New York Subways at the Sixth Seal (Revelation 6)

 

Ashley Fetters
New York City is full of peculiar phenomena—rickety fire escapes; 100-year-old subway tunnels; air conditioners propped perilously into window frames—that can strike fear into the heart of even the toughest city denizen. But should they? Every month, writer Ashley Fetters will be exploring—and debunking—these New York-specific fears, letting you know what you should actually worry about, and what anxieties you can simply let slip away.
The 25-minute subway commute from Crown Heights to the Financial District on the 2/3 line is, in my experience, a surprisingly peaceful start to the workday—save for one 3,100-foot stretch between the Clark Street and Wall Street stations, where for three minutes I sit wondering what the probability is that I will soon die a torturous, claustrophobic drowning death right here in this subway car.
The Clark Street Tunnel, opened in 1916, is one of approximately a dozen tunnels that escort MTA passengers from one borough to the next underwater—and just about all of them, with the exception of the 1989 addition of the 63rd Street F train tunnel, were constructed between 1900 and 1936.
Each day, thousands of New Yorkers venture across the East River and back again through these tubes buried deep in the riverbed, some of which are nearing or even past their 100th birthdays. Are they wrong to ponder their own mortality while picturing one of these watery catacombs suddenly springing a leak?
Mostly yes, they are, says Michael Horodniceanu, the former president of MTA Capital Construction and current principal of Urban Advisory Group. First, it’s important to remember that the subway tunnel is built under the riverbed, not just in the river—so what immediately surrounds the tunnel isn’t water but some 25 feet of soil. “There’s a lot of dirt on top of it,” Horodniceanu says. “It’s well into the bed of the bottom of the channel.”
And second, as Angus Kress Gillespie, author of Crossing Under the Hudson: The Story of the Holland and Lincoln Tunnels, points out, New York’s underwater subway tunnels are designed to withstand some leaking. And withstand it they do: Pumps placed below the floor of the tunnel, he says, are always running, always diverting water seepage into the sewers. (Horodniceanu says the amount of water these pumps divert into the sewer system each day numbers in the thousands of gallons.)
Additionally, MTA crews routinely repair the grouting and caulking, and often inject a substance into the walls that creates a waterproof membrane outside the tunnel—which keeps water out of the tunnel and relieves any water pressure acting on its walls. New tunnels, Horodniceanu points out, are even built with an outside waterproofing membrane that works like an umbrella: Water goes around it, it falls to the sides, and then it gets channeled into a pumping station and pumped out.
Of course, the classic New York nightmare scenario isn’t just a cute little trickle finding its way in. The anxiety daydream usually involves something sinister, or seismic. The good news, however, is that while an earthquake or explosion would indeed be bad for many reasons, it likely wouldn’t result in the frantic flooding horror scene that plays out in some commuters’ imaginations.
The Montague Tube, which sustained severe damage during Hurricane Sandy.
MTA New York City Transit / Marc A. Hermann
Horodniceanu assures me that tunnels built more recently are “built to withstand a seismic event.” The older tunnels, however—like, um, the Clark Street Tunnel—“were not seismically retrofitted, let me put it that way,” Horodniceanu says. “But the way they were built is in such a way that I do not believe an earthquake would affect them.” They aren’t deep enough in the ground, anyway, he says, to be too intensely affected by a seismic event. (The MTA did not respond to a request for comment.)
One of the only real threats to tunnel infrastructure, Horodniceanu adds, is extreme weather. Hurricane Sandy, for example, caused flooding in the tunnels, which “created problems with the infrastructure.” He continues, “The tunnels have to be rebuilt as a result of saltwater corroding the infrastructure.”
Still, he points out, hurricanes don’t exactly happen with no warning. So while Hurricane Sandy did cause major trauma to the tunnels, train traffic could be stopped with ample time to keep passengers out of harm’s way. In 2012, Governor Andrew Cuomo directed all the MTA’s mass transit services to shut down at 7 p.m. the night before Hurricane Sandy was expected to hit New York City.
And Gillespie, for his part, doubts even an explosion would result in sudden, dangerous flooding. A subway tunnel is not a closed system, he points out; it’s like a pipe that’s open at both ends. “The force of a blast would go forwards and backwards out the exit,” he says.
So the subway-train version of that terrifying Holland Tunnel flood scene in Sylvester Stallone’s Daylight is … unrealistic, right?
“Yeah,” Gillespie laughs. “Yeah. It is.”
Got a weird New York anxiety that you want explored? E-mail tips@curbed.com, and we may include it in a future column.

