Use the calendar to select another day or month to view. Click on a day
box to view that day's spectrogram record. Use the << and >> buttons
next to the "Month, Year" title bar to skip forward or backward
one month. Also, use the dropdown menus at the bottom of the calendar to select other months and years, then click the "view" button.
In the "Other Views" box above, select "local" or "global" radio
buttons in the "Scope" column to view local seismic events
or global events.
- Local: Small, close-by seismic events. Locally generated
seismic signals tend to be higher frequency and lower amplitude than large,
distant events. There is more noise in the local display due to traffic,
- Global: Large, distant seismic events. Major,
more distant seismic events generate lower frequency and higher amplitude
seismic signals, which obscure locally generated signals.
When you select "local" you are viewing data which has
had the lower frequencies filtered out. When you select "global" you
are viewing unfiltered data. You may also select a motion vector to view
in the "Motion", column. For more information about this helicorder record see
the helicorder help page.
To see a listing of recent earthquake you might see on the helicorder records view:
You can also use the USGS "Earthquake Travel Time Information and Calculator" page to estimate the arrival times of seismic waves from an epicenter to the Garrett College seismometer.
Use the following coodinates (decimal degrees) for the Garrett College area: