Consider this: in the time that it takes you to read this sentence, at least one earthquake has been recorded somewhere in the world. In fact, there have probably been a hundred or more earthquakes today, most of which were too small to be recorded. Earthquakes are a common natural phenomena, with some 30,000 earthquakes recorded every year. That means there’s at least 50 earthquakes a day around the world.
Living on shaky ground
Oregon is on the cusp of experiencing a major earthquake in the near future. Lying off the coast of Oregon is a massive fault called the Cascadia Subduction Zone. This is the site where one tectonic plate overlaps another. Currently, scientists are predicting that there is a one in three chance of a magnitude-eight earthquake in Cascadia over the next 50 years.
Our region has not produced an earthquake since 1700 and is building up pressure where the Juan de Fuca Plate is subsiding underneath the North American plate.
Portland is just one city within this zone that stands to suffer significant damage as the result of a devastating earthquake. Reports by the Oregon Department of Transportation (ODOT) show that the city’s infrastructure is extremely vulnerable, and a sizeable earthquake could sever many of the major transport routes throughout the city.
More than half of Oregon’s 2,800 state bridges were built before 1970 and as such have no seismic design of any kind, putting them at risk of damage in a quake or other natural disaster. Data collected by the ODOT shows that of the 1,232 lifeline structures identified in Portland, 713 bridges are considered seismically vulnerable or potentially seismically vulnerable. That means that nearly 60 percent of state-identified lifeline bridges could face collapse or be potentially taken out of use after a quake.
Which bridges will be the worst hit?
The Interstate Bridge is a critical connection between Oregon and Washington, carrying some 130,000 cars and trucks daily over the Columbia River along Interstate 5. In a magnitude 8 or 9 Cascadia Subduction Zone quake, this connection is likely to be taken out. The drawbridge towers are likely to collapse, sending giant concrete blocks smashing through the bridge deck, and middle sections of the bridge will crumble into the river, meaning that the bridge will be impassable to traffic. This will also block ships from travelling along the river.
Government records indicate the Ross Island, Hawthorne, Steel and Broadway Bridges are also likely to collapse during a major earthquake. The Morrison and Burnside bridges could remain standing, but with extensive damage. The Marquam and Freemont bridges would survive but would be out of use. Their middle spans would remain but the approaches would collapse, rendering the bridges inaccessible.
Map Credit: Kyle Iboshi,KGQ Portland
Will any bridges be spared?
The recently rebuilt Sellwood Bridge is now Portland’s most earthquake-resilient bridge for car and truck traffic. It has been designed to flex and bend, allowing the bridge to absorb some of the energy created by an earthquake, and preventing it from cracking and falling apart. This new bridge is built into solid bedrock foundation which makes it a lot sturdier than the previous bridge, which lay in soft foundations.
Hope for the best, prepare for the worst
The vulnerability of Portland’s infrastructure is a timely reminder of how our next major earthquake will have devastating consequences for both the city itself, and its inhabitants.
Earthquakes can strike without warning, so it is essential to have a plan in place and be as prepared as possible in the event that one does occur. Preparing the basics for survival and making a plan can minimize the effects of a disaster on you and your loved ones.
As the ODOT reports have shown, Portland’s major transport routes are very likely to be disrupted or destroyed following a major earthquake or natural disaster. This means that movement around the city will be limited, so it is important to be self-reliant in the event that you may not be able to leave your house or access goods and services. The most important thing that our community can do is have an emergency kit in your home. Make sure you have enough supplies (food, water, first aid) to ensure that you and your family can survive at home for three days to a week following a disaster.
There’s no denying that our planet is a very active, and earthquakes are a constant reminder of our vulnerability. So by preparing for the worst, you and your family stand a good chance of getting through.
It was just after midnight when the shaking started.
Initially it was enough of a jolt to wake us all up, but not enough to get me out of bed.
Once I realized it was a big one, and I mean a BIG one, it was already too late. The earth was rumbling like a freight train and the house was swaying side to side. I tried to run for cover, but the power of the earthquake threw me sideways into a chest of drawers.
Winded and bruised, I made it to a doorframe while we waited for the shaking to stop.
It didn’t stop.
The earthquake lasted for two minutes- an eternity.
Once the ground finally settled, an eerie silence filled the house. Whether out of motion sickness or absolute pure fear, I ran to the bathroom to be sick.
After trying to settle back to bed with our hearts racing a million miles an hour, our house suddenly illuminated with a bright light. We went to investigate, assuming the streetlights or a neighbor with a flashlight as the likely culprit.
Instead we witnessed the sky light up in swirls of green and blue, apparently a common, yet terrifying phenomenon after earthquakes. Almost like the earth was reminding us we really have no control of anything.
