Survival: So Simple it's Profound

[Koda]

I think by the time relief/aid/distribution centers are set up things will be mostly ok. Its the time it takes the govt to build/set up those facilities that will be survival of the fittest, chaos.

 

[Camelfilter]

I think by the time relief/aid/distribution centers are set up things will be mostly ok. Its the time it takes the govt to build/set up those facilities that will be survival of the fittest, chaos.

And...never go to an aid camp if you can help it...

Have it in the back of your mind, as a last resort, or used as a step on your way.

 

[MrMillspecer]

I live in an area that's generally safe from the direct devastating effects of most SHTF scenarios, but it will be the probable destination of many seeking safety, I expect that we would see a lot of desperate, hungry, ragged strangers coming to, and moving through, our community.
We have food for 4 for about a year (only 2 of us though, so we could house and feed some younger "help" should the need arise).

Because there will be organized relief aid at multiple locations (churches, food banks, community centers, etc...) anyone asking at my door will be sent there by me. I will also assume that they're at my door because they probably are really looking for something other than a "hand-up" (more like a hands up!) So I will be armed and very suspicious of their real motives. The local relief centers will be pretty much common knowledge by the time they get here (probably by the bus-load from Tri-Cities as it becomes overwhelmed).

I have family left in Lewiston ,my home town, my cousin big Mike worked in law enforcement most his life. Other aunts and uncles. I would head to the Strike and Spare in the orchards for their Turkey sandwich and curly fries first. Hope it doesn't come to that I'd rather hunker down here if anything is left.

 

[etrain16]

Yes but a surge of water will come up the Columbia and reach the Willamette. Portland is in the tidal zone...

Okay, that had me curious, so I did a little Googling. According to our own folks down at OSU. Based on a 9.0 quake and ensuing tsunami hitting the mouth of the Columbia:

They found, in general, that tidal stages are far more important than river flow in determining the impact of a tsunami; that it would have its greatest effect at the highest tides of the year; and that a tsunami would be largely dissipated within about 50 miles of the river's mouth, near Longview, Wash.

Any water level increases caused by a tsunami would be so slight as to be almost immeasurable around the Portland metropolitan area or Bonneville Dam, the study showed. But water could rise as much as 13 feet just inside the mouth of the Columbia River, and almost 7 feet within a few miles of Astoria.

Based on a maximum 9.0 magnitude earthquake and associated tsunami, at the highest tide of the year, the research concluded:

Just offshore, the tsunami would raise water levels about 11.5 to 13 feet.
Just inside the mouth of the Columbia River, the water would rise about 13 feet.
At river mile 6, approaching Hammond, Ore., the river would rise about 10 feet.
At river mile 25, near Welch Island, the river would rise about 1.6 feet.
At river mile 50, near Longview, Wash., there would be no measurable rise in the river.

I'm honestly a bit surprised myself that it wouldn't have a bigger impact as far inland as Portland. I suspect, without doing further searching, that Puget Sound/Seattle might have a bigger impact, but not certain of that.

It would appear dam failures, such as Bonneville, may be the bigger concern for us in the PDX metro area.

Source for the above info: Study outlines impact of tsunami on the Columbia River | News and Research Communications | Oregon State University

 

[Blindranger]

I suspect, without doing further searching, that Puget Sound/Seattle might have a bigger impact, but not certain of that.

I will let others consult the Google, but the impact of a tsunami from the Pacific on Puget Sound/Seattle is equally non-existent. What could impact Puget Sound is a tsunami generated within the Sound itself, due to uplift/subsidence or a large landslide.

 

[Certaindeaf]

Okay, that had me curious, so I did a little Googling. According to our own folks down at OSU. Based on a 9.0 quake and ensuing tsunami hitting the mouth of the Columbia:

They found, in general, that tidal stages are far more important than river flow in determining the impact of a tsunami; that it would have its greatest effect at the highest tides of the year; and that a tsunami would be largely dissipated within about 50 miles of the river's mouth, near Longview, Wash.

Any water level increases caused by a tsunami would be so slight as to be almost immeasurable around the Portland metropolitan area or Bonneville Dam, the study showed. But water could rise as much as 13 feet just inside the mouth of the Columbia River, and almost 7 feet within a few miles of Astoria.

Based on a maximum 9.0 magnitude earthquake and associated tsunami, at the highest tide of the year, the research concluded:

Just offshore, the tsunami would raise water levels about 11.5 to 13 feet.
Just inside the mouth of the Columbia River, the water would rise about 13 feet.
At river mile 6, approaching Hammond, Ore., the river would rise about 10 feet.
At river mile 25, near Welch Island, the river would rise about 1.6 feet.
At river mile 50, near Longview, Wash., there would be no measurable rise in the river.

I'm honestly a bit surprised myself that it wouldn't have a bigger impact as far inland as Portland. I suspect, without doing further searching, that Puget Sound/Seattle might have a bigger impact, but not certain of that.

It would appear dam failures, such as Bonneville, may be the bigger concern for us in the PDX metro area.

