Panama Aftershocks Reveal Likely Fault Solution

All rightee… We have a number of aftershocks that are lighting up the potential fault that ruptured a couple days ago. Here is my page for this earthquake. Here is the USGS page.

The aftershocks are aligned with the north-south transform fault system (named the Colba Ridge) that separates the Cocos plate to the West and the Nazca plate to the East. Here is the local map with historic epicenters in gray and the mainshock and aftershock epicenters plotted as orange circles. Note that many of the historic epicenters also align along this fracture zone.


Here is a map with only the recent epicenters in orange.


Here is an updated moment tensor (Mwb). With these aftershocks, we can better interpret this as rupture on a N-S striking right-lateral fault.

There are 5 moment tensors on the USGS page. For those looking for a refresher on focal mechanisms, here is the USGS page that describes them.

Here is the USGS poster that describes the historic seismicity and plate tectonic setting.

Here is a more comprehensive view of the local and regional tectonics in this region. This is a compilation by Harley M. Benz and others.

Category(s): College Redwoods, earthquake, education, geology, plate tectonics, research

4 Responses in other blogs/articles

  1. […] 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 PFZ in May of 2014. […]

  2. […] 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 PFZ in May of 2014. […]

  3. […] 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 in this map. Orange denotes a hypocentral depth of 0-33 km. There was a swarm further to the north in May of 2014. […]

Leave a Reply

Your email address will not be published. Required fields are marked *

 

This site uses Akismet to reduce spam. Learn how your comment data is processed.