Global Seismic Network Assessment for Teleseismic Detection of Underground Nuclear Explosions
Abstract
The detection capability of a global seismic network is examined on the basis of a probabilistic model: Given the location of seismograph stations with known background noise level, a worldwide grid of epicenters, and amplitude-distance attenuation curves, the detection capability is expressed by the magnitude corresponding to a fixed probability that a specified minimum number of stations detect an event. A globally distributed network of 50 stations is selected and multiwave detection criteria are applied which take variation of attenuation for different wave types into consideration. The extension of amplitude-attenuation curves to include core phases is investigated and effects of regional attenuation are studied. Depending on the detection criterionand attenuation curve, magnitude thresholds of a 50-station network can vary significantly. The largest influence, however, results from changes in station noise data. Reliable estimates of noise statistics can be derived only from continuous measurements in connection with routine event readings. An indirect method to calculate noise parameters is demonstrated by using station detection thresholds. After estimation of noise statistics from station reportings to the international Seismological Centre for 1980, predicted magnitude detection thresholds and empirical values are in good agreement.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1984
- Accession Number
- ADA173335
Entities
People
- Hans-peter Harjes
Organizations
- Leidos