Category Archives: humboldt

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: 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: Mendocino fault Update #1

Today is one of my busiest days of the semester. I am administering a final and my two classes are presenting their video projects. Then, we had this M 6.5 earthquake in the wee hours and a M 7.7 (prelim … Continue reading

Posted in cascadia, earthquake, education, geology, HSU, humboldt, pacific, plate tectonics, strike-slip, Transform

Earthquake Report: Mendocino fault!

I was awake and just logging into my laptop, still in bed, when I first felt some movement. The movement was slight and not impulsive, so I thought it was a small earthquake. Then the shaking reappeared. This is when … Continue reading

Posted in cascadia, earthquake, education, geology, gorda, HSU, humboldt, mendocino, pacific, plate tectonics, strike-slip, subduction, 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: Mendocino fault!

Yesterday there was an earthquake along the eastern extension of the Mendocino fault system. This magnitude M = 4.1 earthquake (here is the USGS website for this earthquake) is a small magnitude, but it was widely felt. I was in … Continue reading

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

Earthquake Report: Gorda Plate!

Last night, while I was preparing an online exam for my students to take while I am at the Geological Society of America Annual Meeting in Denver Colorado, there were a couple earthquakes in the Gorda plate offshore of northern … Continue reading

Posted in cascadia, earthquake, education, geology, gorda, HSU, humboldt, pacific, plate tectonics, strike-slip, subduction

Earthquake Report: Mendocino fault!

Well, I felt that one. The shaking lasted about 5-7 seconds in Manila, CA (where I live). Here is the USGS website for this M = 5.6 earthquake. This earthquake appears to have occurred along the Mendocino fault, a right-lateral … Continue reading

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

Earthquake Report: Bartlett Springs fault system, Lake Pillsbury

We just had a good sized earthquake adjacent to the mapped surface trace of the Bartlett Springs fault, southeast of Lake Pillsbury. Here is the USGS website for the M 5.1 earthquake. Here is my interpretive map that shows the … Continue reading

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