Accession Number:

ADA526961

Title:

The Confidence-Building Measure Role of Seismic Calibration

Descriptive Note:

Conference paper

Corporate Author:

DEPARTMENT OF ENERGY GERMANTOWN MD NATIONAL NUCLEAR SECURITY ADMINISTRATION

Report Date:

2000-09-01

Pagination or Media Count:

7.0

Abstract:

Confidence-Building Measures CBMs under the Comprehensive Nuclear-Test-Ban Treaty CTBT address the political goal of alleviating compliance concerns raised by chemical explosions and the technical goal of calibrating the International Monitoring System IMS ref. Article IV, E, and Part III of the Protocol to the Treaty. The term calibration appears in the Treaty associated only with CBMs and On-Site Inspections OSIs and has different meanings in each case. For OSI, calibration refers to calibration of the on-site monitoring instruments, whereas, for CBMs, it refers to seismic travel-time corrections for specific paths to improve event location. Calibration of a path is either carried out empirically using known sources or compensated for through earth models. Known sources are called calibration or reference events and are characterized by information known as ground truth. In practice, the accuracy of the ground truth varies for different types of reference events. Mining explosions or explosions carried out for the express purpose of calibration have the highest degree of accuracy since the location and origin time are known from direct measurement. An example of a calibration event with less accurate ground truth is an earthquake that occurs within a local network with large enough magnitude to be observed regionally. Such events have location accuracy typically less than 5 km. Outside of mining regions and seismically active regions where reference events are plentiful, path calibration will need to be estimated with earth models developed from studies such as seismic refraction experiments. These models will be the result of the integration of all available information and need to be tested-most likely with dedicated calibration experiments-over the region for which they are considered to be valid. Clearly, developing path calibrations is a large effort that requires the cooperation of scientists all over the world. This paper describes preferred

Subject Categories:

  • Seismology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE