It will be one of the biggest earthquakes
in history. When the Big One finally hits Americaâs
west coast, it will unleash carnage on a scale rarely seen. Buildings will collapse, burying thousands
in rubble. Fires will break out, devastating entire city
blocks. There will be landslides, dam failures, chemical
spills⌠things that, taken alone, would qualify as one of the worst disasters this
side of Hurricane Katrina; but, taken all together, will affect millions. And thatâs just for starters. Minutes after the shaking begins, a vast tsunami
will roll in, washing away coastal communities and inundating hundreds of thousands of square
miles. By the time the wave recedes, North America
will have witnessed its worst-ever natural disaster. The culprit behind all this misery? The Cascadia Megathrust Fault, an offshore
subduction zone capable of unleashing so much energy, itâd make the fabled San Andreas
Big One look like a mere wobble. But rather than being a hypothetical, this
megaquake will soon become reality. Estimates for it happening in the next fifty
years range from a worrying one in ten to a terrifying one in three. Today, weâre exploring both the history
of Cascadia⌠and its apocalyptic future. The Orphan Wave The day before the wave came, there was no
sign that anything was amiss. It had been a mostly clear afternoon across
the islands. The sun was shining, the air was cold and
crisp. Apart from a few cloud patches here and there,
it was about as reasonably nice a day as you could hope to get in winter. Significantly, no-one in the whole of Edo
Period Japan had felt any tremors. There had been none of the earthquakes that
so typified life within the Pacific Ring of Fire. That meant, as people went to bed that evening,
they were completely unprepared for the disaster that would soon befall them. Shortly after midnight ticked over on the
eighth day of the twelfth month of the twelfth year of the Genroku era - or what we would
call January 27, 1700 AD - the wave arrived. It came silently, with no warning. End to end, it measured something in the region
of 600 miles. But it wasnât the length of the tsunami
that caused the problems, but its height. At its peak, the water reached 16 and a half
feet. The worst struck was the Miyako Bay area. In Kuwagasaki, 13 houses were washed away,
and fires started that claimed another 21 buildings. At Tsugaruishi, the waters cascaded half a
mile up the main street, destroying homes and nearly wiping out a shrine. All along the eastern coast, rice paddies
were damaged, homes flooded, and goods destroyed in government storehouses. The most-dramatic moment may have come at
Tanabe, where the mayor watched in horror as the castle moat was breached. But even in lesser-effected areas, people
were still sent running for the hills. Yet, once the waters had finally receded,
it wasnât the damage that people focused on. It was that the wave had happened at all. Japanese records on the relationship between
earthquakes and tsunamis go back to at least the six century. Itâs all part and parcel of surviving in
one of the most seismically-active countries in the world. But the 1700 tsunami had come without a tremor. It had simply appeared in the night - a God
of death rearing out the ocean like some totally dickish version of Poseidon. Had Edo Period Japan been less isolationist,
they mightâve realized they werenât the only ones grappling with the mystery. Some 4,600 miles away, the Native tribes of
North America were struggling to understand what theyâd just seen. Roughly ten hours before the orphan wave swept
into Miyako Bay, the earth below the feet of the Nuu-chah-nulth people, the Makah, the
Yurok, the Tolowa, and hundreds more had shifted violently, transforming the landscape. Unlike the Japanese, though, the Indigenous
peoples of the Pacific Northwest didnât keep written records. Instead, they recorded their histories orally,
telling stories that encoded both legends, and great events from the past. And the events of that night were, without
doubt, some of the greatest any of them had ever seen. Shadow of the Thunderbird The night Thunderbird attacked, she gave no
warning. It was a dark and miserable evening, the sort
of evening thatâs a basic feature of life when you live in the Pacific Northwest and
it never seems to stop raining. In the midst of this gloom, Thunderbird suddenly
swept down out the sky - vast, invisible. She picked up her nemesis Whale in her talons
and hauled him into the air. Far up in the night sky she dropped him, and
Whale went slamming back to Earth. The force of his body shook the world. In the bay, the waters receded, pulled back
into the ocean. The wisest ones saw what this would mean,
and got into their canoes. They were the ones who survived. After the battle came the flood. As the waters rolled back in, villages disappeared. People were swept away. Those who survived saw strange sights after,
