Penn State - Earthquake Seismology

Earth-Motion-Monitor Application
How to Turn Your Old Mac into an Earthquake Monitor

EarthMotionMonitor is a Mac OS X application that I wrote so that I could display seismograms in near real-time in my office and during my natural hazards and seismology classes. Data are available from seismic networks operated by many different groups, but are accessed through the IRIS Consortia ( and the US Geological Survey ( This software is unsupported - I would enjoy hearing if you like it and use it, but I have little time to answer questions or respond to modification requests. The program is free (you get what you pay for),

but I retain all rights related to this software. I have no plans to distribute the source because it uses a number of librararies that are under constant development (if only I was better with software management tools). Special thanks to Victor Ananiev for his ADORB framework, to Philip Crotwell for help with countless DHI questions, and to the IRIS staff who care for the DHI servers running at the IRIS DMC.

Charles J. Ammon
04 January, 2008

Example screen shot of an event from the southwest Pacific region. Each seismogram is self-scaled. The vertical lines show the event origin times (accessed from the USGS NEIC hypocentral information feeds). This is an event view (you can request data from recent events). The program is more generally used in a monitor mode, with specified update time intervals. You can open the graphic in a larger window using your browser to seem more details.

EMMA can store files full of you favorite station lists (see the documentation). You can download the application, the documentation, and supplemental files using the links that follow. Place the preference file (the *.plist) in


and the support folder (EarthMotionMonitor) in

~/Library/Application Support

before launching.

The documentation is a little dated, but the features are more or less the same.


Preferences and Channel Lists (sit)  (zip)

Downloads, Updates, & Miscellaneous Notes:

08 June - 2012: IRIS is shutting down the DHI servers soon because they are moving their distribution tools to web services. I've modified EMMA to work with the WS protocols. These apps are still in beta, but I have tested them on 10-year old macs, and newer intel macs. They seem to work. The DHI versions will stop working soon when the data servers are disabled. In fact, my DHI versions had already become quite unstable, requiring frequent restarts. These are the replacements.

22 July - 2013: IRIS is moving the web services to a new server. These versions of the apps are updated to reflect that change. Please update as soon as you can.

Use the same supplemental files that you used with the old codes, BUT, note that channel location codes that used to be blanks (2 spaces) should be replaced with two dashes - - (no space between the dashes).

Here is a beta version that includes updates to retrieve the origin times from the USGS (they changed their format). This version works with MacOS >= 10.6 on an Intel Mac (WebServices):
Download EMMA (For OS X 10.6+)

This version works with MacOS 10.4-5 on PPC Machines (WebServices):
Download EMMA (For OS X 10.4-5)

If you don't have them already, don't forget the supplemental files listed above (Preferences and Channel Lists). The app takes a little while to load if you have it set for automatic downloads, it downloads the data first (look for the bouncing icon in the dock). If it doesn't appear to be working, check your network and the app's settings (don't have blank fields) and look at the console for download messages.

Penn State Earthquake Seismology

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Last Updated:22 May, 2013