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 CROSSON, R. S. Articles by KEY, S. C. Search for Related Content GeoRef GeoRef Citation

The southern Italy earthquake of 23 November 1980: An unusual pattern of faulting

GEOPHYSICS PROGRAM UNIVERSITY OF WASHINGTON, SEATTLE, WASHINGTON 98195
OSSERVATORIO VESUVIANO, 80056 ERCOLANO, NAPLES, Italy

Abstract

A complex rupture history for the 23 November 1980 magnitude 6.9 Italian earthquake resulted in an unusual pattern of two high-angle, subperpendicular normal faults forming the corner of a down-dropped crustal block. Evidence for this interpretation is from aftershocks, the pattern of strong ground motion, focal mechanism of the mainshock, and two critically placed leveling profiles. Quantitative modeling of leveling profiles using smoothly varying dislocation segments provides confirmation of the fault pattern and specific verification of the existence of a secondary fault which is suborthogonal to the primary fault. Rupture began on the NW-trending main fault with downward motion of the northeast block. About 40 sec after initial motion began, rupture initiated on an orthogonal NE-trending subsidiary fault, propagating away from the main fault. This fault pattern is consistent with tectonic extension in a northeasterly direction.

This article has been cited by other articles:

				Stress Triggering of Conjugate Normal Faulting: Late Aftershocks of the 1983 Ms 7.3 Borah Peak, Idaho, Earthquake Bulletin of the Seismological Society of America, June 1, 2004; 94(3): 828 - 844.

				L. E. Jones and S. E. Hough Analysis of broadband records from the 28 June 1992 Big Bear earthquake: Evidence of a multiple-event source Bulletin of the Seismological Society of America, June 1, 1995; 85(3): 688 - 704. [Abstract] [PDF]

				D. Amorese, J.-R. Grasso, L. M. Plotnikova, B. S. Nurtaev, and R. Bossu Rupture kinematics of the three Gazli major earthquakes from vertical and horizontal displacements data Bulletin of the Seismological Society of America, April 1, 1995; 85(2): 552 - 559. [Abstract] [PDF]

				L. SIRO and C. CHIARUTTINI Source complexity of the 1980 Southern Italian earthquake from the analysis of strong-motion S-wave polarization Bulletin of the Seismological Society of America, December 1, 1989; 79(6): 1810 - 1832. [Abstract] [PDF]

				A. ROVELLI, O. BONAMASSA, M. COCCO, M. DI BONA, and S. MAZZA Scaling laws and spectral parameters of the ground motion in active extensional areas in Italy Bulletin of the Seismological Society of America, April 1, 1988; 78(2): 530 - 560. [Abstract] [PDF]

				F. SABETTA and A. PUGLIESE Attenuation of peak horizontal acceleration and velocity from italian strong-motion records Bulletin of the Seismological Society of America, October 1, 1987; 77(5): 1491 - 1513. [Abstract] [PDF]

				R. WESTAWAY Comment on "The southern Italy earthquake of 23 November 1980: An unusual pattern of faulting" by R. S. Crosson, M. Martini, R. Scarpa, and S. C. Key Bulletin of the Seismological Society of America, June 1, 1987; 77(3): 1071 - 1074. [PDF]

				R. S. CROSSON, M. MARTINI, R. SCARPA, and S. C. KEY Reply to R. Westaway's "Comment on 'The southern Italy earthquake of 23 November 1980: an unusual pattern of faulting'" Bulletin of the Seismological Society of America, June 1, 1987; 77(3): 1075 - 1077. [PDF]