Tag: earthquake

Urgent: Prepare for a Cascadia Earthquake

Minamisanriku, Japan, after the M9.0 earthquake and tsunami in 2011 source: Richard Eisner

If you live in the Pacific Northwest, you should prepare for a large earthquake.

I say this not because I know we will get a large earthquake in the near future, although that’s a notable possibility. Even a probability.

My main reason for saying this is that preparing for an earthquake covers all sorts of disruptive events that are seeming more likely and more imminent.

Consider the likely aftermath of a Cascadia Megaquake, concluded in the 2013 Oregon Resilience Plan:

These are not minor implications. Imagine being 1 to 12 months without clean and available drinking water, and 1 to 3 months without reliable electricity. Something like this will happen. It’s just a matter of time.

But back to my original point. Other disastrous events seem more likely than they used to be. I’ll name a few.

Natural disasters such as wildfires.

Civil unrest. Our nation is becoming more divided than ever, at least in modern history. And the last few years have not helped.

Economic collapse of some sort. The United States and other nations have been on an unsustainable spending spree for decades, but especially the last 15 years or so. The last few years have not helped on this front, either. It’s not going to end well.

I could go on. Global tensions are higher. Russia and Ukraine are currently at war. We are not guaranteed peace in North America.

I do not believe in spreading irrational fear (and I’m not). I suspect you feel it, too. I want to help save lives and help us to prosper as we move into an uncertain future.

The February 2023 earthquake in Turkey and Syria reminded us of how fragile the world is. Source: EERI

Chris Goldfinger went on record with a calculation that there is about a 1 in 3 chance of a Magnitude 8 or higher earthquake off the coast of Oregon in the next 50 years (See “The Really Big One” New Yorker article).

Let us assume that estimate of probability is accurate. Consider what kind of odds we have of any significant disruptive event in the next 50 years- say, a regional, national, or global event, but one that affects us in our location. They’re high… very high.

Many other disruptive events could have similar effects on life and infrastructure in the Pacific Northwest as a large earthquake.

I’ll throw something else out here for consideration. I noticed after the December 2022 M6.4 Ferndale earthquake in northern California, Temblor (an earthquake risk assessment and catastrophe modeling company based in the Bay Area) had this to say: “The (Ferndale) quake produced severe shaking in a lightly populated area, (and) brought the southern tip of the Cascadia Subduction Zone slightly closer to failure…”

Tectonic action is often happening beneath us and off the coast that remind us that the Cascadia Subduction Zone is indeed active, and a large earthquake is looming. The Ferndale earthquake was a recent reminder.

Damage to Molalla High School after the 1993 M5.6 Scotts Mills Earthquake, about 20 miles south of Portland, Oregon

Priorities?

There are many good personal and family goals worthy to be pursued, so earthquake preparedness does not always seem like it needs to be an urgent priority. In addition, our exceedingly distracting world does not help us achieve goals, in general.

Please consider putting earthquake preparedness at or near the top of your list. Or, if you don’t live in earthquake country, preparedness for a particular event that aligns with your region. I would argue that some things we are often encouraged to prioritize should go below earthquake preparedness.

The point of this post is not to get into preparedness details, but think of food, water, sanitation, personal fitness, etc. It’s a time-consuming endeavor and probably needs to be thought of more as a lifestyle change than a checklist of things to get done. A perk about preparedness is that it can overlap with activities that we tend to value in the Pacific Northwest: camping, biking, gardening, hunting, etc.

For information about seismic assessments or retrofitting of a home or building, please see the Cascadia Risk Solutions website.

Whether or not the big earthquake happens in the near future, now is the time to prepare for it.

Home Earthquake Vulnerabilities: Hillside Homes and Geological Concerns

The view from hillside homes can be amazing, but this usually comes with higher earthquake risk.

“Resilience” has become a hot topic in recent years, and rightly so. It’s defined as a region’s ability to rebound after a disaster. We look at cities such as New Orleans after Hurricane Katrina, and now Houston after Hurricane Harvey, and recognize cities that were not resilient to a known disaster coming at some point.

A Cascadia Megaquake is our unprecedented disaster, at least, the one that we are methodically ticking closer to on the geological clock.