The Year of the Sixth Seal is 2026 (Revelation 6:12)

           Sloshing of Earth’s core may spike major earthquakes

By Paul VoosenOct. 30, 2017 , 1:45 PM
The number of major earthquakes, like the magnitude-7 one that devastated Haiti in 2010, seems to be correlated with minute fluctuations in day length.
SEATTLE—The world doesn’t stop spinning. But every so often, it slows down. For decades, scientists have charted tiny fluctuations in the length of Earth’s day: Gain a millisecond here, lose a millisecond there. Last week at the annual meeting of the Geological Society of America here, two geophysicists argued that these minute changes could be enough to influence the timing of major earthquakes—and potentially help forecast them.
During the past 100 years, Earth’s slowdowns have correlated surprisingly well with periods with a global increase in magnitude-7 and larger earthquakes, according to Roger Bilham of the University of Colorado (CU) in Boulder and Rebecca Bendick at the University of Montana in Missoula. Usefully, the spike, which adds two to five more quakes than typical, happens well after the slow-down begins. “The Earth offers us a 5-years heads up on future earthquakes, which is remarkable,” says Bilham, who presented the work.
Most seismologists agree that earthquake prediction is a minefield. And so far, Bilham and Bendick have only fuzzy, hard-to-test ideas about what might cause the pattern they found. But the finding is too provocative to ignore, other researchers say. “The correlation they’ve found is remarkable, and deserves investigation,” says Peter Molnar, a geologist also at CU.
The research started as a search for synchrony in earthquake timing. Individual oscillators, be they fireflies, heart muscles, or metronomes, can end up vibrating in synchrony as a result of some kind of cross-talk—or some common influence. To Bendick, it didn’t seem a far jump to consider the faults that cause earthquakes, with their cyclical buildup of strain and violent discharge, as “really noisy, really crummy oscillators,” she says. She and Bilham dove into the data, using the only complete earthquake catalog for the past 100 years: magnitude-7 and larger earthquakes.
In work published in August in Geophysical Research Letters they reported two patterns: First, major quakes appeared to cluster in time
—although not in space. And second, the number of large earthquakes seemed to peak at 32-year intervals. The earthquakes could be somehow talking to each other, or an external force could be nudging the earth into rupture.
Exploring such global forces, the researchers eventually discovered the match with the length of day. Although weather patterns such as El Nino can drive day length to vary back and forth by a millisecond over a year or more, a periodic, decades-long fluctuation of several milliseconds—in particular, its point of peak slow down about every three decades or so—lined up with the quake trend perfectly. "Of course that seems sort of crazy," Bendick says. But maybe it isn’t. When day length changes over decades, Earth’s magnetic field also develops a temporary ripple. Researchers think slight changes in the flow of the molten iron of the outer core may be responsible for both effects. Just what happens is uncertain—perhaps a bit of the molten outer core sticks to the mantle above. That might change the flow of the liquid metal, altering the magnetic field, and transfer enough momentum between the mantle and the core to affect day length.
Seismologists aren’t used to thinking about the planet’s core, buried 2900 kilometers beneath the crust where quakes happen. But they should, Bilham said during his talk here. The core is “quite close to us. It’s closer than New York from here,” he said.
At the equator, Earth spins 460 meters per second. Given this high velocity, it’s not absurd to think that a slight mismatch in speed between the solid crust and mantle and the liquid core could translate into a force somehow nudging quakes into synchrony, Molnar says. Of course, he adds, “It might be nonsense.” But the evidence for some kind of link is compelling, says geophysicist Michael Manga of the University of California, Berkeley. “I’ve worked on earthquakes triggered by seasonal variation, melting snow. His correlation is much better than what I’m used to seeing.”
One way or another, says James Dolan, a geologist at the University of Southern California in Los Angeles, “we’re going to know in 5 years.” That’s because Earth’s rotation began a periodic slow-down 4-plus years ago. Beginning next year, Earth should expect five more major earthquakes a year than average—between 17 to 20 quakes, compared with the anomalously low four so far this year. If the pattern holds, it will put a new spin on earthquake forecasting.
doi:10.1126/science.aar3598

The Next Major Quake: The Sixth Seal of NYC 3/3/26

         

New York is overdue an earthquake from faults under city

New York is OVERDUE an earthquake from a ‚brittle grid‘ of faults under the city, expert warns

• New York City last experienced a M5 or higher earthquake in 1884, experts say
• It’s thought that these earthquakes occur on a roughly 150-year periodicity 
• Based on this, some say the city could be overdue for the next major quake 

By Cheyenne Macdonald For Dailymail.com

Published: 15:50 EDT, 1 September 2017 | Updated: 12:00 EDT, 2 September 2017

When you think of the impending earthquake risk in the United States, it’s likely California or the Pacific Northwest comes to mind.

