Earthquake multiplets in the southeastern Solomon Islands

Physics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

6

Scientific paper

The 350-km stretch of the Solomon Islands trench that lies adjacent to the islands of Guadalcanal and San Cristobal has been the site of 10 large shallow earthquakes since 1966: June 15, 1966 doublet (Ms = 7.7,7.3), May 20, 21, 1977 quadruplet (Ms = 6.7,7.5,7.5,7.5), November 4,5, 1978 doublet (Ms = 6.9,7.1), and two single events on October 23, 1979 (Ms = 7.1) and February 7, 1984 (Ms = 7.7). Analyses of P-wave first-motions, aftershock distributions, P-wave-forms recorded at epicentral distances of 30° to 90° on the WWSSN, and 256 s-period Rayleigh-wave spectra obtained from the IDA and GDSN networks are used to examine the source characteristics of the events. The close temporal association and large size of earthquakes precluded collection of useful seismograms for the latter of the two 1966 events and the second and third events of the 1977 sequence. P-waveforms analyzed show smooth traces that can be modeled with simple trapezoidal source-time functions located at shallow (15-45 km) depths. Focal mechanisms are consistent with oblique subduction of the Indian plate beneath the Pacific plate at about N73°E. Estimates of seismic moment for individual events range from 0.2 to 2.3 × 1027 dyne-cm. Average stress drops of the sequences are estimated to range between 10 and 40 bars. This section of island arc may have ruptured in a similar sequence of earthquakes during the 1930's. Conversion of the cumulative seismic moment to displacement and averaging over 40 years suggests a convergence rate of about 4.5 cm year-1, about one half of the rates that have been assessed on the basis of seafloor magnetic lineations.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Earthquake multiplets in the southeastern Solomon Islands does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Earthquake multiplets in the southeastern Solomon Islands, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Earthquake multiplets in the southeastern Solomon Islands will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1127333

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.