Don’t Forget About the Sixth Seal (Revelation 6:12)

Fault Lines US

A Look at the Tri-State’s Active Fault Line

Monday, March 14, 2011
Bob Hennelly

The Ramapo Fault is the longest fault in the Northeast that occasionally makes local headlines when minor tremors cause rock the Tri-State region. It begins in Pennsylvania, crosses the Delaware River and continues through Hunterdon, Somerset, Morris, Passaic and Bergen counties before crossing the Hudson River near Indian Point nuclear facility.

In the past, it has generated occasional activity that generated a 2.6 magnitude quake in New Jersey’s Peakpack/Gladstone area and 3.0 magnitude quake in Mendham.

But the New Jersey-New York region is relatively seismically stable according to Dr. Dave Robinson, Professor of Geography at Rutgers. Although it does have activity.

“There is occasional seismic activity in New Jersey,” said Robinson. “There have been a few quakes locally that have been felt and done a little bit of damage over the time since colonial settlement — some chimneys knocked down in Manhattan with a quake back in the 18th century, but nothing of a significant magnitude.”

Robinson said the Ramapo has on occasion registered a measurable quake but has not caused damage: “The Ramapo fault is associated with geological activities back 200 million years ago, but it’s still a little creaky now and again,” he said.

“More recently, in the 1970s and early 1980s, earthquake risk along the Ramapo Fault received attention because of its proximity to Indian Point,” according to the New Jersey Geological Survey website.

Historically, critics of the Indian Point Nuclear facility in Westchester County, New York, did cite its proximity to the Ramapo fault line as a significant risk.

In 1884, according to the New Jersey Geological Survey website, the  Ramapo Fault was blamed for a 5.5 quake that toppled chimneys in New York City and New Jersey that was felt from Maine to Virginia.

“Subsequent investigations have shown the 1884 Earthquake epicenter was actually located in Brooklyn, New York, at least 25 miles from the Ramapo Fault,” according to the New Jersey Geological Survey website.

History Says Expect The Sixth Seal In New York (Revelation 6:12)

History Says New York Is Earthquake Prone

Fault Lines In New York City

Fault Lines In New York City


If the past is any indication, New York can be hit by an earthquake, claims John Armbruster, a seismologist at Columbia University’s Lamont-Doherty Earth Observatory.

Based on historical precedent, Armbruster says the New York City metro area is susceptible to an earthquake of at least a magnitude of 5.0 once a century.

According to the New York Daily News, Lynn Skyes, lead author of a recent study by seismologists at the Lamont-Doherty Earth Observatory adds that a magnitude-6 quake hits the area about every 670 years, and magnitude-7 every 3,400 years.

A 5.2-magnitude quake shook New York City in 1737 and another of the same severity hit in 1884.

Tremors were felt from Maine to Virginia.

There are several fault lines in the metro area, including one along Manhattan’s 125th St. – which may have generated two small tremors in 1981 and may have been the source of the major 1737 earthquake, says Armbruster.

There’s another fault line on Dyckman St. and one in Dobbs Ferry in nearby Westchester County.

“The problem here comes from many subtle faults,” explained Skyes after the study was published.

He adds: “We now see there is earthquake activity on them. Each one is small, but when you add them up, they are probably more dangerous than we thought.”

“Considering population density and the condition of the region’s infrastructure and building stock, it is clear that even a moderate earthquake would have considerable consequences in terms of public safety and economic impact,” says the New York City Area Consortium for Earthquake Loss Mitigation on its website.

Armbruster says a 5.0-magnitude earthquake today likely would result in casualties and hundreds of millions of dollars in damage.

“I would expect some people to be killed,” he notes.

The scope and scale of damage would multiply exponentially with each additional tick on the Richter scale. (ANI)

A Closer Look At The Sixth Seal (Rev 6:12)

A Look at the Tri-State’s Active Fault Line

455544140_86d9192ae5_zMonday, March 14, 2011

The Ramapo Fault is the longest fault in the Northeast that occasionally makes local headlines when minor tremors cause rock the Tri-State region. It begins in Pennsylvania, crosses the Delaware River and continues through Hunterdon, Somerset, Morris, Passaic and Bergen counties before crossing the Hudson River near Indian Point nuclear facility.

In the past, it has generated occasional activity that generated a 2.6 magnitude quake in New Jersey’s Peakpack/Gladstone area and 3.0 magnitude quake in Mendham.

But the New Jersey-New York region is relatively seismically stable according to Dr. Dave Robinson, Professor of Geography at Rutgers. Although it does have activity.

“There is occasional seismic activity in New Jersey,” said Robinson. “There have been a few quakes locally that have been felt and done a little bit of damage over the time since colonial settlement — some chimneys knocked down in Manhattan with a quake back in the 18th century, but nothing of a significant magnitude.”

Robinson said the Ramapo has on occasion registered a measurable quake but has not caused damage: “The Ramapo fault is associated with geological activities back 200 million years ago, but it’s still a little creaky now and again,” he said.

