Feeling a Quake Right Now In Sedro Woolley, WA

a reply to: westcoast

We caught a nice jolt last night down here in
So Cal. 4.1 Devore I believe.. Rattled the wife a bit
but she's used of that from me.

I sure felt the Victoria quake last night, living in the area. I was in bed trying to fall asleep when it happened. It shook the bed violently and it felt like a truck had hit the house. Knowing immediately that it was a quake, I got up out of bed, and decided to investigate. The ground felt like it was moving up and down for a minute after the initial quake. Made it feel like I was temporarily struck by vertigo.

That's one way to wake you up.

Interesting coincidence that the deep tremor (episodic tremor and slip, or ETS) has been active under Vancouver Island for the past 11 days:


source

This shows the most recent deep tremor activity. Realtime tremor map (set to 24hrs):

a reply to: Olivine

Thank you for that. I had been wondering if this is part of something new with the ETS. See Executive Summary here:

pubs.usgs.gov...

It's not a problem until it is. We know so little about Cascadia and the ETS that it's wise to keep our heads up.

It would be nice to know what happened leading up to the last Really Big One in Cascadia. Did warning signs come from Haida Gwaii or the B.C. mainland? I know, I know, the official line is that fault lines are all independent of each other, etc., etc. and don't affect subduction zones.Until someone can tell us exactly what happened leading up to the 1700 EQ in Cascadia, I think it doesn't hurt to keep an eye on the surrounding areas, including what's happening further south right now.

originally posted by: snypwsd
a reply to: westcoast

Its not odd at all. Infact its perfectly normal when you live on or near a fault line.

Really? Is flippancy all you have to add?

I'm quite aware of the faults that transverse the plates under and around me.

While seeing quakes in a seismically active area is NOT odd, this particular one, in fact, is.

First, it is the largest in the Puget Sound region for over a decade. Second, it was reported felt over a huge area by more than 13,000 people. (almost unprecedented reports came in). And yes...it IS odd for this size and depth of quake to have such strong sensor motion. It's because of where it struck. The Puget Sound Basin acts like a giant tub, and the very deep seismic waves literally bounce around in it.

I have lived in this area for over forty years and the only other quake that I felt more than this was the 6.7 Nisqually.

It is also a bit odd that there still haven't been any aftershocks. Makes us a bit on edge!

originally posted by: Olivine
Interesting coincidence that the deep tremor (episodic tremor and slip, or ETS) has been active under Vancouver Island for the past 11 days:

source

This shows the most recent deep tremor activity. Realtime tremor map (set to 24hrs):

The PNSN Director, John Vidale actually pointed this out last night and even said out loud that perhaps there could be a connection.

a reply to: westcoast

I forgot to add in my post above that there is an increased risk of a major EQ during times of the ETS, from what I've read. Is this your understanding, westcoast? With this one not being typical, according to the people who felt it, it's all the more reason to be vigilant.

Wasn't the last ETS atypical too, in the way it moved?

Recent news about magma and tectonic plate movement from John Vidale:

www.king5.com...

It was an interesting sensation here in Vancouver, almost everyone I know felt it, and most were jolted good by it.

I was sleeping, and in a dream where I felt a pressure sensation, and I opened my eyes and it felt like a wave of air followed by an impact, and then a good shake followed by slowly dissipating shaking for over a minute.

Very different feeling than all the other quakes I have felt over the years.

www.vancouversun.com...

"Unfortunately, Tuesday’s release of energy will do nothing to forestall a massive and devastating “megathrust event” that scientists say could come at any time. And that will be a very different kind of earthquake."

I live only 4 miles from the 6.7 that happened in the Nisqually area and it was one of the scariest things I have ever experienced in my lifetime. Glad I did not feel this one! I keep a good eye on the new quake threads in the hopes that we will have some sort of pre-warning to the CSZ letting loose, but wouldn't bet that we will.

Funny, back where I am from you had to worry about tornadoes all the time, and now I just worry about that big one that I keep feeling is coming sometime soon. I know there is only so much one can do but fortune favors the prepared mind! a reply to: westcoast

originally posted by: Olivine
Interesting coincidence that the deep tremor (episodic tremor and slip, or ETS) has been active under Vancouver Island for the past 11 days:

source

This shows the most recent deep tremor activity. Realtime tremor map (set to 24hrs):

This is a bit scary.

a reply to: westcoast

While seeing quakes in a seismically active area is NOT odd, this particular one, in fact, is.

First, it is the largest in the Puget Sound region for over a decade. Second, it was reported felt over a huge area by more than 13,000 people. (almost unprecedented reports came in). And yes...it IS odd for this size and depth of quake to have such strong sensor motion. It's because of where it struck. The Puget Sound Basin acts like a giant tub, and the very deep seismic waves literally bounce around in it.

I believe you, but what is actually odd about it? That it was felt for 150 miles? 13,000 people reporting it in this day and age actually seems like a relatively small number to me. What do you mean by sensor motion? It shook strangely? I don't know a thing about earthquakes, just trying to get a better understanding. My understanding is that quakes in the Eastern US are actually felt farther away than on the West Coast. I may be misinterpreting what you're saying, but it sounds like you're saying that the quake was felt a lot further because of the region. I just read something about a quake that was a 5.0 and felt for 300 miles.

