Structure at the Source Physics Experiment Site Revealed by Large-N Arrays

Session: Explosion Seismology Advances
Type: Oral
Date: 4/29/2020
Time: 03:15 PM
Room: 240
Description: 

The Source Physics Experiment (SPE) is a multi-institutional, multi-disciplinary project that consists of a series of chemical explosions conducted at the Nevada National Security Site (NNSS). The goal of SPE is to understand the complicated effect of geological structures on seismic wave propagation and source energy partitioning, develop and validate physics-based modeling and ultimately better monitor nuclear explosions. The SPE program is multi-phase with the completion of Phase I located in hard rock (granite) in 2017 and the completion of Phase II (DAG – Dry Alluvium Geology) located in weak rock (alluvium) in 2019. Large-N seismic arrays were deployed at both the SPE Phase I and Phase II sites to image the full 3-D wavefields from chemical explosions. The large-N arrays recorded multiple chemical explosions with different yields and depths. For each explosion experiment, the large-N array also recorded weeks of continuous data before and after the explosion. The continuous records include ambient noise, aftershocks and earthquakes. In this work, we use the data recorded by the large-N arrays to study the multi-scale structure at the SPE sites. Our analyses include waves from chemical explosions and earthquakes as well as ambient noise. We reveal distinct geological layers of alluvium, volcanic tuff and sedimentary rocks. Three-dimensional variations of geological structure are observed and will be incorporated into the large modeling efforts to improve our understanding of seismic characteristics from explosions.

Presenting Author: Ting Chen

Authors