“More recently, in the 1970s and early 1980s, earthquake risk along the Ramapo Fault received attention because of its proximity to Indian Point,” according to the New Jersey Geological Survey website.

Historically, critics of the Indian Point Nuclear facility in Westchester County, New York, did cite its proximity to the Ramapo fault line as a significant risk.

In 1884, according to the New Jersey Geological Survey website, the  Rampao Fault was blamed for a 5.5 quake that toppled chimneys in New York City and New Jersey that was felt from Maine to Virginia.

“Subsequent investigations have shown the 1884 Earthquake epicenter was actually located in Brooklyn, New York, at least 25 miles from the Ramapo Fault,” according to the New Jersey Geological Survey website.

The Sixth Seal Long Overdue (Revelation 6:12)

ON THE MAP; Exploring the Fault Where the Next Big One May Be Waiting

The Big One Awaits

The Big One Awaits

By MARGO NASH
Published: March 25, 2001

Alexander Gates, a geology professor at Rutgers-Newark, is co-author of ”The Encyclopedia of Earthquakes and Volcanoes,” which will be published by Facts on File in July. He has been leading a four-year effort to remap an area known as the Sloatsburg Quadrangle, a 5-by-7-mile tract near Mahwah that crosses into New York State. The Ramapo Fault, which runs through it, was responsible for a big earthquake in 1884, and Dr. Gates warns that a recurrence is overdue. He recently talked about his findings.

Q. What have you found?

A. We’re basically looking at a lot more rock, and we’re looking at the fracturing and jointing in the bedrock and putting it on the maps. Any break in the rock is a fracture. If it has movement, then it’s a fault. There are a lot of faults that are offshoots of the Ramapo. Basically when there are faults, it means you had an earthquake that made it. So there was a lot of earthquake activity to produce these features. We are basically not in a period of earthquake activity along the Ramapo Fault now, but we can see that about six or seven times in history, about 250 million years ago, it had major earthquake activity. And because it’s such a fundamental zone of weakness, anytime anything happens, the Ramapo Fault goes.

Q. Where is the Ramapo Fault?

 A. The fault line is in western New Jersey and goes through a good chunk of the state, all the way down to Flemington. It goes right along where they put in the new 287. It continues northeast across the Hudson River right under the Indian Point power plant up into Westchester County. There are a lot of earthquakes rumbling around it every year, but not a big one for a while.

Q. Did you find anything that surprised you?

A. I found a lot of faults, splays that offshoot from the Ramapo that go 5 to 10 miles away from the fault. I have looked at the Ramapo Fault in other places too. I have seen splays 5 to 10 miles up into the Hudson Highlands. And you can see them right along the roadsides on 287. There’s been a lot of damage to those rocks, and obviously it was produced by fault activities. All of these faults have earthquake potential.

Q. Describe the 1884 earthquake.

A. It was in the northern part of the state near the Sloatsburg area. They didn’t have precise ways of describing the location then. There was lots of damage. Chimneys toppled over. But in 1884, it was a farming community, and there were not many people to be injured. Nobody appears to have written an account of the numbers who were injured.

Q. What lessons we can learn from previous earthquakes?

A. In 1960, the city of Agadir in Morocco had a 6.2 earthquake that killed 12,000 people, a third of the population, and injured a third more. I think it was because the city was unprepared.There had been an earthquake in the area 200 years before. But people discounted the possibility of a recurrence. Here in New Jersey, we should not make the same mistake. We should not forget that we had a 5.4 earthquake 117 years ago. The recurrence interval for an earthquake of that magnitude is every 50 years, and we are overdue. The Agadir was a 6.2, and a 5.4 to a 6.2 isn’t that big a jump.

Q. What are the dangers of a quake that size?

A. When you’re in a flat area in a wooden house it’s obviously not as dangerous, although it could cut off a gas line that could explode. There’s a real problem with infrastructure that is crumbling, like the bridges with crumbling cement. There’s a real danger we could wind up with our water supplies and electricity cut off if a sizable earthquake goes off. The best thing is to have regular upkeep and keep up new building codes. The new buildings will be O.K. But there is a sense of complacency.

MARGO NASH

Photo: Alexander Gates, a Rutgers geologist, is mapping a part of the Ramapo Fault, site of previous earthquakes. (John W. Wheeler for The New York Times)

The Sixth Seal: Real Risk, Few Precautions (Revelation 6:12)

Eastern Quakes: Real Risk, Few Precautions

1989 San Francisco Earthquake

1989 San Francisco Earthquake

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.”

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.”

The 6th Seal Awaits, New York Quake (Revelation 6:12)

East Coast vs. West Coast Earthquakes: Same Disaster, Different Creatures
The sixth seal is the New York Earthquake.

