Testing the Effects of Velocity Models for Seismic Location in the DNE18
Virtual Experiment
Abstract
The Dynamic Network Experiment 2018 (DNE18) was a virtual experiment
designed to quantitatively assess current capabilities for multi-modal
data ingestion and processing for nuclear explosion monitoring at the
local/regional scale. This assessment will allow us to identify and
prioritize remaining challenges that need to be met to achieve desired
monitoring capabilities. The experiment was a collaborative effort
between Los Alamos National Laboratory, Lawrence Livermore National
Laboratory, Pacific Northwest National Laboratory, and Sandia National
Laboratories. We describe efforts to test various velocity models for
any bias or other recognizable patterns using two-week, analyst-built
event (ABE) bulletin. The data set includes over 6000 events
manually-built by the analyst using the Utah Seismic Network which
includes about 182 seismo-acoustic stations, 152 of which have analyst
arrival picks. There are active mines in the state of Utah, many of
which are associated with clusters of events. The ABEs include mostly Pg
and Lg arrivals for events within Utah and some just outside the state.
Global events were also picked that included teleseismic P and S as well
as core phases, etc. although these are not included in this study. We
test local, regional, and global P and S velocity models (1-D, 2-D, 3-D)
for their effect on the event locations, paying attention to overall
epicenter shifts, residual reduction, and error ellipses. Many of the
event clusters are good candidates for application of relative
relocation techniques.