Open AccessAutoregressive Representation of Seismic P ‐wave Signals with an Application to the Problem of Short‐Period Discriminants
Author(s) -
Tjestheim D.
Publication year - 1975
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1975.tb00635.x
Subject(s) - autoregressive model , autocorrelation , white noise , seismology , coda , time series , series (stratigraphy) , spectral density , mathematics , event (particle physics) , seismic wave , geology , statistics , statistical physics , physics , paleontology , quantum mechanics
Summary It is shown that seismic P ‐wave signals can be represented by parametric models of autoregressive type. These are models having the form X(t)‐a 1 X(t –1)‐…‐ a p X(t‐p ) = Z(t) where X(t) is the digitized short‐period data time series defined by the P ‐wave signal, and Z(t ) is a white noise series. The autoregressive analysis is undertaken for 40 underground nuclear explosions and 45 earthquakes from Eurasia. For each event a separate analysis of the noise preceding the event as well as of the P ‐wave coda has been included. It is found that in most cases a reasonable statistical fit is obtained using a low order autoregressive model. The autoregressive parameters characterize the power spectrum (equivalently, the autocorrelation function) of the P ‐wave signal and form a convenient basis for studying the possibilities of short‐period discrimination between nuclear explosions and earthquakes. A preliminary discussion of these possibilities is included.