Earthquakes trigger more earthquakes.
———-
UPDATE: Magnitude 6.3 NOV-8 Earthquake At Cascadia Raises More Concern
Scroll down for more…
———-
At the Seismology Lab at the University of Washington, there is concern that the 7.7 magnitude earthquake that occurred on the British Columbia coast over the weekend could affect the Pacific Northwest including Washington, Oregon, and northern California.
“We need to watch the whole region with extra care,” said a seismologist there.
The magnitude 7.7 was a big earthquake, considered one of the most significant along the northwest coast in 60 years.
Reported by NWCN.com in Seattle, scientists also looked to see if the quake affected volcanoes in Washington, and will remain on alert for at least several more weeks. So far, everything is quiet…
The problem is that the West Coast, from Alaska to northern California, is under tremendous geologic pressure as it’s forced up against the basin that forms the Pacific Ocean.
Release the pressure in a major way along one fault, and it can then add to the pressure on another fault. More than 100 aftershocks were recorded following the 7.7, including one of them more than 100 miles south of the quake’s epicenter, thought to be on the Cascadia Subduction zone.
The subduction zone threatens a much larger quake…
a magnitude 9…
from the northern tip of Vancouver Island to Cape Mendicino California.
Such an earthquake would be devastatingly catastrophic, particularly to Seattle, Portland, and all of the cities and towns that run up and down the west coast, even through mid California.
I’m posting this as an alert that something ‘could’ happen as a result of this recent aftershock earthquake, which is well south of the main quake on the Cascadia Subduction zone… this looks potentially ominous.
If you live in or near those regions, examine your existing supplies, food, water, bug-out capabilities. Make a plan. Be ready. Just in case…
UPDATE: It is now being reported that the centuries old and famous “Haida Gwaii” Hot Springs in the region of the 7.7 earthquake… HAS DRIED UP AND GONE COLD.
A Parks Canada inspection party set out to investigate and stepped ashore to find that the island’s three main hot spring pools, which once bubbled with water as warm as 77 Celsius, were bone dry. “Not even a small puddle,” Surrounding rocks, once warm to the touch, were cold.
source: http://news.nationalpost.com/2012/11/02/bc-earthquake-hotspring/
(This is obviously IMO related to the recent B.C. earthquake, and further indicates the great unseen changes that have taken place as a result.)
NOV-8, 6.3 Quake at Cascadia Subduction Zone Raises More Concern
Since the large magnitude 7.7 earthquake of OCT-28, not only have hundreds of aftershocks occurred in the immediate vicinity, but other curious earthquakes have been triggered further south, within the Cascadia subduction zone. On NOV-8 an especially large earthquake shook that region, further indicating that stresses have transferred into that region. Why is this significant? Because the Cascadia fault is EXTREMELY DANGEROUS for the entire Pacific Northwest.
The Cascadia subduction zone (Cascadia fault) is a type of tectonic plate boundary that stretches from northern Vancouver Island to northern California. It is a very long sloping fault that separates the ‘Juan de Fuca’ and North America plates.
Ocean floor is sinking below the continental plate offshore of Washington and Oregon. The North American Plate is moving southwest, riding over the top of the oceanic plate. The Cascadia Subduction Zone is where the two plates meet. Unlike other faults that slide along side each other, this one is particularly dangerous because one plate rides over the top of another.
To make matters worse, the Cascadia fault intersects and transitions with other faults at it’s north and south boundaries, including the infamous San Andreas fault which runs down the length of California. Studies of past earthquakes on both the northern San Andreas Fault and the southern Cascadia subduction zone indicate that quakes on the Cascadia subduction zone may have triggered most of the major quakes on the northern San Andreas during at least the past 3,000 years, with the exception being the great 1906 San Francisco earthquake.
The next rupture of the Cascadia Subduction Zone is anticipated to be capable of causing a magnitude 9+ earthquake and widespread destruction throughout the Pacific Northwest. And in fact, evidence suggests that a major Cascadia earthquake will likely rupture the San Andreas fault as it splits down into California, the combined effects of which would be more than devastating.
Geologists and civil engineers have broadly determined that the Pacific Northwest region is not well prepared for such a colossal earthquake. The tsunami produced may reach heights of approximately 100 ft. The earthquake is expected to be similar to the 2011 Tōhoku earthquake and tsunami, as the rupture is expected to be as long as the 2004 Indian Ocean earthquake and tsunami.