But, experts warn a system of faults making up a ‘brittle grid’ beneath New York City could also be loading up for a massive temblor.

The city has been hit by major quakes in the past, along what’s thought to be roughly 150-year intervals, and researchers investigating these faults now say the region could be overdue for the next event.

Experts warn a system of faults making up a ‘brittle grid’ beneath New York City could also be loading up for a massive temblor. The city has been hit by major quakes in the past, along what’s thought to be roughly 150-year intervals. A stock image is pictured

THE ‚CONEY ISLAND EARTHQUAKE‘

On August 10, 1884, New York was struck by a magnitude 5.5 earthquake with an epicentre located in Brooklyn.

While there was little damage and few injuries reported, anecdotal accounts of the event reveal the frightening effects of the quake.

One newspaper even reported that it caused someone to die from fright.

According to a New York Times report following the quake, massive buildings, including the Post Office swayed back and forth.

And, police said they felt the Brooklyn Bridge swaying ‘as if struck by a hurricane,’ according to an adaptation of Kathryn Miles’ book Quakeland: On the Road to America’s Next Devastating Earthquake.

The rumbles were felt across a 70,000-square-mile area, causing broken windows and cracked walls as far as Pennsylvania and Connecticut.

The city hasn’t experienced an earthquake this strong since.

According to geologist Dr Charles Merguerian, who has walked the entirety of Manhattan to assess its seismicity, there are a slew of faults running through New York, reports author Kathryn Miles in an adaptation of her new book Quakeland: On the Road to America’s Next Devastating Earthquake.

One such fault passes through 125th street, otherwise known as the Manhattanville Fault.

While there have been smaller quakes in New York’s recent past, including a magnitude 2.6 that struck in October 2001, it’s been decades since the last major tremor of M 5 or more.

And, most worryingly, the expert says there’s no way to predict exactly when a quake will strike.

‘That’s a question you really can’t answer,’ Merguerian has explained in the past.

‘All we can do is look at the record, and the record is that there was a relatively large earthquake here in the city in 1737, and in 1884, and that periodicity is about 150 year heat cycle.

‘So you have 1737, 1884, 20- and, we’re getting there. But statistics can lie.

‘An earthquake could happen any day, or it couldn’t happen for 100 years, and you just don’t know, there’s no way to predict.’

Compared the other parts of the United States, the risk of an earthquake in New York may not seem as pressing.

But, experts explain that a quake could happen anywhere.

According to geologist Dr Charles Merguerian, there are a slew of faults running through NY. One is the Ramapo Fault

‘All states have some potential for damaging earthquake shaking,’ according to the US Geological Survey.

‘Hazard is especially high along the west coast but also in the intermountain west, and in parts of the central and eastern US.’

A recent assessment by the USGS determined that the earthquake hazard along the East Coast may previously have been underestimated.

‘The eastern U.S. has the potential for larger and more damaging earthquakes than considered in previous maps and assessments,’ the USGS report explained.

The experts point to a recent example – the magnitude 5.8 earthquake that hit Virginia in 2011, which was among the largest to occur on the east coast in the last century.

This event suggests the area could be subjected to even larger earthquakes, even raising the risk for Charleston, SC.

It also indicates that New York City may be at higher risk than once thought.

A recent assessment by the USGS determined that the earthquake hazard along the East Coast may previously have been underestimated. The varying risks around the US can be seen above, with New York City in the mid-range (yellow).

Quakeland: On the Road to America’s Next Devastating Earthquake on 3/3/26: Revelation 6

               

Quakeland: On the Road to America’s Next Devastating Earthquake

Roger BilhamQuakeland: New York and the Sixth Seal (Revelation 6:12)

Given recent seismic activity — political as well as geological — it’s perhaps unsurprising that two books on earthquakes have arrived this season. One is as elegant as the score of a Beethoven symphony; the other resembles a diary of conversations overheard during a rock concert. Both are interesting, and both relate recent history to a shaky future.