First Posted: 08/23/11 10:26 PM ET Updated: 10/24/11 06:12 AM ET

WASHINGTON (Associated Press)– The East Coast doesn’t get earthquakes often but when they do strike, there’s a whole lot more shaking going on. The ground in the East is older, colder and more intact than the West Coast or the famous Pacific Ring of Fire. So East Coast quakes rattle an area up to 10 times larger than a similar-sized West Coast temblor.

“They tend to be more bang for the buck as far as shaking goes,” said Virginia Tech geology professor James Spotila.

Tuesday’s 5.8-magnitude quake was centered in Virginia and was felt up and down the Eastern seaboard for more than 1,000 miles. There hasn’t been a quake that large on the East Coast since 1944 in New York.

While this was a rarity for the East, a 5.8 quake isn’t unusual for California, Oregon, Washington and Alaska, where one occurs about once a year. Those states have had 103 quakes 5.8 or bigger since 1900, compared to now two in the East.

The tiny island of Trinidad is more quake-prone than the East Coast, said U.S. Geological Survey seismologist Paul Earle.

“In all the years I was at FEMA, there didn’t seem to be a concern for earthquakes on the East Coast,” former Federal Emergency Management Agency chief James Lee Witt said.

Because of geology, earthquakes on the coasts have different triggers and act differently in some ways. And they definitely are felt differently.

One glaring East versus West disparity: When a quake happens in California, geologists usually know what fault ruptured. Tuesday’s quake happened on an unknown fault, and it is likely to remain a mystery.

Because the quake didn’t break the surface “we may never actually map this fault from this earthquake,” Earle said.

The only thing that will help scientists figure out where the break truly occurred are the aftershocks which could help highlight or outline the fault line, said Cornell University seismologist Rowena Lohman.

Most of the times, quakes occur when Earth’s floating giant plates shift, rub against or slip past each other. That’s what happens along California’s San Andreas fault when quakes happen there.

Tuesday’s thrust earthquake was far from the edge of a plate – the nearest are thousands of miles away in the mid-Atlantic or California, said seismologist David Applegate, associate director of natural hazards for the USGS in Reston, Va.

The stresses that cause these kinds of quakes come from far away and mount ever so slowly over time, even building up from the retreat of glaciers at the end of the Ice Age, he said.

Another East versus West contrast: The ground is different in the East in a way that makes the shaking travel much further, allowing people to feel the quake several states and hundreds of miles away.

The rocks in the Earth’s crust in the East are colder, older and harder, which means seismic waves travel more efficiently and over greater distances. Rocks on the West Coast are relatively young and broken up by faults.

“An intact bell rings more loudly than a cracked bell and that’s essentially what the crust is on the East Coast,” USGS seismologist Lucy Jones told a news conference in Pasadena, Calif.

In the East, hurricanes are the worry far more than quakes. Former FEMA chief Witt said people on the West Coast know what to do in an earthquake: drop to the floor, cover their heads and hold on to something sturdy until the shaking stops.

That’s what USGS’s Applegate did in Virginia.

“It’s seared in our heads,” said USGS seismologist Susan Hough in Pasadena. “People back East don’t get that kind of preparedness message.”

Alicia Chang contributed from Los Angeles

The Sixth Seal (NYC Quake) WILL Occur (Rev 6:12)

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Earthquakes in the New York – Philadelphia – Wilmington Urban Corridor

Since colonial times people in the New York – Philadelphia – Wilmington urban corridor have felt small earthquakes and suffered damage from infrequent larger ones. New York City was damaged in 1737 and 1884. Moderately damaging earthquakes strike somewhere in the urban corridor roughly twice a century, and smaller earthquakes are felt roughly every 2-3 years.

Earthquakes in the central and eastern U.S., although less frequent than in the western U.S., are typically felt over a much broader region. East of the Rockies, an earthquake can be felt over an area as much as ten times larger than a similar magnitude earthquake on the west coast. A magnitude 4.0 eastern U.S. earthquake typically can be felt at many places as far as 100 km (60 mi) from where it occurred, and it infrequently causes damage near its source. A magnitude 5.5 eastern U.S. earthquake usually can be felt as far as 500 km (300 mi) from where it occurred, and sometimes causes damage as far away as 40 km (25 mi).

Faults

Earthquakes everywhere occur on faults within bedrock, usually miles deep. Most bedrock beneath the urban corridor was assembled as continents collided to form a supercontinent about 500-300 million years ago, raising the Appalachian Mountains. Most of the rest of the bedrock formed when the supercontinent rifted apart about 200 million years ago to form what are now the northeastern U.S., the Atlantic Ocean, and Europe.

At well-studied plate boundaries like the San Andreas fault system in California, often scientists can determine the name of the specific fault that is responsible for an earthquake. In contrast, east of the Rocky Mountains this is rarely the case. New York City, Philadelphia, and Wilmington are far from the nearest plate boundaries, which are in the center of the Atlantic Ocean and in the Caribbean Sea. The urban corridor is laced with known faults but numerous smaller or deeply buried faults remain undetected. Even the known faults are poorly located at earthquake depths. Accordingly, few, if any, earthquakes in the urban corridor can be linked to named faults. It is difficult to determine if a known fault is still active and could slip and cause an earthquake. As in most other areas east of the Rockies, the best guide to earthquake hazards in the New York – Philadelphia – Wilmington urban corridor is the earthquakes themselves.

