Bulletin of the Seismological Society of America; April 1970; v. 60; no. 2;
p. 629-637
© 1970 Seismological Society of America
Travel-time study of six central Appalachian earthquakes 1962-1968
G. A. BOLLINGER
DEPARTMENT OF GEOLOGICAL SCIENCES VIRGINIA POLYTECHNIC INSTITUTE, BLACKSBURG, VIRGINIA 24061
Abstract
Travel time studies are made of the data from six central Appalachian earthquakes that occurred during the period 1962 through 1968 in the states of Virginia, West Virginia, Maryland, and North Carolina. Arrival times from forty-two station-epicenter pairs served as input data for the study. Epicentral locations were obtained for the six events with an average standard deviation for the travel time residuals of 0.5 seconds. Nineteen Pn observations in the distance range of 300 to 800 km yield a composite Pn travel-time curve given by
with a 0.19 second standard deviation in the travel-time observations. The inverse slope for the Pg phase was found as 6.24 ± 0.03 km/sec and for the Sg or Lg phases as 3.67 ± 0.02 km/sec.
Magnitude determinations using meus of Evernden (1967) are made for two of the five shocks.
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