Left: Cascadia Subduction Zone
Right: Earthquakes since the OCT-28 quake (until this update)
Note the significant recent quakes south of the initial quake (the top cluster)
UPDATE NOV-10, Aftershocks creeping towards Cascadia fault and Vancouver Island…
This could all be inconsequential, while I’m simply pointing out observations.
Link: Video which shows the dangers of volcanoes in the Cascades…
@ Ken, Oh Boy, many friends along that coast… Be Well… o…
I’m inland from that NW Coast.
I have studied computer generated models of earth plate shifts, tsunamis, and spoke with our resident Geologist that lives in our nieghborhood.
I am prepared to the best of my ability and finances at this time.
As you know the world will end without my presence so I just hope that I can have a little comfort and peace of mind as I go.
My family lives here and I am not leaving without them for they are the best of everything in my world.
At least you are INLAND. That’s good. The worst part about your ‘zone’ is that it is subduction, which as you know means more up-and-down shaking which tends to be worse. Since you live in a region of earthquake danger, I imagine that you are probably reasonably prepared and have your dwelling ‘earthquake proof’ or resistant. (e.g. no heavy objects near your bed at night – things that could fall lurch off the walls and hit you, etc.)
Obviously the long term impact of such an event would be terrible beyond imagination since the cities would crumble. Millions displaced. Again though, it is good to think about such things and to at least have some sort of plan…
Yeah that subduction stuff.
I was told my house is built on bedrock but I don’t know that would make a difference. At least it isn’t land fill!
Things are bolted to the walls in some places but the wine glasses are still on the top shelf. I tell everyone LEAVE the kitchen if the Earth Shakes.
My biggest concern actually is the natural gas lines.
I have the tool and know where my neighbors shut off valves are along with mine.
Oh, and the incalculable damage to the cities – that would be unbearable for sooo many.
I am reasonably far away from them and in that type of scenario it isn’t like the way here would be easy or desirable.
Thankful for the farms around me and the family. And all the water I want.
On a positive note, I convinced my landlord to take down the 75 foot rotten tree in my front yard and can now sleep more peaceful with out it’s creaking in the wind. Plus it gave me a cord and half of firewood for next year, Yeah!
Odd that HAARP status monitoring of ‘Sandy’, which shows HAARP activity at landfall to be off the scale, also indicates serious HAARP activity typically associated with earthquakes on the west coast…
I’m about 50 mikes above Portland just off of Interstate 5, bring it on I’m ready. The only thing I worry about is stuck doors both inside and leading outside the house.Lots of 3’x5′ windows throughout though so at least we can still get out Have preps in the house in the garage and in 2 seperate sheds, they can’t all fall down,(can they). Hope for the best prepare for the quake just in case.
i also live between Seattle and Portland on the I 5 corridor. I just hope we are far enough from the action. I do have some preps in place, not sure you can ever have enough.
Are you within spitting distance of Mt. St. Helens too? That’s a concern to us as we are about 40 miles West of the Mt. We have several greenhouses on the property all with their own heat so even if everything made of wood falls down we will have a place to hole up. We would offer the use of a greenhouse if it ever came to that, but if it did I doubt that I-5 would be open to traffic, if it was there at all.
We manufacture greenhouses and so have plenty of poly to throw over any damage but I did like the suggestion that you keep plywood on hand for broken windows. Thanks to all the non left coasters for their thoughts as well as the suggestions.
Hi We’re about to build a greenhouse so it will be ready for next yr.
We are probably within driving distance of you. Any suggestions?
Thanks
Be safe my friends! Praying just a false alarm..
~~~$%%%#$@^#^!!!~~~
And I am planning to move to van island next spring. In my fifties, single female and willing to take it on.
It has always been may dream, so I will take what may come, looking at this as an adventure.
@stayingonplan, Follow your dreams. Just be prepared 😉
We live about 8 miles outside of Forks WA. Way up in the northwest corner of the peninsula. I used to live right on the beach in Clallam Bay. The Indian Ocean earthquake and tsunami convinced me to get the hell off the water. I moved inland 15 miles as the crow flies and about 500′ up in elevation. My biggest mistake? Not realizing that the lake here could pose a problem. The creek that runs right by my house. I can’t believe it. I knew and thought of liquefaction at the beach, why the heck didn’t I even think of it when we bought this house??
