Category Archives: San Andreas

Earthquake Report: Berkeley, CA (Hayward fault)

There was an earthquake last night (local time) in Berkeley, aligned with the Hayward fault. The Hayward fault is one of the synthetic sister faults to the San Andreas fault, the major player in the dextral (right-lateral, strike-slip) plate boundary … Continue reading

Posted in earthquake, education, geology, pacific, plate tectonics, San Andreas, San Francisco, strike-slip

Earthquake Report: Laytonville (northern CA)!

This morning there was a small earthquake in a region of northern California between two major faults that are part of the Pacific-North America plate boundary. The M 4.3 earthquake occurred between the San Andreas fault (SAF) to the west … Continue reading

Posted in earthquake, education, geology, mendocino, plate tectonics, San Andreas, strike-slip

Earthquake Report: Trinidad, California

Early this morning, I was awakened by a mild jolt. I thought, well, seems like a M 3+- nearby. I did not get out of bed. The main shaking lasted a couple of seconds, though it seemed that there was … Continue reading

Posted in cascadia, earthquake, geology, gorda, pacific, plate tectonics, San Andreas, strike-slip, subduction

Earthquake Report: 1992.04.25 M 7.1 Petrolia

The 25 April 1992 M 7.1 earthquake was a wake up call for many, like all large magnitude earthquakes are. Here is my personal story. I was driving my girlfriend’s car (Jen Guevara) with her and some housemates up to … Continue reading

Posted in cascadia, earthquake, education, geology, humboldt, mendocino, pacific, plate tectonics, San Andreas, subduction, tsunami

Earthquake Report: 1700 Cascadia subduction zone 317 year commemoration

Today (possibly tonight at about 9 PM) is the birthday of the last known Cascadia subduction zone (CSZ) earthquake. There is some evidence that there have been more recent CSZ earthquakes (e.g. late 19th century in southern OR / northern … Continue reading

Posted in cascadia, earthquake, education, geology, gorda, HSU, humboldt, oregon, pacific, plate tectonics, San Andreas, subduction, Transform, tsunami, washington

Earthquake Report: 1994 Northridge!

Today is the anniversary of the 1994 M 6.7 Northridge Earthquake. I was living in Arcata at the time (actually in my school bus in a driveway to save money). I remember calling my mom from a pay phone to … Continue reading

Posted in collision, earthquake, education, geology, HSU, los angeles, plate tectonics, San Andreas

Earthquake Report: 2016 Summary Cascadia

Here I summarize the seismicity for Cascadia in 2016. I limit this summary to earthquakes with magnitude greater than or equal to M 4.0. I reported on all but five of these earthquakes. I put this together a couple weeks … Continue reading

Posted in cascadia, earthquake, education, geology, gorda, HSU, humboldt, mendocino, mendocino, oregon, pacific, plate tectonics, San Andreas, strike-slip, subduction, Transform, tsunami

Earthquake Report: Petrolia (CA)

This morning there was a good shaker that was widely felt across the region. I did not feel it. I was probably driving at the time, or grading papers, which can have the same sense-deadening effect. Here is the USGS … Continue reading

Posted in cascadia, earthquake, education, geology, gorda, HSU, mendocino, pacific, plate tectonics, San Andreas, strike-slip, Transform

Earthquake Report: Laytonville (northern CA)!

This morning there was another earthquake in northern CA between the San Andreas (SAF) and Maacama faults (MF). This region has been active for the past few years, with earthquakes in the M 3-4 range. Most recently, there was a … Continue reading

Posted in earthquake, education, geology, HSU, humboldt, mendocino, mendocino, pacific, plate tectonics, San Andreas, strike-slip, Transform

Earthquake Report: Laytonville, CA

Last night we had an earthquake between the Maacama faults and the San Andreas fault. This region has experienced several earthquakes recently, which makes me think that there may be an unmapped fault there (there is no hydrothermal or oil … Continue reading

Posted in earthquake, education, geology, HSU, mendocino, pacific, plate tectonics, San Andreas, strike-slip, Transform