Monthly Archives: January 2015

Earthquake along the South New Hebrides trench

We just had a swarm of shallow seismic activity along the arc above the South New Hebrides trench. The largest magnitude was a Mw 6.0. There was a very deep (~220km) Mw 6.8 just to the north about a week … Continue reading

Posted in Chemeketa Community College, earthquake, education, geology, plate tectonics, subduction, Transform

Stress Changes from Strike Slip Faults

One may ask what are the relations between the Mendocino fault (MF) and the Cascadia subduction zone (CSZ). Earthquakes on both fault systems are responding to the same plate motions. As the Gorda plate moves to the east, relative to … Continue reading

Posted in cascadia, Chemeketa Community College, College Redwoods, earthquake, education, geology, mendocino, plate tectonics, San Andreas, subduction

Mendocino fault Aftershocks: Update

The aftershocks continue following the Mw 5.7 mainshock earthquake swarm along the Mendocino fault. Yesterday I plotted my interpretation for the location of the fault that this swarm may have ruptured upon. Some epicenters have been relocated and appear to … Continue reading

Posted in cascadia, Chemeketa Community College, earthquake, education, geology, humboldt, mendocino, plate tectonics

Mendocino fault earthquake 1/28/15 1:08 PM local time

We just had a good sized shaker, probably on the Mendocino fault system. Today’s earthquake occurred on 1/28/2015 at 1:08 local time. The mainshock, an earthquake of magnitude Mw = 5.7, has an epicenter approximately 20 km due west of … Continue reading

Posted in cascadia, Chemeketa Community College, College Redwoods, earthquake, education, geology, humboldt, mendocino, plate tectonics, San Andreas, Transform

Cascadia’s 315th Birthday

On this morning, 315 years ago, the Cascadia subduction zone fault ruptured as a margin wide earthquake. I here commemorate this birthday with some figures that are in two USGS open source professional papers. The Atwater et al. (2005) paper … Continue reading

Posted in cascadia, Chemeketa Community College, education, geology, humboldt, plate tectonics, subduction, tsunami