HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) References Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by JOHNSON, S. H. Articles by COUCH, R. W. Search for Related Content GeoRef GeoRef Citation

Crustal structure in the North Cascade Mountains of Washington and British Columbia from seismic refraction measurements

DEPARTMENT OF OCEANOGRAPHY OREGON STATE UNIVERSITY, CORVALLIS, OREGON 97331

Abstract

Seismic waves generated by large chemical explosions at Greenbush Lake, British Columbia, were recorded at 15 stations along two profiles which extend from the shot point across the North Cascade Mountains of British Columbia and Washington into western Washington. T = /6.13 expresses the time-distance curve for P_g. The equation T = 6.21 + /7.91 expresses the P_n arrival time along a line of azimuth of 210.4° out to a distance of 519 km and the equation T = 6.85 + /8.06 expresses the P_n arrival time along a line of azimuth of 223.0° out to a distance of 540 km. Calculations, which assume a mantle velocity of 7.96 km/sec, indicate that crustal thickness increases toward the south and decreases toward the west. The average crustal thickness along azimuth 210.4° is 32 km and along 223.0° is 29 km. Amplitude data have large scatter but suggest a Q value near 384 for rocks of the upper mantle beneath the North Cascade Mountains.

This article has been cited by other articles:

				C. E. ZERVAS and R. S. CROSSON Pn observation and interpretation in Washington Bulletin of the Seismological Society of America, April 1, 1986; 76(2): 521 - 546. [Abstract] [PDF]

				C. A. LANGSTON Corvallis, Oregon, crustal and upper mantle receiver structure from teleseismic P and S waves Bulletin of the Seismological Society of America, June 1, 1977; 67(3): 713 - 724. [Abstract] [PDF]

				R. L. MCCOLLOM and R. S. CROSSON An array study of upper mantle velocity in Washington State Bulletin of the Seismological Society of America, April 1, 1975; 65(2): 467 - 482. [Abstract] [PDF]

				R. S. CROSSON Small earthquakes, structure, and tectonics of the Puget Sound region Bulletin of the Seismological Society of America, October 1, 1972; 62(5): 1133 - 1171. [Abstract] [PDF]