Very impressive analysis and breakdown of this paper. I haven’t gotten to read this yet so I really appreciated the summary.
A few of my thoughts:
- The arguments the authors put is compelling for orientation based controls on creeping vs. locking on fault systems and I don’t believe there is any fundamental flaws, and thus it is a strong support to their claim, excluding the argument of wanting more data. Which is why it was published in Nature :)
- Broadly I agree with you that there could probably be more data to support their claim, but this is a ubiquitous problem in geology where there is almost always going to be a lack of data and analysis in pretty much any study. Eventually, you run out of space and time to do a completely comprehensive analysis.
- As far as your argument that geologic controls are *probably* more important than alignment, I completely agree. California is a really complex region to study fault geometry and pointing primarily to alignments is possibly missing a lot of factors. On the coast, you have historic Farallon plate subuction uplift and possible fluid interactions in the crust, stress interactions with the Sierra Nevada-Great Valley block acting as a backstop and transferring stresses to the east, and rotation/extension in the Basin and Range from the northward movement of the Mendocino Triple junction.
- Just one example I’m very familiar with in terms of fault locking is the Alaska subduction zone off the Alaska peninsula. Two neighboring segments have vastly different fault behavior, where one is nearly completely locked, and the other almost entirely creeping. The trench orientation is uniform and plate age is consistent so fault alignment is a non-factor. A similar case exists in Mexico. Obviously subduction zones are a different animal and much larger singluar faults than a complex continental fault system like California, but just one example excluding fault orientations as any kind of factor in slip behavior of a fault.
Thanks again for your analysis, really enjoyed it!
Very impressive analysis and breakdown of this paper. I haven’t gotten to read this yet so I really appreciated the summary.
A few of my thoughts:
- The arguments the authors put is compelling for orientation based controls on creeping vs. locking on fault systems and I don’t believe there is any fundamental flaws, and thus it is a strong support to their claim, excluding the argument of wanting more data. Which is why it was published in Nature :)
- Broadly I agree with you that there could probably be more data to support their claim, but this is a ubiquitous problem in geology where there is almost always going to be a lack of data and analysis in pretty much any study. Eventually, you run out of space and time to do a completely comprehensive analysis.
- As far as your argument that geologic controls are *probably* more important than alignment, I completely agree. California is a really complex region to study fault geometry and pointing primarily to alignments is possibly missing a lot of factors. On the coast, you have historic Farallon plate subuction uplift and possible fluid interactions in the crust, stress interactions with the Sierra Nevada-Great Valley block acting as a backstop and transferring stresses to the east, and rotation/extension in the Basin and Range from the northward movement of the Mendocino Triple junction.
- Just one example I’m very familiar with in terms of fault locking is the Alaska subduction zone off the Alaska peninsula. Two neighboring segments have vastly different fault behavior, where one is nearly completely locked, and the other almost entirely creeping. The trench orientation is uniform and plate age is consistent so fault alignment is a non-factor. A similar case exists in Mexico. Obviously subduction zones are a different animal and much larger singluar faults than a complex continental fault system like California, but just one example excluding fault orientations as any kind of factor in slip behavior of a fault.
Thanks again for your analysis, really enjoyed it!
I learned a lot!
Fascinating and well done!