like canoes stranded in trees. The battle between Thunderbird and Whale was
felt all up and down the Pacific coast. For some who later told the stories, Thunderbird
was the hero, defeating the evil Whale. For others, she was the evil one, attacking
innocent Whale. Yet others insisted the battle took place
not between Thunderbird and Whale, but between Thunderbird and Transformer, the one who created
the world. But the mythic battle between these two great
titans was only one explanation that arose for the shaking Earth and the flood that night
- one mostly centered around modern Oregon. Further afield, vastly different Indigenous
tribes came up with vastly different tales. On Vancouver Island, the First Nations Huu-ay-aht
people told stories of dwarfs living in a giant mountain. That night, they invited a man to dance around
their drum. But the man accidentally kicked the drum and
its sound became trapped in his foot. From that moment on, wherever he walked, his
every step created an earthquake. No sooner had he set foot outside the mountain
than heâd caused a shaking and a flood that swept whole villages away. Down in northern California, the Yurok people
told a similar story. They claimed a being called Earthquake who
had large, heavy feet was running up and down the coast. Every footstep caused the land to split open
and the ocean to come flooding in. According to an oral history collected over
150 years later, the Yurok had all assembled on a big hill and performed a jumping dance
to drive Earthquake away. But while heâd finally left, the devastation
had remained. When they descended the hill again, the Yurok
had found everything theyâd ever known lost under a layer of water. The tale the Tolowa people told was even scarier. They focused not on Earthquake or even the
shaking ground, but on the waters that followed. Everyone the water touched was immediately
turned into a mass of coiling snakes. The only Tolowa to survive were a teenage
boy and girl who managed to outrun the flood by climbing up a hill. When they came down ten days later, the entire
world had been swept clean and replaced with sand, and it was only their children that
stopped the human race from going extinct. There are dozens more stories like these,
and likely hundreds more that were lost to history. But they all have one thing in common. They are the only surviving accounts of what
happened that night. What happened when the Cascadia Megathrust
Fault unleashed its last massive earthquake in 1700, just off the coast of the Pacific
Northwest. Registering at least 9.0 on the Richter Scale,
and likely higher, it transformed the land from California to British Colombia, and triggered
the orphan wave that would so shock Edo Japan. Yet while these stories would still be told
well into the 20th Century, no-one would ever think to take them seriously as a part of
history. No-one would ever assume they were anything
more than legends. By the time modern scientists figured out
the truth behind them, it would already be too late. The Beast Below Now that weâve seen what the Cascadia subduction
zone is capable of - at least in mythologized form - now might be a good time to discuss
what it actually is. Like, where did it come from, and how the
heck is it capable of generating earthquakes powerful enough to create their own myth-cycles? The first part of that question is easy. Just off the west coast of the US, the vast
North American tectonic plate comes into contact with the much smaller oceanic plate of Juan
de Fuca. However, this is âsmallerâ on a relative
scale. Juan de Fuca still measures ninety thousand
square miles. Plates like these are always on the move. Grinding along and rearranging themselves
over millions and millions of years, taking us from a world where you have supercontinents
like Gondwana, to one where you have the continents of today. In an ideal world, all this super-slow moving
around would be accomplished smoothly. Tectonic plates would inch along over the
centuries, and weâd never even notice. But this isnât an ideal world. And, in our less-than-ideal world, these plates
often get stuck. Where they get stuck, you get faults. And where you get faults, you often get earthquakes. The most famous fault of all is probably the
San Andreas Fault in California. That fault is caused by two plates moving
in parallel in opposite directions - in this case the North American and the Pacific plates
- and getting jammed against one another. When enough pressure builds, the plates finally
snap forward, whatâs called a strike slip fault. But there are other types of fault out there,
that operate in wholly different, more dangerous ways. Cascadia is one such fault. Off the coast of Oregon, the Juan de Fuca
