Seismicity of Island Arcs and Other Arc Tectonic Regions of the Circum-Pacific Zone

  1. Leon Knopoff,
  2. Charles L. Drake and
  3. Pembroke J. Hart
  1. Setumi Miyamura

Published Online: 18 MAR 2013

DOI: 10.1029/GM012p0060

The Crust and Upper Mantle of the Pacific Area

The Crust and Upper Mantle of the Pacific Area

How to Cite

Miyamura, S. (2012) Seismicity of Island Arcs and Other Arc Tectonic Regions of the Circum-Pacific Zone, in The Crust and Upper Mantle of the Pacific Area (eds L. Knopoff, C. L. Drake and P. J. Hart), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM012p0060

Author Information

  1. Earthquake Research Institute, University of Tokyo, Japan

Publication History

  1. Published Online: 18 MAR 2013
  2. Published Print: 20 APR 2012

Book Series:

  1. Geophysical Monograph Series

Book Series Editors:

  1. Waldo E. Smith

ISBN Information

Print ISBN: 9780875900124

Online ISBN: 9781118663738

SEARCH

Keywords:

  • Circum-Pacific zone;
  • Earthquakes;
  • Island arcs;
  • Magnitude-frequency relations;
  • Preliminary Determination of Epicenters (PDE);
  • Seismicity;
  • USCGS

Summary

Seismicity of the circum-Pacific regions, including all known island arcs, has been investigated by the computer processing of PDE data for 1965 supplied by the U.S Coast and Geodetic Survey. Magnitude-frequency relations for the different regions seem to suggest the tectonic ages of the respective regions. The relation of seismic activity to depth in each circum-Pacific region reveals the existence of a common aseismic transient layer at a depth of 300–450 km between deep and intermediate earthquakes layers. For Japan to Kamchatka and the Marianas, this minimum seismicity layer shifts to shallower and deeper levels, respectively. Although the deep and intermediate depth earthquakes are distributed on an inclined zone dipping toward the continental side of the arc, they are generally separated by the aseismic transient layer. Only in a certain limited part of the whole length of the arc are they connected by a small irregular-shaped column with fewer foci.