Phenomenology Research Using Past Nevada Test Site Explosion and Earthquake Data
Abstract
We use regional waveform data from the Nevada Test Site (NTS) to investigate phenomenological relationships between recorded amplitude and explosion yield as well as test regional depth estimation procedures. Our goal is to better understand the performance of seismic observables in other regions of monitoring interest, especially at small magnitudes (mb much less than 4.5). Some of the topics we are studying include: stable yield estimation, depth estimation, and Ms:mb performance. We use Lawrence Livermore National Laboratory's NTS explosion database, which consists of several hundred events ranging from approx. 200- to approx. 1500-m depth and yields ranging from a few tenths of a kiloton to the megaton range. In addition to the broadband explosion data, we have a large dataset of well-located earthquakes on the test site with depths ranging from 2 to 17 km and magnitudes ranging between MW 1.5 and 5.7. For yield estimation the relation between teleseismic body wave magnitude (mb) and nuclear explosion yield has been studied extensively over the past several decades for a number of test sites for large (greater than 1 kt) explosions. In this paper we will look at broadband coda, Pg, and Lg from over 260 nuclear explosions to study yield estimation capability by comparing F-factors. For monitoring compliance with a CTBT, small events that are recorded only at regional distances will be used to estimate magnitude and equivalent yield. Past coda studies show that coda-derived magnitudes of earthquakes and explosions are more stable than any direct phase method, including mb(Lg). In fact, single-station coda measurements can be equivalent to a network average of at least ten direct phase measurements over a broad range of frequencies.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2000
- Accession Number
- ADA529927
Entities
People
- Jennifer O'boyle
- Kevin Mayeda
- Michael Pasyanos
- Peter A. Goldstein
- Stephen C. Myers
- William R. Walter
Organizations
- Lawrence Livermore National Laboratory