Data and code from: Using contrasts in horizontal P-wave reflectivity to map the base of the continental lithosphere: Results for the central and eastern U.S.
Data files
Oct 23, 2024 version files 5.34 GB
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hanawalt_cuilik_hawman_archive_march2024_v9.zip
5.34 GB
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README.md
2.92 KB
Abstract
We used seismic P-waves generated by earthquakes in the western Pacific to conduct “echo soundings” of geologic structure beneath the United States. Our goals were to investigate the deep structure of the Appalachian Mountains, determine the thickness of the underlying North American tectonic plate ("lithosphere"), and investigate the nature of flow within the asthenosphere, the layer of less rigid material beneath the plate. After traveling through the Earth’s core, these waves are reflected at Earth’s surface and travel back into the interior, where they are reflected back to the surface by major compositional boundaries. The echoes were recorded by the “Transportable Array” of seismograph stations that moved across the United States from 2004 to 2014. We used a subset of stations from 15 east-west profiles to construct cross sections across the Atlantic Coastal Plain, Appalachian Mountains, and more ancient crust of the continental interior. Our soundings are consistent with results of earlier studies that suggest that the lithosphere gets thicker as it gets older. The lower lithosphere is marked by a significant increase in the number and continuity of reflections, supporting the interpretation of elevated strain in the lowermost lithosphere as well as drag-induced flow in the asthenosphere produced by westward motion of the overlying plate.
Description of the data and file structure
Archive of materials for manuscript entitled Using contrasts in horizontal P-wave reflectivity to map the base of the continental lithosphere: Results for the central and eastern U.S., by Laura E. Hanawalt, Michael P. Cuilik, and Robert B. Hawman
The archive is organized into 7 directories:
- Part 1 contains all the software developed by Hawman for analysis of the seismic waveform data. Three subdirectories contain the source code, make files, and executable files (compiled on macOS version 10.8.4; tested on macOS versions through 10.12.6).
- Part 2 contains the following:
“pkikp_short_summary_of_steps_v23.pdf” (and *.doc version) : a brief description of shell scripts used to generate the results presented in the manuscript. The scripts are broken down into a number of steps: step101, 102, 103, 104, 105, 201, 201newmute, 202, 203, 301, 302, 302env, 303, 401, and 402.
- Part 3 contains binary data files (seismic waveforms downloaded from the IRIS Data Management Center) in SAC format for the 16 earthquakes analyzed for this study, as recorded along lines L through Z of the EarthScope Transportable Array (TA).
- Part 4 contains shell scripts, parameter files, and output files for all steps (101-402) for TA Line W, to illustrate the basic processing flow.
- Part 5 contains shell scripts, parameter files, and output files for steps 101-402 for TA Line V.
- Part 6 contains shell scripts, parameter files, and output files for steps 101-105 for TA Line U.
- Part 7 contains shell scripts, parameter files, and output files for steps 302, 303, 401, and 402 for all TA lines (L through Z).
- Sharing/Access information
Data was originally derived from the following sources:
IRIS Data Management Center (https://www.iris.edu/SeismiQuery)
However, that website is no longer active. Date files can now be downloaded using the following website:
Code/Software
- Part 1 contains all the software developed by Hawman for analysis of the seismic waveform data. Three subdirectories contain the source code, make files, and executable files (compiled on macOS version 10.8.4; tested on macOS versions through 10.12.6).
- Part 2 contains the following:
pkikp_short_summary_of_steps_v23.pdf: a brief description of shell scripts used to generate the results presented in the manuscript. The scripts are broken down into a number of steps: step101, 102, 103, 104, 105, 201, 201newmute, 202, 203, 301, 302, 302env, 303, 401, and 402.
- Part 4 contains shell scripts, parameter files, and output files for all steps (101-402) for TA Line W, to illustrate the basic processing flow.
The original data set was recorded by broadband seismograph stations along Lines L through Z of the Transportable Array as part of the EarthScope project. Waveforms downloaded from the IRIS Data Management Center can be found in "part3" of the archive. Processing of the data is explained in detail in directory "part2". "part4", "part 5", "part 6", and "part7" of the archive contain input files, shell scripts, and output files. The directory "part1" contains all software developed by Hawman for analysis of the seismic waveform data. Three subdirectories contain the source code, make files, and executable files (compiled on macOS version 10.8.4; tested on macOS versions through 10.12.6).
All data files were processed on a UNIX operating system (macOS versions 10.8.4 through 10.12.6). The Seismic Analysis Code (SAC; Goldstein & Snoke, ) was used for preliminary processing (windowing; removal of trace means and trends). Resampling and plotting were carried out using the Colorado School of Mines Seismic Unix (SU) software package (Cohen & Stockwell, 2008). All other processing was carried out using software written by Hawman and included in directory "part1" of this archive. Guidelines for using this software are given in directory "part2". "Part 4" contains shell scripts, parameter files, and output files for all steps (101-402) for Transportable Array Line W, to illustrate the basic processing flow. "Part5" contains shell scripts, parameter files, and output files for steps 101-301 for TA Line V. "Part6" contains shell scripts, parameter files, and output files for steps 101-105 for TA line U. "Part 7" contains shell scripts, parameter files, and output files for steps 302, 303, 401, and 402 for all TA lines (L through Z).