Authorities Expecting The Sixth Seal? (Rev 6:12)

US Raises Threat of Quake but Lowers Risk for Towers

New York Times

Earthquake!

Earthquake!

By SAM ROBERTS

JULY 17, 2014
Here is another reason to buy a mega-million-dollar apartment in a Manhattan high-rise: Earthquake forecast maps for New York City that a federal agency issued on Thursday indicate “a slightly lower hazard for tall buildings than previously thought.”

The agency, the United States Geodetic Survey, tempered its latest quake prediction with a big caveat.

“The eastern U.S. has the potential for larger and more damaging earthquakes than considered in previous maps and assessments,” the agency said, citing the magnitude 5.8 quake that struck Virginia in 2011.

Federal seismologists based their projections of a lower hazard for tall buildings — “but still a hazard nonetheless,” they cautioned — on a lower likelihood of slow shaking from an earthquake occurring near the city, the type of shaking that typically causes more damage to taller structures.

“The tall buildings in Manhattan are not where you should be focusing,” said John Armbruster, a seismologist with the Lamont-Doherty Earth Observatory of Columbia University. “They resonate with long period waves. They are designed and engineered to ride out an earthquake. Where you should really be worried in New York City is the common brownstone and apartment building and buildings that are poorly maintained.”

Mr. Armbruster was not involved in the federal forecast, but was an author of an earlier study that suggested that “a pattern of subtle but active faults makes the risk of earthquakes to the New York City area substantially greater than formerly believed.”

He noted that barely a day goes by without a New York City building’s being declared unsafe, without an earthquake. “If you had 30, 40, 50 at one time, responders would be overloaded,” he said.

The city does have an earthquake building code that went into effect in 1996, and that applies primarily to new construction.

A well-maintained building would probably survive a magnitude 5 earthquake fairly well, he said. The last magnitude 5 earthquake in the city struck in 1884. Another is not necessarily inevitable; faults are more random and move more slowly than they do in, say, California. But he said the latest federal estimate was probably raised because of the magnitude of the Virginia quake.

“Could there be a magnitude 6 in New York?” Mr. Armbruster said. “In Virginia, in a 300 year history, 4.8 was the biggest, and then you have a 5.8. So in New York, I wouldn’t say a 6 is impossible.”

Mr. Armbruster said the Geodetic Survey forecast would not affect his daily lifestyle. “I live in a wood-frame building with a brick chimney and I’m not alarmed sitting up at night worried about it,” he said. “But society’s leaders need to take some responsibility.”

The Ramapo Fault and the Sixth Seal (Revelation 6:12)

Living on the Fault LineRamapo_Fault_Line

A major earthquake isn’t likely here, but if it comes, watch out.

Posted June 15, 2010 by Wayne J. Guglielmo

This chart shows the location of the Ramapo Fault System, the longest and one of the oldest systems of cracks in the earth’s crust in the Northeast. It also shows the location of all earthquakes of magnitude 2.5 or greater in New Jersey during the last 50 years. The circle in blue indicates the largest known Jersey quake.

The couple checked with Burns’s parents, who live in nearby Basking Ridge, and they, too, had heard and felt something, which they thought might have been an earthquake. A call by Burns some 20 minutes later to the Bernardsville Police Department—one of many curious and occasionally panicky inquiries that Sunday morning, according to the officer in charge, Sergeant John Remian—confirmed their suspicion: A magnitude 2.6 earthquake, its epicenter in Peapack/Gladstone, about seven miles from Bernardsville, had hit the area. A smaller aftershock followed about two and a half hours later.

After this year’s epic earthquakes in Haiti, Chile, Mexico, Indonesia, and China, the 2.6 quake and aftershock that shook parts of New Jersey in February may seem minor league, even to the Somerset County residents who experienced them. On the exponential Richter Scale, a magnitude 7.0 quake like the one that hit Haiti in January is almost 4 million times stronger than a quake of 2.6 magnitude. But comparisons of magnitude don’t tell the whole story.

Northern New Jersey straddles the Ramapo Fault, a significant ancient crack in the earth’s crust. The longest fault in the Northeast, it begins in Pennsylvania and moves into New Jersey, trending northeast through Hunterdon, Somerset, Morris, Passaic, and Bergen counties before terminating in New York’s Westchester County, not far from the Indian Point Energy Center, a nuclear power plant. And though scientists dispute how active this roughly 200 million-year-old fault really is, many earthquakes in the state’s surprisingly varied seismic history are believed to have occurred on or near it. The fault line is visible at ground level and likely extends as deep as nine miles below the surface.

