What is coming, Cascadia quake …

[Ca.]

https://twitter.com/x/status/1751344086974386526

 

[Keit]

@Ca. We ask you to read this post and follow the anti-spam recommendations.

 

[Ca.]

@Ca. We ask you to read this post and follow the anti-spam recommendations.

I was under the impression the post (with one video) was consistent with the Haiku's interest in the subject of Cascadia quakes.

But thanks for your input. I am a bit slow in grasping what is recommended and will add that logic with a conversation with links, as advised.

Over the last few months/years, we've come to accept a type of message that consists of only a link to a social media post or article. At first, this was occasional, but has now become very abundant. As a result, some threads have become almost repositories for messages from social networks. This makes especially the threads discussing current events almost unreadable, leads to problems with loading lots of external content, particularly painful for all members with slower internet connection, and drowns out the great comments and exchanges that we all value so much.

The purpose of this forum is discussion and networking, not spamming, and when we spam the forum we are not networking. Although the intention is good, it defeats the purpose of this network.

Obviously, there are exceptions. Sometimes it's fine to just throw out a link. Some threads are not for discussion, but for collecting data (such as the Earth Changes thread) or humor. Use your good sense: as always, context matters!

If you want to simply copy/paste messages from social networks, we encourage you to follow Laura's example on Twitter or Facebook. You can apply this strategy to all the social networks you're a member of: X (Twitter), VK, Mewe, Facebook...

So, in order to return to the original purpose of this forum, any messages that are considered "link spam" will be deleted from now on. If you post a link to an article, video or anything else, we encourage you to share with the members of this forum a brief summary of the article, video or why they should read or watch it. And remember, not all members have the time to read everything or watch every video, and sometimes they'll only have time to read the information that you've shared.

Again, we trust you to exercise good judgement, common sense, and external consideration for other members, for the benefit of us all. Thank you!

 

[luc]

But thanks for your input. I am a bit slow in grasping what is recommended and will add that logic with a conversation with links, as advised.

Besides linking instead of embedding (especially Tweets and Videos, which make the forum experience worse for many people), it would also help to put everything that isn't your own words into quote boxes, ideally even a single one. Another way would be to use the "spoiler" function, which hides the information unless one clicks on it. That way, the posts don't take up so much space and clog the threads. And, as stated in the anti-spam recommendations, we encourage everyone to write a little bit about why they posted the information in the first place.

 

[Ca.]

Thanks, luc for the guidance and recommendations.

 

[Gaby]

Cascadia update, they discovered an ancient tectonic plate, complicating things:

Fragment of lost tectonic plate discovered where San Andreas and Cascadia faults meet

A hidden chunk of an ancient tectonic plate is stuck to the Pacific Ocean floor and sliding under North America, complicating earthquake risk at the Cascadia subduction zone.

www.livescience.com

A hidden chunk of an ancient tectonic plate is stuck to the Pacific Ocean floor and sliding under North America, complicating earthquake risk at the Cascadia subduction zone.

A fragment of a long-lost tectonic plate is sliding under the North American continent in the southern part of the Cascadia subduction zone, scientists have discovered. This leftover plate fragment could pose a new earthquake risk to the region.

New research, published Thursday (Jan. 15) in the journal Science, revealed that the Pioneer Fragment — a leftover bit of an oceanic plate that disappeared under the North American Plate some 30 million years ago — is now stuck to the floor of the Pacific Ocean and is moving northwest along with that plate.

This is happening at a spot called the Mendocino triple junction, where California's famous San Andreas Fault abuts the Cascadia subduction zone. Along the San Andreas, the North American and Pacific plates move alongside one another. At Cascadia, which extends from Cape Mendocino, California, to Vancouver Island, British Columbia, the Juan de Fuca and Gorda oceanic plates dive below North America. That tectonic motion is capable of setting off earthquakes of magnitude 9 and above, according to the Pacific Northwest Seismic Network.

Some evidence suggests that earthquakes in the Cascadia subduction zone might trigger earthquakes along the San Andreas, a possibility that would widen the danger from the Cascadia fault.

While the new findings don't make the risk clear, said study first author David Shelly, a geophysicist at the U.S. Geological Survey in Golden, Colorado, they are a step toward understanding this relationship.

The Pioneer Fragment "does increase the area of contact between what’s effectively the Pacific Plate and the subduction zone," Shelly told Live Science.

Shelly and his colleagues probed the Mendocino triple junction using tiny low-frequency earthquakes and tremors — a kind of seismic shiver that originates deep in the crust and can't be felt without sensitive seismometers. "They’re teeny-tiny events but they often occur on the biggest faults," Shelly said.

By analyzing these events, the researchers determined the direction of subtle plate motions. At Mendocino, the Pacific Plate is sliding northwest against the North American Plate, bumping against the Gorda Plate as it pushes under North America. It's a complex situation, and there are competing explanations for exactly where all the pieces are and where the faultlines run.

Shelly and his colleagues found that the situation is even more complex, because a surprise piece of long-gone Farallon Plate still has an influence on the triple junction. This ancient tectonic plate started subducting under North America 200 million years ago, during the breakup of the supercontinent Pangaea. The Juan de Fuca is one remnant of the Farallon. But now, the researchers found that another remnant got stuck to the Pacific plate. This remnant, the Pioneer Fragment, isn't subducting but rather moving sidelong against the continent.

Meanwhile, bits of the Gorda Plate that got scraped off onto the North American Plate as the two ground together have now seemingly been passed back to the Gorda like a "tectonic hot potato" and may be diving back below North America, Shelly said.

This bit of geological messiness may explain why one of the largest triple junction quakes, the 1992 Cape Mendocino earthquake, had a shallower origin than scientists expected. Because of the extra bits and pieces, "the fault may not be following the oceanic crust itself. It may be shallower than that," Shelly said.

Beyond increasing the surface area of the Pacific Plate that interacts with Cascadia, the Pioneer Fragment might have the potential to cause earthquakes itself. Between the fragment and the North American Plate is a nearly horizontal fault, like the icing in a layer cake.

"We don’t know whether that fault can generate large earthquakes, but it is a fault that isn’t currently in the hazard models," Shelly said. "So it’s something we need to consider in the future."

If it comes back to hazard mode, that would be a significant marker for sure:

Cassiopaean Session Transcripts Search

cassiopaeatranscripts.org

More California seismic activity after 1st of year: San Diego, San Bernardino, North Bakersfield, Barstow: all are fracture points. Hollister, Palo Alto, Imperial, Ukiah, Eureka, Point Mendocino, Monterrey, Offshore San Luis Obispo, Capistrano, Carmel: these are all stress points of fracture in sequence. "Time" is indefinite.