Hi All. Antony Fraser-Smith, a professor of geophysics and electrical engineering at Stanford says he has been "trying to fish for earthquakes." Well he thinks he may have hooked one. Specifically, the magnitude 5.0 temblor that shook Parkfield, California on Dec. 20, 1994.

He has placed his instruments - antennas tuned to pick up ultra-low-frequency electromagnetic waves - at five locations in California where large quakes are expected. If his antennas detect sharp signal changes in the weeks preceding a major earthquake, Fraser-Smith may have discovered a new means to understand - and perhaps predict - how some earthquakes start.

He states. "My instruments detected some magnetic field changes that started a month before the [Parkfield] earthquake," Fraser-Smith said. "They were quite substantial as compared to the normal background noise. They clearly were confined to the Parkfield area, and they didn't stop but continued [for more than a week after the quake] as I would have expected. That was the same pattern I observed after the Loma Prieta earthquake.”

The pattern seen at Parkfield wasn’t as big as those for the Loma Prieta earthquake, but then again the Parkfield earthquake was smaller.

The Loma Prieta quake was measured at a magnitude 7.1. In that event, as at Parkfield, his instruments recorded a sharp change in signals during the month before the quake and continuing for some time afterward.

He does give a word of caution though. He detected similar large signal changes a year earlier, but those were not followed by any nearby earthquakes. Take Care…Don in creepy town

• Parkfield