Geological processes are at work 24-7… 365 days a year-
all over dynamic planet Earth.
Gaze out on the Pacific Ocean.
“Look out at the horizon. What do you see?”
A good spot to fish, place for beautiful sunsets, where storms roll in, clouds?
“Look again at the horizon-
that’s where the subducting plate boundary is.”
On the Oregon Coast, that’s what’s on our tectonic plate.
It’s an impacting visual reminder that plate tectonics are at work close by-
A subduction zone is formed where the edge of the Juan De Fuca Plate converges
with the North American Plate way beneath the ocean floor.
The North American Plate is formed by continental crust which is thicker than
the oceanic crust that forms the Juan De Fuca plate.
The subducting plate boundary is the result where the oceanic crust
slides beneath the continental crust.
In the plate tectonics of the Pacific Northwest,
this geologic configuration is known as the Cascadia Subduction Zone.
Subduction zones are of extreme concern by geologists.
This is where deeper earthquakes tend to occur.
Experts say it’s not a matter of if;
it’s a matter of when the Cascadia Subduction Zone will unleash earthquake forces
strong enough to trigger a catastrophic tsunami event
along the Oregon Coast.
Evacuation Locations: Where to Converge in the event of a Tsunami
The first 20-25 minutes are most critical for survival.
Reaction time starts ticking when the earthquake commences.
While the shaking occurs, escape is delayed by
“take cover, and hold.”
Then… it’s paramount to maximize those precious escape minutes.
Helpful Resources:
TsunamiEvac – NW
Cell phone app. Click on the image for more information.
Evaucation Maps Oregon Department of Geology and Mineral Industries
Collection of 131 maps show tsunami inundation zones. Two zones are depicted on area specific maps to illustrate (1) inundation in the event of a distant tsunami; and, (2) inundation in the event of a local tsunami, such as one originating from the Cascadia Subduction zone offshore. The maps also outline evacuation routes people can take to escape.
The maps are available for free in PDF format. Click on the map icon below. Scroll down the webpage for a list of evacuation map-links for specific Oregon coastal communities.
Oregon Tsunami Information Clearinghouse website-
Please click icon:
This Week’s Photo Challenge: “Converge“
I hope our tectonic plate isn’t converging too rapidly…neighbouring Armenia and Turkey both have a history of destructive earthquakes. I hope too that in Oregon the Cascadia Subduction Zone will not unleash earthquake forces anytime soon.
I agree with you, Jim.
Those are forces that we both would rather not experience! But, someday it will be inevitable as the process of Earth recycling itself continues. Learning about the geology of Oregon has always been a humbling experience… I would imagine you have similar feelings about the tectonics in your part of the world.
After going on line, I discovered that your Earth dynamics include very active crustal-scale faults that trigger the earthquakes you referenced. Interesting that we also both live near lines of mountains with active volcanoes, the Cascades and the Caucasus. What’s on your tectonic plate differs from mine- astonishing to see your region is one of the few places on Earth where THREE continental plates converge- Eurasia, Arabia, and Africa plates!
Let’s both keep hoping that earthquake forces remain still-
~Jane
I have felt four small earth tremors in my life in Cyprus, UK, Greece and here in Georgia. Turkey, our neighbour, has had a few devastating earthquakes in recent history. I wouldn’t like to experience a large earthquake. For a small country (Georgia is the size of Ireland ), we have a rich geography, with mountains higher than any in the Alps, a semi desert area and the littoral landscapes by the Black sea. Oregon looks beautiful in photos with some spectacular National and State parks. On my only visit to the US, I only got as far west as Chicago…one day I’ll have to get over to the Pacific coast.
If you do get to the Pacific coast… I wonder what similarities you will find in our landscapes.
I don’t know how the Cascade heights compare to the Alps… probably the best chance for that would be in the Upper Cascades of Washington state or British Columbia in Canada. (Hum… I might just have to look into that!)
Thank you for expanding my understanding of the geology of the world, Jim. This was an inspiring exchange of comments. Blogging at it’s best, I think 🙂
Yikes Jane – are you trying to scare people to death!!! Your opening shots looks like the boat is about to converge with the rocks! Let’s hope not 😃
LOL!!! I didn’t even see that connection, Tina! But now that you mention it… that fishing boat does look very close to “converging” with disaster!
Perhaps a different lens choice would have put that aspect of the photo in better perspective!
~Jane
Fantastic interpretation of the theme Jane, and such interesting background information!
Thank you! 🙂
Jane,
I recalled my last drive along the Oregon Coast and the signs warning I was in a Tsunami Zone. A bit unsettling to say the least. That is a very interesting graphic of the various plates and how they interact. Here where I live I can find places where over time curbs and fences have been offset by fault movement. A constant reminder, as you pointed out, that the land we live on is on the move.
Patrick
That’s a startling thought, Patrick, to see curbs and fences offset by fault movement. We’ve had a couple very mild earthquakes here which felt very weird- because our house is on a wetland and the ground is primarily mud- the house just kind of rolled. I really don’t want to think about the effects of a significant earthquake…
A geologist friend calls the dynamic earth- Beauty and the Beast. I think he’s correct. The Beauty is what keeps us here!
~Jane
Jane, what an excellent post! This is very clearly explained and fits the theme perfectly. I love your first shot off of the beach. With loved ones living on the Oregon coast, this is always on my mind. Best wishes, WG
Thank you, WG-
I like having opportunities to share this important information whenever the opportunity comes along.
The phone app actually came in handy last summer on one of our camping trips. There was an alert due to a distant earthquake in Alaska. Nothing became of it on the Oregon Coast… but the park ranger was impressed when we asked about the status. He said they were keeping an eye on the reports; reviewed the evacuation plan for the park. We were happy to know tsunami monitoring is routine at Oregon State Park campgrounds!
~Jane
😉 Yes, I remember when those quakes came along. I’m really glad you were able to enjoy your trip without needing to bug out 😉 Cheers! WG
Agreed! That probably was in the time frame when you were out here.
(I hope we’ll be able to meet for coffee next time you visit)
~J