Our city and region have a long way to go to become resilient. If you want to be more convinced of this, please read the Oregon Resilience Plan Executive Summary. It’s been estimated that perhaps 80 percent of our buildings in Oregon do not comply with the current seismic code requirements (this does not mean most of them would fall down, but some of them would)! For most of Portland’s history, buildings have gone up, and remained, with little regard to earthquake forces or effects.

When I think of dangerous buildings to be in during an earthquake, URM’s (unreinforced masonry or brick), hillside homes, soft-story buildings, and old “tilt-up” buildings come to mind.

Yes, hillside homes can be among the most dangerous places to be in an earthquake, and this post is about the seismic hazards unique to this category of buildings.

A hillside neighborhood in northwest Portland.

The basic seismic retrofit that involves strengthening measures implemented in a crawl space or a basement is becoming familiar. But Hillside homes are often not in the conversation, and they need to be.

Hillside homes are common in Portland and other west coast cities. Many of them went up in the 1960’s, when earthquake risk was considered low. They have great views and character. Unfortunately, they can have catastrophic damage in earthquakes.

Hillside homes are by far the most dangerous demographic of single-family residential structures, as measured in recent California earthquake fatalities.

If you live in a hillside home, you are not necessarily in danger during an earthquake. Your structure is just more likely than other homes to be dangerous. I encourage you to take in the information in this post and get a sense of what the risks of your particular home are, so you can take appropriate action.

Some hillside homes seem to compete with each other over which one can defy gravity the most. I’m concerned that gravity may defy some of these houses when the big earthquake shakes for 3 to 5 minutes.

FEMA’s P-50-1 document gives us the following statistics from the 1994 Northridge earthquake (magnitude 6.7) in the Los Angeles area:

  • 114 hillside dwellings were significantly damaged.
  • 15 hillside dwellings collapsed or were so severely damaged that they had to be immediately demolished.
  • Another 15 hillside dwellings were close to collapse.
  • At least four people died in these homes.

Other earthquakes, such as the 1989 Loma Prieta earthquake near San Francisco, have also resulted in hillside home collapses and fatalities.

The remnants of a hillside home after the 1994 Northridge earthquake.

Geology Concerns

We have unique geological risks in the Pacific Northwest with hillside homes. The soil in the hills around here often consists of a top layer of clayey or sandy silt, somewhere on the order of 30 feet deep, underlain with bedrock. Earthquakes can trigger landslides, landslides are more likely in saturated soils, and saturated soils are a common condition in the rain-soaked northwest. This soft layer of soil can slip away under the right conditions.

Remember the winter of 2017? The west hills of Portland had numerous landslides earlier this year. Landslides happen during earthquakes even in dry conditions; imagine what would happen if the big earthquake strikes at the end of a soggy winter?

Landslide risk is not only a concern at the exact site of a house or directly below it; an unstable slope above could be equally damaging. Even a landslide just down the street could destroy the road that accesses the home and cause severe injury or death of neighbors.

I’m not suggesting that most hillside homes will collapse and slide down the hill. But landslide risk is important to know about if you live in the hills, and some houses are in high-risk areas.

A landslide that occurred in an Alaska neighborhood during the Great Alaska Earthquake (M9.2) of 1964.

The Oregon Department of Geology is expecting tens of thousands of landslides to occur during a full rupture of the Cascadia Subduction Zone. The most at-risk areas have been mapped for the entire state of Oregon on a macro level in an online interactive map called “SLIDO“; they include areas where past landslides have been documented and steep slopes with soil characteristics prone to landslides. “A Homeowner’s Guide to Landslides” by the Washington Geological Survey is another helpful tool homeowners can use to qualitatively assess landslide risk.

I’m concerned that the seismic risk to hillside homes in our region may be worse than California, just from landslide risk alone.

A snapshot of Portland on the “SLIDO” landslide hazard map by DOGAMI. Brown and red areas indicate past landslides. Notice that entire neighborhoods have been built on some of these areas.

What this all boils down to is that an adequate seismic risk assessment or retrofit of a hillside home will often need the input of a geotechnical engineer as well as a structural engineer.

If the soil appears sound and landslide risk appears to be low, at the very least a structural engineer that is attentive to slope stability and geological risks is needed. Sometimes a conservative design with the foundation (such as a continuous footing with significant reinforcing) can make up for limited soil information. I’ll discuss this more in my next post.

I’ve become a proponent of FEMA’s “simplified” seismic assessments and perform them regularly on houses. I highly recommend this as a starting point for those concerned about the seismic risk of a hillside home. They are affordable and take into account both structural and geological seismic vulnerabilities. This methodology makes a relatively thorough, first-pass assessment and helps quantify the benefit of a retrofit and the likely costs involved.

For more information about seismic risk assessments and retrofitting, please see the Cascadia Risk Solutions website.

The next post will discuss common structural earthquake vulnerabilities with hillside homes.

Rogue One, structural engineering, and earthquakes

Most structural engineers have experienced a glazed-over look in someone else’s eyes when describing what they do for a living, followed by a response like, “so, you’re an architect?”

There remains ignorance in the public about what structural engineering (and engineering in general) is for.  Other engineering disciplines may be even more confusing; I doubt most people could define the term, “geotechnical”.  Personally, I’m still not 100 percent sure what an industrial engineer does.

I think the fault of this ignorance lies primarily with engineers.  We have an incredibly cool profession and if people understood better what we do, we would probably make more money, quite frankly. Especially if we were passionate about taking our skills and orienting them toward serving the community, region, and world to make it a better place (which is the reason all professions should exist).

Structural engineering seems to be making more inroads into the public sphere in recent years.  It’s always amusing when Hollywood addresses your career. This happened in the latest Star Wars movie, Rogue One (slight spoiler alert if you haven’t seen it).  The movie specified a large building, which reminded me of a dark version of a Dubai hotel, as a site dedicated to structural engineering (among other things) for the Empire.  And there was also the scene of a group of engineers (in lab coats?) being assassinated for apparent faulty design of the Death Star.  Considering the fact that this Death Star weakness led to the downfall of the Empire in subsequent episodes, this was understandable using Imperial logic, I suppose.

The Structural Engineers Association of Oregon has this clear statement defining the profession of structural engineering (good job, whoever wrote it):

Structural Engineering is the practice of analyzing and designing buildings, bridges and other structures to resist forces induced by gravity, wind, and earthquakes and to safely transfer these forces to the ground.

See here for more: http://www.seao.org/resources/aboutstructengr/

Regarding engineering in general, there are a number of good definitions online, but here is my very simple one:

Engineers apply science and mathematics to the real world to solve real world problems.

Engineers and the engineering profession should act as a bridge between the theoretical realm of science/ mathematics and real life.

Consider the large problem of an impending Cascadia megaquake. The science indicating that these earthquakes have happened and that the subduction zone is locked and building up energy has been settled for about 20 years.

Emergency management at the state and federal level has been aware of the threat for a long time also.  The Oregon Resilience Plan, which was a state funded plan addressing the effects of a Cascadia megaquake and its consequences, was published in 2013.

Journalists helped disperse the information about this topic into the homes and hearts of Pacific Northwest residents (thank you Sandi Doughton and Kathryn Schulz, to name two).  For the last couple of years, there has been more mainstream awareness of this issue than ever.  And my experience has been that people are still baffled by the topic and wondering what to do about it.

Here is my exhortation to engineers, particularly those involved in the disciplines of infrastructure (civil, structural, and geotechnical at the forefront). The Cascadia earthquake threat is large enough to involve all of our individual efforts for years. Please consider what part you can play in increasing your personal, community, and regional resilience. We all know more than the average person about earthquakes and what they do to the ground and to structures. Don’t hide in your cubicle or office. Do what you can with your career to help and you will be saving lives when the earthquake happens.

In Portland, engineers know that there are about 1800 URM (brick) buildings which may partially or completely collapse in a large earthquake.  We know many older homes have weak cripple walls, dangerous unreinforced chimneys, and “soft story” weaknesses which will result in damage, injury, and in some cases, loss of life. We know there will likely be long term loss of power and drinking water. We know industrial areas are set to contaminate our rivers with millions of gallons of liquid fuel. Wow, that’s just the tip of the iceberg. Let’s get to work.

