Crustal and Upper Mantle Seismic Velocity Structure of the Former USSR from Peaceful Nuclear Explosions (PNEs) and Chemical Explosion Data
Abstract
In the past forty years, the Ministry of Geology of the former USSR committed vast funds to investigations of the structure of the continental crust and upper mantle by seismic methods. The former USSR is crisscrossed by a network of seismic profiles that are more detailed than in any other part of the world. There are three kinds of profiles: (1) short-range refraction; (2) Deep Seismic Sounding (DSS) profiles; and (3) ultra-long range seismic profiles using Peaceful Nuclear Explosions (PNEs). The main goal of the shortrange refraction work was to image sedimentary cover and basement. Measurements were obtained using 48-60 channel analog instruments with 100 m receiver spacing, and seismograms were recorded on photographic paper by the wiggle trace method. The DSS observations were mainly used for crustal studies. The shotpoint spacing was 30-50 km, and three components of ground displacement were recorded. The refracted and reflected compressional (P) and shear waves (S), and converted waves were interpreted. Ultra-long range PNE-sourced profiles provided information on the structure of the crust and upper mantle to a depth of 670 km. For PNE profiles, up to 400 short-period (1.5-20 Hz), three-component seismometers were deployed every 5-10 km to record ground motion. Thirty-nine PNE shots were detonated for these purposes, with intermediate chemical shots spaced at 40-70 km intervals. These chemical shots had charges ranging from 2000 to 5000 kg. The total length of all of these three types of profiles exceeds 80 thousand kilometers. We present a synthesis of these results in the form of updated maps of depth to basement and depth to Moho in Russia.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2000
- Accession Number
- ADA530294
Entities
People
- A. V. Egorkin
- Sergei Kostyuchenko
- Walter D. Mooney