Why We Are In Trouble At The Sixth Seal (Revelation 6:12)

  

Why NRC Nuclear Safety Inspections are Necessary: Indian Point

Dave Lochbaum

This is the second in a series of commentaries about the vital role nuclear safety inspections conducted by the Nuclear Regulatory Commission (NRC) play in protecting the public. The initial commentary described how NRC inspectors discovered that limits on the maximum allowable control room air temperature at the Columbia Generating Station in Washington had been improperly relaxed by the plant’s owner. This commentary describes a more recent finding by NRC inspectors about animproper safety assessment of a leaking cooling water system pipe on Entergy’s Unit 3 reactor at Indian Point outside New York City.

Indian Point Unit 3: Leak Before Break

On February 3, 2017, the NRC issued Indian Point a Green finding for a violation of Appendix B to 10 CFR Part 50. Specifically, the owner failed to perform an adequate operability review per its procedures after workers discovered water leaking from a service water system pipe.

On April 27, 2016, workers found water leaking from the pipe downstream of the strainer for service water (SW) pump 31. As shown in Figure 1, SW pump 31 is one of six service water pumps located within the intake structure alongside the Hudson River. The six SW pumps are arranged in two sets of three pumps. Figure 1 shows SW pumps 31, 32, and 33 aligned to provide water drawn from the Hudson River to essential (i.e, safety and emergency) components within Unit 3. SW pumps 34, 35, and 36 are aligned to provide cooling water to non-essential equipment within Unit 3.

Fig. 1 (Source: Nuclear Regulatory Commission Plant Information Book) (click to enlarge)

Each SW pump is designed to deliver 6,000 gallons of flow. During normal operation, one SW pump can handle the essential loads while two SW pumps are needed for the non-essential loads. Under accident conditions, two SW pumps are needed to cool the essential equipment. The onsite emergency diesel generators can power either of the sets of three pumps, but not both simultaneously. If the set of SW pumps aligned to the essential equipment aren’t getting the job done, workers can open/close valves and electrical breakers to reconfigure the second set of three SW pumps to the essential equipment loops.

Because river water can have stuff in it that could clog some of the coolers for essential equipment, each SW pump has a strainer that attempts to remove as much debris as possible from the water. The leak discovered on April 27, 2016, was in the piping between the discharge check valve for SW pump 31 and its strainer. An arrow points to this piping section in Figure 1. The strainers were installed in openings called pits in the thick concrete floor of the intake structure. Water from the leaking pipe flowed into the pit housing the strainer for SW pump 31.

The initial leak rate was modest—estimated to be about one-eighth of a gallon per minute. The leak was similar to other pinhole leaks that had occurred in the concrete-lined, carbon steel SW pipes. The owner began daily checks on the leakage and prepared an operability determination. Basically, “operability determinations” are used within the nuclear industry when safety equipment is found to be impaired or degraded. The operability determination for the service water pipe leak concluded that the impairment did not prevent the SW pumps from fulfilling their required safety function. The operability determination relied on a sump pump located at the bottom of the strainer pit transferring the leaking water out of the pit before the water flooded and submerged safety components.

The daily checks instituted by the owner included workers recording the leak rate and assessing whether it had significantly increased. But the checks were against the previous day’s leak rate rather than the initial leak rate. By September 18, 2016, the leakage had steadily increased by a factor of 64 to 8 gallons per minute. But the daily incremental increases were small enough that they kept workers from finding the overall increase to be significant.

The daily check on October 15, 2016, found the pump room flooded to a depth of several inches. The leak rate was now estimated to be 20 gallons per minute. And the floor drain in the strainer pit was clogged (ironic, huh?) impairing the ability of its sump pump to remove the water. Workers placed temporary sump pumps in the room to remove the flood water and cope with the insignificantly higher leak rate. On October 17, workers installed a clamp on the pipe that reduced the leakage to less than one gallon per minute.

The operability determination was revised in response to concerns expressed by the NRC inspectors. The NRC inspectors were not satisfied by the revised operability determination. It continued to rely on the strainer pit sump pump removing the leaking water. But that sump pump was not powered from the emergency diesel generator and thus would not remove water should offsite power become unavailable. Step 5.6.4 of procedure EN-OP-14, “Operability Determination Process,” stated “If the Operability is based on the use or availability of other equipment, it must be verified that the equipment is capable of performing the function utilized in the evaluation.”

The operability determination explicitly stated that no compensatory measures or operator manual actions were needed to handle the leak, but the situation clearly required both compensatory measures and operator manual actions.