We gingerly crept back to bed thinking it was over, but an hour later the tsunami sirens sounded and within 60 seconds we were out the door. Five of us, plus a dog, piled into our car and headed for the hills.
When it came to earthquakes, we thought we were prepared. After the devastating Christchurch earthquake in 2011, the whole country was on edge.
Trying to be proactive, I headed off to my local hardware store to put together an emergency kit. And I went all out. Flashlights, batteries, dust masks, a fire extinguisher, first aid kits, blankets, a radio, gloves, food, and toilet paper – you name it, I bought it. There were enough supplies to look after five housemates and a dog for three days.
“She’ll be right” is a typical Kiwi attitude, so some laughed at what they deemed as me being excessively over-prepared. Just you wait, I joked, you’ll come begging for some supplies in the next earthquake!
I packed up my emergency kit into a large container and gave myself a pat on the back.
But fast-forward to the 7.8 earthquake we experienced two weeks ago, I was kicking myself.
Of course it was a great idea putting together an emergency kit, but with mere minutes to evacuate, we couldn’t take the kit with us, because a) it weighed 70 pounds, b) the container was too big to fit in the car, and c) it was in the laundry cupboard under a heavy toolbox.
While it would have been ideal if we were stuck in our house, in the instance of getting evacuated we couldn’t take it with us.
Panicking and unable to decide what to take, we left with the clothes we were wearing and nothing else.
The power in the whole city was out, and at 1am it seemed like peak hour traffic down our quiet street.
We took shelter at a friend’s house on the hill with some others also trying to get to higher ground. Huddled around a tiny radio, we sat in the dark waiting to hear news about the possible tsunami. It wasn’t until four hours and no tsunami later that we got the all clear to go back home.
Our house was unscathed aside from a few items smashed on the floor, but the full extend of the damage wouldn’t be known until the sun came up.
Roads torn up, buildings on a lean, the coastline uplifted, entire towns cut off from landslides, and the downtown of Wellington, the capital city, closed down. Two people died, one crushed underneath his home.
Photo Credit: Anthony Phelps
Growing up in New Zealand, we practice earthquake drills at school. But you never prepare for the biggest earthquake in New Zealand’s history to hit at midnight.
Bewildered and without power, it’s hard to make sense of the situation and figure out what to do. And although we had an emergency kit, we couldn’t get to it in time and it was too heavy to carry if we were unable to use our car. We needed something lighter, that we could grab in an instant.
Everyone in Wellington knows the risks of where we live. The city is situated right on top of the collision zone where the Australasian Plate meets the Pacific Plate – which often makes for a bit of a bumpy time.
So it’s surprising how unprepared we all are. We know big earthquakes are coming, we know we should plan for it, but we don’t think about getting around to it until it’s too late.
Two weeks after the earthquake, many organizations are still locked out of their offices – some are too dangerous for people to go back inside, and some are now being earmarked for demolition.
The first thing we did when we got back to work was to check our emergency packs. We each have one under our desks with essential items, and practically, it’s in a backpack.
Why didn’t I think of using a backpack? It seems so obvious now. We’ve learned we need to have something we can grab at a moment’s notice if we’re being evacuated again.
The most important thing is to get to a safe area as fast as possible. So an emergency kit in a backpack is perfect for this.
It’s not about being equipped for every scenario, but taking practical steps that will help you get through.
Organizing a portable and practical emergency pack for your home and for your office is the simplest way to be prepared.
Californians are thinking about earthquake preparedness this week, as we observe the 27th anniversary of the Loma Prieta earthquake that rocked the Bay area, causing 67 deaths and $7 billion in damage. The state is encouraging people to make sure they have a plan, and have the essentials in place for the aftermath of another major earthquake.
Over 10.6 million people are participating in the 2016 California ShakeOut at 10:20am, making it the world's largest earthquake drill. During the next big earthquake, and immediately after, is when your level of preparedness will make a difference in how you and others survive and can respond to emergencies. At 10:20am, participants will drop to the floor, take cover, and hold on as the simulating earthquake passes over the course of 60 seconds. Anyone can participate, and people are encouraged to practice their response wherever they happen to be at 10:20am.
Governor Jerry Brown recently signed a bill authorizing a funding plan for an early warning system. Even as the state plans preparation programs, emergency response experts stress the need for each individual and family to have the essentials in place for the aftermath of the next major quake.
We recommend the options at The Earthquake Bag- you can find all-encompassing home bags with food, water, first aid, communication, warmth and light, and tools for survival. Experts say that having an earthquake bag in all the places that you spend a major portion of time is the best way to help work through the complicated aftermath of a major quake.
The California Office of Emergency Services (OES) issued an earthquake advisory warning residents and officials in Ventura, San Diego, San Bernardino, Riverside, Orange, Los Angeles, Kern and Imperial counties that there was a greater possibility of a major earthquake through Oct. 4.
