Regional Seismic Travel Time

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Rapid computation

RSTT computes seismic travel times from tomographic models in microseconds, capturing the major effects of 3D structure in the crust and upper mantle.

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High-resolution tessellation

RSTT uses the GeoTess software library to tessellate the Earth into approximately 1° triangles with radial arrays at each vertex, improving resolution and producing a better tomographic model.

What is RSTT?

RSTT (Regional Seismic Travel Time) is a method, model, and software package that improves the accuracy of regional seismic travel time prediction and event location. The software package includes a computerized representation of 3‐dimensional seismic wave speed for Earth’s crust and shallow mantle and a computer code to calculate travel times for seismic phases that are commonly used to locate events. RSTT was designed with real‐time monitoring in mind, and travel times can be computed on-the-fly in approximately 100 microseconds on a modern laptop.

How does RSTT advance monitoring?

RSTT advances monitoring by improving travel time prediction and location accuracy. By utilizing regional data (within 1500 km of an event), it accounts for the extreme variability in wavespeed in the Earth’s crust. RSTT most greatly improves travel time predictions for regional networks; however, global networks with at least a few stations within regional distance of an event (e.g. the International Monitoring System) also benefit.

The ultimate goal of the RSTT effort is global calibration of the four most prominent regional phases used in monitoring (Pn, Pg, Sn, Lg). RSTT calibrations have been conducted in several regions to date, including North and South America as well as Eurasia. Extension of RSTT calibration to new regions is being pursued through international collaborative efforts.

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The RSTT software is available for download as source code or as a pre-compiled Python module MacOS and Linux.

See the Software page for more information.

Selected publications

Begnaud, M. L., S. C. Myers, B. A. Young, J. R. Hipp, D. Dodge, and W. S. Phillips (2020). Updates to the Regional Seismic Travel Time (RSTT) Model: 1. Tomography. Pure Appl. Geophys., 24 pp. doi: 10.1007/s00024-020-02619-5

Begnaud, M. L., D. N. Anderson, S. C. Myers, B. A. Young, J. R. Hipp, and W. S. Phillips (2021). Updates to the Regional Seismic Travel Time (RSTT) Model: 2. Path-dependent Travel-time Uncertainty, Pure Appl. Geophys., 27 pp. doi: 10.1007/s00024-021-02657-7

Myers, S. C., M. L. Begnaud, S. Ballard, M. E. Pasyanos, W. S. Phillips, A. L. Ramirez, M. S. Antolik, K. D. Hutchenson, J. Dwyer, and C. A. Rowe, and G. S. Wagner (2010). A crust and upper mantle model of Eurasia and North Africa for Pn travel time calculation, Bull. Seismol. Soc. Am., 100(2), pp. 640–656. doi: 10.1785/0120090198

Phillips, W. S., M. L. Begnaud, C. A. Rowe, L. K. Steck, S. C. Myers, M. E. Pasyanos, and S. Ballard (2007). Accounting for lateral variations of the upper mantle gradient in Pn tomography studies. Geophys. Res. Lett., 34(14). 5 pp. doi: 10.1029/2007GL029338

Last Updated: 2022 Apr 25