Original subtitles

(intense music)

‐ [Narrator] Earthquakes.

(people screaming)

So devastating.

So unpredictable.

‐ [Man] Seismologists are as surprised as anybody

when they actually happen.

‐ [Narrator] That even the pros stay on guard.

(explosions booming)

From survival.

‐ [Narrator] To impact.

‐ [Man] Some events are so big

that they literally break the system.

‐ [Narrator] The effects can be apocalyptic.

(intense music)

Earth, air, fire, and water,

essential for human survival,

but in their extreme, destructive

to everything, and everyone in their path.

‐ [Man] Coming down, right now, major tornado.

‐ [Man] Yeah, that's a monster.

‐ [Narrator] These are stories.

‐ [Man] Oh big tower of wet.

‐ Wow. ‐ Whoa, whoa!

‐ [Narrator] Of Apocalypse Earth.

Earthquakes, powerful, spontaneous,

deadly, and profound.

When the planet shifts position,

everything on it must accommodate,

or face destruction.

And when it comes to earthquake activity on the planet,

there's no place as extensive as the Ring of Fire.

The Ring of Fire is an arc of tectonic plate boundaries

that line the fringes of the Pacific Ocean.

It extends 25,000 miles, from South America

along Central and North America's West Coast,

north to Alaska, and then down through Russia, Japan,

and Southeast Asia, all the way to New Zealand.

90% of all earthquakes occur along this line,

as well as 81% of the world's largest.

Up north of the American coast

of the Ring of Fire sits Alaska,

the most earthquake prone in the United States.

It's also one of the most seismically active

regions in the world.

But when it comes to earthquake activity

within the United States,

it's California that comes to mind most often.

In part, because of the history of earthquakes

that have rocked the City of Angels over the years.

(rock music)

Los Angeles is the biggest city in California,

and the second largest in America.

Its beautiful weather, beaches, and strong economy

have attracted 13 million people

to make the metro area their home.

But seismologists believe the city is in jeopardy.

Not from the infamous San Andreas Fault,

but the more recently identified Puente Hills Fault.

Earthquakes occur in California,

because beneath the surface

of this beautiful state are faults.

These consist of tectonic plates,

continually pushing against each other, creating stress.

Eventually, that stress has to be relieved,

and when that happens, the release of energy

and movement is an earthquake.

(earth rumbling)

(trolley clangs)

‐ [Narrator] A century ago, the very first California city

to experience a major quake was San Francisco.

In 1906, the San Andreas Fault, unknown at the time,

literally split the earth open.

That earthquake rocked the Bay Area on April 18th,

and measured a magnitude 7.9 on the Richter scale.

‐ The most costly disaster

in the history of the United States.

Loss of lives anywhere from 3,000 up to 18,000,

so it was quite significant in terms of the losses.

‐ [Narrator] Over 80% of the city was destroyed,

as a result of devastating fires caused by the shaker.

The fires lasted for several days,

leaving more than half of the population homeless.

The Bay Area earthquake is considered

one of the deadliest in US history.

(eerie music)

Southern California has experienced

several major earthquakes of its own, as well.

‐ If you live in earthquake country,

you have to just learn to accept that these things happen,

and that there are unpredictabilities in your life.

‐ [Narrator] The Golden State's temblors come in all sizes,

and happen all the time.

Hard to imagine, but California

has some 37,000 earthquakes every year.

About 100 per day.

Most of them are under magnitude four,

too minor to feel.

Seismologists use a numerical scale,

known as the Richter scale

to quantify the power of earthquakes.

Charles Richter and Beno Gutenberg

determined the magnitude of an earthquake

could be calculated based upon

the amplitude of seismic waves recorded by seismographs.

Each whole number increase in magnitude

represents a 10 fold increase in measured amplitude.

In other words, a 5.0 magnitude earthquake

is about 10 times the amplitude of a 4.0.

And while seismic impact of earthquakes can be measured,

when they will occur still cannot.

‐ We do not know how to predict earthquakes

in the short term.

We can't tell you when an earthquake is going to happen.

We try and forecast them in the long term,

but seismologists are as surprised as anybody

when they actually happen.

‐ Earthquakes scare us

because they're the ultimate out of control experience.

We're always more afraid of what we don't control.

(intense music)

‐ [Narrator] If the Puente Hills thrust fault ruptures,

it could cause a major earthquake

that would have devastating consequences,

especially for the millions of people

who live and work in the Los Angeles metropolitan area.

‐ If we had this seven plus earthquake,

downtown Los Angeles would actually move

by maybe five, six, maybe even 10 feet.

(intense music)

‐ [Narrator] A sobering prospect, but not far‐fetched.

Earthquakes in Southern California have been occurring

for hundreds of millions of years.

For the most part, that's how

the various mountain ranges were formed.

The biggest known earthquake in Southern California

occurred in 1857.

By studying how it deformed the local geology,

scientists determined it was a 7.9 quake.

But because the area was so sparsely populated at the time,

only two deaths were recorded.

‐ That earthquake was probably

larger than the 1906 earthquake,

and if it happened today, it would be a disaster.

‐ LA's never seen an earthquake like that,

but we have had a whole succession

of smaller earthquakes,

but they've all taught us

important lessons in one way or another.

For example, one of the most important earthquakes

in the history of the world

was the 1933 Long Beach earthquake.

‐ [Narrator] In 1933, the population of Los Angeles

was around 1.2 million.

On March 10th, at 5:55 p. m., a 6.4 magnitude earthquake

occurred on the Newport Inglewood fault zone.

The quake itself lasted five seconds,

with about 10 seconds of ground shaking,

and it resulted in 120 deaths.

Many of these fatalities occurred as people

ran out of buildings, and were hit by falling debris.

This footage from a W. C. Fields movie,

which was being filmed that day,

is the only real time recording made of the event.

The quake caused 50 million dollars in property damage,

much of it to structures made of unreinforced masonry.

Many of them were school buildings.

(somber music)

‐ Now fortunately, school was not in session,

so children weren't killed by the hundreds,

but parents were so freaked out by this

that they lobbied the state legislature

to enact the world's first building codes.

‐ [Narrator] The earthquake eliminated all doubts

regarding the need for quake‐resistant design

for structures in California.

‐ There had been a law in Long Beach

requiring buildings to be made out of brick for fire safety.

So they were particularly hard hit

when this earthquake happened, and we now recognize

that mortar just dissolves in an earthquake.

‐ After the Long Beach earthquake,

California enacted legislation, the so‐called Field Act,

that improved the building codes,

and set strict guidelines for public structures

such as school buildings.

‐ [Narrator] Another bill was later introduced

to require that earthquake precautions

be taken for all California buildings.

This was known as the Riley Act,

which became law on May 27th, 1933.

‐ Following the 1933 Long Beach earthquake,

there was a long period of seismic quiet in LA.

Almost 40 years of nothing, no earthquakes.

Interestingly, that coincides

with when LA really exploded in population.

‐ [Narrator] But in 1971, Southern California residents

were reminded that they live in earthquake country.

The area was hit by a massive quake,

bigger than the last one.

On February ninth, a 6.7 magnitude earthquake

occurred on the San Fernando Fault Zone.

Known as the Sylmar Quake, it was caused by a reverse fault,

a type of thrust fault that has

an extremely high angle of vertical movement.

‐ Here in Southern California,

we also have a network of reverse faults

that create our mountains.