Source for the above info: Study outlines impact of tsunami on the Columbia River | News and Research Communications | Oregon State University

They keep going on and on about "a tsunami would be x, x miles inland" but never once do they say how high the tsunami is to start with. 100'? who knows.
I've heard quite a few studies that say Portland will be scoured gone due to the focusing effect of the mouth of the Columbia when the offshore plate gives.
Look at that last large earthquake.. the one that killed that .25 million, it hit "hardest" quite far from the epicenter.. due to the funneling effect of the landmasses there.

 

[MrMillspecer]

Okay, that had me curious, so I did a little Googling. According to our own folks down at OSU. Based on a 9.0 quake and ensuing tsunami hitting the mouth of the Columbia:

They found, in general, that tidal stages are far more important than river flow in determining the impact of a tsunami; that it would have its greatest effect at the highest tides of the year; and that a tsunami would be largely dissipated within about 50 miles of the river's mouth, near Longview, Wash.

Any water level increases caused by a tsunami would be so slight as to be almost immeasurable around the Portland metropolitan area or Bonneville Dam, the study showed. But water could rise as much as 13 feet just inside the mouth of the Columbia River, and almost 7 feet within a few miles of Astoria.

Based on a maximum 9.0 magnitude earthquake and associated tsunami, at the highest tide of the year, the research concluded:

Just offshore, the tsunami would raise water levels about 11.5 to 13 feet.
Just inside the mouth of the Columbia River, the water would rise about 13 feet.
At river mile 6, approaching Hammond, Ore., the river would rise about 10 feet.
At river mile 25, near Welch Island, the river would rise about 1.6 feet.
At river mile 50, near Longview, Wash., there would be no measurable rise in the river.

I'm honestly a bit surprised myself that it wouldn't have a bigger impact as far inland as Portland. I suspect, without doing further searching, that Puget Sound/Seattle might have a bigger impact, but not certain of that.

It would appear dam failures, such as Bonneville, may be the bigger concern for us in the PDX metro area.

Source for the above info: Study outlines impact of tsunami on the Columbia River | News and Research Communications | Oregon State University

Thanks for the info. Seems to be the best research out there at the time. That's good to know.

 

[Ura-Ki]

I still question the Validity of the tidal assessment of the Columbia River experiencing a surge, historically the Columbia has seen many, many surge events that reached FAR inland, even as far as the Willie falls and Bonneville Dam. In my mind, that makes a Rupture surge far more likely to enter the River system and cause major damage! BUT, the Jetties at the mouth of the Columbia would be the major factor, with the Jetties at 2 miles apart, the north jetty being 2.5 miles long, and the south jetty being 6+ miles long ( both in serious disrepair ) and then the river opening up to just under 4 miles wide at Melger, you would get a venturi effect that would force ( or draw in at low tide, or Slack tide) vast amounts of additional flow from an event! Numerous surges have been recorded with tides measured at Bonneville dam of 7 feet and one year, 13 feet! If a Surge event hit at the beginning of a flood tide ( incoming tide) this could bring in almost double the rivers normal outgoing flow, and worse yet, at the top of the flood tide, almost triple the out going tide!

 

[etrain16]

They keep going on and on about "a tsunami would be x, x miles inland" but never once do they say how high the tsunami is to start with. 100'? who knows.
I've heard quite a few studies that say Portland will be scoured gone due to the focusing effect of the mouth of the Columbia when the offshore plate gives.
Look at that last large earthquake.. the one that killed that .25 million, it hit "hardest" quite far from the epicenter.. due to the funneling effect of the landmasses there.

The article I linked to and quoted from says this study by OSU was the most in-depth study of such an event in our area. They didn't state specific wave height from the ocean, but I'm sure these folks are smart enough to consider the worst case scenario. I know a lot has to go into such a calculation including: tides, river level, river current, topology of the area beneath the river, path of the river and the geology of the land bordering the river.

Are they correct? Don't know, but they are certainly far more qualified to make that call than I am.

 

[Certaindeaf]

The article I linked to and quoted from says this study by OSU was the most in-depth study of such an event in our area. They didn't state specific wave height from the ocean, but I'm sure these folks are smart enough to consider the worst case scenario. I know a lot has to go into such a calculation including: tides, river level, river current, topology of the area beneath the river, path of the river and the geology of the land bordering the river.

Are they correct? Don't know, but they are certainly far more qualified to make that call than I am.

I hear you.. I didn't click. You'd think that they'd be able to say that an x on the richter scale would yield a wave x high.. then it would be a matter of what that wave would do to Portland.
That last tsunami wasn't really that big.. but where it was focused the most (a long way from epicenter), it killed a whole lot of people.

 

[Koda]

For comparison, that last tsnnami that hit japan was between 10-20 ft tall.

 

[Koda]

....and their quake was 9.0m

But not all things are equal, their fault line is not even close to the Cascadia line in size

 

[mjbskwim]

Okay, that had me curious, so I did a little Googling. According to our own folks down at OSU. Based on a 9.0 quake and ensuing tsunami hitting the mouth of the Columbia:

They found, in general, that tidal stages are far more important than river flow in determining the impact of a tsunami; that it would have its greatest effect at the highest tides of the year; and that a tsunami would be largely dissipated within about 50 miles of the river's mouth, near Longview, Wash.

Any water level increases caused by a tsunami would be so slight as to be almost immeasurable around the Portland metropolitan area or Bonneville Dam, the study showed. But water could rise as much as 13 feet just inside the mouth of the Columbia River, and almost 7 feet within a few miles of Astoria.

Based on a maximum 9.0 magnitude earthquake and associated tsunami, at the highest tide of the year, the research concluded:

Just offshore, the tsunami would raise water levels about 11.5 to 13 feet.
Just inside the mouth of the Columbia River, the water would rise about 13 feet.
At river mile 6, approaching Hammond, Ore., the river would rise about 10 feet.
At river mile 25, near Welch Island, the river would rise about 1.6 feet.
At river mile 50, near Longview, Wash., there would be no measurable rise in the river.

I'm honestly a bit surprised myself that it wouldn't have a bigger impact as far inland as Portland. I suspect, without doing further searching, that Puget Sound/Seattle might have a bigger impact, but not certain of that.

It would appear dam failures, such as Bonneville, may be the bigger concern for us in the PDX metro area.

Source for the above info: Study outlines impact of tsunami on the Columbia River | News and Research Communications | Oregon State University

Like I was saying earlier,this is all good info and thoughts but if dams break the impact will be much worse.
All of this is speculation. None of the studies can be call facts of what might happen.
So,you have your earth quake. Say John Day fails. Then a tsunami starts from some shift but it pushes waster east toward shore. The Willamet? dam fails
The waters from these events meet inland.
Then you throw those studies away cause the water is going somewhere.
It could look a lot like the Japanese tsunami with waster pushing inland 2 miles
If you are looking at worst case scenarios,that would be it.
Unless it's monsoon season in the NW too

 

[Certaindeaf]

For comparison, that last tsnnami that hit japan was between 10-20 ft tall.

I guess a 9 will yield a 100' tsunami here? Bugger.
Goodbye, Portland.. probably splash Idaho a bit.. who knows.

1700 Cascadia earthquake - Wikipedia

"..Recent findings conclude that the Cascadia subduction zone is more complex and volatile than previously believed. In 2010 geologists predicted a 37 percent chance of an M8.2+ event within 50 years, and a 10 to 15 percent chance that the entire Cascadia subduction zone will rupture with an M9+ event within the same time frame.[18][19] Geologists have also determined the Pacific Northwest is not prepared for such a colossal quake. The tsunami produced could reach heights of 80 to 100 feet (24 to 30 m).[20].."

 

[Ura-Ki]

Doing some more digging, Puget Sound IS big enough to have a Tidal wave generated inside the strait and that could rival any waves recorded on the outside!

Interestingly, the OSU studies do not quote or even list any of the U.S. Coastguard or Corps of Engineers reports or findings on River effects or tide shifts as related to an event like this! Both Agencies have done extensive studies of this, but nothing related to a tidal wave entering any of the systems for an event this size! Another part of the study fails to take into account the off shore depth of ocean near and around the entrance to these waterways, nor the "Ramp effect" of shoaling near land, and these do not show in the results of modeling! Back when the Japan Waves hit Oregon, Several coastal areas saw a three to six foot swell in less then three minutes, THAT is a huge amount of water in a small area and focused into a waterway!!! Tillimook Bay saw a 3.5 foot swell, Brookings saw almost 6 feet and Depot Bay saw almost 4 feet. There are several YouTube Vids of these events showing the waves and the damage they did!

 

[Certaindeaf]

Apparently the last Cascadian event made the Bridge of the Gods.. and wiped out all people lower than 80' above the height of the river in Hood River.. before the quake.
Seattle is sea level and Portland is like 80?.. and 100 miles west of HR?
anyway.. it's all pretty simple
lol

 

[11Charlie]

Yep don't buy a house unless its up on a hill

 

[Camelfilter]

Yep don't buy a house unless its up on a hill

&...can geologically guestimate said hill won't collapse...

 

[11Charlie]

Yes which is why I live where I do.

 

[Howard1955]

Since we're talking about worst-case monsters:

The biggest tsunami recorded was 1,720 feet tall and chances are good it will happen again


"The biggest tsunami recorded was 1,720 feet tall and chances are good it will happen again

Calamity struck at 10pm on July 9, 1958, when a 8.0-Richter-scale earthquake rammed the Alaskan coast up and northward. That impact shook free between 40 million and 60 million cubic yards (30.6 million and 46 million cubic meters) of rock and ice that rimmed the Lituya basin, dumping it 3,000 feet into the bay below. The 1,720-foot monster that reared up as a result shot through the bay at 100 miles per hour (161 kilometers per hour), as Susan Casey details in her book, The Wave: In Pursuit of the Rogues, Freaks and Giants of the Ocean. "