Journalist Kathryn Miles’s Quakeland is a litany of bad things that happen when you provoke Earth to release its invisible but ubiquitous store of seismic-strain energy, either by removing fluids (oil, water, gas) or by adding them in copious quantities (when extracting shale gas in hydraulic fracturing, also known as fracking, or when injecting contaminated water or building reservoirs). To complete the picture, she describes at length the bad things that happen during unprovoked natural earthquakes. As its subtitle hints, the book takes the form of a road trip to visit seismic disasters both past and potential, and seismologists and earthquake engineers who have first-hand knowledge of them. Their colourful personalities, opinions and prejudices tell a story of scientific discovery and engineering remedy.

Miles poses some important societal questions. Aside from human intervention potentially triggering a really damaging earthquake, what is it actually like to live in neighbourhoods jolted daily by magnitude 1–3 earthquakes, or the occasional magnitude 5? Are these bumps in the night acceptable? And how can industries that perturb the highly stressed rocks beneath our feet deny obvious cause and effect? In 2015, the Oklahoma Geological Survey conceded that a quadrupling of the rate of magnitude-3 or more earthquakes in recent years, coinciding with a rise in fracking, was unlikely to represent a natural process. Miles does not take sides, but it’s difficult for the reader not to.

She visits New York City, marvelling at subway tunnels and unreinforced masonry almost certainly scheduled for destruction by the next moderate earthquake in the vicinity. She considers the perils of nuclear-waste storage in Nevada and Texas, and ponders the risks to Idaho miners of rock bursts — spontaneous fracture of the working face when the restraints of many million years of confinement are mined away. She contemplates the ups and downs of the Yellowstone Caldera — North America’s very own mid-continent supervolcano — and its magnificently uncertain future. Miles also touches on geothermal power plants in southern California’s Salton Sea and elsewhere; the vast US network of crumbling bridges, dams and oil-storage farms; and the magnitude 7–9 earthquakes that could hit California and the Cascadia coastline of Oregon and Washington state this century. Amid all this doom, a new elementary school on the coast near Westport, Washington, vulnerable to inbound tsunamis, is offered as a note of optimism. With foresight and much persuasion from its head teacher, it was engineered to become an elevated safe haven.

Miles briefly discusses earthquake prediction and the perils of getting it wrong (embarrassment in New Madrid, Missouri, where a quake was predicted but never materialized; prison in L’Aquila, Italy, where scientists failed to foresee a devastating seismic event) and the successes of early-warning systems, with which electronic alerts can be issued ahead of damaging seismic waves. Yes, it’s a lot to digest, but most of the book obeys the laws of physics, and it is a engaging read. One just can’t help wishing that Miles’s road trips had taken her somewhere that wasn’t a disaster waiting to happen.

Catastrophic damage in Anchorage, Alaska, in 1964, caused by the second-largest earthquake in the global instrumental record.

In The Great Quake, journalist Henry Fountain provides us with a forthright and timely reminder of the startling historical consequences of North America’s largest known earthquake, which more than half a century ago devastated southern Alaska. With its epicentre in Prince William Sound, the 1964 quake reached magnitude 9.2, the second largest in the global instrumental record. It released more energy than either the 2004 Sumatra–Andaman earthquake or the 2011 Tohoku earthquake off Japan; and it generated almost as many pages of scientific commentary and description as aftershocks. Yet it has been forgotten by many.

The quake was scientifically important because it occurred at a time when plate tectonics was in transition from hypothesis to theory. Fountain expertly traces the theory’s historical development, and how the Alaska earthquake was pivotal in nailing down one of the most important predictions. The earthquake caused a fjordland region larger than England to subside, and a similarly huge region of islands offshore to rise by many metres; but its scientific implications were not obvious at the time. Eminent seismologists thought that a vertical fault had slipped, drowning forests and coastlines to its north and raising beaches and islands to its south. But this kind of fault should have reached the surface, and extended deep into Earth’s mantle. There was no geological evidence of a monster surface fault separating these two regions, nor any evidence for excessively deep aftershocks. The landslides and liquefied soils that collapsed houses, and the tsunami that severely damaged ports and infrastructure, offered no clues to the cause.

“Previous earthquakes provide clear guidance about present-day vulnerability.” The hero of The Great Quake is the geologist George Plafker, who painstakingly mapped the height reached by barnacles lifted out of the intertidal zone along shorelines raised by the earthquake, and documented the depths of drowned forests. He deduced that the region of subsidence was the surface manifestation of previously compressed rocks springing apart, driving parts of Alaska up and southwards over the Pacific Plate. His finding confirmed a prediction of plate tectonics, that the leading edge of the Pacific Plate plunged beneath the southern edge of Alaska along a gently dipping thrust fault. That observation, once fully appreciated, was applauded by the geophysics community.

