Accession Number:

ADA568812

Title:

Seismic and Geophysical Characterization of Northern Asia

Descriptive Note:

Conference paper

Corporate Author:

MICHIGAN STATE UNIV EAST LANSING

Report Date:

2011-09-01

Pagination or Media Count:

12.0

Abstract:

We are continuing our research effort to improve the seismic calibration of northern Asia. In conjunction with colleagues from the Geophysical Survey of Russia, we conducted a noise survey and station installation in the Amur region, south of the city of Blagoveschensk. For the noise study, four locations, each separated by about one kilometer, were surveyed. The general region was found to be rather noisy, with higher frequencies 1-20 Hz coinciding approximately to the high noise model, while lower frequencies are approximately between the high and low noise models. The noise is not likely anthropogenic, but may be associated with the large Amur river about 10km distant. We conducted a winter deployment of 9 temporary stations in the vicinity of the Susuman mining district to collect data to develop a locally calibrated set of ground truth GT criteria. The current GT criteria using P arrivals for teleseismic events established by Bondar is generally not applicable to the eastern Russia data set as most arrivals are secondary Pg and Sg Lg onset time picks. The deployed temporary stations supplement 6 permanent stations, and encircle the mining region at varying distances out to about 250km. During the course of the deployment, we recorded 6 mine blasts with yields ranging up to 70 tons. An additional station was deployed at the explosion sites to record the exact origin time and location. Following our earlier work to determine new GT locations for Yakutian peaceful nuclear explosions PNEs, we are now investigating how the new locations influence velocity model determination. Using arrivals from both the eastern Russia regional as well as teleseismic seismic stations we have estimated new origin times for Crystal, Neva-1, Neva-2-1, and Neva-2-3. We used the 3-d velocity model and locator under development at SNL and LANL while holding the new PNE latitude and longitude information fixed. We find differences between the time-distance relationships for Crystal

Subject Categories:

  • Geology, Geochemistry and Mineralogy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE