PDX area - the big one

[The Heretic]

We've all seen these articles right?

When the 'Big One' hits, Portland faces mass casualties, widespread destruction: Study

What I found interesting in this one was this:



It is a map showing the areas of expected ground deformation and by implication, the areas of most possible damage. The article has this image with a link to the actual full sized image if you want to look at it in detail.

The thing I found surprising is that where I live it shows almost no to little damage. I assume because the hills have bedrock? I am not so sure though that the Chehalem ridge won't have landslides, at least surely on the south side where there have been lots of landslides in the past?

The other interesting thing is they show a lot of damage along the rivers - I assume because of the deep sediment beds. I remember when there was a 6.2 earthquake in Anchorage and later that day I went out to the glacier and they said with all the sediment there that it looked like waves on the ocean. So if you live in one of those areas, something to consider.

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[kott0n]

I live in Vancouver metro. I've already accepted I'm not going to be able to get out of town if something happens. Not enough roads and too many people.

 

[Argonaut]

Urban areas face mass destruction in any event. If the enviorment doesn't take them out the human social problems will. No natural event required. Portland could be destroyed by an event that took out Bonneville dam and shut the power off for a couple of years......they can't make there own food, water, or ANYTHING else and are totally reliant on the rest of us. Let's see what happens to LA if the water gets shut off.

 

[mkwerx]

Washington county looks hardest hit in general. Makes me feel so warm n fuzzy that I am in the orange zone like so many others

I hope in one way me and my fam are not home if a big one hits - i doubt our building will fare well. On the other - this is where what supplies we have are, and uf nothing else, I'd like to have my rifles & ammo handy, without having to carry them everywhere I go.

 

[etrain16]

I'm surprised by two things on that map - #1, that there isn't a greater area of extreme movement/liquifaction along the river in downtown PDX - I would have expected that area to be much broader.

#2 - where I live appears to be largely unaffected, though my route home from various locations would certainly be compromised.

Bummer is that our company is moving offices next year and it looks like we're moving closer to danger - and it puts me across one more bridge than I have to cross now. It also adds about 7 miles to my commute. Crossing one river was bad enough, crossing 2 is going to be a much bigger problem.

 

[Sstrand]

I'm sorry but you guys that live in that area I consider as "Collateral damage."

Sheldon

 

[shibbershabber]

Being in east Vancouver, looks like I wont get hammered too hard by the Cascadia... well, the maps dont show our area, but I can estimate anyway.

However, that same study examined the outcome of a potential 6.8 at the fault running along the west hills... THAT one looks to be worse for the PDX metro area than the 'big' one. That one looks like it will hit us up north pretty hard too.

My biggest fear is that ANY disaster hits while my kids are gone on the weekend at their moms.... She moved to Aloha and that area looks like a bad place to be in either scenario... plus my ex and her husband cant even spell preparedness let alone do it.
I pray that they aren't there when it happens.

Considering that roads will be impassable or at least closed for weeks until they can be inspected, etc. I cant imagine them being stuck out there with those fools and no supplies for that long.


Ive got gear and supplies to last us a few months here, my inlaws are fairly stocked up too so my wife and little one will be okay...
My prepping is now focused on getting my kids back home.


Vancouver to Aloha will be quite the gauntlet.

 

[HB of CJ]

They say the approximate odds of the big one happening are about 1 in 10 within the next 30 to 50 years. Pretty good odds of nothing happening within my remaining life time. I hope I am not making a big mistake.

 

[Kruel J]

When it's my time, it's my time. I won't sleep any worse tonight reading this.

 

[11Charlie]

I would actually like to see the updated map of the Vancouver, Battle Ground area. If I am home I am not to worried as we are ready. If at work then it could be an interesting ride/walk home.

 

[Kruel J]

I would actually like to see the updated map of the Vancouver, Battle Ground area. If I am home I am not to worried as we are ready. If at work then it could be an interesting ride/walk home.

If I make it through the big one, I'll find a way to get to your house brother.

 

[justcuz]

Tis, sadly a moot point since unfortunately, unlike an airstrike which citizens have time to kiss their derriere good bye and get with family and loved ones when it hits.

No matter what USGS or OGS says, earthquakes can not be predicted!

The knee jerk approach of this article with damage, death estimates is strictly hyperbole, especially stating '...in 50 years..' is like saying 'you can have an accident, or disease, or death in the family, or, or, or in the next 50 years!'