The NRC inspectors found additional deficiencies in the revised operability determination. The NRC inspectors calculated that a 20 gallon per minute leak rate coupled with an unavailable strainer pit sump pump would flood the room to a depth of three feet in three hours. There are no flood alarms in the room and the daily checks might not detect flooding until the level rose to three feet. At that level, water would submerge and potentially disable the vacuum breakers for the SW pumps. Proper vacuum breaker operation could be needed to successfully restart the SW pumps.

The NRC inspectors calculated that the 20 gallon per minute leak rate without remediation would flood the room to the level of the control cabinets for the strainers in 10 hours. The submerged control cabinets could disable the strainers, leading to blocked cooling water flow to essential equipment.

The NRC inspects calculated that the 20 gallon per minute leak rate without remediation would completely fill the room in about 29 hours, or only slightly longer than the daily check interval.

Flooding to depths of 3 feet, 10 feet, and the room’s ceiling affected all six SW pumps. Thus, the flooding represented a common mode threat that could disable the entire service water system. In turn, all safety equipment shown in Figure 2 no longer cooled by the disabled service water system could also be disabled. The NRC estimated that the flooding risk was about 5×10-6 per reactor year, solidly in the Green finding band.

Fig. 2 (Source: Nuclear Regulatory Commission Plant Information Book) (click to enlarge)

UCS Perspective

“Leak before break” is a longstanding nuclear safety philosophy. Books have been written about it (well, at least one report has been written and may even have been read.)  The NRC’s approval of a leak before break analysis can allow the owner of an existing nuclear power reactor to remove pipe whip restraints and jet impingement barriers. Such hardware guarded against the sudden rupture of a pipe filled with high pressure fluid from damaging safety equipment in the area. The leak before break analyses can provide the NRC with sufficient confidence that piping degradation will be detected by observed leakage with remedial actions taken before the pipe fails catastrophically. More than a decade ago, the NRC issued a Knowledge Management document on the leak before break philosophy and acceptable methods of analyzing, monitoring, and responding to piping degradation.

This incident at Indian Point illustrated an equally longstanding nuclear safety practice of “leak before break.” In this case, the leak was indeed followed by a break. But the break was not the failure of the piping but failure of the owner to comply with federal safety regulations. Pipe breaks are bad. Regulation breaks are bad. Deciding which is worse is like trying to decide which eye one wants to be poked in. None is far better than either.

As with the prior Columbia Generating Station case study, this Indian Point case study illustrates the vital role that NRC’s enforcement efforts plays in nuclear safety. Even after NRC inspectors voiced clear concerns about the improperly evaluated service water system pipe leak, Entergy failed to properly evaluate the situation, thus violating federal safety regulations. To be fair to Entergy, the company was probably doing its best, but in recent years, Entergy’s best has been far below nuclear industry average performance levels.

The NRC’s ROP is the public’s best protection against hazards caused by aging nuclear power reactors, shrinking maintenance budgets, emerging sabotage threats, and Entergy.Replacing the NRC’s engineering inspections with self-assessments by Entergy would lessen the effectiveness of that protective shield.

The NRC must continue to protect the public to the best of its ability. Delegating safety checks to owners like Entergy is inconsistent with that important mission.

