Solved by verified expert:“The Really Big One” by Kathryn ShulzPublished in The New Yorker, July 20, 2015List the major cities in the Cascadia Subduction Zone. How many people live in this region?What are the two continental plates that converge in Cascadia?Shulz eloquently sums the American experience in Cascadia as: “the Pacific Northwest was not a quiet place but a place in a long period of quiet.” Please explain this.What is a ‘ghost forest’? When did the ghost forest in Cascadia assume their ‘apparitional’ form? 5. What is dendrochronology and how does it help us to understand the seismic history of the Cascadia Subduction Zone?How is the eastern shoreline of Japan important in helping us understand the recurrence of earthquakes in Cascadia?How much time elapses between an earthquake in Cascadia and a tsunami in Japan?What is the recurrence interval for major earthquakes in the Cascadia Subduction Zone?Shulz says “The devastation in Japan in 2011 was the result of a discrepancy between what the best science predicted and what the region was prepared to withstand.”This statement is the very heart of the article. Is her argument persuasive? Why or why not?Describe your emotional reaction to the forecasted impacts to people in the Pacific Northwest following a major seismic event.Though not explained well in the article, what is the inundation zone?How much time elapses between a major earthquake and the tsunami in Cascadia?Recall discussions in class (or Google sleuth). What is FEMA? In your opinion, do you perceive the services provided by FEMA to be an essential function of the Federal government?When referring to Hollywood, Shulz posits that “apocalyptic visions are a form of escapism, not a moral summons, and still less a plan of action. Where we stumble is in conjuring up grim futures in a way that helps to avert them.” Is this article effective in stirring momentum for earthquake preparedness? Why or why not?If movies and magazine articles are ineffective as a moral summons in averting undesirable societal outcomes to natural disasters, then which institutions are best suited to convey scientific information in a way that will leverage political and economic resources to protect people and economies from catastrophe?
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Annals of Seismology
JULY 20, 2015 ISSUE
The Really Big One
An earthquake will destroy a sizable portion of the coastal Northwest. The question is when.
BY KATHRYN SCHULZ
The next full-margin rupture of the Cascadia subduction
zone will spell the worst natural disaster in the history of
the continent.
ILLUSTRATION BY CHRISTOPH NIEMANN; MAP BY ZIGGYMAJ /
GETTY
W
hen the 2011 earthquake and tsunami
struck Tohoku, Japan, Chris Goldfinger was
two hundred miles away, in the city of Kashiwa, at an
international meeting on seismology. As the shaking
started, everyone in the room began to laugh.
Earthquakes are common in Japan—that one was
the third of the week—and the participants were,
after all, at a seismology conference. Then everyone
in the room checked the time.
Seismologists know that how long an earthquake lasts is a decent proxy for its
magnitude. The 1989 earthquake in Loma Prieta, California, which killed sixty-three
people and caused six billion dollars’ worth of damage, lasted about fifteen seconds and
had a magnitude of 6.9. A thirty-second earthquake generally has a magnitude in the
mid-sevens. A minute-long quake is in the high sevens, a two-minute quake has entered
the eights, and a three-minute quake is in the high eights. By four minutes, an
earthquake has hit magnitude 9.0.
When Goldfinger looked at his watch, it was quarter to three. The conference was
wrapping up for the day. He was thinking about sushi. The speaker at the lectern was
wondering if he should carry on with his talk. The earthquake was not particularly
strong. Then it ticked past the sixty-second mark, making it longer than the others that
week. The shaking intensified. The seats in the conference room were small plastic desks
with wheels. Goldfinger, who is tall and solidly built, thought, No way am I crouching
under one of those for cover. At a minute and a half, everyone in the room got up and
went outside.
It was March. There was a chill in the air, and snow flurries, but no snow on the ground.
It was March. There was a chill in the air, and snow flurries, but no snow on the ground.
Nor, from the feel of it, was there ground on the ground. The earth snapped and popped
and rippled. It was, Goldfinger thought, like driving through rocky terrain in a vehicle
with no shocks, if both the vehicle and the terrain were also on a raft in high seas. The
quake passed the two-minute mark. The trees, still hung with the previous autumn’s dead
leaves, were making a strange rattling sound. The flagpole atop the building he and his
colleagues had just vacated was whipping through an arc of forty degrees. The building
itself was base-isolated, a seismic-safety technology in which the body of a structure rests
on movable bearings rather than directly on its foundation. Goldfinger lurched over to
take a look. The base was lurching, too, back and forth a foot at a time, digging a trench
in the yard. He thought better of it, and lurched away. His watch swept past the threeminute mark and kept going.