It shows us that these mountain front faults,

the ones that are creating our high mountains,

pose a very significant risk to the Los Angeles area.

(rubble clattering)

‐ [Narrator] The Sylmar earthquake killed 65 people,

and caused more than half a billion dollars

in property damage.

It was a wake up call

about a particular kind of construction.

(dramatic music)

‐ Much of Los Angeles was built in the 1950s and '60s,

and in 1971, we saw that a very common style of buildings

called non‐ductile reinforced concrete performed very badly.

Understatement of the year.

The Olive View Hospital, where the first floor disappeared,

was one of these non‐ductile reinforced concrete buildings.

‐ [Narrator] Non‐ductile is a technical term for brittle.

The last type of structure

you'd want to be located in during an earthquake.

In fact, the Olive View Hospital collapse

killed three patients, and a hospital worker.

(sirens wailing)

At the time of the Sylmar earthquake,

it was widely believed

that the Field and Riley Acts

were sufficient protection against earthquakes.

But while the building of new brick structures

had been outlawed, there were still many

pre‐existing brick buildings that were vulnerable.

‐ The city of Los Angeles took the controversial step

of requiring the strengthening

of existing old brick buildings.

‐ [Narrator] As for the non‐ductile

reinforced concrete buildings,

that was a different story.

Because there were so many of these

throughout the Los Angeles metro area,

no law was passed requiring current owners to retrofit.

Only that new buildings of this type could not be built.

‐ So it showed us that in fact

we had a ways to go in terms of

improving our building codes,

and that we needed to be very careful about our use of land.

‐ [Narrator] After the earthquake,

the California Legislature enacted the Alquist‐Priolo Bill,

which required the mapping of active fault zones.

Whenever faults are found,

they are integrated into seismic hazard maps.

compelled to review these maps

in order to be aware of potential risks.

Despite the fact that the Los Angeles area

had suffered through two major quakes,

it continued to experience massive population growth.

By 1987, there were 3.3 million people in the city,

and millions more in the surrounding areas.

On October 1st, 1987, the LA area

experienced the Whittier Narrows earthquake.

A 5.9 magnitude event that occurred on a blind thrust fault

some 16 miles east of downtown Los Angeles.

Three days later, a magnitude 5.3 aftershock occurred,

causing additional damage.

Three people died as a direct result of the temblors.

Five other deaths were attributed

indirectly to these events.

The Whittier Narrows earthquake in 1987,

and then the Northridge quake in '94,

once again prompted efforts

to enhance safety and emergency preparation.

These two quakes also brought blind thrust faults

to the attention of seismologists and policy makers.

They determined that a rupture

of the Puente Hills blind thrust fault

could result in an energy release some 15 times greater

than that of the Northridge earthquake,

the worst in Los Angeles history so far.

‐ [Man] The Puente Hills earthquake would be

one of the worst events we can imagine here in Los Angeles.

(somber music)

‐ [Narrator] When it comes to earthquake activity,

seismologists do not consider

the Northridge quake of '94 as the big one.

Nonetheless, it's the worst

Los Angeles has suffered thus far.

On January 17th, 1994, at 4:30 a. m.,

residents were awakened to a terrible and powerful rumbling.

The quake, centered near Northridge,

northwest of downtown Los Angeles,

had a moderate magnitude of 6.7.

But the ground velocity,

the speed at which a point on the ground

moved during the shaking,

was the highest ever instrumentally recorded

in an urban area in North America.

The actual quake lasted about seven seconds,

with ground shaking about twice that long.

In that relatively short period of time,

the temblor devastated entire neighborhoods.

But its path of destruction

seemed to hopscotch across the city.

‐ We understand these variations to be associated

with the complexities of the earthquake itself,

as well as the earth beneath our feet.

I mean, some places have very weak soils, and shake a lot.

Others are on hard rock, and the shaking is not so bad.

The Northridge earthquake indicated

how variable those processes can be.

‐ [Narrator] Closer to the epicenter, the powerful shaking

caused an apartment complex to collapse.

(somber music)

16 residents were killed.

Office buildings also collapsed.

But due to the early hour, hardly anyone was at work.

‐ Everybody was in their wooden houses,

and our wooden houses are amazing structures

to resist earthquakes.

‐ [Narrator] Had the quake occurred four hours later,

when people were up and about,

perhaps thousands would have been killed

throughout the city.

(eerie music)

Aftershocks triggered the collapse of many structures,

already weakened by the initial shock.

The quake challenged some longstanding assumptions.

It damaged at least 120 steel frame high‐rises,

which were supposed to withstand a quake.

The steel was expected to absorb the vibrations, and bend.

Instead, there were fractures.

‐ The connections between the columns

and the beams came loose,

and those connections are quite critical

to maintain the lateral resistance of the building.

‐ [Narrator] Some of these structures

were 20 miles from the epicenter,

the initial point of the quake's rupture.

But distance from the epicenter

has been a confusing issue for the general public.

In actuality, it is the distance from the fault plane,

the entire length of the moving tectonic plates

that often determines damage.

‐ There are usually other parts of the fault

that give off more energy than the epicenter,

'cause it builds up steam, and is rupturing out

so that the maximum energy release in Northridge

was coming out under Chatsworth,

and up under the Granada Hills area.

‐ [Narrator] And yet, there was major damage to the south.

Part of the Santa Monica freeway collapsed.

‐ That freeway overpass looked a little isolated

from the rest of the damage.

As it turns out, it's in an area we call La Cienega,

which means in Spanish, the swamp,

and it turns out that soft, swampy materials

tend to experience larger ground shaking.

‐ [Narrator] Subsequent to the quake, 680,000 residents

were without power, gas, water, or telephone service,

and lacked these utilities for days.

The Northridge earthquake proved to be

the most costly quake in United States history.

40 billion dollars in damages,

with 63 related deaths, and 12,000 injured.

Previous to this quake,

seismologists had focused primarily

on areas vulnerable to the San Andreas fault.

But the Northridge earthquake

persuaded scientists to widen their scope.

‐ It occurred in a place

where we didn't expect such an event.

In particular, it was on a buried fault structure

that has vertical motion.

We call these types of structures blind thrust faults.

‐ [Narrator] That's a fault which is buried

below the surface, hence the name blind,

and consists of two tectonic plates.

In a rupture, one will grind up and over the other.

‐ These are faults that, you know,

they're not as big as the San Andreas, but they're right,

literally in the case of the Puente Hills thrust,

directly beneath the city.

‐ [Narrator] The Puente Hills blind thrust fault,

aimed at a 45 degree angle from below downtown Los Angeles,

is a sleeping geological monster.

‐ Of any potential earthquakes in the United States,

Puente Hills is really the most threatening.

‐ [Narrator] Seismologists believe that this monster

could wake up, and unleash a deadly force,

the likes of which Los Angeles has never before experienced.

(intense music)

‐ [Narrator] For decades, Southern Californians

have lived with the fact that earthquakes will come.

They will strike without warning,

and cause death and destruction.

So geologists and seismologists,

in anticipation of the next big one,

are in a race against time

to determine where the faults are,

and what they're capable of doing.

Following the 1987 Whittier Narrows earthquake,

and the 1994 Northridge quake,

seismologists became increasingly aware

of a threat from not just the San Andreas fault.

This animation, created by

the Southern California Earthquake Center,

provides a comprehensive look at the problem.

The San Andreas is depicted

by the colored diagonal ribbon in the center of the screen.