Support from UCS members make work like this possible. Will you join us? Help UCS advance independent science for a healthy environment and a safer world.he Hudson River. The six SW pumps are arranged in two sets of three pumps. Figure 1 shows SW pumps 31, 32, and 33 aligned to provide water drawn from the Hudson River to essential (i.e, safety and emergency) components within Unit 3. SW pumps 34, 35, and 36 are aligned to provide cooling water to non-essential equipment within Unit 3. Fig. 1 (Source: Nuclear Regulatory Commission Plant Information Book) (click to enlarge) Each SW pump is designed to deliver 6,000 gallons of flow. During normal operation, one SW pump can handle the essential loads while two SW pumps are needed for the non-essential loads. Under accident conditions, two SW pumps are needed to cool the essential equipment. The onsite emergency diesel generators can power either of the sets of three pumps, but not both simultaneously. If the set of SW pumps aligned to the essential equipment aren’t getting the job done, workers can open/close valves and electrical breakers to reconfigure the second set of three SW pumps to the essential equipment loops. Because river water can have stuff in it that could clog some of the coolers for essential equipment, each SW pump has a strainer that attempts to remove as much debris as possible from the water. The leak discovered on April 27, 2016, was in the piping between the discharge check valve for SW pump 31 and its strainer. An arrow points to this piping section in Figure 1. The strainers were installed in openings called pits in the thick concrete floor of the intake structure. Water from the leaking pipe flowed into the pit housing the strainer for SW pump 31. The initial leak rate was modest—estimated to be about one-eighth of a gallon per minute. The leak was similar to other pinhole leaks that had occurred in the concrete-lined, carbon steel SW pipes. The owner began daily checks on the leakage and prepared an operability determination. Basically, “operability determinations” are used within the nuclear industry when safety equipment is found to be impaired or degraded. The operability determination for the service water pipe leak concluded that the impairment did not prevent the SW pumps from fulfilling their required safety function. The operability determination relied on a sump pump located at the bottom of the strainer pit transferring the leaking water out of the pit before the water flooded and submerged safety components. The daily checks instituted by the owner included workers recording the leak rate and assessing whether it had significantly increased. But the checks were against the previous day’s leak rate rather than the initial leak rate. By September 18, 2016, the leakage had steadily increased by a factor of 64 to 8 gallons per minute. But the daily incremental increases were small enough that they kept workers from finding the overall increase to be significant. The daily check on October 15, 2016, found the pump room flooded to a depth of several inches. The leak rate was now estimated to be 20 gallons per minute. And the floor drain in the strainer pit was clogged (ironic, huh?) impairing the ability of its sump pump to remove the water. Workers placed temporary sump pumps in the room to remove the flood water and cope with the insignificantly higher leak rate. On October 17, workers installed a clamp on the pipe that reduced the leakage to less than one gallon per minute. The operability determination was revised in response to concerns expressed by the NRC inspectors. The NRC inspectors were not satisfied by the revised operability determination. It continued to rely on the strainer pit sump pump removing the leaking water. But that sump pump was not powered from the emergency diesel generator and thus would not remove water should offsite power become unavailable. Step 5.6.4 of procedure EN-OP-14, “Operability Determination Process,” stated “If the Operability is based on the use or availability of other equipment, it must be verified that the equipment is capable of performing the function utilized in the evaluation.” The operability determination explicitly stated that no compensatory measures or operator manual actions were needed to handle the leak, but the situation clearly required both compensatory measures and operator manual actions. The NRC inspectors found additional deficiencies in the revised operability determination. The NRC inspectors calculated that a 20 gallon per minute leak rate coupled with an unavailable strainer pit sump pump would flood the room to a depth of three feet in three hours. There are no flood alarms in the room and the daily checks might not detect flooding until the level rose to three feet. At that level, water would submerge and potentially disable the vacuum breakers for the SW pumps. Proper vacuum breaker operation could be needed to successfully restart the SW pumps. The NRC inspectors calculated that the 20 gallon per minute leak rate without remediation would flood the room to the level of the control cabinets for the strainers in 10 hours. The submerged control cabinets could disable the strainers, leading to blocked cooling water flow to essential equipment. The NRC inspects calculated that the 20 gallon per minute leak rate without remediation would completely fill the room in about 29 hours, or only slightly longer than the daily check interval. Flooding to depths of 3 feet, 10 feet, and the room’s ceiling affected all six SW pumps. Thus, the flooding represented a common mode threat that could disable the entire service water system. In turn, all safety equipment shown in Figure 2 no longer cooled by the disabled service water system could also be disabled. The NRC estimated that the flooding risk was about 5×10-6 per reactor year, solidly in the Green finding band. Fig. 2 (Source: Nuclear Regulatory Commission Plant Information Book) (click to enlarge) UCS Perspective “Leak before break” is a longstanding nuclear safety philosophy. Books have been written about it (well, at least one report has been written and may even have been read.) The NRC’s approval of a leak before break analysis can allow the owner of an existing nuclear power reactor to remove pipe whip restraints and jet impingement barriers. Such hardware guarded against the sudden rupture of a pipe filled with high pressure fluid from damaging safety equipment in the area. The leak before break analyses can provide the NRC with sufficient confidence that piping degradation will be detected by observed leakage with remedial actions taken before the pipe fails catastrophically. More than a decade ago, the NRC issued a Knowledge Management document on the leak before break philosophy and acceptable methods of analyzing, monitoring, and responding to piping degradation. This incident at Indian Point illustrated an equally longstanding nuclear safety practice of “leak before break.” In this case, the leak was indeed followed by a break. But the break was not the failure of the piping but failure of the owner to comply with federal safety regulations. Pipe breaks are bad. Regulation breaks are bad. Deciding which is worse is like trying to decide which eye one wants to be poked in. None is far better than either. As with the prior Columbia Generating Station case study, this Indian Point case study illustrates the vital role that NRC’s enforcement efforts plays in nuclear safety. Even after NRC inspectors voiced clear concerns about the improperly evaluated service water system pipe leak, Entergy failed to properly evaluate the situation, thus violating federal safety regulations. To be fair to Entergy, the company was probably doing its best, but in recent years, Entergy’s best has been far below nuclear industry average performance levels. The NRC’s ROP is the public’s best protection against hazards caused by aging nuclear power reactors, shrinking maintenance budgets, emerging sabotage threats, and Entergy.Replacing the NRC’s engineering inspections with self-assessments by Entergy would lessen the effectiveness of that protective shield. The NRC must continue to protect the public to the best of its ability. Delegating safety checks to owners like Entergy is inconsistent with that important mission. Support from UCS members make work like this possible. Will you join us? Help UCS advance independent science for a healthy environment and a safer world.