Engineers are a key to helping bridge our gap between what we now know (the science) and resilience. But not just engineers… every one of us can help and I would argue that we have a duty to make steps toward preparedness.

Science =>  =>  =>  => => (our gap)  =>  =>  =>  =>  => Resilience

Journalists

Engineers

Emergency Planners/ Responders

City and State Leaders

Heavy Industry

Everyone

You and me

How to Cure Earthquake Anxiety

The reality of a potential impending large earthquake in the Pacific Northwest has made its way to the general public in the last few years.  When the New Yorker article “The Really Big One” came out in the summer of 2015, many of us were shocked and genuinely scared.  After some initial shock wore off, people reacted in a number of ways ranging from buying earthquake insurance to storing up food and water to just living with a new level of anxiety they hadn’t known before (the latter probably being the most common reaction).  I recall talking to an insurance agent soon afterward and he told me that it was crazy how many people had rushed to buy earthquake insurance recently.  He didn’t miss a beat transitioning to sales mode in his next statement, which was something like, “you should consider buying some also to protect your family.”

But what should we actually do with this information that is new to many of us? And, to address the title of this blog post, how do we deal with “earthquake anxiety”?

Consider this goofy story as an anxiety illustration:  I was recently in a restroom at Starbucks and the lock on the door didn’t give me any evidence that it worked. This mattered because the door opened to a view of the coffee line and cash register. I played with the lock and couldn’t gain any confidence in it.  It made almost no sound when I pressed it, and it didn’t seem to even change position. Opening and closing the door a couple of times didn’t verify it’s functionality, except for a small, barely audible click. I reluctantly used the restroom anyway, but not without some anxiety.

That’s already too much information with the personal restroom story.  But here’s the point about anxiety: it is caused by feeling like you have no control over a potential problem.  The solution, I believe, is a combination of taking purposeful action that addresses the problem and letting go of control over the things you don’t have control over.

Consider how much lower my anxiety in the restroom would have been if the door had a deadbolt that made a loud noise as it was being engaged and it visibly could be seen sliding into place through the crack in the door. In the same way, adequate earthquake preparedness steps give you confidence that you have addressed the problem and will likely survive “the really big one”, and even thrive in the aftermath and be able to help others.

I just mentioned that the solution to earthquake anxiety is to take purposeful action that addresses the problem and to let go of control over things you don’t have control over.  The first step involves practical actions, many of which could be accomplished by anyone living in the Pacific Northwest.  The second is more related to mental health, psychology, etc, which I’m not an expert on (but see Matthew 6:25-34 if you are inclined as I am to address this through the lens of faith).

I will dive into some specifics in further posts, mainly related to actions we can take, but for now I want to point out that we can only do what we can do.  We can’t control when an earthquake (or any future high stress event) will come, but we can make a huge difference in our resilience when it does.  A head-in-the-sand approach is irrational and will not make anxiety go away.  Also, resigning to the overwhelm of tasks ahead is not a good approach, either: “I’m not going to do anything because there would be too much to do”, or “it will happen if it happens” are examples of this kind of thinking.

The work ahead in earthquake resilience can indeed be overwhelming, but even just a first few steps can make a big difference on an individual or family level than not being prepared at all.  A good preparedness plan will add redundancy to whatever plans you put in place.  This is a topic, that, if you plan to live in the northwest for a long time, is very important.  What should your next steps be in 2017 to make yourself and your family more earthquake resilient? If you have no ideas, stay tuned here…

Cascadia residents pay attention: the Ring of Fire is alive and active

A couple of large earthquakes struck the Ring of Fire in the last 2 weeks: a magnitude 7.8 in New Zealand on November 14th and a 6.9 (according to USGS) on November 21st off the coast of Japan.

I’m fascinated by earthquakes, particularly since I’ve made a decision to focus my career on earthquake resilience.  But even if you’re not as into them as I am, the awesome power of earthquakes was undeniable last week in New Zealand.  And the Japan earthquake is another reminder of the need for preparedness in the Pacific Northwest.

