Geobulletin alpha

The San Juan Bautista Earthquakes as recorded at Modesto Junior College 

We have a simple classroom seismometer installed on the third floor of our Science Community Center at Modesto Junior College. It nicely captured the two earthquakes from San Juan Bautista that took place last night just five minutes apart. In the record above you can see the 3.6 magnitude foreshock on the left side, and the larger 4.2 magnitude quake in the center. This seismogram

4.2 Magnitude Earthquake near San Juan Bautista 

What else are you going to call a restaurant situated right on the San Andreas? A 4.2 magnitude earthquake struck at 10:26 PM PST tonight about 3 miles south of the town of San Juan Bautista in the Coast Ranges of Central California (the official USGS report is here). It was preceded by a magnitude 3.6 foreshock at 10:21 PM. It was felt over a fairly large region, but quakes of this

San Francisco Earthquake Day 

The San Francisco earthquake of 1906 began right offshore at 5:13 a.m. on this date and swiftly radiated to the north and south along the San Andreas fault, causing ground ruptures from Shelter Cove to San Juan Bautista. Many cities, not just San Francisco, suffered severe damage from shaking and fire, but Frisco was the largest city on the west coast and naturally grabbed all the headlines. Thousands of people died, and well-constructed buildings that withstood the earthquake succumbed to the [...]

The Northern San Andreas Fault 

It's been a while since I paid a visit to the San Andreas fault, but that's what I did today. California's best-known geological feature is peppered with exhibits these days, and today's locality has a formal earthquake trail that runs along the trace of the 1906 surface rupture. I include it in my gallery of the northern part of the fault. This gallery starts at the north end and works down, from the Alder Creek locality on the Pacific coast down to San Juan Bautista, where the 1906 rupture [...]

San Francisco Earthquake Day 

The San Francisco earthquake of 1906 began right offshore at 5:13 a.m. on this date and swiftly radiated to the north and south along the San Andreas fault, causing ground ruptures from Shelter Cove to San Juan Bautista. Many cities, not just San Francisco, suffered severe damage from shaking and fire, but Frisco was the largest city on the west coast and naturally grabbed all the headlines. Thousands of people died, and well-constructed buildings that withstood the earthquake succumbed to the [...]