Applying Source and Path Corrections to Improve Discrimination in China,

PDF Version Also Available for Download.

Description

Monitoring the Comprehensive Test Ban Treaty (CTBT) to magnitude levels below 4.0 will require use of regional seismic data recorded at distances of less than 2000 km. To improve regional discriminant performance we tested three different methods of correcting for path effects, and the third method includes a correction for source-scaling. We used regional recordings of broadband from stations in and near China. Our first method removes trends between phase ratios and physical parameters associated with each event-station path. This approach requires knowledge of the physical parameters along an event-station path, such as topography, basin thickness, and crustal thickness. Our ... continued below

Physical Description

14 p.

Creation Information

Hartse, H.E., Taylor, S.R., Phillips, W.S., Randall, G.E. December 31, 1997.

Context

This report is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this report can be viewed below.

Who

People and organizations associated with either the creation of this report or its content.

Sponsor

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this report. Follow the links below to find similar items on the Digital Library.

Description

Monitoring the Comprehensive Test Ban Treaty (CTBT) to magnitude levels below 4.0 will require use of regional seismic data recorded at distances of less than 2000 km. To improve regional discriminant performance we tested three different methods of correcting for path effects, and the third method includes a correction for source-scaling. We used regional recordings of broadband from stations in and near China. Our first method removes trends between phase ratios and physical parameters associated with each event-station path. This approach requires knowledge of the physical parameters along an event-station path, such as topography, basin thickness, and crustal thickness. Our second approach is somewhat more empirical. We examine spatial distributions of phase amplitudes after subtracting event magnitude and correcting for path distance. For a given station, phase, and frequency band, we grid and then smooth the magnitude-corrected and distance-corrected amplitudes to create a map representing a correction surface. We reference these maps to correct phase amplitudes prior to forming discrimination ratios. Our third approach is the most complicated, but also the most rigorous. For a given station and phase, we invert the spectra of a number of well-recorded earthquakes for source and path parameters. We then use the values obtained from the inversion to correct phase amplitudes for the effects of source size, distance, and attenuation. Finally,the amplitude residuals are gridded and smoothed to create a correction surface representing secondary path effects. We find that simple ratio- parameter corrections can improve discrimination performance along some paths (such as Kazakh Test Site (KTS) to WMQ), but for other paths (such as Lop Nor to AAK) the corrections are not beneficial. Our second method, the empirical path correction surfaces, improves discrimination performance for Lop Nor to AAK paths. Our third method, combined source and path corrections, has only been tested at WMQ (primarily using KTS explosions and northwest China earthquakes), but the method successfully corrects for source-scaling and propagation effects. We favor this combined source and path correction technique over the other correction methods, and we plan to test this method at other Asian stations. 11 refs., 7 figs.

Physical Description

14 p.

Notes

OSTI as DE98000617

Source

  • Research symposium on monitoring a comprehensive test ban treaty, Orlando, FL (United States), 23-25 Sep 1997; Other Information: DN: [540 459900]

Language

Item Type

Identifier

Unique identifying numbers for this report in the Digital Library or other systems.

  • Other: DE98000617
  • Report No.: LA-UR--97-2644
  • Report No.: CONF-970967--
  • Grant Number: W-7405-ENG-36
  • Office of Scientific & Technical Information Report Number: 618158
  • Archival Resource Key: ark:/67531/metadc690782

Collections

This report is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

What responsibilities do I have when using this report?

When

Dates and time periods associated with this report.

Creation Date

  • December 31, 1997

Added to The UNT Digital Library

  • Aug. 14, 2015, 8:43 a.m.

Description Last Updated

  • Feb. 29, 2016, 1:08 p.m.

Usage Statistics

When was this report last used?

Yesterday: 0
Past 30 days: 0
Total Uses: 7

Interact With This Report

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

International Image Interoperability Framework

IIF Logo

We support the IIIF Presentation API

Hartse, H.E., Taylor, S.R., Phillips, W.S., Randall, G.E. Applying Source and Path Corrections to Improve Discrimination in China,, report, December 31, 1997; New Mexico. (digital.library.unt.edu/ark:/67531/metadc690782/: accessed September 20, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.