THAT is now my biggest worry. Our house is a one story, problem is there is an L shape. Need to reinforce that section. We have large 3×6 windows that will go to be sure, but a ton of plastic and tarps to cover if the house still stands. I also have a small one room 10×20″ studio that is detached from the house, so it may make it. Etc etc. Have lots of storable food all over the place and plenty of water but if my house actually stays standing (square and rectangular are best, those L’s etc are weak spots) I wonder if it won’t just get sucked into muck through liquefaction or if the lake burps some nasty stuff up.
So much for getting up off the beach. And we are a bit under water on the value of the house due to this nice little pop in the housing bubble (I’m being very sarcastic, the economy is in crisis mode of course)
I think we are stuck. And I don’t really like it. Darn it. So word to the wise. Follow your instincts all the way through, not just partially through.
@Chris, You made an excellent move getting off the beach! Truly, if that subduction zone goes one day, there will be an enormous tsunami. One thing that comes to mind when you mention your large windows breaking (and they probably would break in such an earthquake), it would be a good idea to keep 4×8 sheets of plywood on hand (which could also be used for other sorts of makeshift repairs.
Not to mention the devastation to be caused in Hawaii and Japan from the resultant tsunami that would cross the Pacific.
Just wanted to let y’all know that I just came from the grocery store, and they are stocking furiously, I couldn’t buy any red meat, the senior citizens were in there by the herds, and I’m thinking there thinking inflation. Of course that’s why I was there. Just adding some more staple items. But I went to the hunting section and all the camp was almost gone, and of course I was just picking up some water purification tablets, and I ran into two old ladies buying lots of tarps. Just interesting. Well the beagle pups are loose. Got to go
Looks as though the Cascadia fault is trying to unzip. And when it does… Great timing for this article Ken!
I’ve just been asked when a 9 pointer hits can it be felt over a 1000 miles away sorry to ask such a question
Yes, I would say so. Having said that, the more shallow the earthquake, the stronger it is felt on the surface. In addition, the type of earthquake and the geography of the land itself will make a difference. In fact, it has just been discovered how earthquakes on the East coast of the US are felt much more strongly due to the ground itself.
The event in BC was felt in Kauai, although it took some time to reach there (I don’t remember exactly). My sister lives over there and lots of people in her town felt it. VERY concerning!
TR in OR
It is astounding when you think about the forces at work… feeling it in Hawaii! It is stunning when you think about it. Imagine now if you will… a magnitude 9. Or maybe you should not…
Great information. I live 170 miles south east from the earthquake in Port Hardy last night. I live in Powell River, across from Vancouver Island, sheltered from several islands. I am curious as to what effect a earthquake with a magnitude of 9 or more in one of those areas would cause much damage here. My children are heading to the island next weekend and the weekend after and I am a little worried because this zone seems to be very unstable at this pint in time.
@Powellriveritte, Apart from the probable destruction of building structures, the tsunami would be unprecedented in our times (height: same or probably worse than Japan?). Here’s the thing… no one knows when this will happen. Even given what has happened recently. I’m pointing out the obvious though, in that there has been significant activity in this region, and it may spell T R O U B L E. This is not a prediction. It is an observation.
Hi I noticed a powell river person was concerned about the tsunami, I’ve lived on vancouver island for 41 years, was raised in comox… It is my understanding that in the event of a major earthquake, that it would be the west coast of the island that would get the tsunami. I would actually think powell river would be fairly safe from the tsunami.
As the “Anon” said… Check out what has been going on @ HaarpStatus.com… They Have Also added a link to “ChemTrail Dispersal (Real Time) on this site… Survive-All… Awareness is Preparedness… o…
Yeah… HAARP activity looks interesting today. Seems to be pummelling your West Coast. California was lit up red this morning and now the ‘rarely happens red’ seems to have spread to most of the western states. With a new nicely circular patch appearing just above Texas… Stay safe over there.
Oh, damn! Moving to San Francisco Bay Area this weekend! PLANS to prep for all possibilities, but none COMPLETED yet! It would totally suck to be there unprepared with a catastrophe looming ahead. *sigh*
@Pamela7762, I lived just east of SF in the East Bay Area for 15 years during my last career stint and commuted to the city each day (I no longer live in CA). I highly encourage you to be well prepared with an earthquake plan, and a kit (for your vehicle and your home). That region is entirely dependent upon operating infrastructure, and when it goes (not IF but WHEN), it will be absolutely catastrophic. In all probability, the Hayward fault (East Bay) is destined to rip next with a magnitude 7+. Sorry to be a Debbie Downer… 😉
The big one is assumed to originate in the Hayward fault or San Andreas fault-I think that a Cascadian Megatrust will be more destructive than both combined- Iam really concerned I think about it every single day- It is just anytime now.
