- #1
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Discussion Overview
The discussion centers around the relationship between slip faults and the generation of tsunamis, particularly focusing on the implications of supershear slip and the geological characteristics of different fault types. Participants explore the conditions under which slip faults can lead to significant tsunami events, comparing various tectonic settings.
Discussion Character
- Exploratory, Technical explanation, Debate/contested
Main Points Raised
- Some participants seek clarification on the definition of "supershear" in the context of seismic slip velocities.
- Questions are raised regarding the risk of tsunami generation from the mid-Atlantic Ridge compared to other regions like the San Andreas Fault and Gulf of Aqaba.
- One participant explains that the mid-Atlantic Ridge is a spreading center, which differs from strike-slip fault environments, suggesting this may influence tsunami generation potential.
- Another participant notes that the mid-Atlantic Ridge contains numerous transform faults, indicating a complex fault system that may still contribute to seismic activity.
Areas of Agreement / Disagreement
Participants express differing views on the tsunami generation potential of various geological settings, with some agreeing on the nature of the mid-Atlantic Ridge while others question the implications of fault types and their configurations.
Contextual Notes
There are unresolved questions regarding the specific conditions required for tsunami generation from different fault types, as well as the implications of fault geometry and slip velocity on seismic events.
Who May Find This Useful
Individuals interested in geophysics, tectonics, and tsunami generation mechanisms may find this discussion relevant.
- #2
Twigg
Science Advisor
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My background in geophysics is weak, but I have a couple questions.
"Supershear" means the peak velocity of the slip is greater than the S-wave speed (but less than the P-wave) speed, right?
Also, the article notes that the San Andreas and Gulf of Aqaba share a similar risk. Why not the mid-Atlantic ridge? Are there no regions on the Atlantic coast with the right geometry to generate tsunamis via this mechanism or do the earthquakes have to be closer to the bay? Or do supershear earthquakes not occur in the mid-Atlantic?
"Supershear" means the peak velocity of the slip is greater than the S-wave speed (but less than the P-wave) speed, right?
Also, the article notes that the San Andreas and Gulf of Aqaba share a similar risk. Why not the mid-Atlantic ridge? Are there no regions on the Atlantic coast with the right geometry to generate tsunamis via this mechanism or do the earthquakes have to be closer to the bay? Or do supershear earthquakes not occur in the mid-Atlantic?
- #3
Tom.G
Science Advisor
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The mid-Atlantic Ridge is a spreading center (moving apart at 2.5cm per yr.), not a region where the tectonic plates are sliding past each other, as they are
around the Pacific Ocean.
You might find this site interesting:
http://portal.gplates.org/#SEAFLOOR
Cheers,
Tom
around the Pacific Ocean.
You might find this site interesting:
http://portal.gplates.org/#SEAFLOOR
Cheers,
Tom
- #4
davenn
Science Advisor
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They are a good mix of both. The spreading ridge is sliced up like a loaf of bread with dozens ( probably 100's ) of transform ( strike-slip ) faultsTom.G said:
here's just a quick section out of Google Earth. ALL those horizontal lines are transform faults chopping up the MOR