Current Activity | update | gps | tilt | long-term monitoring data

Following a swarm of deep earthquakes centered just south of the caldera in late April 2002, seismicity was at a barely elevated level until July 2004, far lower than those of the months prior to the 1975 and 1984 eruptions. Starting in July 2004, however, a swarm of small (magnitude less than 3), deep (>40 km), long-period earthquakes occurred below the southern part of the caldera and adjacent areas. This swarm appeared to be over by the end of December 2004. Deep long-period earthquakes continue but at a much lower rate. Note that the date of the earthquake plot below may not be today's date. The plot date reflects that of the last earthquake plotted and not the date of the plot itself. If no earthquakes occur within this mapped area, that plot date won't change until another earthquake is plotted.