This is certainly becoming a very scary situation. I know it would be devastating to the people there, however, can you tell us what adverse effects there would be for the rest of the country? Is there anything we need to do to prepare? We live in Texas in the Dallas area. I know prayer is powerful, but I also believe in taking actions to prepare. Thanks for posting this info.
@Pam, “IF” this were to come to pass in this time frame, for those who do not live in the Pacific Northwest or California, the effects will be primarily economic and supply shortages. One would have to analyze the businesses that contribute to our economy that reside in these locations, and estimate the effects. Stock market sell-off? A big sell-off could potentially crash the system. How many refineries, etc. are there? Sky High gas prices? One of the biggest hits will be the ports of import. Most of the products from China come in through the west coast. Needless to say, the follow-on loss of life would be enormous as well. Fires raging.
A side effect could be volcanic eruption(s) in the region, as there are many there. That would bring on a new set of problems…
Well, hate to say it, but sounds like we’re just screwed. :-/
The initial blow is going to be deafening- Discovery Bay, Ca
I’ve a question – Where is the water flowing now that the hot springs have gone cold? And an ancillary question to that – is there an inflow from the sea into the subduction zone?
There may be a correlation with the recent HAARP readings and a build-up of hydrothermal pressure underground.
It is very interseting how that the centuries famous Hot Springs suddenly dried up and went cold. Like you said, where is the water flowing now? Pressures must be released somewhere…
From what I understand when water dissapears from the surface it is sucked into the earth.
We’re traveling from the East Coast to California for Thanksgiving. I’ve had a sense of foreboding about making this trip. Hubby thinks I’m being ridiculous. Now seeing this, I’m seriously freaked out. How would the Chino area be affected with a quake like this?
@Andie, Chino is well south of the ‘northern San Andreas’ and Pacific Northwest. Having said that… ‘what if’ the entire San Andreas ripped? Okay, now I’m just scare mongering… seriously, don’t freak out. I’m just posting the facts about the current curious quake locations there, as well as opinion. This thing might hold together for another hundred years… or 100 minutes.
Thanks! I’ll calm down now and try to enjoy this trip. 🙂
Just think if it causes a ripple effect, saint Helene, or god forbid Yellowstone.
What about people that live further away, like Utah? Would affects would we feel?
@bek, the same as those just described… If you do not live in the Pacific Northwest, particularly near the coast, or in northern CA, then the effects (apart from the shaking that you will surely feel), will be follow-on.
Bek42002: I’m sure you are aware of the faults that are in the valley west of Salt Lake City and those that are around Park City, Ut.
I don’t think a Northwest Subduction earthquake would activate your faults, having said that, I think you should prepare as you would knowing the earthquake likelihood in your area. Check your area earthquake history and that will give you an indication. Best of luck to ya.
Trees within falling distance to hit your house or garage can create a very dangerous environment. Get rid of them ASAP. I did and am glad. We have under ground power to our house with telephone poles far enough away that no
problem exists. Preparations (food, water, First Aid Supplies, required medicines, shelter, means to protect my property) are all in place.
Ready to shut off gas, water and power if necessary.
Am able to “Bug-In” or “Bug-Out” whatever the situation calls for.
Now for the praying part.
I was stationed in Everett Wa. in 1965 during that earthquake. Also was stationed in Spokane, Wa. when Mt. St Helens blew her top. Now being prepared is part of our lifestyle.
I live in the Vancouver area of British Columbia…right on the coast, in the Municipality of Surrey.
I am wondering what kind of damage would we receive – being just west of Richmond Municipality, which is right on the coastline.
As you must know, we have the Burrard Inlet and the Fraser River here, which pour into English Bay and then into the Strait of Juan de Fuca, which lies between Vancouver Island and the Mainland.
I have been doing amateur seismic reports on my humble website for over 5 years and have never seen a 7.7 Mag. on or near the Island, such as this past week.
With that, the 6.4 Mag. which they are saying, that hit off the coast the Island, but, when I mapped it, it was smack on, the upper end of the Island.
What do we have to look forward to, in the event of a 9 Mag. here and how far inland will the inundation be?
What elevation is a safe elevation with 100 miles inland?