Each one of the other colored ribbons

represents the new threat, a vast network

of blind thrust faults below the LA metro area, and beyond.

Using a technique called seismic reflection,

Harvard University professor and seismologist John Shaw,

and University of California at San Diego

professor Peter Shearer,

were able to discover the existence

of the previously unknown Puente Hills blind thrust fault.

It runs 25 to 30 miles from Northern Orange County,

through downtown Los Angeles,

and all the way to Beverly Hills.

Seismologists now believe the 1987 Whittier Narrows quake

was actually a partial rupture of the Puente Hills fault.

Subsequent study revealed it has ruptured many times,

over thousands of years.

‐ We're standing above the eastern end

of the Puente Hills blind thrust fault.

You can't see anything where we're walking right here,

but the reason the road behind me rises up

is because this hill behind me has been uplifted

in hundreds of earthquakes

on the Puente Hills blind thrust fault.

‐ [Narrator] It's unlike a strike slip fault,

like the San Andreas, which consists of two tectonic plates

on a horizontal orientation.

A thrust fault consists of two planes,

and when it ruptures, one rises up above the other,

causing the earth to rise above it,

and stay that way permanently.

(eerie music)

A rupture of a larger portion of the Puente Hills fault

could cause widespread disaster

the likes of which we haven't seen in a modern era quake.

‐ If you tried to design the worst possible fault

in the worst possible location for Los Angeles,

you'd come up with the Puente Hills blind thrust.

‐ [Narrator] To understand it further,

the Southern California Earthquake Center

commissioned seismologist Robert Graves

to create a computer model of probability scenarios.

By feeding it with data about the fault's characteristics,

and the geological conditions

throughout the LA area, it shows

how a Puente Hills thrust fault rupture would spread.

‐ What we're looking at in the animation

is we see the ground begins to shake

as the earthquake starts,

and there are some small ripples,

and they begin to propagate out

from the area around the epicenter.

What is very striking is that as the waves propagate

away from the earthquake,

they are actually interacting with the geological layers

in the sedimentary structure of the LA basin.

The waves become trapped, and they start bouncing around,

and they actually build up very large ground motions,

very large waves.

‐ [Narrator] According to the results of the simulations,

a Puente Hills thrust fault earthquake

could result in 250 billion dollars

worth of property damage.

Seismologists have even turned to NASA for help.

Incredibly, the geology of earthquakes

can be studied from outer space.

GPS satellites send signals,

which help scientists to continually map the earth.

By comparing the data over time,

minute changes in certain areas are revealed.

Using this method, scientists have concluded

that the land surface of Los Angeles is being squeezed

at a rate of .2 inches per year.

So, at that rate, when will Puente Hills erupt?

‐ Good news is that our research suggests

that this thing only generates large earthquakes

every few thousand years,

so they're extremely rare events.

The flip side of that, the bad news,

is that when they occur, they appear to be very large.

Something well in excess of magnitude seven,

possibly as large as magnitude 7.5.

(intense music)

‐ [Narrator] Studies of a rupture

of the Puente Hills fault are grim.

The losses predicted are for a disaster

10 to 15 times greater than the 1994 Northridge earthquake.

Clearly, it would put LA to the ultimate test.

The state spent billions after the 1994 Northridge quake

to retrofit more than 2,100 freeway overpasses.

(ominous music)

But, are the citizens of LA prepared?

‐ We can't imagine that the boys in white hats

are gonna come riding in to save us

after a large event.

We saw in Katrina, that in fact,

some events are so big that they literally break the system.

(intense music)

‐ [Narrator] In a worst case scenario,

Southern Californians who survive the initial impact

of a major quake will have to cope

with a difficult aftermath.

They'll be better equipped if they've

heeded the advice of experts

to take the initiative to prepare.

The big one will happen.

It's not a matter of if, but when.

(helicopter whirring)

Northern California had its own reminder

of earthquake volatility back in 1989.

The devastation was massive, but baseball,

literally, helped save the day.

(intense music)

It's a perfect day for baseball in Northern California.

As inter city rivals, the San Francisco Giants,

and the Oakland As gear up

for game three of the 1989 World Series.

The whole city is watching, but fans have no idea

that Mother Earth is about to take a game ending swing.

(dramatic music)

60 miles away, the San Andreas fault suddenly snaps.

(earth rumbling)

The deadly fault runs almost the length of California,

and directly underneath San Francisco.

(intense music)

At a magnitude 6.9, this is the most powerful earthquake

in nearly a century.

It quickly spreads terror and destruction across the city.

(flames crackling)

(sirens wailing) ‐ Are you okay?

(dramatic music)

‐ [Narrator] On the two level Bay Bridge,

a 50 foot section of the upper deck

collapses without warning.

The enormity of the disaster

leaves Oakland Fire Lieutenant Mark Hoffman

and his crew stunned.

The violent shaking destroys a mile and a quarter section

of the double decker Nimitz freeway,

causing the upper level to crash onto the lower level,

and hundreds of vehicles below.

‐ [Narrator] Rescuers desperately

try to locate trapped motorists.

‐ There was a zone about four feet deep

over most of the length of the collapsed area.

Every 75 or 100 feet or so,

there was a deep beam that came down,

and of course crushed anything under it,

but that also provided this confined space

in which people could survive.

‐ [Narrator] Underneath all that rubble,

Tim Petersen fights for his life.

The injured man is battling broken ribs,

a punctured lung, and internal bleeding.

‐ It's hard to even breath.

The lung is leaking air,

so I figured there was no surviving it.

It was gonna kill me.

‐ [Narrator] After six agonizing hours,

there's a glimmer of hope.

‐ I can hear all these sounds above,

so I was yelling to them,

and somebody did crawl down and finally yelled to me

and said, "Hey, I'm gonna go get somebody.

"I can't believe there's anybody alive down in here."

‐ [Narrator] The firefighter finds a path

through the debris.

‐ It's a small tunnel you had to crawl into

to get to where I was.

I mean, you can't describe somebody crawling down in there.

This thing is still falling,

and I mean talk about risking your life,

talk about a hero.

‐ Get out of the way!

‐ Remarkably, there were only 42 fatalities

in the Cypress structure.

Considering how many cars could've been there,

this is a remarkably low number.

(somber music)

‐ [Man] Diane, give me a three point search here.

‐ [Narrator] Despite the horrific human toll,

the catastrophe could've been much worse.

Had it not been for the World Series.

‐ The game started at five p. m.,

so most people got off work early, got home,

and then the earthquake occurred at 5:04.

So just when the Interstate 880 freeway

should've been jammed with cars,

it was virtually empty.

(earth rumbling) (intense music)

‐ [Narrator] New York is not the first city

that comes to mind as being at risk

for dangerous earthquakes.

But just a few miles below the New York City area

lay several earthquake faults.

125 years ago, the New York area was hit by an earthquake.

‐ The largest earthquake that we know of

historically in New York City is the 1884 earthquake,

roughly magnitude five.

‐ [Narrator] August 10th, 1884, an earthquake rumbled up

from underneath the Atlantic Ocean.

The epicenter of the quake was 17 miles south of city hall,

off the coast of Rockaway Beach.

10 o'clock in the morning, unprepared citizens

across the city were shocked to find themselves

grabbing for walls,

calming startled carriage horses,

and ducking from falling bricks, as the whole city shook.

Thousands of chimneys in the city

were broken in the magnitude five quake.