During the past 230 years or so, New Jersey has been at the epicenter of nearly 170 earthquakes, according to data compiled by the New Jersey Geological Survey, part of the United States Department of Environmental Protection. The largest known quake struck in 1783, somewhere west of New York City, perhaps in Sussex County. It’s typically listed as 5.3 in magnitude, though that’s an estimate by seismologists who are quick to point out that the concept of magnitude—measuring the relative size of an earthquake—was not introduced until 1935 by Charles Richter and Beno Gutenberg. Still, for quakes prior to that, scientists are not just guessing.

“We can figure out the damage at the time by going back to old records and newspaper accounts,” says Won-Young Kim, a senior research scientist at Columbia University’s Lamont-Doherty Earth Observatory in Palisades, New York, directly across the New Jersey border. “Once the amount and extent of contemporary damage has been established,” Kim says, “we’re then able to gauge the pattern of ground shaking or intensity of the event—and from there extrapolate its probable magnitude.”

Other earthquakes of magnitude 5 or higher have been felt in New Jersey, although their epicenters laying near New York City. One—which took place in 1737 and was said to have been felt as far north as Boston and as far south as northern Delaware—was probably in the 5 to 5.5 range. In 1884, an earthquake of similar magnitude occurred off New York’s Rockaway Beach. This well-documented event pulled houses off their foundations and caused steeples to topple as far west as Rahway. The shock wave, scientists believe, was felt over 70,000 square miles, from Vermont to Maryland.

Among the largest sub-5 magnitude earthquakes with epicenters in New Jersey, two (a 3.8 and a 4.0) took place on the same day in 1938 in the Lakehurst area in Ocean County. On August 26, 2003, a 3.5 magnitude quake shook the Frenchtown/Milford area in Hunterdon County. On February 3 of last year, a 3.0 magnitude quake occurred in the Morris County town of Mendham. “A lot of people felt this one because of the intense shaking, although the area of intensity wasn’t very wide,” says Lamont-Doherty’s Kim, who visited the site after the event.

After examining the known historical and geological record, Kim and other seismologists have found no clear evidence that an earthquake of greater than 5.3 to 5.5 magnitude has taken place in this area going back to 1737. This doesn’t mean, of course, that one did not take place in the more remote past or that one will not occur in the future; it simply means that a very large quake is less likely to occur here than in other places in the east where the seismic hazard is greater, including areas in South Carolina and northeastern New York State.

But no area on the East Coast is as densely populated or as heavily built-up as parts of New Jersey and its neighbors. For this reason, scientists refer to the Greater New York City-Philadelphia area, which includes New Jersey’s biggest cities, as one of “low earthquake hazard but high vulnerability.” Put simply, the Big One isn’t likely here—but if it comes, especially in certain locations, watch out.

Given this low-hazard, high-vulnerability scenario, how far along are scientists in their efforts to predict larger magnitude earthquakes in the New Jersey area? The answer is complex, complicated by the state’s geographical position, its unique geological history, the state of seismology itself, and the continuing debate over the exact nature and activity of the Ramapo Fault.

Over millions of years, New Jersey developed four distinct physiographic provinces or regions, which divide the state into a series of diagonal slices, each with its own terrain, rock type, and geological landforms.

The northernmost slice is the Valley and Ridge, comprising major portions of Sussex and Warren counties. The southernmost slice is the Coastal Plain, a huge expanse that covers some three-fifths of the state, including all of the Shore counties. Dividing the rest of the state are the Highlands, an area for the most part of solid but brittle rock right below the Valley and Ridge, and the lower lands of the Piedmont, which occupy all of Essex, Hudson, and Union counties, most of Bergen, Hunterdon, and Somerset, and parts of Middlesex, Morris, and Passaic.

For earthquake monitors and scientists, the formation of these last two provinces—the Highlands and the Piedmont—are of special interest. To understand why, consider that prior to the appearance of the Atlantic Ocean, today’s Africa was snuggled cozily up against North America and surrounded by a single enormous ocean. “At that point, you could have had exits off the New Jersey Turnpike for Morocco,” says Alexander Gates, professor of geology and chair of the department of Earth and Environmental Sciences at Rutgers-Newark.

Under the pressure of circulating material within the Earth’s super-hot middle layer, or mantle, what was once a single continent—one that is thought to have included today’s other continents as well—began to stretch and eventually break, producing numerous cracks or faults and ultimately separating to form what became the Atlantic Ocean. In our area, the longest and most active of these many cracks was the Ramapo Fault, which, through a process known as normal faulting, caused one side of the earth’s crust to slip lower—the Piedmont—relative to the other side—the Highlands. “All this occurred about 225 million years ago,” says Gates. “Back then, you were talking about thousands of feet between the Highlands and the Piedmont and a very active Ramapo Fault.”

