Aleutian subduction zone earthquake near the Amlia fracture zone!

Last night, as I was ending my day, there was a swarm of seismicity near the Amlia fracture zone. This morning, there were more earthquakes. This swarm is west of a swarm in early August 2015 near Nikolski. Here is the USGS web site for the M 5.6 earthquake. The Nikolski Swarm included a M 6.9 earthquake. Here is my page about the July portion of the Nikolski Swarm.

Below is a map that shows these two swarms. I placed the USGS moment tensor for the M 5.6. I placed a moment tensor / focal mechanism legend in the upper right corner of the map. There is more material from the USGS web sites about moment tensors and focal mechanisms (the beach ball symbols). Both moment tensors and focal mechanisms are solutions to seismologic data that reveal two possible interpretations for fault orientation and sense of motion. One must use other information, like the regional tectonics, to interpret which of the two possibilities is more likely.


This is a USGS graphic that shows a cross section of the Aleutian subduction zone that is a part of the “Eastern Aleutian Volcanic Arc Digital Model.’

This map, that I put together for the July portion of the Nikolski Swarm, shows some recent historic earthquakes and their moment tensors for this region of the Aleutian subduction zone.

Here is a map that shows regions of slip for historic earthquakes put together by Peter Haussler (USGS).

Category(s): alaska, College Redwoods, earthquake, education, geology, HSU, plate tectonics, subduction

4 Responses in other blogs/articles

  1. […] region has been active lately, with a M 5.6 and related swarm in September of 2015. Here is a map from that earthquake […]

  2. […] This region was active in September of 2015 also. Here is my earthquake report from that series of earthquakes. […]

  3. […] region was active in September of 2015 also. Here is my earthquake report from that series of earthquakes. Below is a map from this 2015/09 report that shows some late 20th and early 21st century […]

  4. […] region near the Amlia fracture zone was active in September of 2015 also. Here is my earthquake report from that series of earthquakes. Below is a map from this 2015/09 report that shows some late 20th and early 21st century […]

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