(94.03.24)田中大使ＣＤ（ＣＴＢＴ）

TOKYO WORKSHOP ON CTB VERIFICATION

STATEMENT BY H.E. MR. YOSHITOMO TANAKA

TO THE CONFERENCE ON DISARMAMENT

Geneva, 24 March 1994

　 Let me congratulate you, Mr. President, on your assumption of the Presidency of the Conference when it addresses important issues for the international community and assure you of our full cooperation.

　 I have taken the floor today to report to the Conference on the Tokyo Workshop on CTB Verification held last week.

　 The Government of Japan hosted a Workshop on CTB Verification from Monday 14 to Wednesday 16 of March, aiming at:

(1) identifying problems of CTB Verification based primarily on seismological methods and trying to seek ways to cope with them in order to promote the CTBT negotiations, and

(2) acquainting the workshop participants with Japanese seismic monitoring technologies which could be applicable to the International Seismic Monitoring System (ISMS).

　 38 experts and officials from 24 countries, i.e. Australia, China, the Czech Republic, Egypt, Finland, France, Germany, Hungary, India, Indonesia, Italy, Japan, Mexico, the Netherlands, New Zealand, Norway, Pakistan, Peru, the Russian Federation, South Africa, Spain, Switzerland, the United Kingdom and the United States actively participated in the discussions, briefings and demonstrations held at the Japanese Ministry of Foreign Affairs and Meteorological Agency. In the plenary meeting where both seismologists and officials in charge of CTBT negotiations were present, they discussed the issues of (1) effectiveness of seismological verification technologies, (2) estimated cost of seismological verification, (3) operation of a seismological verification system in a CTB and (4) means to supplement seismological verification for a CTB. I should like to take this opportunity to thank the Netherlands, the United States, Norway and Australia whose representatives made presentations on the 4 issues respectively, and other participant countries for the comments which their representatives made.

　 Although the discussions were held in an informal manner to encourage the participants as qualified individuals to exchange their views freely, with no aim of adopting a final document or a report of conclusions, the Japanese Delegation feels it may be useful to highlight for the Conference some of the interesting points raised in the Workshop.

　 With respect to "effectiveness of seismological verification technologies", among the important questions addressed in the Workshop were such questions as how one could identify a possible nuclear explosion out of so many seismic events taking place everyday and who should be responsible for conducting such a task. A reply given in the Workshop was that while the ultimate responsibility for the identification work might rest with the National Data Center of each State Party to the CTBT, the International Data Center could do significant work and that the room left for the final judgement of the national authority might be relatively limited. In this connection, it was pointed out that the IDC would expeditiously publish seismic bulletins which would include information on the origin time, the location, the depth, the body and surface wave magnitudes of the seismic events detected by the monitoring network, and would keep all relevant information on seismic waves, and that the identification work might be greatly facilitated by such information made available by the IDC. If a seismic event is located at the bottom of the ocean or in a highly populated area, it is unlikely that it was a nuclear explosion. If the epicenter is found to be deeper than 10 km, the event is probably a natural earthquake. The ratio of the body and surface wave magnitudes and the pattern of the wave form will make a decisive contribution to identifying whether the seismic event in question is a natural earthquake or not. Though it may be difficult for the IDC to give a final analysis on all seismic events, it was argued in the Workshop that it would be useful to agree to the procedure with which the IDC would group all seismic data into two categories, namely those which indicate that the event in question is a natural phenomenon and those which raise a doubt that a nuclear explosion may have occurred.

　 As for "estimated cost of seismological verification", cost estimates for GSETT-3 were given. It was stated that the overall annual operational costs for GSETT-3 might be US$ 30 Million, as the communication costs could be as high as $ 12 Million, and a suggestion was made to consider exemption or reduction of local tariffs to cut the communications costs.

　 No doubt these figures will provide an important basis for the consideration of a future CTBT verification system. Some of the issues which require decisions of a political nature will be how these costs should be borne among the CTBT Organization and States Parties, and whether we need to consider making a special fund in the future Organization.

　 With respect to "means to supplement seismological verification for a CTB", the participants were reminded of the valuable CD papers including a questionnaire which had already been circulated in the Verification Working Group.

　 And last but not least, the Japan Meteorological Agency showed the participants the automated seismic detection system already in operation in Japan. The Agency completely opened to the seismic experts the program of a fully automated method for detecting the arrival times of seismic waves and its application to an on-line processing system, providing them with the papers and floppy disks on the theory with the formulae, diagrams, tables, charts, etc.. Japan believes that this method can substantially contribute to the formation of a reliable and cost-effective CTBT verification system.

　 In conclusion, Mr. President, the Japanese Delegation hopes that the Tokyo Workshop has given additional food for thought to the participant countries and will make some contribution to the important CTBT negotiations under way here in Geneva.

Thank you, Mr President.