The Earth’s crust, which is 20 to 25 miles thick, is not a single, solid shell, but is broken into seven vast tectonic plates, which drift atop the soft, underlying mantle. Although the northeast-trending Ramapo Fault neatly divides two of New Jersey’s four physiographic provinces, it does not form a so-called plate boundary, as does California’s infamous San Andreas Fault. As many Californians know all too well, this giant fault forms the boundary between two plates—to the west, the Pacific Plate, and to the east, the North American Plate; these rub up against each other, producing huge stresses and a regularly repeating pattern of larger earthquakes.

The Ramapo Fault sits on the North American Plate, which extends past the East Coast to the middle of the Atlantic, where it meets the Mid-Atlantic Ridge, an underwater mountain range in constant flux. The consequences of this intraplate setting are huge: First, as Gates points out, “The predictability of bigger earthquakes on…[such] settings is exceedingly poor, because they don’t occur very often.” Second, the intraplate setting makes it more difficult to link our earthquakes to a major cause or fault, as monitors in California can often do.

This second bit of uncertainty is especially troubling for some people, including some in the media who want a neat story. To get around it, they ignore the differences between plate settings and link all of New Jersey’s earthquakes, either directly or implicitly, to the Ramapo Fault. In effect, such people want the Ramapo Fault “to look like the San Andreas Fault,” says Gates. “They want to be able to point to one big fault that’s causing all of our earthquakes.”

Gates does not think that’s the case, and he has been working with colleagues for a number of years to prove it. “What we have found is that there are smaller faults that generally cut from east to west across the northeast-trending Ramapo Fault,” he explains. “These much smaller faults are all over the place, and they’re actually the ones that are the active faults in the area.”

But what mechanisms are responsible for the formation of these apparently active auxiliary faults? One such mechanism, say scientists, is the westward pressure the Atlantic Ocean exerts on the North American Plate, which for the most part resists any movement. “I think we are in an equilibrium state most of the time,” says Lamont-Doherty’s Kim.

Still, that continuous pressure on the plate we sit on causes stress, and when that stress builds up sufficiently, the earth’s crust has a tendency to break around any weak zones. In our area, the major weak zone is the Ramapo Fault—“an ancient zone of weakness,” as Kim calls it. That zone of weakness exacerbates the formation of auxiliary faults, and thereby the series of minor earthquakes the state has experienced over the years.

All this presupposes, of course, that any intraplate stress in this area will continue to be released gradually, in a series of relatively minor earthquakes or releases of energy. But what if that were not the case? What if the stress continued to build up, and the release of large amounts of energy came all at once? In crude terms, that’s part of the story behind the giant earthquakes that rocked what is now New Madrid, Missouri, between 1811 and 1812. Although estimates of their magnitude have been revised downward in recent years to less than magnitude 8, these earthquakes are generally regarded as among the largest intraplate events to have occurred in the continental United States.

For a number of reasons—including the relatively low odds that the kind of stored energy that unleashed the New Madrid events could ever build up here—earthquakes of plus-6 magnitude are probably not in our future. Still, says Kim, even a magnitude 6 earthquake in certain areas of the state could do considerable damage, especially if its intensity or ground shaking was of sufficient strength. In a state as geologically diverse and densely populated as New Jersey, this is a crucial wild card.

Part of the job of the experts at the New Jersey Geological Survey is to assess the seismic hazards in different parts of the state. To do this, they use a computer-simulation model developed under the direction of the Federal Emergency Management Agency, known as HAZUS, for Hazards US. To assess the amount of ground shaking likely to occur in a given county during events ranging in magnitude from 5 to 7 on the Richter Scale, NJGS scientists enter three features of a county’s surface geology into their computer model. Two of these features relate to the tendency of soil in a given area to lose strength, liquefy, or slide downhill when shaken. The third and most crucial feature has to do with the depth and density of the soil itself and the type of bedrock lying below it; this is a key component in determining a region’s susceptibility to ground shaking and, therefore, in estimating the amount of building and structural damage that’s likely to occur in that region. Estimates for the various counties—nine to date have been studied—are sent to the New Jersey Office of Emergency Management, which provided partial funding for the project.

To appreciate why this element of ground geology is so crucial to earthquake modelers, consider the following: An earthquake’s intensity—which is measured on something called the Modified Mercalli Scale—is related to a number of factors. The amount of energy released or the magnitude of an event is clearly a big factor. But two earthquakes of the same magnitude can have very different levels of intensity; in fact, it’s quite possible for a lower magnitude event to generate more ground shaking than a higher magnitude one.

In addition to magnitude, other factors that affect intensity are the distance of the observer or structure from the epicenter, where intensity is the greatest; the depth beneath the surface of the initial rupture, with shallower ruptures producing more ground shaking than deeper ones; and, most significantly, the ground geology or material that the shock wave generated by the earthquake must pass through.

As a rule, softer materials like sand and gravel shake much more intensely than harder materials, because the softer materials are comparatively inefficient energy conductors, so whatever energy is released by the quake tends to be trapped, dispersing much more slowly. (Think of a bowl of Jell-O on a table that’s shaking.)

