When a long-predicted Magnitude 6.0 earthquake finally struck Central California near the town of Parkfield on Sept. 28, 2004, a Nicholas School team led by seismology professor Peter Malin recorded the event with a number of seismographs placed deep in the pilot hole of a major geological observatory project being drilled to study the San Andreas fault. Malin is in the school’s Division of Earth of Ocean Sciences.

Recordings from one instrument at a depth of 3,465 feet underground were subsequently converted to a form that allowed information about earthquake waves to be turned into a sound portrait of the event, beginning with the main jolt and followed by a series of aftershocks.

The quake caused no injuries and minimal property damage, but was of great interest to American geologists. In 1984 the United States Geological Survey predicted that a Magnitude 6 temblor would occur on the San Andreas fault near Parkfield within five years of 1988.

That prediction, which was based on past events, turned out to be considerably premature.

Researchers like Malin, who have been monitoring the Parkfield area for years with a bevy of instruments, are now studying data from the Sept. 28 event to assess how it alters the science of earthquake dynamics and prediction.