Oh, shit, Goldfinger thought, although not in dread, at first: in amazement. For decades,
seismologists had believed that Japan could not experience an earthquake stronger than
magnitude 8.4. In 2005, however, at a conference in Hokudan, a Japanese geologist
named Yasutaka Ikeda had argued that the nation should expect a magnitude 9.0 in the
near future—with catastrophic consequences, because Japan’s famous earthquake-andtsunami preparedness, including the height of its sea walls, was based on incorrect
science. The presentation was met with polite applause and thereafter largely ignored.
Now, Goldfinger realized as the shaking hit the four-minute mark, the planet was
proving the Japanese Cassandra right.
For a moment, that was pretty cool: a real-time revolution in earthquake science. Almost
immediately, though, it became extremely uncool, because Goldfinger and every other
seismologist standing outside in Kashiwa knew what was coming. One of them pulled
out a cell phone and started streaming videos from the Japanese broadcasting station
NHK, shot by helicopters that had flown out to sea soon after the shaking started. Thirty
minutes after Goldfinger first stepped outside, he watched the tsunami roll in, in real
time, on a two-inch screen.
In the end, the magnitude-9.0 Tohoku earthquake and subsequent tsunami killed more
than eighteen thousand people, devastated northeast Japan, triggered the meltdown at
the Fukushima power plant, and cost an estimated two hundred and twenty billion
dollars. The shaking earlier in the week turned out to be the foreshocks of the largest
earthquake in the nation’s recorded history. But for Chris Goldfinger, a paleoseismologist
at Oregon State University and one of the world’s leading experts on a little-known fault
line, the main quake was itself a kind of foreshock: a preview of another earthquake still
to come.
M
ost people in the United States know just one fault line by name: the San
Andreas, which runs nearly the length of California and is perpetually rumored
to be on the verge of unleashing “the big one.” That rumor is misleading, no matter what
the San Andreas ever does. Every fault line has an upper limit to its potency, determined
the San Andreas ever does. Every fault line has an upper limit to its potency, determined
by its length and width, and by how far it can slip. For the San Andreas, one of the most
extensively studied and best understood fault lines in the world, that upper limit is
roughly an 8.2—a powerful earthquake, but, because the Richter scale is logarithmic,
only six per cent as strong as the 2011 event in Japan.
“Perhaps I’ve said too much.”
Just north of the San Andreas, however, lies another
fault line. Known as the Cascadia subduction zone, it
runs for seven hundred miles off the coast of the
Pacific Northwest, beginning near Cape Mendocino,
California, continuing along Oregon and
Washington, and terminating around Vancouver
Island, Canada. The “Cascadia” part of its name comes from the Cascade Range, a chain
of volcanic mountains that follow the same course a hundred or so miles inland. The
“subduction zone” part refers to a region of the planet where one tectonic plate is sliding
underneath (subducting) another. Tectonic plates are those slabs of mantle and crust that,
in their epochs-long drift, rearrange the earth’s continents and oceans. Most of the time,
their movement is slow, harmless, and all but undetectable. Occasionally, at the borders
where they meet, it is not.
Take your hands and hold them palms down, middle fingertips touching. Your right
hand represents the North American tectonic plate, which bears on its back, among other
things, our entire continent, from One World Trade Center to the Space Needle, in
Seattle. Your left hand represents an oceanic plate called Juan de Fuca, ninety thousand
square miles in size. The place where they meet is the Cascadia subduction zone. Now
slide your left hand under your right one. That is what the Juan de Fuca plate is doing:
slipping steadily beneath North America. When you try it, your right hand will slide up
your left arm, as if you were pushing up your sleeve. That is what North America is not
doing. It is stuck, wedged tight against the surface of the other plate.
Without moving your hands, curl your right knuckles up, so that they point toward the
ceiling. Under pressure from Juan de Fuca, the stuck edge of North America is bulging
upward and compressing eastward, at the rate of, respectively, three to four millimetres
and thirty to forty millimetres a year. It can do so for quite some time, because, as
continent stuff goes, it is young, made of rock that is still relatively elastic. (Rocks, like us,
get stiffer as they age.) But it cannot do so indefinitely. There is a backstop—the craton,
that ancient unbudgeable mass at the center of the continent—and, sooner or later,
North America will rebound like a spring. If, on that occasion, only the southern part of
the Cascadia subduction zone gives way—your first two fingers, say—the magnitude of
the resulting quake will be somewhere between 8.0 and 8.6. That’s the big one. If the
the resulting quake will be somewhere between 8.0 and 8.6. That’s the big one. If the
entire zone gives way at once, an event that seismologists call a full-margin rupture, the
magnitude will be somewhere between 8.7 and 9.2. That’s the very big one.
Flick your right fingers outward, forcefully, so that your hand flattens back down again.