East Coast Quakes and the Sixth Seal: Revelation 6

                

Items lie on the floor of a grocery store after an earthquake on Sunday, August 9, 2020 in North Carolina.

East Coast Quakes: What to Know About the Tremors Below

By Meteorologist Dominic Ramunni Nationwide PUBLISHED 7:13 PM ET Aug. 11, 2020 PUBLISHED 7:13 PM EDT Aug. 11, 2020

People across the Carolinas and Mid-Atlantic were shaken, literally, on a Sunday morning as a magnitude 5.1 earthquake struck in North Carolina on August 9, 2020.

Centered in Sparta, NC, the tremor knocked groceries off shelves and left many wondering just when the next big one could strike.

Fault Lines

Compared to the West Coast, there are far fewer fault lines in the East. This is why earthquakes in the East are relatively uncommon and weaker in magnitude.

That said, earthquakes still occur in the East.

According to Spectrum News Meteorologist Matthew East, “Earthquakes have occurred in every eastern U.S. state, and a majority of states have recorded damaging earthquakes. However, they are pretty rare. For instance, the Sparta earthquake Sunday was the strongest in North Carolina in over 100 years.”

While nowhere near to the extent of the West Coast, damaging earthquakes can and do affect much of the eastern half of the country.

For example, across the Tennesse River Valley lies the New Madrid Fault Line. While much smaller in size than those found farther west, the fault has managed to produce several earthquakes over magnitude 7.0 in the last couple hundred years.

In 1886, an estimated magnitude 7.0 struck Charleston, South Carolina along a previously unknown seismic zone. Nearly the entire town had to be rebuilt.

Vulnerabilities

The eastern half of the U.S. has its own set of vulnerabilities from earthquakes.

Seismic waves actually travel farther in the East as opposed to the West Coast. This is because the rocks that make up the East are tens, if not hundreds, of millions of years older than in the West.

These older rocks have had much more time to bond together with other rocks under the tremendous pressure of Earth’s crust. This allows seismic energy to transfer between rocks more efficiently during an earthquake, causing the shaking to be felt much further.

This is why, during the latest quake in North Carolina, impacts were felt not just across the state, but reports of shaking came as far as Atlanta, Georgia, nearly 300 miles away.

Reports of shaking from different earthquakes of similar magnitude.

Quakes in the East can also be more damaging to infrastructure than in the West. This is generally due to the older buildings found east. Architects in the early-to-mid 1900s simply were not accounting for earthquakes in their designs for cities along the East Coast.

When a magnitude 5.8 earthquake struck Virginia in 2011, not only were numerous historical monuments in Washington, D.C. damaged, shaking was reported up and down the East Coast with tremors even reported in Canada.

Unpredictable

There is no way to accurately predict when or where an earthquake may strike.

Some quakes will have a smaller earthquake precede the primary one. This is called a foreshock.

The problem is though, it’s difficult to say whether the foreshock is in fact a foreshock and not the primary earthquake. Only time will tell the difference.

The United State Geological Survey (USGS) is experimenting with early warning detection systems in the West Coast.

While this system cannot predict earthquakes before they occur, they can provide warning up to tens of seconds in advance that shaking is imminent. This could provide just enough time to find a secure location before the tremors begin.

Much like hurricanes, tornadoes, or snowstorms, earthquakes are a natural occuring phenomenon that we can prepare for.

The USGS provides an abundance of resources on how to best stay safe when the earth starts to quake.