Japan recently, in the scheme of things, had an 8.9 +/- earthquake which moved the island 8 +/- feet and shifted the earth's axis by 4 inches. ( Quake moved Japan coast 8 feet, shifted Earth's axis - CNN.com )

This stated, the initial event is considered the P compressional wave which causes the ground to move forward and backward rapidly and S shear wave cause the ground to move side to side and actually do not do any major damage, but the surface love and Rayleigh waves are elliptical retrograde waves which cause the earth to slowly "roll" which causes buildings to move up...then down and causes the massive damage shown on media and move islands.

seismology 101 is over, suffice to say, this happens in split seconds, especially when the epicenter is closer to the surface and under the area.

there absolutely no time since olde (oh and new) buildings, or city infrastructure, e.g., roads, bridges, etc., were not built on 'what if' building codes of something occurring in the future, therefore everything will collapse instantly killing huge amounts of citizens.

those who appear outside the projected epicenter will be stranded, as the infrastructure around them will be cut off from transportation, electricity, water, ad nauseam.

bottom line, you can't predict when, you can't prepare cuz you don't know when, you can't react fast enough to save yourself or your loved one from the surface waves causing the buildings, bridges, roads collapsing around you, so you might as well ignore the shock and awe and the sky could fall article(s) and enjoy yourselves.

kinda like Washingtonians worrying about Rainer or St. Helens blowing up (oh wait Helen already did) or Oregonians worrying about Hood, Jefferson, or , or or or the other what-ifs existing in this world.

PS: they even do zombie projects based on computer projections...personally, i'd worry more about a zombie apocalypse or pandemic of 1917's world wide epidemic.

 

[Argonaut]

Tis, sadly a moot point since unfortunately, unlike an airstrike which citizens have time to kiss their derriere good bye and get with family and loved ones when it hits.

No matter what USGS or OGS says, earthquakes can not be predicted!

The knee jerk approach of this article with damage, death estimates is strictly hyperbole, especially stating '...in 50 years..' is like saying 'you can have an accident, or disease, or death in the family, or, or, or in the next 50 years!'

Japan recently, in the scheme of things, had an 8.9 +/- earthquake which moved the island 8 +/- feet and shifted the earth's axis by 4 inches. ( Quake moved Japan coast 8 feet, shifted Earth's axis - CNN.com )

This stated, the initial event is considered the P compressional wave which causes the ground to move forward and backward rapidly and S shear wave cause the ground to move side to side and actually do not do any major damage, but the surface love and Rayleigh waves are elliptical retrograde waves which cause the earth to slowly "roll" which causes buildings to move up...then down and causes the massive damage shown on media and move islands.

seismology 101 is over, suffice to say, this happens in split seconds, especially when the epicenter is closer to the surface and under the area.

there absolutely no time since olde (oh and new) buildings, or city infrastructure, e.g., roads, bridges, etc., were not built on 'what if' building codes of something occurring in the future, therefore everything will collapse instantly killing huge amounts of citizens.

those who appear outside the projected epicenter will be stranded, as the infrastructure around them will be cut off from transportation, electricity, water, ad nauseam.

bottom line, you can't predict when, you can't prepare cuz you don't know when, you can't react fast enough to save yourself or your loved one from the surface waves causing the buildings, bridges, roads collapsing around you, so you might as well ignore the shock and awe and the sky could fall article(s) and enjoy yourselves.

kinda like Washingtonians worrying about Rainer or St. Helens blowing up (oh wait Helen already did) or Oregonians worrying about Hood, Jefferson, or , or or or the other what-ifs existing in this world.

PS: they even do zombie projects based on computer projections...personally, i'd worry more about a zombie apocalypse or pandemic of 1917's world wide epidemic.

The bottom line is........life is temporary and no one gets out alive. No one really knows how or when they are going to die........precautions are fine but many situations are just going to kill you. It is a little like musical chairs. Is an earthquake going to get you, or heart disease, or cancer or get hit by a bus..........(I have two distant grandfathers that were beheaded).........everyone's time here will end.

 

[Member 34319]

May it be quick and painless.

Otherwise, well, bubblegum!!!

 

[justcuz]

The bottom line is........life is temporary and no one gets out alive. No one really knows how or when they are going to die........precautions are fine but many situations are just going to kill you. It is a little like musical chairs. Is an earthquake going to get you, or heart disease, or cancer or get hit by a bus....everyone's time here will end.

 

[The Heretic]

Being in east Vancouver, looks like I wont get hammered too hard by the Cascadia... well, the maps dont show our area, but I can estimate anyway.