When the next very big earthquake hits, the northwest edge of the continent, from
California to Canada and the continental shelf to the Cascades, will drop by as much as
six feet and rebound thirty to a hundred feet to the west—losing, within minutes, all the
elevation and compression it has gained over centuries. Some of that shift will take place
beneath the ocean, displacing a colossal quantity of seawater. (Watch what your fingertips
do when you flatten your hand.) The water will surge upward into a huge hill, then
promptly collapse. One side will rush west, toward Japan. The other side will rush east, in
a seven-hundred-mile liquid wall that will reach the Northwest coast, on average, fifteen
minutes after the earthquake begins. By the time the shaking has ceased and the tsunami
has receded, the region will be unrecognizable. Kenneth Murphy, who directs FEMA’s
Region X, the division responsible for Oregon, Washington, Idaho, and Alaska, says,
“Our operating assumption is that everything west of Interstate 5 will be toast.”
In the Pacific Northwest, the area of impact will cover* (#editorsnote) some hundred and
forty thousand square miles, including Seattle, Tacoma, Portland, Eugene, Salem (the
capital city of Oregon), Olympia (the capital of Washington), and some seven million
people. When the next full-margin rupture happens, that region will suffer the worst
natural disaster in the history of North America. Roughly three thousand people died in
San Francisco’s 1906 earthquake. Almost two thousand died in Hurricane Katrina.
Almost three hundred died in Hurricane Sandy. FEMA projects that nearly thirteen
thousand people will die in the Cascadia earthquake and tsunami. Another twenty-seven
thousand will be injured, and the agency expects that it will need to provide shelter for a
million displaced people, and food and water for another two and a half million. “This is
one time that I’m hoping all the science is wrong, and it won’t happen for another
thousand years,” Murphy says.
In fact, the science is robust, and one of the chief scientists behind it is Chris Goldfinger.
Thanks to work done by him and his colleagues, we now know that the odds of the big
Cascadia earthquake happening in the next fifty years are roughly one in three. The odds
of the very big one are roughly one in ten. Even those numbers do not fully reflect the
danger—or, more to the point, how unprepared the Pacific Northwest is to face it. The
truly worrisome figures in this story are these: Thirty years ago, no one knew that the
Cascadia subduction zone had ever produced a major earthquake. Forty-five years ago, no
one even knew it existed.
“I’ll do what everybody does—sell this startup just before we have to hire a female employee.”
n May of 1804, Meriwether Lewis and William
I
n May of 1804, Meriwether Lewis and William
Clark, together with their Corps of Discovery, set
off from St. Louis on America’s first official crosscountry expedition. Eighteen months later, they
reached the Pacific Ocean and made camp near the
present-day town of Astoria, Oregon. The United
States was, at the time, twenty-nine years old.
Canada was not yet a country. The continent’s far expanses were so unknown to its white
explorers that Thomas Jefferson, who commissioned the journey, thought that the men
would come across woolly mammoths. Native Americans had lived in the Northwest for
millennia, but they had no written language, and the many things to which the arriving
Europeans subjected them did not include seismological inquiries. The newcomers took
the land they encountered at face value, and at face value it was a find: vast, cheap,
temperate, fertile, and, to all appearances, remarkably benign.
A century and a half elapsed before anyone had any inkling that the Pacific Northwest
was not a quiet place but a place in a long period of quiet. It took another fifty years to
uncover and interpret the region’s seismic history. Geology, as even geologists will tell
you, is not normally the sexiest of disciplines; it hunkers down with earthly stuff while
the glory accrues to the human and the cosmic—to genetics, neuroscience, physics. But,
sooner or later, every field has its field day, and the discovery of the Cascadia subduction
zone stands as one of the greatest scientific detective stories of our time.
The first clue came from geography. Almost all of the world’s most powerful earthquakes
occur in the Ring of Fire, the volcanically and seismically volatile swath of the Pacific
that runs from New Zealand up through Indonesia and Japan, across the ocean to Alaska,
and down the west coast of the Americas to Chile. Japan, 2011, magnitude 9.0;
Indonesia, 2004, magnitude 9.1; Alaska, 1964, magnitude 9.2; Chile, 1960, magnitude
9.5—not until the late nineteen-sixties, with the rise of the theory of plate tectonics,
could geologists explain this pattern. The Ring of Fire, it turns out, is really a ring of
subduction zones. Nearly all the earthquakes in the region are caused by continental
plates getting stuck on oceanic plates—as North America is stuck on Juan de Fuca—and
then getting abruptly unstuck. And nearly all the volcanoes are caused by the oceanic
plates sliding deep beneath the continental ones, eventually reaching temperatures and
pressures so extreme that they melt the rock above them.