plate is trying its best to burrow its way under the North American plate - a process
known as subduction. It should be sliding neatly underneath, but
instead itâs gotten stuck. As a result, the North American plate is compressing,
the entire landmass getting squeezed by about one and a half inches a year. As the plate compresses, pressure builds. When it finally gets too much for the Earth
to bear, the plate will suddenly shift, and all that energy will be unleashed. The result? Well, letâs just look at a list of famous
earthquakes caused by subducting plates: Alaska, 1964. Death toll: 131. Chile, 1960. Death toll: up to 7,000. Japan, 2011. Death toll: over 18,000. In other words, the potential is there for
the Cascadia quake to be one big mother. But thatâs only its potential. Although the fault runs between 600 and 700
miles - all the way from Cape Mendocino, California, to Vancouver Island - not all regions are
equally active. The central zone is pretty quiet. Almost silent. On the other hand, the northern and southern
portions show constant activity. This is both interesting, and somewhat relieving,
because faults donât necessarily let rip all at once. The most likely possibility for the next major
Cascadia quake is that only the southern section, focused around north California, will go. In that case, the resulting quake would register
around 8.0 or 8.6 on the Richter scale. Now thatâs still big. About as big as the fabled San Andreas Big
One will be. But itâs not an Armageddon-sized event. In modern history, the US has had at least
four bigger quakes - although none of them took place outside Alaska. On the other hand, itâs possible that the
entire Cascadia fault could give way. Known as a full margin rupture, this could
produce a quake with a magnitude of 9.2. Because the Richter scale is logarithmic,
such a Cascadia megaquake would be around 30 times bigger than anything the San Andreas
fault could possibly produce. It would be the joint-biggest quake in US
history, alongside the 1964 Alaska quake, and the joint second biggest quake the world
has ever seen. But the weird thing is that the Cascadia almost
never produces minor quakes. If you live in the Pacific Northwest, chances
are youâve never felt even a middling 4.0 quake - the sort of quake that wakes you up,
wondering if your bedmate ate too many chilli burritos the night before. This lack of serious quakes is almost the
opposite of what youâd expect to happen along a subduction zone. And itâs the reason no-one discovered what
Cascadia was capable of until the 1980s. By then, weâd already spent centuries building
beside it some of the most earthquake-vulnerable towns in American history. Finding the Fault That we discovered Cascadia at all is down to pure,
dumb luck. When Lewis and Clark arrived in Oregon in
1805, it had already been over a century since the last full margin rupture in 1700. The land they found was peaceful, quiet. Seemingly the ideal place to build new settlements. Never mind all those persistent Native American
and First Nations stories about the land getting all shaky. That was just a load of buffalo dung, right? White settlers continued to think that all
the way into the 20th Century. Even when geologists identified the Cascadia
subduction zone in the 1970s, everyone was all like: âWell, thereâs never been a serious quake
in Oregon. Must be an aseismic fault!â In fact, they were so sure Cascadia was inactive
that the U.S. Nuclear Regulatory Commission began planning a slew of nuclear power plants
in the region. Just before giving the greenlight, the Commission
decided to check with the U.S. Geological Survey and make sure the fault was as harmless
as everyone assumed it was. The USGS came back with two possibilities. Possibility one: Cascadia really was a super-quiet
fault. Possibility two: it was a Chile-style fault. This made everyone immediately sit up and
start paying attention. Chile is a big deal in the field of earthquakes,
because itâs home to some of the worst on Earth. The largest quake in recorded history took
place off the coast in 1960, killing up to 7,000. That quake, too, was caused by a subduction
fault. If Cascadia really was like Chile - mostly
quiet, but occasionally apocalyptic - who knew what it might be capable of? Over the next few years, scientists began
to seriously study the Pacific Northwest for signs of a previous megaquake. By 1984, theyâd begun to find evidence of
huge floods, landslides, and tsunamis. But not enough to actually declare Cascadia
active. Finally, geologist Ruth Ludwin of the University
of Washington hit upon an intriguing idea. There might be no written records of a pre-European
quake in the region, but what about Native oral histories? So they checked westcoast tales for likely
