Hypo-theses

The Baja California Earthquake was recorded moderately well at Keele University, UK. This was the view on the display monitor in our foyer that greeted me this morning.

Extracting the earthquake from the data stream gives this.

… and trying to fit it to the travel-time curves gives this …

Note that the P-wave is not recorded well. This is probably due to the fact that with a north-west to south-east strike-slip fault mechanism, and the path to Keele is on a north-east azimuth. Consequently, the P-wave will be nodal towards Keele, that is almost no P-wave energy will be emitted in this direction.

This earthquake has spawned a whole series of aftershocks. Here is the current (as of 11:00 GMT 05/04/2010) map from the USGS data on Google Earth.

There was a small earthquake just south of Nantwich, Cheshire on January 31st, 2010 which we recorded here at Keele.

The earthquake magnitude has been determined by the Geological survey to be 1.3

The tremor is most likely related to subsidence or collapse due to dissolution of salt. The bedrock here is the Wilkesley Halite and in the Google Maps image of the earthquake location below salt dissolution features can be seen. A word of warning though as this location from the British Geological Survey is unlikely to be precise.

View Nantwich Quake in a larger map