The S wave project for focal mechanism of the Alaska earthquake sequence 1964 / William Stauder, G.A Bollinger

By: Stauder, William [autor]
Contributor(s): Bollinger, G.A | Defense Advanced Research Projects Agency | Air Force. Cambridge Research Laboratories
Material type: TextTextLanguage: Spanish Publisher: Bedford: Air force Cambridge research Laboratories; 1966Description: 124 hojas: ilustraciones, mapas; 28 x 25 cmContent type: text Media type: unmediated Carrier type: volumeSubject(s): Terremotos -- Alaska | SismologíaDDC classification: 551.229 798/S798 Scope and content: Focal mechanisms have been determined for one preshock, for the main shock, and for more than 25 aftershocks of the Alaska earthquake of March 28, 1964. For the main shock a single nodal plane with a strike azimuth of 66°, dip 85° southeast, is determinable from the polarity of the P wave. This plane may be taken either as a plane normal to the fault motion (thrust faulting) or as the fault plane (dip‐slip motion on a near‐vertical plane). A combination of P wave first motion and S wave polarization data make possible the determination of both nodal planes in each shock studied of the aftershock sequence. One of these planes is near vertical and closely resembles the nodal plane of the main shock; the other dips 5° to 15° to the northwest or north. For earthquakes of the Kodiak Island region, the near‐vertical plane has the same orientation as that of the main shock. For earthquakes to the east of Prince William Sound, this plane shows a systematic change in orientation corresponding to the change in trend of the tectonic features. Three earthquakes that have foci at increasing depths along the line of greatest flexure of the tectonic features differ from the others. The difference in character of these foci probably provides an important clue to the right interpretation of the motion in the main shock. Although the focal mechanism solutions for the shocks are subject to the same ambiguity of interpretation as that of the main shock, criteria which favor a thrust hypothesis are advanced from the interrelation of the foci. From dislocation theory it is shown that differential slip and/or a dipping thrust plane explain satisfactorily the observed vertical displacements at the surface.
Tags from this library: No tags from this library for this title.
    Average rating: 0.0 (0 votes)
Item type Current location Call number Copy number Status Date due Barcode Item holds
Libros Libros BIBLIOTECA DE ING. DE GEOLOGIA Y PETROLEOS
551.229798/S798 (Browse shelf) Ej. 1 Available 150206
Total holds: 0

Misc. No.: AFCRL-66-572.

Misc. No.: Scientific report. No. 1.

Accession No.: 8652

Incluye: referencias bibliográficas hojas 123-124

Focal mechanisms have been determined for one preshock, for the main shock, and for more than 25 aftershocks of the Alaska earthquake of March 28, 1964. For the main shock a single nodal plane with a strike azimuth of 66°, dip 85° southeast, is determinable from the polarity of the P wave. This plane may be taken either as a plane normal to the fault motion (thrust faulting) or as the fault plane (dip‐slip motion on a near‐vertical plane). A combination of P wave first motion and S wave polarization data make possible the determination of both nodal planes in each shock studied of the aftershock sequence. One of these planes is near vertical and closely resembles the nodal plane of the main shock; the other dips 5° to 15° to the northwest or north. For earthquakes of the Kodiak Island region, the near‐vertical plane has the same orientation as that of the main shock. For earthquakes to the east of Prince William Sound, this plane shows a systematic change in orientation corresponding to the change in trend of the tectonic features. Three earthquakes that have foci at increasing depths along the line of greatest flexure of the tectonic features differ from the others. The difference in character of these foci probably provides an important clue to the right interpretation of the motion in the main shock. Although the focal mechanism solutions for the shocks are subject to the same ambiguity of interpretation as that of the main shock, criteria which favor a thrust hypothesis are advanced from the interrelation of the foci. From dislocation theory it is shown that differential slip and/or a dipping thrust plane explain satisfactorily the observed vertical displacements at the surface.

FACULTAD DE GEOLOGIA Y PETROLEOS

BIGP Donación 17/02/2010 $ 0.01 Ej. 1 Biblioteca Facultad de Geología - Petróleos 71504

There are no comments on this title.

to post a comment.
Share

Powered by Koha