In contrast, harder materials, like the solid rock found widely in the Highlands, are brittle and break under pressure, but conduct energy well, so that even big shock waves disperse much more rapidly through them, thereby weakening the amount of ground shaking. “If you’ve read any stories about the 1906 earthquake in San Francisco, you know the most intense damage was in those flat, low areas by the Bay, where the soil is soft, and not in the hilly, rocky areas above,” says Karl Muessig, state geologist and NJGS head.

The map that accompanies the online version of the NJGS’s Earthquake Loss Estimation Study divides the state’s surface geology into five seismic soil classes, ranging from Class A, or hard rock, to Class E, or soft soil (state.nj.us/dep/njgs/enviroed/hazus.htm).

Although the weakest soils are scattered throughout the state, including the Highlands, which besides harder rock also contains areas of glacial lakes, clays, and wetlands, they are most evident in the Piedmont and the Coastal Plain. “The largest expanses of them are in coastal areas where you have salt marshes or large glacial lakes, as in parts of the Passaic River basin,” says Scott Stanford, a research scientist with NJGS and lead author of the estimate. Some of the very weakest soils, Stanford adds, are in areas of filled marshland, including places along the Hudson waterfront, around Newark Bay and the Meadowlands, and along the Arthur Kill.

Faults in these areas—and in the coastal plain generally—are far below the ground, perhaps several hundred to a thousand feet down, making identification difficult. “There are numerous faults upon which you might get earthquake movement that we can’t see, because they’re covered by younger sediments,” Stanford says.

This combination of hidden faults and weak soils worries scientists, who are all too aware that parts of the coastal plain and Piedmont are among the most densely populated and developed areas in the state. (The HAZUS computer model also has a “built environment” component, which summarizes, among other things, types of buildings in a given area.) For this reason, such areas would be in the most jeopardy in the event of a large earthquake.

“Any vulnerable structure on these weak soils would have a higher failure hazard,” Stanford says. And the scary truth is that many structures in New Jersey’s largest cities, not to mention New York City, would be vulnerable, since they’re older and built before anyone gave much thought to earthquake-related engineering and construction codes.

For example, in the study’s loss estimate for Essex County, which includes Newark, the state’s largest city, a magnitude 6 event would result in damage to 81,600 buildings, including almost 10,000 extensively or completely; 36,000 people either displaced from their homes or forced to seek short-term shelter; almost $9 million in economic losses from property damage and business interruption; and close to 3,300 injuries and 50 fatalities. (The New York City Area Consortium for Earthquake Loss Mitigation has conducted a similar assessment for New York City, at nycem.org.)

All of this suggests the central irony of New Jersey geology: The upland areas that are most prone to earthquakes—the counties in or around the Ramapo Fault, which has spawned a network of splays, or auxiliary faults—are much less densely populated and sit, for the most part, on good bedrock. These areas are not invulnerable, certainly, but, by almost all measures, they would not sustain very severe damage, even in the event of a higher magnitude earthquake. The same can’t be said for other parts of the state, where the earthquake hazard is lower but the vulnerability far greater. Here, the best we can do is to prepare—both in terms of better building codes and a constantly improving emergency response.

Meanwhile, scientists like Rutgers’s Gates struggle to understand the Earth’s quirky seismic timetable: “The big thing with earthquakes is that you can commonly predict where they are going to occur,” Gates says. “When they’re going to come, well, we’re nowhere near being able to figure that out.”

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Planning for the Big One

For the men and women of the state police who manage and support the New Jersey Office of Emergency Management (OEM), the response to some events, like hurricanes, can be marshalled in advance. But an earthquake is what responders call a no-notice event.

In New Jersey, even minor earthquakes—like the one that shook parts of Somerset County in February—attract the notice of local, county, and OEM officials, who continuously monitor events around the state from their Regional Operations and Intelligence Center (The ROIC) in West Trenton, a multimillion dollar command-and-control facility that has been built to withstand 125 mph winds and a 5.5 magnitude earthquake. In the event of a very large earthquake, during which local and county resources are apt to become quickly overwhelmed, command and control authority would almost instantly pass to West Trenton.

Here, officials from the state police, representatives of a galaxy of other state agencies, and a variety of communications and other experts would assemble in the cavernous and ultra-high tech Emergency Operations Center to oversee the state’s response. “A high-level earthquake would definitely cause the governor to declare a state of emergency,” says OEM public information officer Nicholas J. Morici. “And once that takes place, our emergency operations plan would be put in motion.”

Emergency officials have modeled that plan—one that can be adapted to any no-notice event, including a terrorist attack—on response methodologies developed by the Federal Emergency Management Agency (FEMA), part of the U.S. Department of Homeland Security. At its core is a series of seventeen emergency support functions, ranging from transportation to firefighting, debris removal, search and rescue, public health, and medical services. A high-magnitude event would likely activate all of these functions, says Morici, along with the human and physical resources needed to carry them out—cranes and heavy trucks for debris removal, fire trucks and teams for firefighting, doctors and EMTs for medical services, buses and personnel carriers for transportation, and so on.