Fountain tells this story through the testimony of survivors, engineers and scientists, interweaving it with the fascinating history of Alaska, from early discovery by Europeans to purchase from Russia by the United States in 1867, and its recent development. Were the quake to occur now, it is not difficult to envisage that with increased infrastructure and larger populations, the death toll and price tag would be two orders of magnitude larger than the 139 fatalities and US$300-million economic cost recorded in 1964.

What is clear from these two books is that seismicity on the North American continent is guaranteed to deliver surprises, along with unprecedented economic and human losses. Previous earthquakes provide clear guidance about the present-day vulnerability of US infrastructure and populations. Engineers and seismologists know how to mitigate the effects of future earthquakes (and, in mid-continent, would advise against the reckless injection of waste fluids known to trigger earthquakes). It is merely a matter of persuading city planners and politicians that if they are tempted to ignore the certainty of the continent’s seismic past, they should err on the side of caution when considering its seismic future.

Here is the Sixth Seal Zone in NYC on 3/3/26 (Revelation 6:12)

         

Here are the hidden earthquake zones you don’t know about

April 13, 20204 Min Read

Let’s get able to (probably) rumble.

A report this week from the Los Angeles Instances took a have a look at what a devastating earthquake may do to Los Angeles — and the classes to be discovered from the calamitous 6.three magnitude quake in 2011 that every one however flattened Christchurch, New Zealand.

However whereas People are conscious of the San Andreas fault and the seismic exercise in California, which has wreaked havoc in San Francisco and Los Angeles, there are different, lesser-known fault traces in the United States that fly dangerously underneath the radar. These cracks in the crust have prompted appreciable harm in the previous — and scientists say will achieve this once more.

Virginia Seismic Zone

Richmond, VirginiaShutterstock

In 2011, New Yorkers had been jolted by a 5.eight magnitude earthquake that shook the East Coast from New Hampshire all the approach down by means of Chapel Hill, North Carolina. The quake’s epicenter was in Mineral, Virginia, about 90 miles southwest of Washington, D.C., and was so highly effective that Union Station, the Pentagon and the Capitol Constructing had been all evacuated.

The quake woke lots of people in the northeast as much as the Virginia Seismic Zone (VSZ) under the Mason Dixon — and the consequential results it may have on main cities alongside the East Coast. The final time the VSZ prompted a lot chaos was in 1867 when it launched an earthquake of 5.6-magnitude — the strongest in Virginia’s historical past.

Ramapo Fault Zone

Shutterstock

It’s not simply the Virginia Seismic Zone New Yorkers have to fret about. Nearer to house is the Ramapo Fault Zone, which stretches from New York by means of New Jersey to Pennsylvania and was most energetic tens of millions of years in the past throughout the formation of the Appalachian Mountains. It’s answerable for a number of of the fault traces that run by means of New York Metropolis, together with one underneath 125th Avenue. In line with a New York Publish report in 2017, “On common, the area has witnessed a reasonable quake (about a 5.zero on the Richter scale) each hundred years. The final one was in 1884. Seismologists say we will anticipate the subsequent one any day now.” Enjoyable occasions!

The New Madrid Seismic Zone

This 150 mile-long sequence of faults stretches underneath 5 states: Illinois, Missouri, Arkansas, Tennessee and Kentucky, and is answerable for 4 of the largest earthquakes in the historical past of the United States, which befell over three months from December 1811 and February 1812. The quakes had been so robust the mighty Mississippi River flowed backward for 3 days. Fortunately, the space was not as populated as it’s now, so the harm was restricted. Nonetheless, a FEMA report launched in 2008 warned {that a} quake now could be catastrophic and end in “the highest financial losses as a consequence of a pure catastrophe in the United States.”

The Northern Sangre de Cristo Fault

Downtown Trinidad, Colorado Shutterstock

In 2011, a magnitude 5.three quake hit Trinidad, Colorado, one other space that has seen little seismic exercise on such a big scale. In line with the Colorado Division of Homeland Safety and Emergency Administration, The Sangre de Cristo Fault, which lies at the base of the Sangre de Cristo Mountains alongside the japanese fringe of the San Luis Valley, and the Sawatch Fault, which runs alongside the japanese fringe of the Sawatch Vary, are “two of the most distinguished probably energetic faults in Colorado” and that “Seismologists predict that Colorado will once more expertise a magnitude 6.5 earthquake at some unknown level in the future.”

