We just had a good sized shallow compressional earthquake in the northern part of the 2011 Tohoku-Oki earthquake slip region. The USGS web page lists the magnitude at Mw 6.7. Here is a great summary of the tectonics of this…
Northern Mid Atlantic Ridge: Charlie Gibbs fracture zone
We had a large Mw 7.1 earthquake today along the Charlie Gibbs fracture zone, which is the longest transform plate boundary fault system in the North Atlantic, which offsets the Reykjanes Ridge from the Mid Atlantic Ridge. Here is a…
Panama fracture zone strikes again
We have another earthquake along the Panama fracture zone (PFZ) plate boundary. There are numerous sub-parallel transform (strike-slip) faults in this region. The most recent earthquake is a M = 5.7 and is plotted as the most southerly orange dot…
Jan 31, 2015 Panama fracture zone shakes it up
There was another earthquake along the Panama fracture zone today, following a couple from earlier in the month. Today, there was a Mb 5.1, while on 1.16/2015 there was a Mw 6.6. There was a swarm along strike with the…
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…
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…
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…
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…
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…
Sumatra-Andaman subduction zone 2014/12/26: Slip, Deformation, and Energy
Here is an update to my post earlier on the 2004 Sumatra-Andaman subduction zone earthquake of 2004/12/26 (about a decade ago). This series of plots show the large variation in non unique slip models for this earthquake. The authors divide…