Webicorders are simply long seismograms that are "wrapped", much as a
word processor wraps a long sentence or paragraph into many lines. They are
useful for viewing seismic activity at a single station over a long period of time.
The PNSN already provides a subset of stations in webicorder form. This
interface is an experiment to see if we can serve all of our stations out. We are
initially encouraged by the results and are eager to hear comments at
seis_info@ess.washington.edu .
Stations are shown with triangles. Click on a triangle to see the webicorders
for that particular station. The PNSN consists of three principal types of stations:
- Short Period (SP, red): Seismic stations that are sensitive to frequencies
above 1-2 Hz. Usually set at a high-gain so they often "clip" during a nearby
earthquake. Short period instruments are excellent for locating small earthquakes
and tend to be robust in adverse conditions(like volcanoes).
- Broadband (BB, blue): Seismic stations that are sensitive to a broad range of
frequencies, often down to 40 second periods or more. Good for analyzing
large earthquakes at large distances and for noise studies.
- Strong Motion (SM, black): Seismic stations that are built to stay on-scale
even in the largest earthquakes at close distances. These stations are
often located in buildings or school and are vital for studying the local effects
of large earthquakes.
Several links are present for each station. The 6-hour link represents the current
data the network has available. The 12 and 24 hour plots are updated hourly. The 6-
hour links may be down during times of eruptions or moderate earthquakes.
When clicking the 6 hour link, a white page with the message "Error: could not get helicorder data, check channel (code)." means
that the station is broken and not reporting. This is normal. Other links for that station will
also be broken.