NNSA - National Nuclear Security Administration

09/16/2020 | News release | Distributed by Public on 09/16/2020 10:04

NNSA team improves model to pinpoint nuclear testing locations

The team, from Los Alamos National Laboratory, Lawrence Livermore National Laboratory, and Sandia National Laboratories, recently delivered a revision of the Regional Seismic Travel Time (RSTT) monitoring technology to a division of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) in Vienna.

The improved software was the result of years of development and includes almost a decade's worth of new data on the geophysical model of Earth's crust and upper mantle. The data set now includes information spanning all seven continents and ocean floor areas where earthquakes and other seismic events occur, providing more detail and improving the confidence in locations the system identifies.

'This is a great example of U.S. technical leadership helping the world,' said Dr. Brent Park, NNSA Deputy Administrator for Defense Nuclear Nonproliferation. 'If you have a more accurate seismic event location, you can use the other tools in your toolbox to determine whether or not a suspicious event was a clandestine nuclear test.'

One such tool that can help confirm nuclear blasts is detecting radioactive noble gases, which are created during nuclear explosions and are difficult to hide. By providing a high-confidence seismic source location, RSTT helps the world's noble gas detection experts focus their efforts on a specific area, enhancing accuracy.

RSTT was originally developed by the National Laboratories in the late 2000s, and they have helped hone the model and software ever since. Because of its utility in nuclear explosion monitoring, the U.S. government shared it with the CTBTO in 2012, where it has become a mainstay of the organization's operations.

RSTT is publicly available for download at