Monthly Archives: May 2015

Historic Seismicity Animations: Izu-Bonin, Mariana: 1940 – 2015

Following up on the seismicity in the western Pacific, I put together a couple animations. My post about the deep mainshock (magnitude M = 7.8 ) is here. My second post has some aftershocks plotted (and some foreshocks), as well … Continue reading

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

Triggered Earthquakes: Izu-Bonin

Well, we had a large magnitude earthquake (M = 6.2) triggered by the M 7.8 deep earthquake along the Izu-Bonin Trench. Here is my post from yesterday. Note the triggered earthquake is in a region where there were earthquakes about … Continue reading

Posted in asia, Chemeketa Community College, education, Extension, geology, HSU, plate tectonics, subduction

Earthquake in Izu-Bonin!

Early this morning (luckily I was not awake at the time) we had a really deep (~677km) M = 7.8 extensional earthquake along the Bonin Trench in the western Pacific. Here is the USGS page for this earthquake. Here is … Continue reading

Posted in Chemeketa Community College, education, Extension, geology, HSU, plate tectonics, subduction, tsunami

Animation of Seismicity along the Alaska/Aleutian Arc

This took me just a few minutes to put together. I searched the USGS earthquakes website with a rectangular search area for earthquakes greater than M = 6.0, downloaded the google Earth kml file with epicenters colored by depth (and … Continue reading

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Earthquake along the Alaska Penninsula!

We just had an earthquake along the Alaska Peninsula. The magnitude is currently set at 6.7 on the USGS website. The Peninsula is a volcanic arc that forms as a result of the subduction of the Pacific plate beneath the … Continue reading

Posted in alaska, Chemeketa Community College, education, geology, HSU, strike-slip, subduction

Gorda earthquake triggered a Gorda earthquake?

We just had an earthquake along the nodal plane of the Gorda plate earthquake earlier today. Here is the USGS web page for the Gorda M = 4.3 earthquake and here is the USGS web page for the Gorda plate … Continue reading

Posted in cascadia, Chemeketa Community College, education, geology, gorda, HSU, humboldt, strike-slip

Gorda plate earthquake: 2010 zone strikes again

Early this morning we had a small rumbler offshore of northern California, generally in the same location as the 2010.01.10 earthquake. I remember the 2010 earthquake very well as the ground shaking lasted over 20 seconds in Manila. Here is … Continue reading

Posted in cascadia, Chemeketa Community College, education, geology, HSU, humboldt, mendocino, strike-slip

Mid Atlantic Ridge Plate Boundary

In the past week, there have been a few earthquakes along the Mid Atlantic Ridge (MAR) and some associated fracture zones. The Mid Atlantic Ridge is a divergent plate boundary. As the plates move apart, the asthenosphere is decompressed and … Continue reading

Posted in atlantic, Chemeketa Community College, education, Extension, geology, HSU, plate tectonics, strike-slip, Transform

Sandwich Islands Earthquake… mmmm

We just had a M 5.8 earthquake in the volcanic arc region of the Scotia subduction zone. The moment tensor (currently) shows an extensional mechanism. I will post more on this as I am about to hit the road. Here … Continue reading

Posted in Chemeketa Community College, education, Extension, geology, HSU, subduction

Santa Cruz (western Pacific) Earthquake Swarm!

The past couple of days have brought us a series of large magnitude strike-slip earthquakes along a plate boundary between the Solomon Trench and the New Hebrides Trench. I posted about the first earthquake here and here. This swarm of … Continue reading

Posted in asia, Chemeketa Community College, education, geology, HSU, Indonesia, plate tectonics, strike-slip, Transform