The Cascadia Subduction Zone

One in every of the most probably harmful fault traces lies north of California, stretching between Oregon and Washington. Main cities like Portland, Seattle and Vancouver lie alongside the Cascadia Subduction Zone, which scientists say has the functionality of a 9.zero or 10 magnitude earthquake — 16 occasions extra highly effective than the 1906 quake which ravaged San Francisco. A quake of this magnitude would have devastating penalties on infrastructure and will probably set off large tsunamis. The risk is so nice, the BBC even did a nifty video on the potential MegaQuake risk.

The Sixth Seal in NYC on March 3, 2026 (Revelation 6:12)

 

NEW YORK IS 40 YEARS OVERDUE A MAJOR EARTHQUAKE AND AMERICA ISN'T PROPERLY PREPARED, 'QUAKELAND' AUTHOR KATHRYN MILES TELLS TREVOR NOAH

BY TUFAYEL AHMED ON 9/27/17 AT 9:28 AM
Updated | An earthquake is long overdue to hit New York and America isn’t prepared, author and environmental theorist Kathryn Miles told Trevor Noah on Tuesday’s Daily Show.
Miles is the author of a new book, Quakeland, which investigates how imminently an earthquake is expected in the U.S. and how well-prepared the country is to handle it. The answer to those questions: Very soon and not very well.
“We know it will, that’s inevitable, but we don’t know when,” said Miles when asked when to expect another earthquake in the U.S.
She warned that New York is in serious danger of being the site of the next one, surprising considering that the West Coast sits along the San Andreas fault line.
“New York is 40 years overdue for a significant earthquake...Memphis, Seattle, Washington D.C.—it’s a national problem,” said Miles.
Miles told Noah that though the U.S. is “really good at responding to natural disasters,” like the rapid response to the hurricanes in Texas and Florida, the country and its government is, in fact, lagging behind in its ability to safeguard citizens before an earthquake hits.
“We’re really bad at the preparedness side,” Miles responded when Noah asked how the infrastructure in the U.S. compares to Mexico’s national warning system, for example.
“Whether it’s the literal infrastructure, like our roads and bridges, or the metaphoric infrastructure, like forecasting, prediction, early warning systems. Historically, we’ve underfunded those and as a result we’re way behind even developing nations on those fronts.”
Part of the problem, Miles says, is that President Donald Trump and his White House are not concerned with warning systems that could prevent the devastation of natural disasters.
“We can invest in an early warning system. That’s one thing we can definitely do. We can invest in better infrastructures, so that when the quake happens, the damage is less,” said the author.
“The scientists, the emergency managers, they have great plans in place. We have the technology for an early warning system, we have the technology for tsunami monitoring. But we don’t have a president that is currently interested in funding that, and that’s a problem.”
This article has been updated to reflect that Miles said New York is the possible site of an upcoming earthquake, and not the likeliest place to be next hit by one.

Real Risk, Few Precautions for the Sixth Seal in NYC (Revelation 6:12)

