives when the next tsunami strikes, as it will.
Other countries will be following the events in Japan because again, as in the Indian Ocean event of 2004 The "boxing day tsunami", an unexpected large magnitude tsunami struck in a region where there was significant preparedness . After 2004, countries surrounding the Indian Ocean developed major new mitigation strategies. In the Pacific the Americans, refined and improved the far-field warning systems, that were very effective on March 11th 2011. It is wise to recall that the Pacific Regional Warning system was set up in 1946 after a large earthquake and far field tsunami off of Alaska. All these large events lead to new and improved mitigation. The Japan tsunami of March 2011 will prove no exception.
Commercially, there is also considerable potential for the development of the proposed methodology of integrating desk based interpretations of high resolution satellite imagery of devastated regions and validating these with field surveys. BGS is working closely with ImageCat Inc within the International Charter, Space and Major Disasters. ImageCat have agreed to collaborate on the Japanese event and so far have interpreted medium resolution satellite imagery that will form the basis for our interpretation of higher resolution satellite data (such as GeoEye) that provides a resolution of up to.0.5 m.
BGS is one of only two organisations in the UK that are trained as Charter Project Managers so we are aware that the Charter is only activated during the period of a disaster and is only for disaster response during emergency management. The Charter includes a Value-Adding component, but our proposal goes beyond the remit of the Charter and includes research into the integrated technologies required in the field and the interpretation of the derived data for better understanding of tsunami events worldwide. We will also investigate links to other initiatives including the GEO Supersites initiative, which is based primarily on radar data.
Although the proposal is an urgent one to acquire fragile field data, the proposed methodology is groundbreaking because:
* For the first time, after a tsunami, this high resolution satellite imagery has been released immediately after the event. The methodology will provide an integrated system for interoperable digital field data collection,
* In the future if the methodology is developed, both desk-based interpretations and field data will be immediately available in digital form for use by responsive humanitarian teams as well as specialist tsunami experts, and
* The digital data will be available in the future for improving tsunami runup models used in developing mitigation strategies of both warning and evacuation.
The results will be used by government hazard managers in Japan, for developing new mitigation strategies. Following major tsunami events in 1923, 1933, 1960, 1983, and 1993, Japanese society progressively implemented more sophisticated responses to tsunami hazard, including relocating houses and employing forecasting methods. There is no doubt that after the 11th March event major changes in mitigation will take place, involving improved defence structures, tsunami-resistant town development and evacuation procedures based on better forecast warning and that these changes need to be based on a solid foundation of observational evidence on the impact of the tsunami. The data acquired during the forthcoming surveys will thus be essential for use by government hazard managers in developing these new strategies. The result will be major new coastal construction works and the saving of lives when the next tsunami strikes, as it will.
Other countries will be following the events in Japan because again, as in the Indian Ocean event of 2004 The "boxing day tsunami", an unexpected large magnitude tsunami struck in a region where there was significant preparedness . After 2004, countries surrounding the Indian Ocean developed major new mitigation strategies. In the Pacific the Americans, refined and improved the far-field warning systems, that were very effective on March 11th 2011. It is wise to recall that the Pacific Regional Warning system was set up in 1946 after a large earthquake and far field tsunami off of Alaska. All these large events lead to new and improved mitigation. The Japan tsunami of March 2011 will prove no exception.
Commercially, there is also considerable potential for the development of the proposed methodology of integrating desk based interpretations of high resolution satellite imagery of devastated regions and validating these with field surveys. BGS is working closely with ImageCat Inc within the International Charter, Space and Major Disasters. ImageCat have agreed to collaborate on the Japanese event and so far have interpreted medium resolution satellite imagery that will form the basis for our interpretation of higher resolution satellite data (such as GeoEye) that provides a resolution of up to.0.5 m.
BGS is one of only two organisations in the UK that are trained as Charter Project Managers so we are aware that the Charter is only activated during the period of a disaster and is only for disaster response during emergency management. The Charter includes a Value-Adding component, but our proposal goes beyond the remit of the Charter and includes research into the integrated technologies required in the field and the interpretation of the derived data for better understanding of tsunami events worldwide. We will also investigate links to other initiatives including the GEO Supersites initiative, which is based primarily on radar data.
Although the proposal is an urgent one to acquire fragile field data, the proposed methodology is groundbreaking because:
* For the first time, after a tsunami, this high resolution satellite imagery has been released immediately after the event. The methodology will provide an integrated system for interoperable digital field data collection,
* In the future if the methodology is developed, both desk-based interpretations and field data will be immediately available in digital form for use by responsive humanitarian teams as well as specialist tsunami experts, and
* The digital data will be available in the future for improving tsunami runup models used in developing mitigation strategies of both warning and evacuation.