The USGS says that data indicates a one percent chance of a magnitude 7 or greater earthquake on the Southern San Andreas fault within the next seven days- about 600 times higher than the normal risk level.
Officials are preaching caution and calm, but are encouraging people to take the opportunity to prepare a quake plan and get emergency supplies gathered. FEMA and most other agencies recommend at least 2-3 days of food and water, communication and light tools, shelter and warmth, and other preparedness tools.
“California is earthquake country. We must always be prepared and not let our guard down,” says OES Director Mark Ghilarducci. “The threat of an earthquake on the San Andreas fault hasn’t gone away, so this is another important opportunity for us to revisit our emergency plans and learn what steps you need to take if a significant earthquake hits.”
More than 200 earthquakes have been recorded in the past few days. This marks only the third time since earthquake sensors were installed in 1932 that this part of the state has seen such a swarm.
Scientists estimate that a big earthquake happens in this area once every 150 or 200 years, so experts think the region is long overdue for a major quake. The San Andreas fault’s southern stretch has not ruptured since about 1680 — more than 330 years ago.
“Any time there is significant seismic activity in the vicinity of the San Andreas fault, we seismologists get nervous,” said Thomas H. Jordan, director of the Southern California Earthquake Center, “because we recognize that the probability of having a large earthquake goes up.”
In 2008, USGS researchers simulated a magnitude 7.8 earthquake in the Salton Sea part of the San Andreas fault. The USGS simulation predicts that when the fault hits Cajon Pass, Interstate 15 and rail lines could be severed. Inland Empire towns could become a cascade of fallen brick, crushing people under collapsed buildings that had never been retrofitted.
Los Angeles would feel shaking for a full minute (compared to only 7 seconds during the 1994 Northridge earthquake). The quake could reach as far as Oxnard, Bakersfield and Santa Barbara. About 1,600 fires could likely spread across Southern California due to broken gas and electric lines, and powerful aftershocks of up to 7 magnitude could affect as far away as San Diego county.
The ShakeOut simulation puts the death toll at 1,800 people, and such an earthquake could cause 50,000 injuries and $200 billion in damage.
Before and after (simulated) photos of the Alaskan Way Viaduct (photo credits, Google and Washington State DOT)
Why So Dangerous?
While the Cascadia Subduction zone is a scary prospect, the Seattle and Tacoma faults are likely the more serious earthquake threat to the populous Seattle–Tacoma area. A 2002 study (also by the Earthquake Engineering Resources Institute) estimated that a magnitude 7 earthquake on the Seattle Fault would damage approximately 80 bridges in the Seattle–Tacoma area and kill or injure thousands. There is concern that such an earthquake on the Seattle Fault would devastate unreinforced masonry buildings, of which the city has thousands. The fault runs under some of the oldest areas with the least-reinforced buildings- concentrated in Capitol Hill, Pioneer Square, and the International District.
The Perfect Storm
The damage from a Seattle fault earthquake would be massive, but the landslides that follow will be severe. "In Seattle, there's kind of a perfect storm of characteristics because the fault goes right through the city, it's wet, and there are steep slopes all around," according to USGS scientist Kate Allstadt. "If you look at Seattle, there's houses everywhere. They're built on slopes and on hills. We're looking at the possibility of having buildings falling down slopes into Lake Washington or the Puget Sound," she said.
Now half a million people live directly above the fault. Mansions are perched on steep hillsides. Entire neighborhoods are nestled in what are old landslide scars. Most buildings were built before building codes were updated to take into account the Seattle Fault in 2000. What is going to happen when tectonic forces push the fault over its threshold again?
Trying to Catch Up on Preparedness
The Seattle Fault was only first recognized as a significant seismic danger in 1992. Along with the Cascadia Subduction Zone, these faults have been identified as threats in just the last 2-3 decades. The region has moved slow, but it takes a generation for society to truly understand and prepare for a new disaster threat. While California has had hundreds of years to get prepared, it feels like we are just beginning.
This fault runs right under the city of Seattle, and we're still finding new things almost every year. Eric Holdeman, former director of the King County Office of Emergency Management, said we shouldn’t expect outsiders to swoop in and save us when a long-anticipated massive earthquake hits (and it will hit, we just don’t know when).
Holdeman said most individual Seattleites aren't ready for a quake. “People overestimate their capacity to survive a natural disaster,” he said. “Start thinking about urban camping. Think about being on your own for two weeks.”
Have a family communication plan – decide where you would meet them should disaster strike. You know you should have an earthquake bag in place, so stop putting it off and get it done. It’s important to have a smart, well-thought-out bag you can trust. If you don’t have time to track down the best tools and materials to do it right The Earthquake Bag makes it easy. It’s our mission to make sure everyone either buys one of ours or builds one of their own. Everyone is safer when we all are more prepared individually.