Parapets came down, windows were shattered.

Luckily, there were very few

injuries, and no fatalities.

The East Coast from New York south to Maryland,

and north to Vermont was rocked by seismic waves.

An area covering roughly 70,000 square miles.

In fact, in terms of seismic hazard,

New York City is the fourth most

at risk city in the country,

following San Francisco,

Los Angeles,

and Seattle.

People sometimes confuse seismic hazard with seismic risk,

but they are not the same.

‐ Because risk is really not only defined

by the natural hazard.

There are two more ingredients that go into risk.

Hazard is one.

The other is the value of the assets

that are exposed to that hazard,

and there is plenty of valuable assets

concentrated in the New York City metropolitan area.

‐ [Narrator] The third ingredient is the vulnerability,

or what is sometimes called fragility of those assets

with respect to the hazard.

Meaning seismic shaking and other seismic hazards.

‐ In this area, roughly every 100, 250 years

a magnitude five occurs.

Magnitude six is in the order of 1,000 years.

Magnitude seven are almost beyond imagination,

but they can, unfortunately, occur.

‐ [Narrator] On the Richter scale

that measures an earthquake's impact,

each whole number increase in magnitude

represents a tenfold increase in measured amplitude.

In other words, a 5.0 magnitude earthquake

is about 10 times the amplitude of a 4.0.

Since 1737, at least six earthquakes

of magnitude 5.1 or higher have struck New York State.

The 1737 quake was also centered near New York City,

but New York is not alone.

One of the earliest recorded events

took place over 250 years ago in Massachusetts.

An earthquake estimated to be magnitude 6.0 to 6.3.

‐ For the northeastern part of the United States,

the earthquake that really defines

what we think the earthquake hazard is

is the 1755 Cape Ann earthquake.

We think it was centered

just east of Cape Ann, Massachusetts.

(tense music)

That earthquake did major damage in Boston,

in Portsmouth, New Hampshire, Portland, Maine.

It was felt up to Halifax, Nova Scotia,

felt down as far south as Winyah, South Carolina.

‐ [Narrator] Other East Coast and Midwestern cities

have been devastated by killer quakes.

‐ There are clusters of earthquakes in the Carolinas,

South Carolina, North Carolina,

around Charleston in particular.

‐ [Narrator] On August 31st, 1886,

just two years after the 1884 earthquake in New York City,

a massive earthquake ripped through

the coastal city of Charleston, South Carolina.

(earth rumbling)

Estimates based on damage patterns and historical records

put the Charleston quake at magnitude 6.5 to 7.3.

More than 2,000 buildings were damaged in Charleston.

Between 60 and 100 people lost their lives.

The Charleston quake was felt as far north as Manhattan,

as far west as Omaha, Nebraska,

and as far south as Cuba.

(intense music)

But there are more recent reminders

of devastating earthquakes along the East Coast.

‐ I was 18 years old at the time, and like I say,

it was an event that I will never forget.

‐ [Narrator] Just after midnight on a July night in 1944,

a magnitude 5.9 earthquake erupted

in the sleepy town of Massena, New York.

‐ It was the first major earthquake

that this area had experienced.

‐ We had gone out to celebrate our graduation.

There was a few of us that went out to the local bar,

and had a few beers.

And about 12 o'clock, we closed the place down.

Then we decided we'd better get home.

It was a very, very quiet night.

You could hear a pin drop.

I stepped in the door,

put my foot on the first step, and bang.

That the earthquake hit.

(intense music)

‐ I woke up feeling as if

there was a freight train going very fast

past the door of my room, and the bed was shaking.

‐ I could hear dishes rattling.

‐ Just like somebody had picked ya up, and shoved ya.

‐ I think every other person on the street

was out in the middle of the street

in their pajamas and robes.

‐ [Narrator] The earthquake ripped through Massena,

and across the border into neighboring Cornwall, Ontario.

(glass shattering)

‐ The fault runs from the northwest to the southeast,

across the river, and through the towns

of Cornwall and Massena.

(sirens wailing)

The next day, I think the full force

of what had happened hit.

People were wandering around the town like zombies.

‐ [Narrator] The two small towns of Massena, New York,

and Cornwall, Ontario suffered

more than two million dollars in property damage.

About 50 million in today's dollars.

90% of the brick chimneys were destroyed,

and brick masonry and concrete structures

suffered severe damage.

Plumbing and house foundations were ruined.

(intense music)

The Massena earthquake has been closely studied

by East Coast seismologists and others

as an example of the kind of damage

a smaller earthquake can do in an area

of mainly brick and masonry buildings.

‐ The Massena earthquake was interesting

because it showed what an earthquake

that is not quite six can do to the type of construction

that we still have a lot of around in New York City.

(horn blares)

‐ One of those kinds of earthquakes

centered right near one of our major metropolitan areas,

like Boston or New York, would cause significant damage.

‐ [Narrator] In fact, an earthquake on August 23, 2011

in Central Virginia, only underscored that awareness.

The 5.8 shaker was felt by an estimated

1/3 of the US population.

As far north as Maine, as far west as Chicago,

and as far south as the tip of Florida.

That trembler caused two to 300 million dollars

in property damage, including the Washington Monument,

and National Cathedral in Washington DC.

Earthquakes continue to rumble under the city to this day.

Could the next New York quake

do more than just rattle the city's nerves?

(tense techno music)

‐ [Narrator] In recent years, earthquakes have continued

to shake buildings right underneath

Manhattan streets and sidewalks.

(siren blaring)

Just one month after the World Trade Center attack in 2001,

a magnitude 2.6 earthquake centered right

at 55th Street and 8th Avenue

rumbled up from the Earth.

City officials were initially concerned

there had been another terrorist attack.

‐ Mayor Giuliani was very concerned

that an explosion had gone off

somewhere in the sewer system in New York City.

Well, they couldn't find, of course,

where that explosion was going on,

because the earthquake occurred

five miles beneath the city,

near Central Park, actually.

‐ We had an earthquake back in January,

very similar kind of thing.

Made noise, shook a little in certain places, not in others.

People probably reacted more to this one

because of the events of September 11

and then this thing since then.

(tense music)

‐ [Narrator] These mini quakes are nature's way

of reminding us that if the big one

comes rumbling up through the Earth

and rips apart one of the largest cities in the world,

the death and destruction could be enormous.

(suspenseful music)

The earthquake history of New York

and the rest of the East Coast

could have been very different.

The metropolitan area has a geological history

that is as diverse as the city itself.

(upbeat music)

Scientists have learned a great deal more

about this ancient geology

from a relatively new field of study, plate tectonics.

‐ We learned in the second half of the 20th century

that the way the Earth works is basically

by way of the theory of plate tectonics.

‐ [Narrator] Plate tectonics is the geological theory

that there is a layer of plates

or rock covering the globe that is in a slow,

but constant drift across the surface of the Earth.

In other words, the surface of the earth is not fixed,

but is in constant motion, like slow moving bumper cars

that periodically collide with one another.

These plates generally extend out

and under the sea around the world's land masses.

The North American plate extends roughly

from the western edge of the United States,

all the way east to the middle

of the North Atlantic ocean floor.

‐ So, most earthquakes occur at plate boundaries

where the plates rub against each other.

‐ An earthquake is a sudden slip

of the two sides across a fault.

So, the rock makes a movement suddenly

and releases stress.

