"Slow" earthquake expected this week on the Big Island

In January 2005, a silent ("aseismic") earthquake struck Hawaii's Kīlauea Volcano. The red arrows correspond to the motions of individual GPS stations (black triangles) during that two-day event, which triggered a swarm of very small seismic earthquakes (black circles). Scientists want to find out if silent events in other parts of the world also generate tiny earthquakes, information that one day may prove useful in seismic hazard forecasting. Credit: Emily Desmarais/Stanford University.