From what I've read, no one seems to think there was anything odd. I know so little about it I don't have much of an opinion either way.

I'm just glad we're all safe. I really should start learning more about this. Any tips for a guy that lives in an old ranch style house? This place seems incredibly sturdy compared to newer construction I've lived in, and it's obviously survived everything for the last 50 years, but I'd prefer to do anything I can to insure it's going to be safe. Love my little house, plan on staying here for awhile and then renting it out again, so it may make sense to get someone out and look at the foundation and stuff right?

a reply to: Domo1

It's my understanding that single-story wood-framed houses are incredibly resilient to earthquake motions, just be sure that your sill plates are firmly anchored to the foundation.

originally posted by: Domo1
a reply to: westcoast

While seeing quakes in a seismically active area is NOT odd, this particular one, in fact, is.

First, it is the largest in the Puget Sound region for over a decade. Second, it was reported felt over a huge area by more than 13,000 people. (almost unprecedented reports came in). And yes...it IS odd for this size and depth of quake to have such strong sensor motion. It's because of where it struck. The Puget Sound Basin acts like a giant tub, and the very deep seismic waves literally bounce around in it.

I believe you, but what is actually odd about it? That it was felt for 150 miles? 13,000 people reporting it in this day and age actually seems like a relatively small number to me. What do you mean by sensor motion? It shook strangely? I don't know a thing about earthquakes, just trying to get a better understanding. My understanding is that quakes in the Eastern US are actually felt farther away than on the West Coast. I may be misinterpreting what you're saying, but it sounds like you're saying that the quake was felt a lot further because of the region. I just read something about a quake that was a 5.0 and felt for 300 miles.

From what I've read, no one seems to think there was anything odd. I know so little about it I don't have much of an opinion either way.

I'm just glad we're all safe. I really should start learning more about this. Any tips for a guy that lives in an old ranch style house? This place seems incredibly sturdy compared to newer construction I've lived in, and it's obviously survived everything for the last 50 years, but I'd prefer to do anything I can to insure it's going to be safe. Love my little house, plan on staying here for awhile and then renting it out again, so it may make sense to get someone out and look at the foundation and stuff right?

Assuming you already have an earthquake emergency kit, adequate water and food, and keep your vehicle gassed up, there are some small, relatively inexpensive ways to stay safe. Anchor your freestanding cabinets and TV to the walls. Falling objects cause injury, obviously. This recent EQ happened when many people were in bed. Make sure the bedroom is free of objects that could fall on the bed. Again, anchor bedside cabinets to the wall, and consider placement of lamps, etc. Consider latches for your kitchen cabinets, like the ones used in holiday trailers. Childproofing plastic latches may not be strong enough for all purposes. There are EQ readiness websites to help you. Simple, inexpensive adaptations to your home can go a long way. You're fortunate to live in a single-storey house. Having said that, are there any unhealthy trees too close to the house that may need large, overhanging limbs removed, or removal altogether?

originally posted by: Olivine
a reply to: Domo1

It's my understanding that single-story wood-framed houses are incredibly resilient to earthquake motions, just be sure that your sill plates are firmly anchored to the foundation.

Here's one of the many sites on getting a home EQ-ready:

usinsuranceagents.com...

One thing mentioned elsewhere is the use of window film or heavy curtains in bedrooms, and placement of beds away from windows, if possible.

originally posted by: westcoast

The PNSN Director, John Vidale actually pointed this out last night and even said out loud that perhaps there could be a connection.

Here is a very short article with John stating this, as you said. Link

John Vidale at the Pacific Northwest Seismic Network says there has been slow slip under Vancouver Island over the past week. He thinks it could have prompted the 4.8 quake.

"We wonder about that, since the slow slip does load the part of the subduction zone that we expect to deliver a magnitude 9 earthquake some day,” Vidale said. “But it's complicated, so it's something we're studying pretty carefully."

I really like this video about the importance of preparedness. James Roddey puts things in understandable terms:

youtu.be...

Love the tinfoil hats, the Monty Python music at the end and the suggestion to bribe your neighbors with beer and cookies in advance, in case you need help after an EQ. He tackles a serious issue with humor.

I find it interesting how this earthquake has been played north and south of the border. Canadian media showed images of the earthquake on land in the Saanich area, between Sidney and Victoria, B.C. As we know now, it was near San Juan Island. Canadian officials placed it at 4.3, but have now upgraded it. There's obviously a need to review more than one source of information if you live in a seismic zone and hope to understand what's going on in a timely fashion. Science isn't pure, and involves opinion and outside influence. Something to bear in mind for the future.

Is there a change in the locking mechanism of the CSZ right now?

geodesygina.com...

I don't know if this has been posted in other Cascadia threads:

oregonstate.edu...

EQs in the plate itself may affect movement along the plate boundary.