candidates. What they found was terrifying. There were upwards of 40 myths, spread across
various tribes, that all seemed to record a massive quake and tsunami. When those that could be dated were given
an approximate range, it was found they all clustered around 1700. Clearly, something was going on. Over the next few years, more and more rigorous
analysis was done, more surveys undertaken. At last, in 1996, scientists writing in Nature
pieced together the last time Cascadia had unleashed the Big One. At 9pm on January 26, 1700, a 9.0 magnitude
quake had struck the Pacific. Two impossibly big waves had formed, one rushing
into America and drowning untold Native tribes; the other whisking off toward Japan, where
it would strike ten hours later. But the worrying news didnât stop there. By analyzing deposits left by the tsunamis,
other researchers were able to calculate how many times in history Cascadia had ruptured. The number they arrived at was 41 megaquakes
over 10,000 years. That may sound like a long time, but when
you average it out, you find it means one rupture every 250-odd years. No, your math doesnât deceive you. 1700 plus 250 means we shouldâve been expecting
a quake around 1950. In other words, weâre now very much overdue
for another Cascadia Big One. So letâs find out what will happen when
it finally arrives. Disaster As we mentioned earlier, there are multiple
ways Cascadia could rupture, ranging from âargh!â to âAAAAARGH!â. For simplicityâs sake, this section is gonna
assume an âAAAARGH!â-scenario, measuring 9.2 on the Richter scale. This, then, is how it might play out. The first thing youâll notice is that all
the dogs are acting loopy. Thatâs because the compression wave will
have just hit, a sort of early-warning system built into earthquakes, but one only certain
animals can detect. Sadly, humans arenât among those animals,
so youâll just stand around thinking âOK, this is weird, all the dogs are freaking out.â Enjoy those long seconds of confusion while
they last. It may well be the last time youâll ever
enjoy anything again. Roughly 30 seconds after Fido starts going
bananas, the seismic waves will hit. At first it will be freaky. But then the shaking will last longer and
longer and get more and more powerful, and it will go from worrying to actively life-threatening. Unlike California, the Pacific Northwest only
brought in strict building codes in 1994. That means any structure built before the
â90s will be in danger of immediate collapse. As the shaking increases, houses will start
to fall on their occupants. Schools will collapse. Airports. Fire stations. All told, itâs thought that up to a million
buildings in the region might fall down. Three thousand schools could collapse, along
with two thirds of all hospitals. Thousands will be crushed to death. Tens of thousands will be trapped in the rubble. And this is only the beginning. As gas lines rupture, fires will break out. The electrical grid will fail. Up to half of all highway bridges will fall
down. Remember that awful bridge collapse in Italy
in 2018 that traumatized the nation? Well, now imagine that scenario repeating
not dozens, but hundreds of times, from northern California to British Colombia. Elsewhere, the quake will trigger deadly landslides
- up to 30,000 of them in the Seattle area alone. Inland, dams will fail, causing floods. There will be chemical spills, gas leaks,
explosions. By the time the shaking subsides, 6 minutes
after the dogs started howling, the Pacific Northwest will be unrecognizable. Up to 75 percent of buildings will have been
compromised. There will be a cascade of separate disasters
to deal with, from fires to hazardous waste spills. In short, the aftermath of the quake will
be miserable. But youâll have no time to stop and think
about that. The moment the fault ruptured, the northwest
edge of North America will have dropped six feet, and rebounded up to a hundred feet west. A lot of this movement will have happened
under the ocean, creating a 600-mile long wave out at sea that is now rushing toward
the western seaboard. Those dazed minutes of horror after the ground
stops moving will be your last chance to run. And, believe me, running is exactly what youâll
need to do. Bad as the quake itself will be, it will have
nothing on what comes next. When the tsunami hits, everything will get
a million times worse. Drowning Man When the Cascadia tsunami arrives, youâll
have no trouble spotting it. At its lowest point, the water will reach
a height of 20ft. At its highest, it will crest over 100ft. When it reaches the coast, it will be moving
at 12 miles per hour, sweeping everything from boats to cars to human bodies along with
it. At this point, our narrative branches into
different parallel universes, depending on when the quake strikes. If it happens in winter, then the maximum
