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This very nice scientist Nicole knows wanted to help put Deathquakenami in perspective. She mostly just made it worse. Also, Nicole wants to get even more mileage out of that Space Needle image she created.

This post is generously sponsored by Elliot Norwood, to whom Deathquakenami presents a clear and present danger.

Everything on Earth is always moving: air currents move across the surface and up and down and in spinning eddies; water flows in the oceans and across the surfaces of continents; lava trickles through the crust and erupts; the rocks in the crust deform and grind against each other and break; thousands of miles of solid rock flow like slow, crushing silly putty in the mantle; the outer core of molten metal spins and eddies; and the solid metal inner core spins in place. It is all in motion, and it is happening on a spinning ball, in a system full of huge rocks hurtling through space around a enormous, unpredictable fusion reactor, all within a moving, spinning galaxy.

In other words, no place is really safe for us squishy living creatures and the little things we build. There is nowhere to hide from all possible hazards: violent windstorms, blizzards, tornadoes, dust storms, rock falls, lightning storms, hurricanes and cyclones, hailstorms, landslides, prolonged hot or cold spells, droughts, flooding rivers and coasts, geomagnetic storms, forest fires, explosive volcanic eruptions, lava flows, mudflows, avalanches, earthquakes, tsunamis, meteorite impacts. Every place on Earth, from deep underground to up in the atmosphere, experiences some of those events, some of the time. You live in a dynamic, hazardous world. At best, you can navigate the risks and live the best life possible in the midst of that.

Plate tectonics has determined that some places are more prone to particular hazards (earthquakes, volcanic eruptions) than others, though. Solid crust and the attached upper mantle lithosphere (the plate) is relatively rigid, and the stresses caused by plate motion are mostly released by deformation and breakage along the boundaries of plates. The majority of earthquakes and volcanic eruptions occur near those boundaries, as a direct result of plate motion. So while stress can be transmitted across a plate and accommodated by slip along an ancient fault surface far from a tectonic boundary, in, say, Virginia or the Ozarks, most slipping occurs at active tectonic margins, like in the Pacific Northwest; and while some of that slippage occurs quietly and smoothly with no one noticing, much of it happens during violent fracture events. So like most subduction zones, the Cascade region is capable of very large earthquakes caused by slip along major faults. And in between earthquakes, stress between the plates builds up like a compressed spring at their margin, causing the crust to bulge elastically.



Map of tectonic boundaries in the Cascadia region (USGS), and cartoon showing cross-section models across the Cascadia subduction zone before and after a major earthquake (ECY/Washington coast). We are currently in the “before” scenario, with a measurable elastic bulge present along the coast of the Pacific Northwest; the “after” scenario would cause a dramatic drop in elevation along that coast.

Because Earth systems are interconnected –the ocean overlies the solid Earth and is in direct contact with it, resting on it – a large, submarine earthquake accommodating mostly vertical slip will push up or drop down a large mass of ocean water, and the rebound will initiate a very long-wavelength water wave with sufficient energy to travel large distances: a tsunami. The normal hazards associated with any steep-terrained coastal area (like flooding and landslides) can be exacerbated by a major earthquake that both releases a large coastal bulge and triggers a major tsunami.

This week’s New Yorker article is well researched and clearly written, but the information about the risks to the Pacific Northwest is mostly not new. The big story here is not that there is a significant earthquake and tsunami risk in Cascadia: scientists and officials have known that for decades. The important revelation is how little has been done to plan for such an event.

We have a great example of how an industrialized nation with a lot of resources and reasonably good infrastructure can coexist with the natural hazards present along an active tectonic margin: Japan aggressively monitors and prepares for earthquakes, tsunamis, and volcanoes, with overall great success. Japan has a population of 127 million people, overwhelmingly located at the coast. The death count of the 2011 Tohoku earthquake and tsunami was only 18,550 people. That is, frankly, remarkable: this was the fourth largest earthquake in recorded global history, in a very densely populated region, with a tsunami that averaged 10 meters (33 feet) high at the coast with a peak of 40.5 meters (133 feet) in the most focused location. For comparison, the Indonesian earthquake and tsunami had a casualty count over 200,000, because there were no warning or alert systems, no systematic education efforts, and no measures in place to deliver relief and resources in the immediate aftermath of the event. And researchers are already using the Tohoku outcome to develop even better preparation methods for the future.

Two very obvious factors are necessary to take a geologic event from just geologically interesting to disaster: 1) people and valuable property have to be in harm’s way; and 2) preparation, mitigation, and response must be insufficient for them to survive it. (I should note that when human lives are saved through preventative or mitigating measures, it is typically at enormous expense: as we come to survive hazardous events better and better, the cost of lost infrastructure and property increases rapidly.) Unfortunately, our coasts look like this:

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Population distribution by county in the United States.

Most people in the world live in coastal regions. So much for #1, then – it’s too late to just not be there.

So if the goal is to reduce the impact of a major event to the level of a non-disaster, that leaves the second approach: prepare, mitigate, and respond well. When people are already living in harm’s way, preparation is everything. We would be smart to emulate Japan’s example, but instead in many ways we have starved the government bodies and programs responsible for monitoring hazards, issuing warnings, and implementing mitigation and response programs.