However, that same study examined the outcome of a potential 6.8 at the fault running along the west hills... THAT one looks to be worse for the PDX metro area than the 'big' one. That one looks like it will hit us up north pretty hard too.

My biggest fear is that ANY disaster hits while my kids are gone on the weekend at their moms.... She moved to Aloha and that area looks like a bad place to be in either scenario... plus my ex and her husband cant even spell preparedness let alone do it.
I pray that they aren't there when it happens.

Considering that roads will be impassable or at least closed for weeks until they can be inspected, etc. I cant imagine them being stuck out there with those fools and no supplies for that long.


Ive got gear and supplies to last us a few months here, my inlaws are fairly stocked up too so my wife and little one will be okay...
My prepping is now focused on getting my kids back home.


Vancouver to Aloha will be quite the gauntlet.

This is why I tried for years to move back to the Portland area, and why I stayed on this side of the Columbia and the Willamette. Even so, it will be hard for my kids to make it up here, but for now it is the best I can do and still live close enough to them and work.

Work is a problem too. I work in a very old multi-story building that is very close to the west hills and the fault. It is a very strong building, but I am leery as to whether it would survive. OTOH - the other office buildings of my employer are right on top of a different fault, not just near it, and they are on even deeper sediment not to mention very much closer to the river and sea level, and on the wrong side of the river.

Two more years and I will be retiring.

 

[CoastRange57]

The thing I found surprising is that where I live it shows almost no to little damage. I assume because the hills have bedrock? I am not so sure though that the Chehalem ridge won't have landslides, at least surely on the south side where there have been lots of landslides in the past?

Depending on where you are at in relation to past past landslides and how much soil and matter are left on top of the bed rock left to slide off. I am a bit west of you and have looked at a lot of the hills and you can clearly see where the past landlsides were. They were pretty massive and probably include some bed rock shear as well. True the south side of Chehalem Ridge is a lot steeper as a result of those landslides, so areas where the hills are not so steep. There is an area to the northwest of Forest Grove where and entire subdivision / area of town is built on a past landslide, that probably has the potential to move farther given the right situation.

 

[The Heretic]

Depending on where you are at in relation to past past landslides and how much soil and matter are left on top of the bed rock left to slide off. I am a bit west of you and have looked at a lot of the hills and you can clearly see where the past landlsides were. They were pretty massive and probably include some bed rock shear as well. True the south side of Chehalem Ridge is a lot steeper as a result of those landslides, so areas where the hills are not so steep. There is an area to the northwest of Forest Grove where and entire subdivision / area of town is built on a past landslide, that probably has the potential to move farther given the right situation.

Yup - there are maps of those landslides and if you know to look you can see where they happened. When I bought this place I knew this could happen, but the north side is less prone to that.

What gets me is that these hills are not from an uplift from what I have read, but are from the massive floods when the ice dam broke thousands of years ago. So not sure where the bedrock cam from - I assume these hills were mostly sediment.

 

[cigars]

Initially when it hits it will be a neighbor helping neighbor scenario. After matters stabilize, hundreds of thousands will begin the long foot path towards home. Given several days, most will have made it. Then the fun begins. Many will have no homes due to either the initial raw destruction or gas fires. Some of those who prepped will have access to their supplies, some will not. If road ways are operable, National Guard and FEMA might make it to distribution points with supplies. After the first week of no supplies and general chaos, civility will take a vacation.
Don't expect normalcy for quite some time. Many will die
during the event, but many will die because of the
aftermath. As they say, keep your powder dry.

 

[CoastRange57]

What gets me is that these hills are not from an uplift from what I have read, but are from the massive floods when the ice dam broke thousands of years ago. So not sure where the bedrock cam from - I assume these hills were mostly sediment.

The bedrock was pre existing to the Missoula Floods that brought all the sediment to this area. The various soil types in Western Oregon are place and formed from settling out when the Floods finally reached the ocean. The heavier sandy soils, awesome for agriculture settled out in the Sandy area, as well as deposits of the sandy Marquam / Willamette soils in the Canby / Mollalla areas.

You can see the erratics, the huge rocks that made it in with the floods and settled out in the farm / plains areas. We dug out a few in a friends field, there are some pretty impressive ones in the Sheridan area as well as the hills on Burkhalter Rd. There was a huge one found on the ball fields at Farmington School some years ago. Just dug a deeper hole and rolled the rock into it.

I spent a couple years in college going on field trips around Northwest Oregon with my major being agriculture engineering and soil science. A lot of time spent in pits looking at soil profiles.

Hopefully this all holds off until we get moved to out hilltop in Central Oregon. No factor there.