possible death toll is around 71,000 - the number of people who live in the inundation
zone. Since many of them will run for high ground,
the actual death toll will be far lower. But even in this better-case scenario, itâs
still estimated a third of the population will be too elderly or disabled to escape
the wave. But if the quake hits during a summer holiday
- like, say, on the July 4th weekend - we could be looking at carnage on an unprecedented
scale. In Oregon alone, itâs estimated over 150,000
people could be on the beaches; with another 17,000 at risk in Washington State. Thatâs not even including those on Vancouver
Island. Altogether, you could be looking at nearly
200,000 people right in the tsunamiâs path. Some would escape. Most wouldnât. As the seawater moves inland, over 100,000
square miles will be flooded out. Buildings that survived the quake will be
swept away. Entire towns will drown. When the New Yorker interviewed Fema regional
director Kenneth Murphy in 2015 about the tsunamiâs aftermath, he cheerfully replied: âOur operating assumption is that everything
west of Interstate 5 will be toast.â For those not up on their US geography, this
includes not just Seattle and Portland, but also Eugene, Salem, and - up in Canada - Victoria,
and Vancouver itself. About half an hour after the compression wave
hit, the tsunamiâs onward march will end. By then, seven million people will have been
affected and the Pacific Northwest annihilated. The statistics will be brutal. Fema estimates that, given a winter quake,
some 13,000 will be killed outright, and another 27,000 injured - easily making it the worst
natural disaster in US history. On top of that, up to a million people will
have lost their homes; and another 2.5 million be in urgent need of food and fresh water. But this is just in winter. Were the wave to strike when Oregonâs beaches
are at their fullest, in the middle of a hot public holiday in summer, then the death toll
could skyrocket. At time of writing, the worst North American
disaster on record is the 2010 Haiti quake, which killed between 100,000 and 160,000 people. Horrible as it is to say, a summer Cascadia
quake could top even that. But, before you go rushing to build an earthquake-proof
shelter on the tallest hill you can find, just remember: this probably wonât happen
in your lifetime. The odds of Cascadia unleashing its full might
in the next fifty years are one in ten. Thatâs about ten times higher than weâd
like it to be, but still on the low-ish side. Much more likely is an 8.0 quake thatâs
damaging, but with a death toll in the hundreds rather than the thousands. So, yeah. Realistically, the Cascadia probably isnât
going to unleash Hell on your butt. Still, just in case we do happen to live in
that unfortunate, ten percent chance universe, thereâs something else you should probably
know. Weâve been aware for a while that the Cascadia
and San Andreas faults both connect; brushing together just offshore of Mendocino County. A couple of years ago, researchers decided
to see if the two had any affect on one another. By dating the geological remains of previous
San Andreas quakes and comparing them to the remains of Cascadia quakes, they were able
to make an unsettling discovery. Over the last 3,000 years, a major Cascadia
quake had caused the San Andreas fault to also rupture between 9 and 11 times. That means that, almost every time Cascadia
unleashes the Big One, itâs followed by San Andreas also bringing about the earthquake
apocalypse. Just think. The sheer, staggering death toll in this video
may just be the beginning. Unaffected by Cascadia, LA and San Francisco
could then be hammered by a devastating quake all their own. Such a one-two punch would affect every single
person living on the west coast. Its would cause chaos all the way from Canada
to Mexico. And thereâs a little under a one in ten
chance of it happening by 2070. As this video ends, weâll leave you with
the following thought: Itâs often said we should live every day
like itâs our last. Itâs a somewhat trite saying, one that essentially
means you should try and grasp opportunities and make the most of what you have. Well, if you live on the west coast of America,
you might want to start taking it literally. Because if Cascadia goes off, it really will
be the end. The end of everything youâve ever known.
For a second I thought "maybe it'll be better to be a part of a larger political union when something like that happens"
But then the idea of feds in DC actually helping states/people in need processed through my head and remembered that's not going to happen
Related
The big one might be the catalyst for people to wake up and see that communities working together is more effective than a large, LARGE, govt that can choose whether to ignore its subregions.