PSU Seismograph Earthquake Traces
The links below show the seismograph image recorded at Portland State University, in Portland, Oregon, for magnitude 6.0 or greater earthquakes. Some of them do not show up well at PSU! Smaller earthquakes are listed only if they were closer to PSU and have a good trace. Earthquake records are from the IRIS database (http://www.iris.washington.edu/).
The quality of the trace depends on the magnitude and distance from the epicenter. The seismometer is located in the basement of a university building in downtown Portland. This is a noisy environment, so the earthquake usually has to be greater than magnitude 5 before it show up well (unless it is very close!). The P-wave shadow zone is from about 103 to about 120°.
The plots linked here are daily summary plots in GIF (linked to date) and PDF, in some cases we have also linked GIF and PDF images of 2-hour windows of data, where one line represents 5 minutes, as opposed to 1 hour in the daily summary plots.