The Pacific Northwest sits squarely within the Ring of Fire. Off its coast, an oceanic
plate is slipping beneath a continental one. Inland, the Cascade volcanoes mark the line
where, far below, the Juan de Fuca plate is heating up and melting everything above it. In
other words, the Cascadia subduction zone has, as Goldfinger put it, “all the right
anatomical parts.” Yet not once in recorded history has it caused a major earthquake—or,
for that matter, any quake to speak of. By contrast, other subduction zones produce major
earthquakes occasionally and minor ones all the time: magnitude 5.0, magnitude 4.0,
magnitude why are the neighbors moving their sofa at midnight. You can scarcely spend
magnitude why are the neighbors moving their sofa at midnight. You can scarcely spend
a week in Japan without feeling this sort of earthquake. You can spend a lifetime in many
parts of the Northwest—several, in fact, if you had them to spend—and not feel so much
as a quiver. The question facing geologists in the nineteen-seventies was whether the
Cascadia subduction zone had ever broken its eerie silence.
In the late nineteen-eighties, Brian Atwater, a geologist with the United States
Geological Survey, and a graduate student named David Yamaguchi found the answer,
and another major clue in the Cascadia puzzle. Their discovery is best illustrated in a
place called the ghost forest, a grove of western red cedars on the banks of the Copalis
River, near the Washington coast. When I paddled out to it last summer, with Atwater
and Yamaguchi, it was easy to see how it got its name. The cedars are spread out across a
low salt marsh on a wide northern bend in the river, long dead but still standing. Leafless,
branchless, barkless, they are reduced to their trunks and worn to a smooth silver-gray, as
if they had always carried their own tombstones inside them.
What killed the trees in the ghost forest was saltwater. It had long been assumed that
they died slowly, as the sea level around them gradually rose and submerged their roots.
But, by 1987, Atwater, who had found in soil layers evidence of sudden land subsidence
along the Washington coast, suspected that that was backward—that the trees had died
quickly when the ground beneath them plummeted. To find out, he teamed up with
Yamaguchi, a specialist in dendrochronology, the study of growth-ring patterns in trees.
Yamaguchi took samples of the cedars and found that they had died simultaneously: in
tree after tree, the final rings dated to the summer of 1699. Since trees do not grow in the
winter, he and Atwater concluded that sometime between August of 1699 and May of
1700 an earthquake had caused the land to drop and killed the cedars. That time frame
predated by more than a hundred years the written history of the Pacific Northwest—
and so, by rights, the detective story should have ended there.
But it did not. If you travel five thousand miles due
west from the ghost forest, you reach the northeast
coast of Japan. As the events of 2011 made clear, that
coast is vulnerable to tsunamis, and the Japanese
have kept track of them since at least 599 A.D. In
that fourteen-hundred-year history, one incident has
long stood out for its strangeness. On the eighth day
of the twelfth month of the twelfth year of the
Genroku era, a six-hundred-mile-long wave struck
the coast, levelling homes, breaching a castle moat, and causing an accident at sea. The
Japanese understood that tsunamis were the result of earthquakes, yet no one felt the
Japanese understood that tsunamis were the result of earthquakes, yet no one felt the
ground shake before the Genroku event. The wave had no discernible origin. When
scientists began studying it, they called it an orphan tsunami.
Finally, in a 1996 article in Nature, a seismologist named Kenji Satake and three
colleagues, drawing on the work of Atwater and Yamaguchi, matched that orphan to its
parent—and thereby filled in the blanks in the Cascadia story with uncanny specificity.
At approximately nine o’ clock at night on January 26, 1700, a magnitude-9.0 earthquake
struck the Pacific Northwest, causing sudden land subsidence, drowning coastal forests,
and, out in the ocean, lifting up a wave half the length of a continent. It took roughly
fifteen minutes for the Eastern half of that wave to strike the Northwest coast. It took
ten hours for the other half to cross the ocean. It reached Japan on January 27, 1700: by
the local calendar, the eighth day of the twelfth month of the twelfth year of Genroku.
Once scientists had reconstructed the 1700 earthquake, certain previously overlooked
accounts also came to seem like clues. In 1964, Chief Louis Nookmis, of the Huu-ay-aht
First Nation, in British Columbia, told a story, passed down through seven generations,
about the eradication of Vancouver Island’s Pachena Bay people. “I think it was at
nighttime that the land shook,” Nookmis recalled. According to another tribal history,
“They sank at once, were all drowned; not one survived.” A hundred years earlier, Billy
Balch, a leader of the Makah tribe, recounted a similar story. Before his own time, he
said, all the water had receded from Washington State’s Neah Bay, then suddenly poured
back in, inundating the entire region. Those who survived later found canoes hanging
from the trees. In a 2005 study, Ruth Ludwin, then a seismologist at the University of
Washington, together with nine colleagues, collected and analyzed Native American
reports of earthquakes and saltwater floods. Some of those reports contained enough
information to estimate a date range for the events they described. On average, the
midpoint of that range was 1701.
It does not speak well of European-Americans that such stories counted as evidence for a
proposition only after that proposition had been proved. Still, the reconstruction of the
Cascadia earthquake of 1700 is one of those rare natural puzzles whose pieces fit
together as t …
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