New Britain and Bougainville: tectonic domains?

I was taking a looksie at the different moment tensors for the years of 2000, 2010, 2014, and March 2015. I noticed that the transform plate boundary on the eastern side of the South Bismarck plate may separate segments of the subduction fault formed by the downgoing Solomon Sea plate (as it subducts beneath the South Bismarck plate to the north and the Pacific plate to the east). Earthquakes to the west of this transform fault (fault segment colored green) show northwest-southeast oriented compression. The earthquakes to the east of this transform fault (colored orange)show northeast-southwest compression. The transform fault appears to have ruptured in 2000 with a Mw 8.0 earthquake. I outlined the March 2015 swarm with a polygon that has dots as fill, within the region of NW-NE Compression. I placed the fault boundaries onto the Google Earth imagery (bathy is a combination of coarse SRTM data from Smith and Sandwell and some fine bathy in some locations). These fault boundaries are very imprecisely located. Here is a post that has some of the geography/plates/etc. labeled. Here is my initial post regarding the Mw 7.5 earthquake.

Category(s): Chemeketa Community College, education, geology, HSU, plate tectonics, subduction, Transform, tsunami

12 Responses in other blogs/articles

  1. […] There have been lots of earthquakes in this region lately and I will momentarily add links to my earlier posts… Here is one… […]

  2. […] Here is a post comparing the New Britain region with the adjacent Bougainville region. 2015.03.30 […]

  3. […] Here is a map that shows some of the large earthquakes in this region from 1996 through 2015. Refer to the moment tensor legend to help interpret the moment tensors for each earthquake. All, but one, are compressional solutions. Note how all the compressional earthquakes have roughly the same strike, oriented relative to the plate convergence vectors (blue arrows). The Aleutian arc may have slip partitioning that results in clockwise rotation of blocks instead of forearc sliver faults. I would have suspected that the strike of the thrust earthquakes would rotate with the strike of the subduction zone (like that occurs at the intersection of the New Britain and Solomon trenches). […]

  4. […] I mentioned, there has been a flurry of seismic activity along the New Britain and Solomon trenches to the east and earthquakes along the Molucca Strait to the […]

  5. […] 2015.03.30 update #3 tectonic domains […]

  6. […] Here is a post comparing the New Britain region with the adjacent Bougainville region. 2015.03.30 […]

  7. […] Here is a map that shows some of the large earthquakes in this region from 1996 through 2015. Refer to the moment tensor legend to help interpret the moment tensors for each earthquake. All, but one, are compressional solutions. Note how all the compressional earthquakes have roughly the same strike, oriented relative to the plate convergence vectors (blue arrows). The Aleutian arc may have slip partitioning that results in clockwise rotation of blocks instead of forearc sliver faults. I would have suspected that the strike of the thrust earthquakes would rotate with the strike of the subduction zone (like that occurs at the intersection of the New Britain and Solomon trenches). […]

  8. […] Solomon trenches intersect. This feeds into the tectonic domains discussed in my map above and also here. I include the figure caption below as a […]

  9. […] Solomon trenches intersect. This feeds into the tectonic domains discussed in my map above and also here. I include the figure caption below as a […]

  10. […] Solomon trenches intersect. This feeds into the tectonic domains discussed in my map above and also here. I include the figure caption below as a […]

  11. […] Solomon trenches intersect. This feeds into the tectonic domains discussed in my map above and also here. I include the figure caption below as a […]

  12. […] Solomon trenches intersect. This feeds into the tectonic domains discussed in my map above and also here. I include the figure caption below as a […]

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