The determination of focal mechanisms using P- and S- Wave data
Advanced Search
Select up to three search categories and corresponding keywords using the fields to the right. Refer to the Help section for more detailed instructions.

Search our Collections & Repository

For very narrow results

When looking for a specific result

Best used for discovery & interchangable words

Recommended to be used in conjunction with other fields

Dates

to

Document Data
Library
People
Clear All
Clear All

For additional assistance using the Custom Query please check out our Help Page

The NOAA IR serves as an archival repository of NOAA-published products including scientific findings, journal articles, guidelines, recommendations, or other information authored or co-authored by NOAA or funded partners. As a repository, the NOAA IR retains documents in their original published format to ensure public access to scientific information.
i

The determination of focal mechanisms using P- and S- Wave data

Filetype[PDF-93.37 MB]


Select the Download button to view the document
This document is over 5mb in size and cannot be previewed

Details:

  • Personal Author:
  • Corporate Authors:
  • NOAA Program & Office:
  • Description:
    The National Oceanic and Atmospheric Administration computes focal plane solutions using P-wave first motion, S-wave polarization angles, and combinations of the two. These calculations have been programmed for a CDC-6600 computer. A new method is used, based on a maximum-likelihood argument implemented by the generation of a rigorously derived score surface on a discrete grid.The combined score is of the form a(P-score) + b(S-score) where a and b and the score values are derived by a maximum—likelihood argument.For the P-solution and S-solution, the computer system also produces contoured fiducial regions about the poles of the focal planes on an equal-area projection of the lower focal hemisphere. This permits an evaluation of the quality of the solutions and makes possible the comparison of solutions for different earthquakes. These contoured limits have a probabilistic interpretation as 95-percent fiducial regions, a term explained in the context of the general problem of the construction of confidence regions. A new graphical method for P-wave solutions makes possible the construction of exact boundaries of the regions of possible variation. The Aleutian earthquake of May 14,19 69, is analyzed, and the solution shows good agreement between the observed P-wave first motions and the S-polarization angles. This analysis gives practical support to the validity of combined solutions.
  • Keywords:
  • Series:
  • Document Type:
  • Rights Information:
    Public domain
  • Compliance:
    Library
  • Main Document Checksum:
  • Download URL:
  • File Type:

Supporting Files

  • No Additional Files
More +

You May Also Like

Checkout today's featured content at repository.library.noaa.gov

Version 3.27.1