An automated time-window selection algorithm for seismic tomography
Abstract
We present FLEXWIN, an open source algorithm for the automated selection of time windows on pairs of observed and synthetic seismograms. The algorithm was designed specifically to accommodate synthetic seismograms produced from 3-D wavefield simulations, which capture complex phases that do not necessarily exist in 1-D simulations or traditional traveltime curves. Relying on signal processing tools and several user-tuned parameters, the algorithm is able to include these new phases and to maximize the number of measurements made on each seismic record, while avoiding seismic noise. Our motivation is to use the algorithm for iterative tomographic inversions, in which the synthetic seismograms change from one iteration to the next. Hence, automation is needed to handle the volume of measurements and to allow for an increasing number of windows at each model iteration. The algorithm is sufficiently flexible to be adapted to many tomographic applications and seismological scenarios, including those based on synthetics generated from 1-D models. We illustrate the algorithm using data sets from three distinct regions: the entire globe, the Japan subduction zone, and southern California.
Additional Information
© 2009 The Authors. Journal compilation © 2009 RAS. Accepted 2008 December 23. Received 2008 December 23; in original form 2008 May 29. This is contribution No. 10003 of the Division of Geological & Planetary Sciences (GPS) of the California Institute of Technology. We acknowledge support by the National Science Foundation under grant EAR-0711177. Daniel Chao received additional support from a California Institute of Technology Summer Undergraduate Research Fellowship. The numerical simulations for this research were performed on the GPS Dell cluster. The facilities of the IRIS Data Management System, and specifically the IRIS Data Management Center, were used for access to waveform and metadata required in global scale examples of this study. The IRIS DMS is funded through the National Science Foundation and specifically the GEO Directorate through the Instrumentation and Facilities Program of the National Science Foundation under Cooperative Agreement EAR-0004370. Additional global scale datawere provided by the GEOSCOPE network. We thank the Hi-net Data Center (NIED), especially Takuto Maeda and Kazushige Obara, for their help in providing the seismograms used in the Japan examples. For the southern California examples, we used seismograms from the Southern California Seismic Network, operated by California Institute of Technology and the U.S.G.S. The FLEXWIN code makes use of filtering and enveloping algorithms that are part of SAC (Seismic Analysis Code, Lawerence Livermore National Laboratory) provided for free to IRIS members. We thank Brian Savage for adding interfaces to these algorithms in recent SAC distributions. We thank Vala Hjorleifsdottir for her constructive suggestions during the development of the code. We thank Jeroen Ritsema and an anonymous reviewer for insightful comments that helped improve the manuscript.Attached Files
Published - Maggi2009p4592Geophys_J_Int.pdf
Files
| Name | Size | Download all |
|---|---|---|
|
md5:a77ed82fd0072726a811cc2c5fb214b4
|
2.2 MB | Preview Download |
Additional details
- Eprint ID
- 15684
- Resolver ID
- CaltechAUTHORS:20090909-084529982
- EAR-0711177
- NSF
- EAR-0004370
- NSF
- Caltech Summer Undergraduate Research Fellowship (SURF)
- Created
-
2009-09-10Created from EPrint's datestamp field
- Updated
-
2021-11-08Created from EPrint's last_modified field
- Other Numbering System Name
- Division of Geological and Planetary Sciences Contribution
- Other Numbering System Identifier
- 10003