        By WILLIAM K. STEVENS

Published: October 24, 1989
AN EARTHQUAKE as powerful as the one that struck northern California last week could occur almost anywhere along the East Coast, experts say. And if it did, it would probably cause far more destruction than the West Coast quake.
The chances of such an occurrence are much less in the East than on the West Coast. Geologic stresses in the East build up only a hundredth to a thousandth as fast as in California, and this means that big Eastern quakes are far less frequent. Scientists do not really know what the interval between them might be, nor are the deeper-lying geologic faults that cause them as accessible to study. So seismologists are at a loss to predict when or where they will strike.
But they do know that a temblor with a magnitude estimated at 7 on the Richter scale – about the same magnitude as last week’s California quake – devastated Charleston, S.C., in 1886. And after more than a decade of study, they also know that geologic structures similar to those that caused the Charleston quake exist all along the Eastern Seaboard.
For this reason, ”we can’t preclude that a Charleston-sized earthquake might occur anywhere along the East Coast,” said David Russ, the assistant chief geologist of the United States Geological Survey in Reston, Va. ”It could occur in Washington. It could occur in New York.”
If that happens, many experts agree, the impact will probably be much greater than in California.Easterners, unlike Californians, have paid very little attention to making buildings and other structures earthquake-proof or earthquake-resistant. ”We don’t have that mentality here on the East Coast,” said Robert Silman, a New York structural engineer whose firm has worked on 3,800 buildings in the metropolitan area.
Moreover, buildings, highways, bridges, water and sewer systems and communications networks in the East are all older than in the West and consequently more vulnerable to damage. Even under normal conditions, for instance, water mains routinely rupture in New York City.
The result, said Dr. John Ebel, a geophysicist who is the assistant director of Boston College’s Weston Observatory, is that damage in the East would probably be more widespread, more people could be hurt and killed, depending on circumstances like time of day, and ”it would probably take a lot longer to get these cities back to useful operating levels.”
On top of this, scientists say, an earthquake in the East can shake an area 100 times larger than a quake of the same magnitude in California. This is because the earth’s crust is older, colder and more brittle in the East and tends to transmit seismic energy more efficiently. ”If you had a magnitude 7 earthquake and you put it halfway between New York City and Boston,” Dr. Ebel said, ”you would have the potential of doing damage in both places,” not to mention cities like Hartford and Providence.
Few studies have been done of Eastern cities’ vulnerability to earthquakes. But one, published last June in The Annals of the New York Academy of Sciences, calculated the effects on New York City of a magnitude 6 earthquake. That is one-tenth the magnitude of last week’s California quake, but about the same as the Whittier, Calif., quake two years ago.
The study found that such an earthquake centered 17 miles southeast of City Hall, off Rockaway Beach, would cause $11 billion in damage to buildings and start 130 fires. By comparison, preliminary estimates place the damage in last week’s California disaster at $4 billion to $10 billion. If the quake’s epicenter were 11 miles southeast of City Hall, the study found, there would be about $18 billion in damage; if 5 miles, about $25 billion.
No estimates on injuries or loss of life were made. But a magnitude 6 earthquake ”would probably be a disaster unparalleled in New York history,” wrote the authors of the study, Charles Scawthorn and Stephen K. Harris of EQE Engineering in San Francisco.
The study was financed by the National Center for Earthquake Engineering Research at the State University of New York at Buffalo. The research and education center, supported by the National Science Foundation and New York State, was established in 1986 to help reduce damage and loss of life from earthquakes.
The study’s postulated epicenter of 17 miles southeast of City Hall was the location of the strongest quake to strike New York since it has been settled, a magnitude 5 temblor on Aug. 10, 1884. That 1884 quake rattled bottles and crockery in Manhattan and frightened New Yorkers, but caused little damage. Seismologists say a quake of that order is likely to occur within 50 miles of New York City every 300 years. Quakes of magnitude 5 are not rare in the East. The major earthquake zone in the eastern half of the country is the central Mississippi Valley, where a huge underground rift causes frequent geologic dislocations and small temblors. The most powerful quake ever known to strike the United States occurred at New Madrid, Mo., in 1812. It was later estimated at magnitude 8.7 and was one of three quakes to strike that area in 1811-12, all of them stronger than magnitude 8. They were felt as far away as Washington, where they rattled chandeliers, Boston and Quebec.
Because the New Madrid rift is so active, it has been well studied, and scientists have been able to come up with predictions for the central Mississippi valley, which includes St. Louis and Memphis. According to Dr. Russ, there is a 40 to 63 percent chance that a quake of magnitude 6 will strike that area between now and the year 2000, and an 86 to 97 percent chance that it will do so by 2035. The Federal geologists say there is a 1 percent chance or less of a quake greater than magnitude 7 by 2000, and a 4 percent chance or less by 2035.
Elsewhere in the East, scientists are limited in their knowledge of probabilities partly because faults that could cause big earthquakes are buried deeper in the earth’s crust. In contrast to California, where the boundary between two major tectonic plates creates the San Andreas and related faults, the eastern United States lies in the middle of a major tectonic plate. Its faults are far less obvious, their activity far more subtle, and their slippage far slower. 