Landslides, open fissures, stranded cows, and the seafloor lifting up out of the ocean are the images that struck me the most.

This drone video of a ground fault rupture in New Zealand looks like Lord of the Rings style special effects. I can easily imagine an army of orcs falling into the ground as it opened up:

And here’s a good article from CNN about the seafloor being raised.  The coast has been permanently changed in a dramatic way (unless an earthquake reverses it):

http://www.cnn.com/2016/11/18/asia/nz-earthquake-pics/

Regarding Monday’s Japan earthquake, the Japan Weather Agency is calling it an aftershock from the 2011 magnitude 9.0 megaquake.  It caused a small tsunami and seems to have shaken people up a bit (bad pun intended) but caused little damage.

It’s been estimated that we have a 37% chance of experiencing an 8.0 or higher Cascadia Subduction Zone earthquake in the next 50 years.  This is a helpful statistic and I intend to bring it up often.  The main application for us in the Northwest is that we have a high risk of this event occurring if we intend to live in this region for long.  It makes sense to prepare for it, but once you start thinking of the implications, it quickly becomes overwhelming from the individual level up to the state agencies.  The bottom line is that an adjustment in lifestyle is needed for all of us living in this region.  More to come on this topic…

How will a Cascadia megaquake compare with these recent earthquakes?  The magnitude will be greater; between an 8.0 and 9.0 and possibly even higher.  Ground fault rupture as shown in the video above won’t likely be an issue, at least not a primary one, as the fault is off the coast between the continental and oceanic plates.  Vertical displacement will likely occur, as the coast is expected to drop on the order of 6 feet relative to sea level.  This, along with the accompanying tsunami, has drastic implications for the low lying coastal areas. Strong ground shaking over a huge region will damage older infrastructure like brick buildings and 100 year old homes not attached well to their foundations.  Landslides are to be expected throughout the region.  Soil will liquify in saturated sandy soils such as near rivers.  This has terrible implications for industrial areas like northwest Portland and just south of downtown Seattle near the Duwamish Waterway.

My personal mission is to help inspire as many individuals and families as possible to be resilient when this event occurs.  If you’ve started preparing or making lifestyle changes, I’m interested in hearing from you as I’m sure I’m not the first person to do so.  I also want to hear from those of you who want to do something but are not sure what to do.  What are the questions you have and what concerns you the most?

Making ourselves and our region more resilient is a marathon, not a sprint.  So, take a breath and put some thought into this topic.  Don’t lose sleep over it, take action instead!

Welcome to the Cascadia Risk blog

Greetings.  My name is B.J. Cure and my goal is to help residents of the Pacific Northwest become earthquake resilient.  You may have found your way here because you are concerned about this risk and are unsure what to do.

Here’s a key statistic: We’ve got about a 37% chance of an 8.0 to 9.0 megaquake occurring off the coast of the Pacific Northwest in the next 50 years, and we’re currently unprepared as a society for this event.  If the quake were to happen today, casualties would likely be in the tens of thousands, major environmental disasters would unfold, and the regional economy would be crippled.  In fact, it could result in the worst economic hit the U.S. has ever seen.  I was shocked when I first heard these facts a number of years ago, but I am convinced that they are indeed facts, and the threat is real.

Word has gotten out to the public more in recent years of the Cascadia Subduction Zone and the potential for huge earthquakes.  You may not need to be convinced of the risk if you are reading this.  Although I want to be another voice in raising earthquake awareness, my main aim on this site is to direct individuals and homeowners (you) on exactly what you need to do.  This blog is the beginning of this effort.  More to follow.

The facts are a bit frightening, and we have a few choices as residents of the Pacific Northwest.  We could bury our heads in the sand, so to speak, and just continue living the way we have.  Ignorance is bliss, and the odds of the megaquake not happening in the next 50 years appear to be greater than it actually occurring.  No action is an option.  We could also become aware of the risk and do nothing, living with some anxiety about what could happen.  I’m writing this because my choice is to make some preparations and modify my lifestyle so that I can live in this area and face the future with hope.  I hope you’ll join me on this journey.