Penn State - Earthquake Seismology

A Simple Seismic Station Animation

The link below is to a simple animation of seismic station distributions for the last 40 years or so. These are only the stations that are listed in the IRIS data base, many stations from places such as Japan and China are not included. Still, enough stations are included to give you a "feel" for the field-based efforts in observational earthquake seismology.

The large green symbols are permanent stations in the IRIS GSN and GeoScope seismic networks that have been operating more or continuously since the early 1990's (for the most part). These are the highest quality stations with the broadest bandwidths and often, but not always, relatively lower noise levels. The GSN/GeoScope stations are not the only permanent high-quality stations, a number of regional seismic networks have been operating for roughly the same time period.

You have to watch the animation a few times to see all the interesting patterns in seismometer deployment, including the increasing size of temporary deployments, the growth of regional networks, the substantial US Array undertaking, etc. The earliest maps are affected by the conversion of stations to digitize-able, or digital systems as well as station existence and location.


Citation: A simple seismic station history, 1975-2017, Charles J. Ammon, Penn State.

A Sample Homework Exercise

Watch the animation of the history of seismic stations that you can find on the following web page:∼cammon/SeisStationAnimations/

The best approach is to let the animation play through once, then use the slider to go back and forth watching different seismic deployments. What kinds of things do seismologists seem to do? Write a few sentences describing the broad, overall patterns that you observe in the deployment of those seismic stations. Do you see any patterns that favor certain regions over others? Why might such patterns exist? Do you see any evolution in the patterns with time? Why might things change with time? Relate what you see to the science of earthquake seismology, which has goals of studying earthquakes and Earth's interior.

Penn State Earthquake Seismology

Department of Geosciences