Thanks,
Layna Jan Wilson.
Ok this is a little concerning. But what I am worried about is the volcanos. Mt. Saint Helens and Mt. Hood. Could those possibly go off?
@conway10, In my opinion, ‘to be worried’ is the wrong thing. Instead, ‘to be prepared’ is what you should be thinking. To answer your question though, there’s no way to know.
Ready here in boise more worried about the after affect with refugees and the like
And yet we hear nothing in mainstream media. But we know about Kim Kardashains hairstyles and other celebrity news. People need to know this information so they can be prepared. Don’t get me wrong, its ok to have a little entertainment in life, but our country is consumed with it so much that nobody really knows what is going on around them. I bet most in those areas are clueless.
Baker, Rainier, St Helens, Hood, Jefferson, Shasta, I’m sure I forgot one or two.
Isn’t it great to have the Cascades and thousands of acres of forests in your back yard? Until you remember this.
Oh and the beautiful Saun Juans and Island chains, until you remember this.
I do beleive, but could be wrong, that those islands were once part of the mainland?
Some land masses may rise while others fall.
There is no way to know which way the marbles will roll.
Personaly, I will enjoy this country while I may and if parts survive to carry on and you never hear from me again, you will know that I wasn’t at the part that survived.
am in the UK but am thinking and praying for everyone right along the whole coast and inland, we cant fight nature,just need to do all we can to be ready! stay safe everyone, stay safe.x
There are sources which indicate an astronomical/astrological relation to the activity in the Cascadia fault… in particular the Transit of Venus and 6 month window after-effects, which in 2004 produced the quake/tsunami in Banda Ache, these transits occur in pairs w/8 year interval, since the 2nd transit last June we are still in the 6 month window, which ends around the winter solstice.. If you observe the NASA maps of the transits you will see something interesting in the rising and setting areas of the transit, we might be safe w/ Earth activity deep in the central Pacific, or it might come closer to home. Some astrologers consider that the San Juan Islands were formed as result of astronomical gravity induced earthquake. The yogis and wise in Asia are all deeply concerned for the well being of all and many people are generating good-will for all beings, and forgiveness and gratitude for the Earth and all Her residents.
O’siyo,hello,we live near Mt.Mcloughlin Oregon at around the 2000 ft,we are pretty much prepared but what about the mountain,any signs,we do live in a Volcanic area.I’d say about 20mi from the Mountain.Thank You.Bill Little Eagle.
All our family lives on the west coast. Prayers for everyone.
…and we might not see another earthquake in that fault zone for years. One just doesn’t know.
any ideas on which direction the tsunami would travel? 360 degrees & spread out from the epicenter? am located in SE Alaska (Sitka) & actually was riding the Alaskan ferry back up during the 7.7 quake which I didn’t even feel although some ferry workers felt it. I just assumed it was a small rough spot in the ocean. Thanks for the heads up
A tsunami does not become very apparent unless and until it begins to reach the shoreline. The shoreline itself (the grade of the land leading up to the shore) will affect just how high the wave will reach.
Here are some interesting links.
Pacific Northwest Tsunami Interactive Map
West Coast Tsunami Warning Center
Time to look up and pray.Of course being as prepared as we can be is a good idea.
My mother lives on the Mid. Oregon coast,a block from the ocean.
I live on the San Jacinto and San Andreas fault line intersection.
i live in Hammond/Warrenton Oregon should i be worried
It is better to be prepared than worried. I suppose that worrying could be a motivator to take some preparedness actions though. The first step is recognizing risk. The next steps are planning and doing something about it…
so… another qauke in alaska this time, being prepared is always good, living in fear is not. I’ve lived on vancouver island for over 41 years. We don’t get hurricanes, or tornadoes or volcanic eruptions, mass flooding. What I am trying to say is…No where is safe in this world, and living in fear isn’t the answer 🙂
@Felicity, You are exactly right. There are risks everywhere, and many are associated with the natural surroundings of where you live. The key is simply recognizing them and having a plan. Once someone starts making a plan, the worrying will go away! It’s like medicine 😉
How would SE Alaska come through this?
Regarding SE Alaska, Probably not so good, along the coast. Here’s the thing… The smart thing to do if you live along the coast, and you feel an obviously large earthquake, get to higher ground. Making a plan and having a route in mind BEFORE such a disaster, could save your life.