‐ [Narrator] This rubbing at the western edge

of the North American plate

where it meets the Pacific plate

has resulted in a long history of devastating earthquakes.

(upbeat music)

But there are key differences between earthquakes

that happen at the edge of a tectonic plate

and those that happen in the middle of a plate.

‐ Within the center of the plate,

it's more of the squeezing kinds of earthquakes

that build mountains, as we have, for instance,

in the Northeastern United States.

‐ Most famous in the United States

is the New Madrid area in the central United States

along the Mississippi River Valley.

They are in the New York and in the Boston areas

and all the way up to the Canadian border

in the northeastern United States.

(swooshing techno music)

‐ [Narrator] About 220 million years ago,

a fused continent known as Pangea,

comprised of several of our modern continents,

began to break apart.

In the wake of this upheaval,

the modern North Atlantic Ocean appeared.

‐ And now, New York sits

right on the edge of this continent.

‐ [Narrator] Near the end of the last Ice Age,

the New York area and the rest of the East Coast

experienced another significant set

of geological developments.

‐ Some 10,000 years ago, the glaciers

started to slowly retreat.

But what they did before they left,

they polished everything clear,

and they carved out the weakest spots in the rock.

(pensive music)

‐ [Narrator] The glaciers carved deep valleys

along the underlying fault lines.

‐ These black lines here are the most active faults

now in the modern geological time.

The most prominent of them

is the 125th Street fault that runs here.

‐ [Narrator] The 125th Street fault is clearly visible

from its valley‐like geology.

‐ The glaciers hollowed out the shape of Manhattan

to follow those fault lines, and that's why

we have, actually, these shapes of Manhattan.

‐ [Narrator] If there is a slip along one of these faults,

devastating seismic waves could be released

up to the Earth's surface.

(ominous music)

(rumbling)

The first seismic wave initially stretches

and squeezes the rock.

The other seismic wave is the shear wave

that bends the rock sideways.

It is this second wave that gives us the horizontal shaking

that causes so much damage to buildings.

(tense music)

(alarms, sirens blaring)

(clattering)

Seismic waves on the East Coast

travel farther than they do on the West Coast.

‐ At the edge of the plate,

there is so much earthquake activity going on

that it'd shatter the plate.

So it's a little bit like your windshield

that has a lot of cracks in it

because someone threw a stone in it,

and there's still light coming through,

but you can't see through very clearly.

The same thing with the seismic waves

where those plates are broken by prior earthquakes,

the seismic waves go sort of through,

but it's not very clear.

(ominous music)

Here in the eastern United States,

we can feel earthquakes as small as magnitude one.

Certainly, magnitude two are wildly felt

all over New York City, for instance,

Californians have no clue

that there was a magnitude two earthquake.

So, if a three and a half or four

occurs here on the East Coast,

everybody is up in arms.

Californians say, "Okay, we had a four today

this morning," and keep drinking their coffee.

‐ [Narraechno music)

‐ [Narrator] If a major earthquake should hit New York,

vulnerable building types and varied geology

could be a dangerous mix waiting to combust.

One of the most dangerous components of this deadly brew

is a geological phenomenon known as soil liquefaction.

Soil liquefaction is when partially

or fully saturated soil, such as landfill,

loses firmness due to the shaking of an earthquake.

When this happens, the ground

becomes liquified, much like quicksand.

This can then result in structural instability.

(energetic chase music)

The 1989 Loma Prieta earthquake that struck San Francisco,

magnitude 7.1, was a tragic example of liquefaction.

(ominous music)

Before 1906, there was no Marina District in San Francisco.

After the 1906 quake, a swampy area downtown

was filled in with debris from the earthquake

and covered over with dirt.

Houses were built, and the area

became a popular neighborhood.

83 years later, when the next major earthquake hit,

the loose soil caused tremendous damage in the district.

(sirens blaring)

‐ The problem is, when you fill these areas

with sand and dirt, they will shake

more strongly than the nearby rock areas.

Kind of like shaking a bowl of Jello.

‐ [Narrator] Liquefaction could severely harm

similar landfill areas in New York City.

As history has shown, even a magnitude 5 earthquake

could severely damage thousands of buildings.

(tense music)

And risk analysis experts estimate

that if a magnitude 7 were to strike

in the same location as the 1884 quake,

it could kill more than 6,000 people.

13,000 more could be injured.

(tense music)

‐ We estimate that in a worst‐case scenario,

something like a 7 magnitude earthquake,

over 30 million people will be impacted by the event.

‐ [Narrator] A major metropolis like New York

requires an incredibly complex underground infrastructure.

(tense music)

‐ Power lines, and water lines, gas lines

are always susceptible to ground shaking

from a major earthquake.

‐ [Narrator] There are also sanitation canals

that carry away wastewater,

and steam pipes delivering heat to large buildings.

‐ There is a whole spider network of stuff

going on underground.

‐ [Narrator] Ironically, you may be safer underground

during an earthquake, than you would be

standing in the middle of 42nd Street.

‐ Generally speaking, you are better off underground

because the amplitude of shaking diminishes

as you go deeper into the Earth.

It's safer to be underground than above ground,

or in a building that sticks way out and shakes.

‐ [Narrator] A vivid example of this occurred

during the deadly Mexico City earthquake in 1985.

Soil liquefaction destroyed hundreds of buildings.

But below ground, the subway system was almost unscathed.

Within hours, subways were up and running around the city.

But there are vulnerable spots

underground in New York, particularly where

different infrastructure systems intersect.

Water mains may break.

‐ There are sewer pipes that are very brittle.

Many of them are cast iron.

That's a very bad material to respond to an earthquake.

‐ [Narrator] Moving back above ground,

one sees the biggest danger

posed by an earthquake: buildings.

(tense music)

In 1995, New York City finally adopted

a seismic building code.

This was a major step in making

all new construction safer from earthquake damage.

‐ The biggest difference that we would have now

in our seismic building codes

for the eastern part of the United States

is the requirement for stronger connection,

so that if a building gets pushed sideways

in earthquake shaking, the connections don't break.

So, if you have a vertical beam

and you have a horizontal beam,

the horizontal beam will now be attached

more strongly to the vertical beam,

so that if it shakes, you don't break the bolts

or break the welds and have the beam come down.

‐ [Narrator] Bridges and pre‐code buildings, however,

will remain a major problem

if an earthquake hits the East coast.

(siren blaring)

‐ [Narrator] A major challenge for older cities

on the East Coast in terms of earthquakes

is bringing building codes up to date.

‐ The building codes for cities like New York or Boston

generally apply only to new buildings.

By not reinforcing old buildings,

we always take the chance that the earthquake will occur

before that building gets replaced with a new building.

And that's a major in our eastern cities.

‐ [Narrator] But there are other potentially deadly problems

that could befall some of Manhattan's newest

and most densely populated neighborhoods.

Areas like Battery Park City.

Before the World Trade Center was built,

this area at the southwestern tip of Manhattan

was mostly Hudson River water.

But thousands of tons of dirt dug up

for the foundations of the towers

created acres of new ground.

Ground that developers wanted to build on.

And just as San Franciscans created

a new neighborhood in the Marina District,

New Yorkers created their own neighborhood

built on landfill.

‐ They took the piers, filled in sand,

and then built wonderful high‐rise buildings.

They are well‐engineered,

but they were not engineered with earthquakes in mind.

