Today we had a small magnitude, M = 3.5, earthquake near Point Arena. Based upon the location and focal mechanism, I interpret this to have been a north-northwest striking right-lateral (dextral) strike-slip earthquake. The fault that ruptured is likely either…
Earthquake near the Santa Cruz Islands (western Pacific)!
We just had an earthquake near the Santa Cruz Islands in the western Pacific Ocean. Here is the USGS web page for this earthquake. Here is a map that I quickly put together with the moment tensor from the M…
Earthquake in the Solomons!
While I was away from the office, we had a M 6.7 earthquake near the Solomon Islands. Here is a link to the USGS website for the M = 6.7 and M = 6.0 earthquakes. While the epicenter plots near…
Springfield Earthquake!
It took me a couple days to catch up with things, so I missed posting about this earthquake until now. We had a Mw = 4.2 earthquake northeast of Eugene on the morning of 2015.07.04. Here is the USGS web…
Andaman Sea Earthquake!
Today we had a small earthquake in the Andaman Sea, west of Thailand and east of the Andaman Isles (India). The Andaman Sea is a region of backarc spreading and connects the Sumatra fault (a (strike-slip) sliver fault that accommodates…
Mid Atlantic Ridge Earthquake!
Yesterday (I was busy preparing revisions to a paper that was due, the 5th 18 hr day in a row) there was a large earthquake along a fracture zone (transform plate boundary) near the Mid Atlantic ridge (MAR). Here is…
Redding Earthquakes: 1945-2015
There have not been many earthquakes since 1945 in this region. Below is a map that shows the largest earthquake as a M = 5.4 earthquake from 1998.11.26. Here is the USGS query that I used to create this map.…
Earthquake in Redding, CA!
We just had a small earthquake in Redding, California. The shaking was felt as far as 40 km from the epicenter, which was not deep (so probably in the North America plate). The focal mechanism shows that this was a…
Movies: Seismic Record of a Deep Izu-Bonin Earthquake
Scientists at the National Research Institute for Earth Science and Disaster Prevention have collected and processed seismic data from the High Sensitivity Seismograph Network Japan (Hi-net). They created movies of these data, in map view. Here is the page where…
Los Angeles: Newport Inglewood Earthquake!
Last night, we had another earthquake on the Newport Inglewood fault (NIF) system. This fault ruptured in 1933, which led to Long Beach adopting the most strict building codes in the nation. Later, these codes were adopted by the state,…