Those of you in the region of the San Francisco Bay are probably wondering what the likelihood that this recent and ongoing swarm of earthquakes in the San Ramon area may lead to a larger earthquake. I do not know,…
Cascadia subduction zone: Tectonic Earthquakes of the Pacific Northwest
IRIS and the US Geological Survey have recently produced an educational video about tectonic earthquakes in the region of the US Pacific Northwest. The project was funded by the National Science Foundation. The Video YT link for the embedded video…
Plate Tectonics: 200 Ma
Gibbons and others (2015) have put together a suite of geologic data (e.g. ages of geologic units, fossils), plate motion data (geometry of plates and ocean ridge spreading rates), and plate tectonic data (initiation and cessation of subduction or collision,…
Gulf of California Earthquakes! (first update)
Here is an update to the early morning post… I have prepared an updated map that shows the fracture zones, spreading ridges, transform faults, and basins in the region of seismicity from the past 24 hours. Here is the map.…
Gulf of California Earthquakes! (first post)
We just had a few earthquakes in the Gulf of California (GOC). The results are early, so there is not a moment tensor plotted yet (updated map shows it now). The epicenters plot in the Farallon Baisn. The Gulf of…
Earthquake between the San Andreas and Maacama!
Saturday morning (2015.08.29), residents in Fort Bragg were awakened by a M 3.6 earthquake along a fault that lies between the San Andreas fault (SAF) to the west and the Maacama fault (MF) to the east. Here is the USGS…
Earthquake near the Santa Cruz Islands (western Pacific)!
Yesterday we had a large magnitude earthquake along a plate boundary that connects the South Solomon trench with the New Hebrides trench. This region had a swarm of earthquakes in May. Here is the USGS website for the M 6.6…
Solomon Islands Earthquake!
Today we had another earthquake in this tectonically active region of the world. Initially posted as a magnitude 7.0, the USGS considers this a M = 6.6 earthquake. Here is a map showing the epicenter as an orange circle. I…
Small Earthquake near Point Arena!
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 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…