A Lack Of Vigilance Before The Sixth Seal (Revelation 6:12)

                Faults Underlying Exercise Vigilant Guard

Story by: (Author NameStaff Sgt. Raymond Drumsta – 138th Public Affairs Detachment
Dated: Thu, Nov 5, 2009
This map illustrates the earthquake fault lines in Western New York. An earthquake in the region is a likely event, says University of Buffalo Professor Dr. Robert Jacobi.
TONAWANDA, NY — An earthquake in western New York, the scenario that Exercise Vigilant Guard is built around, is not that far-fetched, according to University of Buffalo geology professor Dr. Robert Jacobi.
When asked about earthquakes in the area, Jacobi pulls out a computer-generated state map, cross-hatched with diagonal lines representing geological faults.
The faults show that past earthquakes in the state were not random, and could occur again on the same fault systems, he said.
“In western New York, 6.5 magnitude earthquakes are possible,” he said.
This possibility underlies Exercise Vigilant Guard, a joint training opportunity for National Guard and emergency response organizations to build relationships with local, state, regional and federal partners against a variety of different homeland security threats including natural disasters and potential terrorist attacks.
The exercise was based on an earthquake scenario, and a rubble pile at the Spaulding Fibre site here was used to simulate a collapsed building. The scenario was chosen as a result of extensive consultations with the earthquake experts at the University of Buffalo’s Multidisciplinary Center for Earthquake Engineering Research (MCEER), said Brig. Gen. Mike Swezey, commander of 53rd Troop Command, who visited the site on Monday.
Earthquakes of up to 7 magnitude have occurred in the Northeastern part of the continent, and this scenario was calibrated on the magnitude 5.9 earthquake which occurred in Saguenay, Quebec in 1988, said Jacobi and Professor Andre Filiatrault, MCEER director.
“A 5.9 magnitude earthquake in this area is not an unrealistic scenario,” said Filiatrault.
Closer to home, a 1.9 magnitude earthquake occurred about 2.5 miles from the Spaulding Fibre site within the last decade, Jacobi said. He and other earthquake experts impaneled by the Atomic Energy Control Board of Canada in 1997 found that there’s a 40 percent chance of 6.5 magnitude earthquake occurring along the Clareden-Linden fault system, which lies about halfway between Buffalo and Rochester, Jacobi added.
Jacobi and Filiatrault said the soft soil of western New York, especially in part of downtown Buffalo, would amplify tremors, causing more damage.
“It’s like jello in a bowl,” said Jacobi.
The area’s old infrastructure is vulnerable because it was built without reinforcing steel, said Filiatrault. Damage to industrial areas could release hazardous materials, he added.
“You’ll have significant damage,” Filiatrault said.
Exercise Vigilant Guard involved an earthquake’s aftermath, including infrastructure damage, injuries, deaths, displaced citizens and hazardous material incidents. All this week, more than 1,300 National Guard troops and hundreds of local and regional emergency response professionals have been training at several sites in western New York to respond these types of incidents.
Jacobi called Exercise Vigilant Guard “important and illuminating.”
“I’m proud of the National Guard for organizing and carrying out such an excellent exercise,” he said.
Training concluded Thursday.

The Next Major Quake: The Sixth Seal of NYC: Revelation 6

        

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).

Here is the Sixth Seal Zone (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.

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

The Sixth Seal Long Overdue (Revelation 6)

    

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

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

USGS Evidence Shows Power of the Sixth Seal (Revelation 6:12)

       

New Evidence Shows Power of East Coast Earthquakes
Virginia Earthquake Triggered Landslides at Great Distances

Released: 11/6/2012 8:30:00 AM USGS.gov

Earthquake shaking in the eastern United States can travel much farther and cause damage over larger areas than previously thought.

U.S. Geological Survey scientists found that last year’s magnitude 5.8 earthquake in Virginia triggered landslides at distances four times farther—and over an area 20 times larger—than previous research has shown.

“We used landslides as an example and direct physical evidence to see how far-reaching shaking from east coast earthquakes could be,” said Randall Jibson, USGS scientist and lead author of this study. “Not every earthquake will trigger landslides, but we can use landslide distributions to estimate characteristics of earthquake energy and how far regional ground shaking could occur.”

“Scientists are confirming with empirical data what more than 50 million people in the eastern U.S. experienced firsthand: this was one powerful earthquake,” said USGS Director Marcia McNutt. “Calibrating the distance over which landslides occur may also help us reach back into the geologic record to look for evidence of past history of major earthquakes from the Virginia seismic zone.”