I was hoping for a brighter picture for the Juneau area. We are surrounded by islands to break up tsunamis! The 7.7 in BC was noticeable, but actually had to be told we had an earthquake. I just felt nauseous for a few minutes with that one.
It’s all connected, I’m thinking the next maybe california
Ken… how would one be able to get to higher ground, when the bridges are all washed out ?
If one’s only access to higher ground is by way of bridges, then your statement is accurate. So… a smart thing to do immediately following a MAJOR quake would be to get the heck out of there as soon as possible.
The fact is, living right at the coast, near one of the most dangerous faults in the world, one which is well known to ‘someday’ rip a magnitude 9+, well, is risky business. There are consequences to one’s actions…
yes and a mag 9 will move the island 5 meters north west so b.c. ferries can charge more for islanders to get to the mainland
one in Russia now… the ring of fire is very active
why continental earthquakes are not triggered more than 9 magnitude???
Anyone who reads this now and says, “Well, that didn’t happen…” Please don’t ignore the possibility. The pressure continues to build in 2015, the earthquakes along the Juan De Fuca Plate are increasing in number and magnitude. We know this plate is going to shift at some point. Unfortunately, 90% of the population is negating the possibility and are not prepared for any emergency, let alone a 9.0. It will be hell here. If you haven’t read it, there is a great, informative book called “Full Rip 9.0” that explains this fault and it’s effect on the Oregon and Washington populations. It’s very scientific but very readable.
I have a question about how far inland a large quake/tsunami would go. I live in the Hayward Hills/Castro Valley area and my family and I have recently been prepping with more of a purpose, if you will. I guess this would be a two part question.
If a 7.7 quake hit the Hayward Fault – what would that look like to the people that live in that area? What do you think the chances for survival would be? I know we are all talking hypothetically here but I need some peace of mind.
Second question would be – If the big 9.0 quake hit how far inland would 100 foot swells go? Are the Hayward Hills without a doubt going to be consumed by the water?
I saw your post on 300 ft swells on the east coast. Have you done anything similar for the west coast? That would be awesome.
One more question – What area would you recommend living with the quake and this horrible drought in mind?
This scares me! I have been trying to warn people and everyone says “They have be that for years- not going to happen in our life”. Well, I would rather be safe than sorry! I grew up in Washington and love the Pacific Northwest, but I would leave now if I could. I live right along interstate 5 (just east), but the freeway is less than a mile from my home and work!
They now say everything east of I5 will be toast? What does that mean for anyone along I5? Probably the same scenario? 🙁 I don’t like it. Not one bit…
It should scare you… the Cascadia Subduction zone is THE most dangerous in the U.S. at this time. Apparently the most likely major quake to occur next. But when? That is the question… When that thing ruptures, it’s going to be horrendous.
I live in Forks Washington, I’ve lived here 95% of my life, I have been recently researching online to try and see if I am safe here in Forks from the Tsunami when “the big one” hits. I can’t find any answers nor any evacuation route to higher ground!! I find this disturbing nonetheless. Forks is 99 feet above sea level currently. I also would like to know how far inland a 100 foot wave would reach?
Another disturbing fact is there is only one road out that runs north and south directly through town and it runs right along the coast you can actually pull over take a few steps and be ON the beach if you go south, north isn’t much better and leads you to downtown Port Angeles which is right on the water… :-/ I think I’m trapped…
@Olivia, when you feel the quake, simply (and immediately) do what you can to get out to higher ground before the sheeple do… Also, assume that all bridges will be destroyed – so pre-plan a way out without bridges.
Hi, Richard, In Sequim, on the 100 foot high (?) glacial ridge 2-3 miles south of the mouth of the Dungeness River. I’ll probably survive quake and sunami and hope I’ll have enough supplies to last a couple of months until I can get out of here if there’s something better. Cheers, Rich
Richard m ,,,,,,i just spent a month doing a engineering eval for project ,take a look a soil liquificatioan for a hazard ,,if you have gravel underlying you may be ok ,,,but if it’s soil or clay look out ,, in Japan folks were killed by soil liquificatioan ,dry ground acted like quick sand ,,
OH,
Sounds like he is on a glacial till hillock. Might be some slope stability issues, but if he is 100′ above the surrounding land, his water table will likely be down a ways, unless the hill he is on is backed up to a water body. Liquefaction can be an issue in unconsolidated soils with a high water table, as you find along coastal regions and river delta. Just my thoughts. But you are right, he should take a look at the stability of his ground, big earthquakes do funny things.