Any large earthquake would be ”vastly more serious” in the older cities of the East than in California,  said Dr. Tsu T. Soong, a professor of civil engineering at the State University of New York at Buffalo who is a researcher in earthquake-mitigation technology at the National Center for Earthquake Engineering Research. First, he said, many buildings are simply older, and therefore weaker and more  vulnerable to collapse. Second, there is no seismic construction code in most of the East as there is in California, where such codes have been in place for decades.
The vulnerability is evident in many ways. ”I’m sitting here looking out my window,” said Mr. Silman, the structural engineer in New York, ”and I see a bunch of water tanks all over the place” on rooftops. ”They are not anchored down at all, and it’s very possible they would fall in an earthquake.”
 Many brownstones, he said, constructed as they are of unreinforced masonry walls with wood joists between, ”would just go like a house of cards.” Unreinforced masonry, in fact, is the single most vulnerable structure, engineers say. Such buildings are abundant, even predominant, in many older cities. The Scawthorn-Harris study reviewed inventories of all buildings in Manhattan as of 1972 and found that 28,884, or more than half, were built of unreinforced masonry. Of those, 23,064 were three to five stories high.
Buildings of reinforced masonry, reinforced concrete and steel would hold up much better, engineers say, and wooden structures are considered intrinsically tough in ordinary circumstances. The best performers, they say, would probably be skyscrapers built in the last 20 years. As Mr. Silman explained, they have been built to withstand high winds, and the same structural features that enable them to do so also help them resist an earthquake’s force. But even these new towers have not been provided with the seismic protections required in California and so are more vulnerable than similar structures on the West Coast.
Buildings in New York are not generally constructed with such seismic protections as base-isolated structures, in which the building is allowed to shift with the ground movement; or with flexible frames that absorb and distribute energy through columns and beams so that floors can flex from side to side, or with reinforced frames that help resist distortion.
”If you’re trying to make a building ductile – able to absorb energy – we’re not geared to think that way,” said Mr. Silman.
New York buildings also contain a lot of decorative stonework, which can be dislodged and turned into lethal missiles by an earthquake. In California, building codes strictly regulate such architectural details.
Manhattan does, however, have at least one mitigating factor: ”We are blessed with this bedrock island,” said Mr. Silman. ”That should work to our benefit; we don’t have shifting soils. But there are plenty of places that are problem areas, particularly the shoreline areas,” where landfills make the ground soft and unstable.
As scientists have learned more about geologic faults in the Northeast, the nation’s uniform building code – the basic, minimum code followed throughout the country – has been revised accordingly. Until recently, the code required newly constructed buildings in New York City to withstand at least 19 percent of the side-to-side seismic force that a comparable building in the seismically active areas of California must handle. Now the threshold has been raised to 25 percent.
New York City, for the first time, is moving to adopt seismic standards as part of its own building code. Local and state building codes can and do go beyond the national code. Charles M. Smith Jr., the city Building Commissioner, last spring formed a committee of scientists, engineers, architects and government officials to recommend the changes.
”They all agree that New York City should anticipate an earthquake,” Mr. Smith said. As to how big an earthquake, ”I don’t think anybody would bet on a magnitude greater than 6.5,” he said. ”I don’t know,” he added, ”that our committee will go so far as to acknowledge” the damage levels in the Scawthorn-Harris study, characterizing it as ”not without controversy.”
For the most part, neither New York nor any other Eastern city has done a detailed survey of just how individual buildings and other structures would be affected, and how or whether to modify them.
”The thing I think is needed in the East is a program to investigate all the bridges” to see how they would stand up to various magnitudes of earthquake,” said Bill Geyer, the executive vice president of the New York engineering firm of Steinman, Boynton, Gronquist and Birdsall, which is rehabilitating the cable on the Williamsburg Bridge. ”No one has gone through and done any analysis of the existing bridges.”
In general, he said, the large suspension bridges, by their nature, ”are not susceptible to the magnitude of earthquake you’d expect in the East.” But the approaches and side spans of some of them might be, he said, and only a bridge-by-bridge analysis would tell. Nor, experts say, are some elevated highways in New York designed with the flexibility and ability to accommodate motion that would enable them to withstand a big temblor.
Tunnels Vulnerable
The underground tunnels that carry travelers under the rivers into Manhattan, those that contain the subways and those that carry water, sewers and natural gas would all be vulnerable to rupture, engineers say. The Lincoln, Holland, PATH and Amtrak tunnels, for instance, go from bedrock in Manhattan to soft soil under the Hudson River to bedrock again in New Jersey, said Mark Carter, a partner in Raamot Associates, geotechnical engineers specializing in soils and foundations.
Likewise, he said, subway tunnels between Manhattan and Queens go from hard rock to soft soil to hard rock on Roosevelt Island, to soft soil again and back to rock. The boundaries between soft soil and rock are points of weakness, he said.
”These structures are old,” he said, ”and as far as I know they have not been designed for earthquake loadings.”
Even if it is possible to survey all major buildings and facilities to determine what corrections can be made, cities like New York would then face a major decision: Is it worth spending the money to modify buildings and other structures to cope with a quake that might or might not come in 100, or 200 300 years or more?
”That is a classical problem” in risk-benefit analysis, said Dr. George Lee, the acting director of the Earthquake Engineering Research Center in Buffalo. As more is learned about Eastern earthquakes, he said, it should become ”possible to talk about decision-making.” But for now, he said, ”I think it’s premature for us to consider that question.”