‐ For areas where you can't get down to the rock itself,

the typical construction practice

is to put down many, many pilings,

and just let the friction of the pilings

trying to push into the soil hold the building up.

‐ [Narrator] These buildings could be vulnerable

to liquefaction in a major New York quake.

‐ That's exactly the kind of material

we have in Battery Park City

and other places in New York City.

So, now we have a situation

where we have very beautiful buildings,

very expensive buildings,

both residential and business buildings,

in an area that will have amplified shaking.

(tense music)

‐ [Narrator] But it's not just buildings

that could collapse.

There are other hazards, such as bridges,

and elevated train stations.

Klaus Jacob takes us down to street level

to demonstrate that engineers

from a much earlier period

of New York City building history

were trying to prepare for earthquake hazards.

‐ So, here we are, right smack

where the 125th Street fault

crosses Broadway and Manhattan.

‐ [Narrator] Normally, the subway runs underground,

but when the engineers tried to build the subway

through the rock in the fault zone,

they realized it would be a difficult challenge.

‐ So, they stayed level and built

the bridge across the valley.

So, this bridge is there,

because the fault is there.

The bridge is a document for the fault.

(mellow music)

And what you see here is actually a hinge,

which rotates like this.

Why did they do that?

Well, there's the fault over there,

and they thought the fault would move vertically,

so the bridge could adjust.

What they didn't know is that the fault

doesn't move this way here.

Nowadays, it moves this way.

What they should have done is do it this way,

the axis, and then move around like this

to accommodate the horizontal fault movement.

For 1905, that's really very advanced engineering.

Of course, they got it wrong,

but I think they did a very good job in at least trying

to accommodate earthquakes and fault motion.

‐ [Narrator] But good intentions won't be enough

if a major earthquake shakes New York to its foundation.

For a major urban center such as New York,

recovery from this kind of mega disaster

could take many months.

(mellow music)

‐ We estimate that the amount of property damage

in a major earthquake would be

in the order of $250 billion of property damage.

But, of course, you have to add to that

the damage to business interruption,

so that the total economic disruption in dollar terms

is likely to be at least half a trillion dollars.

If it's a moderate earthquake

in the 6 or 7 magnitude range,

then even after six months, we'll be a long way

from having all the reconstruction

and the rebuilding complete.

(upbeat music)

‐ One of the things I am feeling ever better about

as a seismologist working

in the northeastern part of the country

is that the awareness of earthquakes is growing.

We think about preparedness.

We have more seismic provisions in our building codes.

There are more and more schools

that are doing earthquake drills, as well as fire drills.

So, we're gradually becoming more aware and more planned

for how we would deal with an earthquake,

if it were to occur.

The problem is, of course,

most people in the northeastern United States,

most people in New York, most people in Philadelphia,

most people in Boston don't think

that they will ever face a damaging earthquake.

And that is just a fallacy

that we could be proven wrong on someday.

(ominous music)

‐ [Narrator] For the island nation of Haiti,

a catastrophic earthquake in 2010

proved just how tragic

the lack of strong building codes can be.

(dramatic music)

Port‐au‐Prince, the capital of Haiti,

a country mired in grinding poverty.

(ominous music)

A 7.0 earthquake rips across the island nation.

(clamoring)

Panicked Haitians realize this is unlike anything

they've ever felt before.

(energetic chase music)

(crashing)

‐ It was relatively shallow.

So, this earthquake started at a depth

of about maybe eight miles or so.

‐ An earthquake that's shallow, that's near the surface,

that means more of that energy is dumped on the surface.

‐ The earthquake in Haiti was a perfect storm

of very intense ground shaking and very weak buildings.

(rumbling)

None of the buildings in Haiti were designed

to resist earthquake forces.

They don't have any effective building codes.

‐ [Narrator] Across the region,

the massive quake delivers a punishing blow.

(speaking in foreign language)

American filmmaker Dan Woolley has just checked

into a hotel when disaster strikes.

(crashing)

‐ I heard the explosive sounds

of the building starting to crack,

and I started to feel the ground move underneath me.

And within three seconds, everything went dark.

(tense thumping music)

‐ [Narrator] The hotel pancakes into a pile of rubble,

knocking Dan unconscious.

‐ When I come to my senses,

I find myself in complete darkness.

I would put my hand in front of my face

and I couldn't even see that.

‐ His location in the hotel,

I think, is what saved his life.

He was between a stairwell and the elevators,

both of which tend to be core structures

with concrete block walls,

which will have more strength

than other more open areas in the building.

‐ [Narrator] Dan uses the flash from his camera

to see the tight space he's been trapped in,

and something else that terrifies him.

‐ I pulled up my pant leg,

and as I shone the light of my camera on my leg,

I saw the worst injury I'd ever seen in my life.

It was just split open from just below my knee

to just above my ankle.

‐ [Narrator] Dan snaps another picture

and spots a safer place to be.

‐ I saw an elevator car

with its door open, on the lobby floor.

And I just thought, you know, by what kind of miracle

is this open and available for me?

And I decided to take the risk

and crawl the 20 feet to the elevator.

And right after I reached the elevator,

the building started to shake again.

(suspenseful music)

We were hit with the first aftershock,

which was a 6.0 aftershock.

And I knew that that move had saved my life.

‐ [Narrator] Dan hopes someone will come to his aid

before he bleeds to death.

Meanwhile, aftershocks continue to rumble.

(energetic chase music)

Finally, after being buried in debris

for 65 agonizing hours,

Dan hears the words he's been praying for.

‐ I heard a voice coming down

from the shaft of the elevator.

"I'm here to get you out of there."

And all of a sudden, I had hope and I knew,

"Okay, this is not gonna end here.

This is not gonna end today."

‐ [Rescuer] Come on.

‐ [Rescuer] All right, we're gonna get you

something to drink first.

(somber music)

‐ [Narrator] The final death toll is astronomical.

And as a result of inadequate building codes,

over one million people were left homeless.

(energetic chase music)

(mellow music)

‐ [Narrator] The heartland of America has seen

its share of natural disasters:

killer tornadoes and floods that have destroyed buildings

and swept away entire towns.

But despite its landlocked position in the country,

earthquake danger also lurks beneath its fertile fields.

‐ [Narrator] Memphis, Tennessee sits 50 miles south

of one of the most dangerous earthquake faults in America.

‐ [Narrator] The New Madrid fault line.

‐ A major quake in the New Madrid zone

would create unimaginable havoc in Memphis, Tennessee,

which is the closest city to the New Madrid fault

and built largely of brick.

‐ I think the first reaction to an earthquake,

even if you're a seismologist today

is this fundamental sense of terror.

It just, out of a clear blue sky,

it's like somebody's picking up your house

and shaking it back‐and‐forth.

‐ [Narrator] The prospect of an earthquake in the heartland

may seem unimaginable, but it's actually happened before.

‐ [Narrator] One of America's worst earthquakes

occurred 200 years ago in the heart of the country.

‐ The mother of all earthquakes in the United States

was in 1811 and 1812 in an obscure place

in southern Missouri, where Missouri, Kentucky,

Arkansas, and Illinois all meet, called New Madrid.

‐ [Narrator] December, 1811,

The weather was warmer than usual

in New Madrid, Missouri.

‐ There were about five or 600 people living in New Madrid.

It was a thriving river city.

It was located on the largest S curve

in that section of the river.

‐ A little after two in the morning on December 16th,

the Earth sort of came unglued

with the first of the earthquakes.