This is where an expert like Tom Rafferty comes in. Rafferty is a Geographic Information Systems Specialist attached to the OEM. His job during an emergency is to keep track electronically of which resources are where in the state, so they can be deployed quickly to where they are needed. “We have a massive database called the Resource Directory Database in which we have geolocated municipal, county, and state assets to a very detailed map of New Jersey,” Rafferty says. “That way, if there is an emergency like an earthquake going on in one area, the emergency managers can quickly say to me, for instance, ‘We have major debris and damage on this spot of the map. Show us the location of the nearest heavy hauler. Show us the next closest location,’ and so on.”

A very large quake, Rafferty says, “could overwhelm resources that we have as a state.” In that event, OEM has the authority to reach out to FEMA for additional resources and assistance. It can also call upon the private sector—the Resource Directory has been expanded to include non-government assets—and to a network of volunteers. “No one has ever said, ‘We don’t want to help,’” Rafferty says. New Jersey officials can also request assistance through the Emergency Management Assistance Compact (EMAC), an agreement among the states to help each other in times of extreme crisis.

“You always plan for the worst,” Rafferty says, “and that way when the worst doesn’t happen, you feel you can handle it if and when it does.”

Contributing editor Wayne J. Guglielmo lives in Mahwah, near the Ramapo Fault.

The Next Big ONE: The Sixth Seal Of New York City

ON THE MAP; Exploring the Fault Where the Next Big One May Be Waiting

Ramapo Fault Line

By MARGO NASH
Published: March 25, 2001

Alexander Gates, a geology professor at Rutgers-Newark, is co-author of ”The Encyclopedia of Earthquakes and Volcanoes,” which will be published by Facts on File in July. He has been leading a four-year effort to remap an area known as the Sloatsburg Quadrangle, a 5-by-7-mile tract near Mahwah that crosses into New York State. The Ramapo Fault, which runs through it, was responsible for a big earthquake in 1884, and Dr. Gates warns that a recurrence is overdue. He recently talked about his findings.

Q. What have you found?

A. We’re basically looking at a lot more rock, and we’re looking at the fracturing and jointing in the bedrock and putting it on the maps. Any break in the rock is a fracture. If it has movement, then it’s a fault. There are a lot of faults that are offshoots of the Ramapo. Basically when there are faults, it means you had an earthquake that made it. So there was a lot of earthquake activity to produce these features. We are basically not in a period of earthquake activity along the Ramapo Fault now, but we can see that about six or seven times in history, about 250 million years ago, it had major earthquake activity. And because it’s such a fundamental zone of weakness, anytime anything happens, the Ramapo Fault goes.

Q. Where is the Ramapo Fault?

A. The fault line is in western New Jersey and goes through a good chunk of the state, all the way down to Flemington. It goes right along where they put in the new 287. It continues northeast across the Hudson River right under the Indian Point power plant up into Westchester County. There are a lot of earthquakes rumbling around it every year, but not a big one for a while.

Q. Did you find anything that surprised you?

A. I found a lot of faults, splays that offshoot from the Ramapo that go 5 to 10 miles away from the fault. I have looked at the Ramapo Fault in other places too. I have seen splays 5 to 10 miles up into the Hudson Highlands. And you can see them right along the roadsides on 287. There’s been a lot of damage to those rocks, and obviously it was produced by fault activities. All of these faults have earthquake potential.

Q. Describe the 1884 earthquake.

A. It was in the northern part of the state near the Sloatsburg area. They didn’t have precise ways of describing the location then. There was lots of damage. Chimneys toppled over. But in 1884, it was a farming community, and there were not many people to be injured. Nobody appears to have written an account of the numbers who were injured.

Q. What lessons we can learn from previous earthquakes?

A. In 1960, the city of Agadir in Morocco had a 6.2 earthquake that killed 12,000 people, a third of the population, and injured a third more. I think it was because the city was unprepared.There had been an earthquake in the area 200 years before. But people discounted the possibility of a recurrence. Here in New Jersey, we should not make the same mistake. We should not forget that we had a 5.4 earthquake 117 years ago. The recurrence interval for an earthquake of that magnitude is every 50 years, and we are overdue. The Agadir was a 6.2, and a 5.4 to a 6.2 isn’t that big a jump.

Q. What are the dangers of a quake that size?

A. When you’re in a flat area in a wooden house it’s obviously not as dangerous, although it could cut off a gas line that could explode. There’s a real problem with infrastructure that is crumbling, like the bridges with crumbling cement. There’s a real danger we could wind up with our water supplies and electricity cut off if a sizable earthquake goes off. The best thing is to have regular upkeep and keep up new building codes. The new buildings will be O.K. But there is a sense of complacency.

MARGO NASH