scwfparam versus gmew

When it comes to generating shake maps with the USGS ShakeMap program there are two main ways to get the job done:

1) Earthworm’s gmew + localmag modules; or
2) SeisComP’s scwfparam module.

Last week a client asked me which I recommended. I responded that though both systems generate the xml files required by ShakeMap, I recommend observatories implement the SeisComP solution as scwfparam has many advantages over gmew:

scwfparam’s advantages over gmew include:

  • Whereas gmew generates a single xml input file for ShakeMap, scwfparam can be configured to automatically update the strong motion data available to ShakeMap as the event location is refined.
  • scwfparam has an option to remove after shocks
  • scwfparam outputs the processed waveforms and their spectra in addition to the xml files
  • And gmew has this limitation: “Some warnings about this program: Currently gmew does not know to wait for trace data to appear in the wave_servers. So when run as an Earthworm module, it may not be able to obtain enough trace data for adequate processing. You may want to run gmew manually after all the desired trace data has accumulated in the wave_server.” (source:

With SeisComP the focus is on the end-user experience:

  • SeisComP’s graphical user interfaces facilitate troubleshooting and system quality control. You can even configure scwfparam from a graphical user interface without using the command line
  • SeisComP’s centralized, database-driven solution for instrument response files, station and event parameters makes it easy to add and maintain new modules like scwfparam.
  • SeisComP’s user community is always ready to respond to your questions
  • Bug fixes (critical and non-critical ones) are issued continuously throughout the year

Share your experience! All thoughts, opinions and recommendations are welcome.


2 comment(s) on “scwfparam versus gmew

  1. Hi Branden,The second bullet in your list above is also mostly handled by gmew where you can get SAC files of the output synthetic waveforms.The fourth bullet in your benefits of scwfparam over gmew can be handled if you correctly configure gmew to wait a calculated amount of time to collect waveforms (extraDelay is the setting). Sure you could misconfigure this, and sure some waveforms could be delayed, but it should be pretty straight forward to get this delay correct in 99% of cases. Also, there are ways to launch gmew now in a triggered mode, so that if you get more data later on, you can relaunch it.Perhaps we need to revisit gmew some more to get it up to the same speed as scwfparam with respect to the other issues…Cheers,Paul

  2. Paul:

    The new triggered mode is great news. I will have to read into how the triggering is working. At scwfparam it is driven by user-defined changes in magnitude. We have our system set up so that if the magnitude changes by 0.5 units, a new shake map is automatically generated and the display updated.

    Saludos, B

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