(rumbling) (clattering)

‐ There was an great roar

that's compared in the accounts

to thunder or heavy artillery.

And the ground started shaking,

and people were thrown from their beds.

Furniture was overturned.

(clattering)

And in the middle of the night in 1811,

you would have no idea what this was.

‐ [Narrator] Intense seismic waves radiated

in all directions for hundreds of miles.

(pensive music) (lightning crackles)

‐ The thing about New Madrid is that

it's in the middle of a vast alluvial plain.

And the seismic shocks from it spread unrestricted

across certainly eastern America.

‐ [Narrator] The quake was felt as far away

as New York, Boston, Montreal,

and Charleston, South Carolina,

where it rang the bells of Saint Phillips Episcopal church.

(bells pealing)

‐ People went running into the street

in their night clothes,

and birds of all kinds

were screeching and flying about,

cattle were stampeding.

‐ [Narrator] With the Earth convulsing,

it was impossible to stand.

‐ They threw themselves on the ground

and started praying in fear.

And one couple grabbed all their children,

ran into the street.

The mother suddenly realizes

that they've left the infant behind.

And she says to her husband, "Go get the baby."

He starts back to the house

and the ground is shaking so badly,

he's thrown to the ground a dozen times

before he can finally get to the house,

crawl inside, reach the baby, and get back out.

(suspenseful music)

‐ [Narrator] George Crist, living 100 miles

north of New Madrid, wrote this account.

‐ [George] There was a great quaking

of the Earth this morning.

Tables and chairs turned over, knocked around.

All of us knocked out of bed.

The roar I thought would leave us dead.

(shattering)

All you could hear was screams from people and animals.

(screaming)

I don't know how we lived through it.

‐ [Narrator] There were no seismographs in 1811

to record the shock.

But based on eyewitness accounts

and destruction reports,

seismologists believe the quake

measured 8.0 on the Richter Scale,

10 times stronger than the 1906 earthquake in San Francisco.

(suspenseful music)

And the horror wasn't over.

Frightened residents next confronted inexplicable

large clouds of strange gas seeping from the Earth.

‐ There was a sulfurous smell,

which came up out of the bowels of the Earth.

‐ [Narrator] Escaping into the darkness,

many people reported seeing bizarre flashing lights.

‐ The lights are not unique.

There are other earthquakes where people

have said that they've seen them.

The explanation is that it has something to do

with the squeezing of the rocks.

They emit electrical signals.

They call that piezoelectric effect.

‐ [Narrator] After a night of terror, the sun came up,

but dawn brought no relief from the tremors.

‐ There were rumblings and shakes all through the night.

And then at 7:00 a. m., there was another shock,

at least as hard as the first and maybe worse.

And it kept going all through the day.

(rumbling)

‐ [Narrator] Many homes and barns

that endured the 2:00 a. m. shaker

now clattered to the ground

from this massive aftershock.

(clattering)

With daylight, people could see the earthquake destruction.

(ominous music)

(loud cracking)

‐ There were also these large fissures created.

Sometimes they were four and five feet across

and 10 miles long.

There are several accounts of buildings

being swallowed up into the fissures.

‐ [Narrator] Not only was the land in turmoil.

The Mississippi River and lakes in the region

were thrown from their banks.

‐ There were huge disruptions along the river valley.

The water of the Mississippi River

was sloshed around like a bath tub.

Banks caved in and took trees with them.

‐ Probably the most dramatic thing that happened

was a huge piece of land was thrust up,

and this piece of land crossed the river.

And so all this water comes down river,

and hits this impediment.

Well, it's like when you're in a bath tub

and you push the water away from you,

there's only one place it can come, back towards you.

And so, a 30‐foot high wall of water

goes rushing back upstream.

‐ [Narrator] Incredibly, the mighty Mississippi

flowed backwards.

(waves burbling)

Churning against uplifted land,

it retreated from its normal course,

charging back upstream toward Illinois.

(tense music)

At 11:00 a. m., there was yet another massive aftershock,

estimated to be close to 8 on the Richter scale,

(clattering)

the third huge seismic event in less than 12 hours.

(ominous music)

Two hunters near the town of Little Prairie

witnessed something shocking.

‐ They describe the waters of the lake

draining away in this earthquake.

This area was described as a prairie.

That part of the ground got lifted up in the aftershock,

such that the shallow lake just disappeared.

And they were there watching this go on.

‐ [Narrator] During these large aftershocks,

the Earth belched up immense quantities of sand and debris

from unusual gaping fissures in the ground.

Geologists call these strange geysers sand blows.

(bursting)

‐ So, we're talking about a lot of sand

being blown up through the face of the Earth,

sometimes a hundred feet high.

And of course, it's bringing up whatever is down there.

‐ [Narrator] These sand volcanoes

are the result of soil liquefaction.

As the shaking saturated Earth compacts,

pressure builds up, until a vent or fissure is forced open.

This brings the watery sand mixture blasting to the surface.

(noisy gushing)

‐ These things can be 15, 20‐feet deep.

You can still see evidence of these sand blows

throughout the Boot Hill region of Missouri

and down into the northeastern Arkansas.

‐ [Narrator] Massive flooding along the river

forced people to flee to higher ground.

‐ The town of Little Prairie,

which was actually hit harder

than New Madrid in the first day of earthquakes,

was flooded and the town evacuated.

‐ These people were scared to death.

They had just witnessed a calamitous event,

and they were moving across a landscape

that they knew very well, but it had been

so dramatically affected by the fissures

it would have been like a war zone.

‐ [Narrator] Amazingly, the largest shock was yet to come.

Their hell had only begun.

(ominous music)

‐ [Narrator] The cities of Memphis and St. Louis

lie in the heartland of America,

a place of bedrock values and fertile farmlands.

(mellow music)

There is little concern for an obscure earthquake fault

that cuts through the region.

A fault that has wreaked havoc in the past,

unsettling life, and transforming the landscape.

(tense music)

Early on the morning of December 16th, 1811,

an 8.0 earthquake erupting near the community

of New Madrid, Missouri shook the ground

for hundreds of miles in all directions.

(shattering)

Aftershocks continued to rumble

through the area over the next month.

Residents abandoned their splintered cabins

and set up makeshift shelters,

with temperatures hovering just below freezing.

Still, the shaking continued.

‐ The Earth stayed in motion for quite a long time,

as much as a month.

‐ [Narrator] After people calmed down,

they began to rebuild,

only to be terrorized again.

‐ Then on January 23rd, 1812,

there was another monstrous earthquake.

And it created very much the same type of hysteria

that resulted from the December 16th quake.

‐ [Narrator] These were shocking events,

but only precursors of what was to come.

(thuds)

Frightened residents believed

they were suffering the wrath of God.

‐ If all of a sudden, the hand of God

comes down and strikes right where you're at,

there's just a natural tendency to take that

as a sign that maybe you need to clean up your act.

And certainly, that happened in New Madrid.

The ground was in a constant state of unrest

with the aftershocks, they just have the sense

that it was moving almost constantly.

(somber music)

‐ [Narrator] Then on February 7th, 1812,

the New Madrid fault unleashed

its most violent earthquake to date,

8 plus on the Richter scale.

(rumbling)

‐ February 7th is what the locals called the hard shock,

which is kind of amazing, by all accounts,

the biggest earthquake of the sequence.

The fault crossed the Mississippi River

in three different places.