Unfortunately, it is very hard to convince people to spend their collective funds and energy preparing for high-risk, low-frequency events. The human brain conceives of risk and probability… poorly. Important cognitive and other biases come into play, including: selection biases in gathering and evaluating hazard data sets (for example, over- or underestimating the frequency or maximum size of events because the data collection timeline is too short), fallacies like gambler’s and hot-hand for truly random events (mistaken beliefs that the probability of a random event will change in response to its recent frequency), negativity bias (the stronger psychological impact of negative or traumatic thoughts and events) and loss aversion (the tendency to more strongly avoid losses than to acquire gains), probability neglect (tendency to disregard probabilities in decision making, either neglecting or inflating risks), and the affect heuristic (making decisions principally based on emotional response); but especially the availability heuristic (favoring recent or more vividly remembered events over less striking ones when making decisions; think of the increased concern and panic following, say, the New Yorker article vs. the general complacency about this issue the day before!) and normalcy bias (the tendency of people living in a hazardous area to underestimate the likelihood and severity of a disaster; think of a frog in a slowly heated pot). Your brain just fundamentally misjudges frequency and risk, especially for rare, catastrophic events, so you simply cannot trust it when making value judgments about the best ways to prepare for these events.

Expert guidance, though, hopefully takes those biases into account as much as possible, and in a place like the U.S., agency officials usually have enough experience and training in the pitfalls of hazard management to avoid the more common rookie mistakes (for example, responding to one disaster by increasing the sensitivity of future alerts, which proportionally increases false alarms and ultimately decreases public confidence so people stop heeding warnings). Politicians aren’t usually trained in this work and suffer from the same human errors in judgment as the rest of us, with an elevated aversion to risking public displeasure – but good ones will listen to the experts and agencies even when it’s politically inconvenient. And a smart government should not ask the public to vote on whether or not to fund efforts that are both so important and so evocative of illogical judgment.

In other words, and particularly for Cascadia: please tell your Pacific Northwest government officials to consult with appropriate experts and then implement good evacuation routes and improve local infrastructure, with an eye toward earthquake, tsunami, flood, and landslide safety. If funding for hazard mitigation and preparation is up for a public vote or referendum, consider voting and even campaigning for it. And if you must live there and have the ability to relocate locally, please try to choose a location that isn’t sitting on loose mud, that is well above both the coast and local river levels, that is not near or on steep slopes, and that has good access to major transportation routes for evacuation, and avoid building new construction or infrastructure in more hazardous locations.

For everyone else: I guarantee that you live in a risky place, too, because it is in this universe. Please read FEMA (for U.S. residents) and local government hazard guidelines for your area and follow their preparation recommendations. Learn some basic, general hazardous event safety tips.* If you are relocating to a new area, some places (like particular places in the Pacific Northwest, or the city of New Orleans) are particularly hazardous, so if you have the freedom to choose you may wish to consider another destination. And if you lack that regional choice but can freely decide where to live or own property locally, please don’t rely on programs like government-subsidized flood insurance to determine whether a location is safe: subsidies can distort perceptions of risk and have encouraged many people to build and live in harm’s way. In general, if a piece of property is uninsurable for a hazard considered high-risk in your region (like flood insurance for properties near large rivers), consider choosing another location instead, to the extent that you can. Insurance risk models are very sophisticated and not governed by cognitive bias, so they are usually among the best risk assessments available.

And then please, please go live your life without obsessing any further. If there is nowhere in the solar system that you can go to escape natural hazards, and your perceptions of the risks are probably either much too high or much too low, then there is no point in being consumed by worry. Take some intelligent, well-informed, relatively straightforward precautions, try to make reasonable choices to minimize your local risks, and then enjoy living on this spectacular, dynamic Earth.


*A partial list of helpful tips:

If you’re in an electrical storm with no shelter, and your hair starts to stand up, remove all metal objects from your body and squat low to the ground, with your heels or knees together if you are physically able. Don’t lie down on the ground. If it’s available, shelter in a car or sturdy building instead.

If there is a tornado approaching and you have no shelter, DO lie down, in the lowest ditch you can find (not in an underpass) and protect your head. Shelter in a sturdy, windowless basement or building if you can, but do NOT shelter in a car.

In an earthquake, head for open ground away from buildings; if you cannot quickly escape the building, shelter under sturdy furniture instead. Do NOT stand in doorways.

Keep an emergency bag (change of clothes, extra water, important documents, emergency food for you and pets) ready to go if you live in forest fire country and the risk is considered elevated.

Similar emergency kits are a good idea for homes and cars for other hazards that can lead to evacuation, like volcanic eruptions, hurricanes in coastal regions, and serious floods if you are near the coast or a body of water. Check your local recommendations!

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Lynne explores how magma is made by studying the mineralogical, chemical, and isotopic makeup of igneous rocks. She also teaches geology, plays music, dances, and hangs out with her fabulous fluffy pets.

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