Organisations
People |
ORCID iD |
| David Tappin (Principal Investigator) | |
| Colm Jordan (Co-Investigator) |
Publications
Goto K
(2011)
New insights of tsunami hazard from the 2011 Tohoku-oki event
in Marine Geology
Richmond B
(2012)
Erosion, deposition and landscape change on the Sendai coastal plain, Japan, resulting from the March 11, 2011 Tohoku-oki tsunami
in Sedimentary Geology
Tappin D
(2014)
Did a submarine landslide contribute to the 2011 Tohoku tsunami?
in Marine Geology
| Description | With regard to the research on the tsunami sediment there were two aspects; i) it can be used to identify inland inundation distances that may be compared to past events and, ii) it can also be used to identify diagnostic criteria which allow the discrimination of sediments laid down by tsunami from other high energy mechanisms such as storms and sea level high stands. With regard to the research on the source of the tsunami, the recognition that a submarine landslide likely contributed to the high runups north of the main rupture means that downstream mitigation must be based on more complex tsunami generation that hitherto recognised. Our results show that the 2011 tsunami inundated up to 4.5 km inland but that the >0.5 cm-thick sand deposit extended only 2.8 km (62% of the inundation distance). Farther inland the tsunami deposit continued as a mud layer to the inundation limit. This means that mapping the inland limit of tsunami inundation for older events may be misleading if these are interpreted as maximum inundation; the older tsunamis may be interpreted as much smaller than they actually were. In the instance of the Japan, our newly acquired data on the 2011 event suggest that previous estimates of paleotsunamis (e.g. 869 AD Jogan earthquake and tsunami) in this area have probably been underestimated. With regard to discriminating tsunami from other high energy deposits, our new work also shows that recently deposited tsunami sediments are laminated. Previously this feature was considered to be a major feature of sediments laid down by storms. With regard to the tsunami impact on coastlines it readily became apparent during the field work that there was a major difference between those coasts protected by 'hard' engineering structures, compared to those coastlines which were not. Previously it was considered that 'protected' coasts might not be as badly impacted as 'natural' or unprotected coasts. Our results show that when 'hard' engineered embankments are overtopped by unexpectedly high tsunami they are particularly vulnerable to undercutting and collapse. Our approach to response mapping of areas impacted by devastating tsunamis using digital data interpreted in the office, and exported into the filed on robust propose built laptops for field recording was proved very successful. Studying sediments immediately after they are laid down is critical to observing their essential features, as the deposits are very fragile and are rapidly altered and degraded by human and natural processes. During fieldwork we mapped; i) tsunami inundation, ii) the sediments laid down, iii) tsunami wave heights and, iv) the flow direction of the tsunami waves as they inundated the coastal area. |
| Exploitation Route | The results of the project have thrown a new light on many aspects of tsunami sedimentation and impact, all of which have been published in peer reviewed journals, and disseminated to the public through numerous lectures. It is now apparent that previous methods of identifying maximum inland tsunami inundation only from sand may result in an underestimate of tsunami and hence earthquake magnitude. With regard to tsunami impact, it is apparent that some coastal defence structures may actually result in more damage than if the coast had been undefended. A major downstream development has been the organisation of a multidisciplinary workshop involving scientist, engineers, NGOs and government planners from all major ministries. The workshop objectives were to emphasise the importance of tsunami hazard science to the development of improved response and mitigation strategies. The results were that people involved in response and mitigation did not use the science, in many instances thus was because they were not sufficiently aware and/or did not have the background to understand. We are now attempting to address this situation, by organising workshops and seminars that bring together scientists and potential users of scientific data. With regard to the submarine landslide tsunami source, this need to be validated by further marine surveys and considered in future mitigation strategies. |
| Sectors | Agriculture, Food and Drink,Communities and Social Services/Policy,Education,Environment,Leisure Activities, including Sports, Recreation and Tourism,Government, Democracy and Justice,Culture, Heritage, Museums and Collections,Transport |
| URL | http://www.bgs.ac.uk/research/highlights/2011/japanTsunamiFieldWork.html |
| Description | By other researchers in identifying the impact of older tsunamis. All published papers have been cited in later peer reviewied papers By engineers in developing improved methods of coastal protection. |
| First Year Of Impact | 2012 |
| Sector | Healthcare |
| Impact Types | Economic |
| Description | NERC Urgency grants |
| Amount | £65,000 (GBP) |
| Funding ID | NE/S015930/1 |
| Organisation | Natural Environment Research Council |
| Sector | Public |
| Country | United Kingdom |
| Start | 12/2018 |
| End | 05/2019 |