(ominous music)

‐ [Narrator] The region, which had been under

so much stress and strain, could handle no more.

(waves crashing)

This third earthquake generated a new round

of bizarre events, more sand blows,

foul vapors, and collapsing riverbanks.

(waves crashing)

Incredibly, 3,000 square miles of land

east of the Mississippi River subsided,

in some places, by 10 feet.

(somber music)

Enormous amounts of water from the Mississippi

poured into the depressed area,

and formed a massive lake in just a few hours.

(somber music)

These floodwaters covered a dense hardwood forest

and killed all of the trees except the Bald Cypress,

which thrive in water.

This body of water, called Reelfoot Lake,

still exists today.

Pictures taken just 70 years ago during a seasonal drought

show hundreds of stumps just below the surface.

The Bald Cypress left in these waters

tell the story of this instant lake.

‐ Well, Bald Cypress has a big root system called knees.

And they have a bulb that grows at the water level.

One of the interesting aspects of the subsidence

and why know that it was three feet of subsidence,

is that after the earthquake,

so with the next 10 to 20 years,

these trees grew a second bulbous area,

three feet above the previous one.

‐ [Narrator] Severe aftershocks continued

for several months.

By the time it was over, the region had endured

more than 2,000 quakes and aftershocks,

the most intense series of quakes

ever experienced in North America.

No one knows how many died

because the area was sparsely settled.

‐ From the eyewitness accounts,

I've been able to pinpoint about 100 deaths

in the New Madrid earthquake series.

I think it's quite possible that there could have been

a number more than that, say, maybe as many as 500,

because there had to have been many people

on the river who were just never accounted for

because so many boats were lost on the river.

‐ [Narrator] It would take some time

before things returned to normal in the region.

(thunder crackling)

‐ For at least a year afterwards,

many of the residents of New Madrid

lived in a tent city.

Other people left the area,

but soon they started drifting back,

as people are wont to do.

‐ [Narrator] After a century of relative quiet,

memories of these quakes faded,

and cities were built up again,

with little knowledge of the hazard in the Earth below.

Some, like Memphis, are dangerously close

to the faults that erupted in 1812.

(tense music)

‐ If we had a series of New Madrid quakes today,

comparable to what happened 200 years ago,

the effect on infrastructure,

like highways and bridges,

could be cataclysmic.

(tense music)

‐ [Narrator] The heartland of America

is sitting on a geological time bomb.

(clattering)

St. Louis, Missouri and Memphis, Tennessee

are located near the most active seismic zone

east of the Rocky Mountains.

This puts both cities in the cross hairs

of a devastating shaker.

Just 150 miles south of the city,

and 15 miles beneath the Earth's surface,

lies the New Madrid fault,

ready to deliver an eight‐point earthquake

that will topple buildings,

buckle highways, destroy bridges,

and create a mega disaster across the region.

The historical record tells the tale.

(electronic music)

‐ [Narrator] Nearly 200 years ago, people in this region

had first‐hand experience with not just one,

but a series of monster quakes.

The United States Geological Survey

has plotted worldwide earthquakes

from the last 50 years.

A great majority of them fall into a predictable pattern.

‐ Most earthquakes in the world occur along plate boundaries

where two tectonic plates are moving past one another.

And as they try to move, the rocks resist

until they break and you have earthquakes.

(upbeat techno music)

‐ [Narrator] But there is an active earthquake area

located in southeastern Missouri,

on the banks of the Mississippi,

the New Madrid seismic zone.

(ominous music)

4,000 earthquakes registered here over the last 20 years.

And no one knows exactly why.

‐ The theory of plate tectonics

provides an excellent explanation

as to why we have earthquakes

over most of the world,

but it doesn't explain why we have earthquakes

right in the middle of a plate.

It violates what the theory would suggest.

(ominous music)

‐ [Narrator] Though not part of a plate boundary.

there is some evidence that there may be

an ancient fault line under New Madrid,

now buried beneath 3,000 feet of Mississippi sediment.

‐ This entire part of the United States is under compression

from essentially the Mid‐Atlantic Ridge,

and the pressure of that pushing

all the way through this area.

We know for a fact that underneath this area

lies an ancient rift, a major fault system

that is 600 million years old.

These faults have been activated

various times through history

and have recently turned on.

(tense music)

‐ The problem today is that

what was hitherto an unpopulated part of America

is now very populated.

There are two cities that are most at risk.

One is Memphis to the south,

and one is St. Louis to the north.

‐ [Narrator] And between these cities today

lies a complex network of roads,

bridges, and communication links.

The geologic clock is ticking for New Madrid.

Crisscrossing faults could erupt in a massive quake

that would make the 1811 and 12 shakers

seem like a dress rehearsal.

Yet, questions still loom over the Midwest:

when will another earthquake erupt,

and will the residents be ready?

(tense techno music)

With three‐dimensional geologic mapping technology,

Roy van Arsdale has modeled this subterranean world,

hoping to find some answers.

‐ Well, we're compiling all kinds of information

that we can get in terms of deep information.

‐ [Narrator] Using sound waves, scientists determine

the composition of the rocks and subsoil,

a geological snapshot of the terrain

under the Mississippi sediments.

This second layer is five miles below the surface.

‐ We're looking at what's called the Precambrian surface

in these multi‐colored depiction.

And what you can also see is that

the Precambrian geology is broken by faults.

That's what these planes are that displaced that surface.

And there are earthquakes occurring

along these two particular faults.

These faults are oriented in such a way

that it looks like they are trending towards Memphis

and Shelby County, the star in the model,

so we expect that they probably do pass

beneath where we are right now.

‐ [Narrator] Next, they plot onto the geography

the locations of earthquakes in the region since 1995.

‐ There've been earthquakes occurring

over a long period of time,

but these are the earthquakes

that are well located.

With the earthquakes in this pseudo 3‐D projection,

they look like a shotgun blast

until you rotate the model,

that you see that the earthquakes

align themselves along the plane.

What you're looking at now is the Reelfoot fault

and the earthquakes are popping off along that fault plane.

‐ [Narrator] There it is.

(upbeat techno music)

Pretty small, just 149 miles long

compared to the San Andreas fault

that stretches more than 700 miles.

(upbeat techno music)

But it packs a devastating punch

because seismic waves travel easily through Midwest bedrock.

(upbeat techno music)

Seismic intensity maps of the 1811 event

show destructive shaking in each of these quakes,

stretching for more than 350 miles

from the epicenters on the New Madrid fault line.

‐ Clearly, the New Madrid earthquakes were big events,

and they were felt all the way to the Atlantic seaboard,

and they really rocked the whole mid‐continent.

That makes them big, potentially damaging events

and the kind of quakes that we really worry about.

‐ If conditions stay the same

as they've been for the past thousand years,

another series of earthquakes comparable to

the 1811 and 1812 series, is inevitable.

‐ [Narrator] That seems to be

the recurring theme among seismologists.

When it comes to these massive tremors,

it's not a matter of if, but when.

‐ We have to realize that the magnitude

of the biggest disasters that we can imagine

are really catastrophic in proportion.

And there's no way, really, for governments to prepare.

‐ [Narrator] And then, how to cope in the aftermath.

‐ There would be aftershocks

that would take place afterward,

that can be just as nerve‐wracking

as the main shock.

‐ [Lucy] It's the secondary failures, the compounding,

that takes us from disaster to catastrophe.

‐ The consequences could be devastating.