Near-real-time information products for Mount St. Helens -- tracking the ongoing eruption

The rapid onset of energetic seismicity on September
23, 2004, at Mount St. Helens caused seismologists at the
Pacific Northwest Seismic Network and the Cascades Volcano Observatory to quickly improve and develop techniques
that summarized and displayed seismic parameters for use by
scientists and the general public. Such techniques included
webicorders (Web-based helicorder-like displays), graphs
showing RSAM (real-time seismic amplitude measurements),
RMS (root-mean-square) plots, spectrograms, location maps,
automated seismic-event detectors, focal mechanism solutions, automated approximations of earthquake magnitudes,
RSAM-based alarms, and time-depth plots for seismic events.
Many of these visual-information products were made available publicly as Web pages generated and updated routinely. The graphs and maps included short written text that
explained the concepts behind them, which increased their
value to the nonseismologic community that was tracking
the eruption. Laypeople could read online summaries of the
scientific interpretations and, if they chose, review some of
the basic data, thereby providing a better understanding of the
data used by scientists to make interpretations about ongoing eruptive activity, as well as a better understanding of how
scientists worked to monitor the volcano.