Great video! The similarity to Kaikoura struck me immediately and had me chasing up Kaikoura and triple junction.. and came up with "Triple junction kinematics accounts for the 2016 Kaikoura earthquake from Xuhua Shi et al. which invokes a separate plate on the accretionary edge of the convergent margin starting from Kaikoura and extending all the way up to Tonga. How has this been received in the community? Does it have any credence?
Lots to unpack in this paper. I understand the desire to create a microplate between the volcanic arc and the subduction zone (essentially the forearc and the accretionary wedge) but then we could also invoke the same here in Cascadia land. It is clear, from paleomag and geodetics, that our forearc is moving at a different relative velocity from the backarc (North America) much like what these authors see in NZ. There are indeed great similarities between the two tectonic systems and they are really complex. NZ's is much more seismically potent as it produces waaaay more significant eqs. than ours. Thanks for pointing out this paper.
Hey all! Nate, here. Just wanted to let you all know that RP headquarters and the team are all ok. It has been quite the experience. Our office escaped all damage, however my personal house was pretty trashed inside. Lot's of broken stuff and no power for about 16 hours. My kids and I were able to get things cleaned up and we were thankful we were fairly well prepared with generators and other supplies. Alanna, William, and the rest of the team are all ok and faired well. Thanks for the concern and thanks for listening!
Thank you for the update! Happy to see that you all made it through with only minor damage. Cheers.
Hey all! Nate, here. Just wanted to let you all know that RP headquarters and the team are all ok. It has been quite the experience. Our office escaped all damage, however my personal house was pretty trashed inside. Lot's of broken stuff and no power for about 16 hours. My kids and I were able to get things cleaned up and we were thankful we were fairly well prepared with generators and other supplies. Alanna, William, and the rest of the team are all ok and faired well. Thanks for the concern and thanks for listening!
Great video! The similarity to Kaikoura struck me immediately and had me chasing up Kaikoura and triple junction.. and came up with "Triple junction kinematics accounts for the 2016 Kaikoura earthquake from Xuhua Shi et al. which invokes a separate plate on the accretionary edge of the convergent margin starting from Kaikoura and extending all the way up to Tonga. How has this been received in the community? Does it have any credence?
Here's a little information about the Mendocino Triple Junction (MTJ) area that just spawned this earthquake. One reason we are one of most seismically active areas in US.
Fascinating Geoff. I didn't realize that the subduction was moving north like that. Thank you for the rabbit hole...
2:30 something last night, MyShake yelled at me "EARTHQUAKE EARTHQUAKE EARTHQUAKE" and the little indicator told me it was a 6.3 and I should DROP! COVER! HOLD ON!
but we were 200 miles from the epicenter, so didn't feel a thing. And I'd forgotten I'd installed the app. But, it seems to work.
Here's a little information about the Mendocino Triple Junction (MTJ) area that just spawned this earthquake. One reason we are one of most seismically active areas in US.
It was a significant event that caused large accelerations in the area of Ferndale (reported 0.9 g - If an acceleration exceeds 1 g that means it is flying). There doesn't seem to be a lot of structural damage except for Fernbridge that crosses the Eel River and connects Ferndale to the rest of the world. It is an amazing bridge https://en.wikipedia.org/wiki/... so I'm hoping it is a settlement/liquefaction problem with the approaches and not the main span. A great source of information is https://earthjay.com (he is currently traveling to the area but will have information within the next 24 hours). It appears to be an earthquake in the oceanic Gorda plate which is subducting beneath North America. It is a common earthquake source. We had a similar event exactly one year prior to this one (just a coincidence).
It was a significant event that caused large accelerations in the area of Ferndale (reported 0.9 g - If an acceleration exceeds 1 g that means it is flying). There doesn't seem to be a lot of structural damage except for Fernbridge that crosses the Eel River and connects Ferndale to the rest of the world. It is an amazing bridge https://en.wikipedia.org/wiki/... so I'm hoping it is a settlement/liquefaction problem with the approaches and not the main span. A great source of information is https://earthjay.com (he is currently traveling to the area but will have information within the next 24 hours). It appears to be an earthquake in the oceanic Gorda plate which is subducting beneath North America. It is a common earthquake source. We had a similar event exactly one year prior to this one (just a coincidence).
So you leave the door open to keep it well ventilated, then when the Tsunami is coming you discover that there is a nest of poisonous snakes in there...
If I am not mistaken, you could see the transition in wave form there. Geomorph can tell which ones.. I'm guessing the first sloshing was secondary and the final side to side motion was caused by love waves. (yes you read correctly).
Funny I hadnât seen this thread earlier. It can be really difficult to determine the wave forms traveling through small bodies of water in buildings since there is so much interference (constructive and destructive) happening. Also, the building is an oscillator that is responding to ground motion based on its own peculiar characteristics (how it is attached to the ground, how tall it is, orientation, etc.). So, with all of those caveats, it looks like the video misses the p-wave (makes sense seeing they had time to grab the camera and turn it on), the first part could be an s-wave and the second set could be surface waves (especially when they start rotating). Pretty cool.
We saw those when visiting somewhere. They looked so depressing, but I guess maybe that’s better than death? Maybe.
So you leave the door open to keep it well ventilated, then when the Tsunami is coming you discover that there is a nest of poisonous snakes in there...
yeah, but looking at it again, the distinction is not that clear. I think it was just me seeing patterns where none exist. At first I thought the water was going back and forth and then side to side but it's doing both movements in both phases.
And the quake was quite deep so it would if anything be p and s waves and not rayleigh or love waves, if I understand them correctly, which is unlikely.
However, there were two phases, which could be due to reflection, i.e. two sets of s-waves offset from each other. dunno.
You have a symmetrically asymmetrical tub with the ledge at the one end. It causes a wave all by itself just as a reef on the ocean floor does. Then it rises, breaks, hits the back end for a backwash wave of a type that would not exist if the bottom of the tub was the same throughout. And what is the alignment of the tub in relation to the shock wave, perpendicular or an oblique angle, etc. And was the shock wave itself uniform or distorted ?
What you do have is total chaos in regards to the waves present. This situation is very similar to what we have up here in the Great Lakes, (especially Erie which is very shallow with an average depth of just 55 feet) with swells coming from multiple directions all at the same time, especially in storms. What you saw in the tub is very similar to the wave action that took the Edmund Fitzgerald as it tried to approach and pass through a narrow strait in a brutal storm. Waves reflecting off the banks interacting with wind driven waves from the storm. IIRC the final analysis was waves coming from 5 different directions all at once. And the bow and stern sitting atop the respective crests of two swells leaving the length of the hull out of the water and the weight unsupported a tad too long causing it to snap in half in the middle. Storm waves on the GL's can get up to 50 feet at times, and are very irregular with the short fetches.
We saw those when visiting somewhere. They looked so depressing, but I guess maybe thatâs better than death? Maybe.
So you leave the door open to keep it well ventilated, then when the Tsunami is coming you discover that there is a nest of poisonous snakes in there...