資料2 国際評価の結果について

Chris Newhall氏からの主な評価

 

Japan has long been a world leader in both the science and mitigation of earthquake and volcanic hazards. The proposal sent for review draws significantly from previous, very successful programs in earthquake and eruption studies, and it is wise to keep these core programs.

・・・

The earthquake community has long been divided between advocates of probabilistic forecasts, based solely on statistical recurrence, vs. deterministic “predictions” based on a full understanding of how faults build toward rupture. Many volcanologists including this reviewer reject that dichotomy. When we are forecasting the outcome of volcanic unrest, we often use event trees with probabilities on each branch or scenario. Probabilities are estimated using a variety of data and reasoning, very often using a working hypothesis about processes that are causing the unrest. The concept of hybrid probabilistic forecasting, based both on history and statistics AND on interpretations of process is described in:

Marzocchi, W., Neri, A., Newhall, C.G., Papale, P., 2007, Probabilistic volcanic hazard and risk assessment. Eos, Trans. Am. Geophys. Union, 88:32, p. 318 and

http://www.agu.org/eos_elec/2007/32-318.html

・・・

We can use numerical models, conceptual models, experiments, monitoring, and history as a guide. The key word in the last sentence is “and.” No single approach is sufficient.

・・・

Both models and event trees force us to try to understand whole systems.

・・・

The proposal to establish accessible databases for seismic and volcanic information is good. Seismology has already moved far in that direction and volcanology is starting to do the same.

・・・

I strongly recommend that this new database effort in Japan be readily compatible with WOVOdat.

・・・

The high quality of Japan’s earthquake and volcano problems has not diminished as a result of the Tohoku-oki earthquake and tsunami. Confidence may have been shaken, yes, but the quality remains high. In my opinion, the only major changes that are needed are the proposed new emphases on multiple scenarios including extream events, probabilities thereof, and data sharing. Because extreme events are so rate,they require a view across the broadcast possible timeframes(up to geographic) and spiral dimensions(entire subduction zones or arcs), and the tracking of multiple scenarios with time-variant probabilities.

 

 

Jean-Paul Montagner氏からの主な評価

 

・・・

I think that, to my opinion and from the international point of view, Japanese universities and research institutions are presently making the best science in the world on earthquake and volcanic eruption phenomena.

・・・

Most of the proposed actions are already ongoing and this revised version only focus on some specific points that arose since march 2011.

・・・

The revised version proposes updated observing system (particularly on the seafloor), improved data management system, computer facilities, field and laboratory experiments, and scientific research.

・・・

As for me, the most important point of the proposal is the improvement of the observation system.

・・・

Another important point is the increased need for HPC (High Performance Computing) system for modeling and simulating seismic, volcanic and geophysical processes.

・・・

It is difficult to know who do what, how is the whole governance of the system? It might be useful to have an organization charts with arrows showing how the information is centralized and redistributed.

・・・

In conclusion, this proposal tries to correct some imperfections of the previous programme and to incorporate new ideas following the Tohoku-Oki earthquake. The new scientific issues which are put forward since the Giant Japanese earthquake, are well investigated by the Japanese scientific community. The proposed programme is going in the right direction and must be supported. More specific examples, and some priorities must be defined more clearly, and the organisational governance of the whole system must be clarified.

 

 

Ramon Carbonell氏からの主な評価

 

・・・

Also within this Part 1. The subsections entitled: (Why scientists failed to forecast the giant Earthquake) and (Current state and limitations of Earthquake forecasting research) are, perhaps the most important subsections of the document. They could probably be unified to avoid repetitions and its title should probably be changed to: Difficulties and/or major problems in forecasting giant Earthquakes.

・・・

Within the actions to related to promote joint international research and international cooperation a link to the European research Institutions and European research programs promoted by the European Research Council, the European Science foundation within the Framework Programs (currently FP-7) is lacking.For example the current research program could benefit from the relatively large scale EPOS project (http://www.epos-eu.org/) funded by the EU FP7 or others related to seismic risk and hazard also funded by the EU. European Countries such as Italy and Greece are also prone to Earthquakes and could also provide a link to the project.

 

The document establishes in detail a relatively large number of aspect which should be covered during the development of the project within the theme of Public awareness and outreach, undoubtedly this is a carefully prepared guideline perhaps the only point that could be included is and effort to develop documentary, film material similar to the series produced by National Geographic or Discovery channel, perhaps some sort of interaction with this or similar companies could be explored.

・・・

 

 

Thomas H. Jordan氏からの主な評価

 

・・・

There are good opportunities for improving observations related to giant earthquakes through the development of seafloor instrumentation and other monitoring technologies. In this highly technological area, Japan is clearly the REVIEW OF DRAFT REPORT 2 international leader, so such developments can build on existing capabilities.

・・・

・・・

In the reprioritized program, it is essential that Japan maintain the excellence of its existing networks of seismographic and geodetic instruments, as well as its strong research program to use these observations for improving probabilistic seismic hazard analysis (PSHA).

・・・

Giant earthquakes are devastating but extremely rare events. The concern about the possibility of a giant earthquake in the Nankai Trough is justified; a strong research program should be mounted to evaluate all aspects of this possibility, and the population should be prepared accordingly. But a balanced program should consider giant events in their appropriate relation to inland earthquakes, intra-slab earthquakes, and megathrust earthquakes of smaller magnitude. The report is not very explicit about the research needed to further the knowledge of these other sources, especially the much more frequent occurrence of damaging inland earthquakes.

・・・

In general, the report does not present the opportunities for new research in the specific context of recently acquired scientific knowledge. While I recognize this is difficult to do in a relatively brief and urgent document, the plan would be strengthened if it distilled the leading-edge results that strongly motivate or condition new research.

・・・

・・・

However, the overall plan for collecting and utilizing geologic data is weak and could be strengthened.

 

Similar comments pertain to studies of strong ground motions caused by earthquakes,

・・・

・・・

The ERI Joint Usage/Research Centers is explicitly mentioned in the report; the DPRI Joint Usage/Research Centers is not, although both could play important roles.

・・・

・・・

From my perspective as an outsider, the pace at which research results have been incorporated into past hazard assessments appears to have been slowed by a disconnection between university and government research centers,

・・・

 

 

William L. Ellsworth氏からの主な評価

 

・・・

Despite these difficulties, tremendous scientific achievements have been made in understanding the source process of this great earthquake, thanks in large part to the wise investments the Government of Japan made in basic observation systems following the 1995 Hyogo-ken Nambu earthquake.

・・・

・・・

I would strongly 2 recommend to you that the revision of the long-term (time-independent) probabilistic seismic hazard map for Japan receive the top priority under the revised plan.

・・・

Establishing the potential and frequency of such events received too little attention in the original FY2009-FY2013 plan and its revision should make addressing this deficiency its top priority.

 

お問合せ先

研究開発局地震・防災研究課

(研究開発局地震・防災研究課)