This study will help inform earthquake hazard and risk assessments as well as emergency preparedness, whether for landslides or other earthquake effects.

This study also supports existing research showing that although earthquakes  are less frequent in the East, their damaging effects can extend over a much larger area as compared to the western United States.

The research is being presented today at the Geological Society of America conference, and will be published in the December 2012 issue of the Bulletin of the Seismological Society of America.

The USGS found that the farthest landslide from the 2011 Virginia earthquake was 245 km (150 miles) from the epicenter. This is by far the greatest landslide distance recorded from any other earthquake of similar magnitude. Previous studies of worldwide earthquakes indicated that landslides occurred no farther than 60 km (36 miles) from the epicenter of a magnitude 5.8 earthquake.

“What makes this new study so unique is that it provides direct observational evidence from the largest earthquake to occur in more than 100 years in the eastern U.S,” said Jibson. “Now that we know more about the power of East Coast earthquakes, equations that predict ground shaking might need to be revised.”

It is estimated that approximately one-third of the U.S. population could have felt last year’s earthquake in Virginia, more than any earthquake in U.S. history. About 148,000 people reported their ground-shaking experiences caused by the earthquake on the USGS “Did You Feel It?” website. Shaking reports came from southeastern Canada to Florida and as far west as Texas.

In addition to the great landslide distances recorded, the landslides from the 2011 Virginia earthquake occurred in an area 20 times larger than expected from studies of worldwide earthquakes. Scientists plotted the landslide locations that were farthest out and then calculated the area enclosed by those landslides. The observed landslides from last year’s Virginia earthquake enclose an area of about 33,400 km2, while previous studies indicated an expected area of about 1,500 km2from an earthquake of similar magnitude.

“The landslide distances from last year’s Virginia earthquake are remarkable compared to historical landslides across the world and represent the largest distance limit ever recorded,” said Edwin Harp, USGS scientist and co-author of this study. “There are limitations to our research, but the bottom line is that we now have a better understanding of the power of East Coast earthquakes and potential damage scenarios.”

The difference between seismic shaking in the East versus the West is due in part to the geologic structure and rock properties that allow seismic waves to travel farther without weakening.

Learn more about the 2011 central Virginia earthquake.

East Coast Still Unprepared For The Sixth Seal (Revelation 6:12)

 

East Coast Earthquake Preparedness
By By BEN NUCKOLS
Posted: 08/25/2011 8:43 am EDT
WASHINGTON — There were cracks in the Washington Monument and broken capstones at the National Cathedral. In the District of Columbia suburbs, some people stayed in shelters because of structural concerns at their apartment buildings.
A day after the East Coast’s strongest earthquake in 67 years, inspectors assessed the damage and found that most problems were minor. But the shaking raised questions about whether this part of the country, with its older architecture and inexperience with seismic activity, is prepared for a truly powerful quake.
The 5.8 magnitude quake felt from Georgia north to Canada prompted swift inspections of many structures Wednesday, including bridges and nuclear plants. An accurate damage estimate could take weeks, if not longer. And many people will not be covered by insurance.
In a small Virginia city near the epicenter, the entire downtown business district was closed. School was canceled for two weeks to give engineers time to check out cracks in several buildings.
At the 555-foot Washington Monument, inspectors found several cracks in the pyramidion – the section at the top of the obelisk where it begins narrowing to a point.
A 4-foot crack was discovered Tuesday during a visual inspection by helicopter. It cannot be seen from the ground. Late Wednesday, the National Park Service announced that structural engineers had found several additional cracks inside the top of the monument.
Carol Johnson, a park service spokeswoman, could not say how many cracks were found but said three or four of them were “significant.” Two structural engineering firms that specialize in assessing earthquake damage were being brought in to conduct a more thorough inspection on Thursday.
The monument, by far the tallest structure in the nation’s capital, was to remain closed indefinitely, and Johnson said the additional cracks mean repairs are likely to take longer. It has never been damaged by a natural disaster, including earthquakes in Virginia in 1897 and New York in 1944.
Tourists arrived at the monument Wednesday morning only to find out they couldn’t get near it. A temporary fence was erected in a wide circle about 120 feet from the flags that surround its base. Walkways were blocked by metal barriers manned by security guards.
“Is it really closed?” a man asked the clerk at the site’s bookstore.
“It’s really closed,” said the clerk, Erin Nolan. Advance tickets were available for purchase, but she cautioned against buying them because it’s not clear when the monument will open.
“This is pretty much all I’m going to be doing today,” Nolan said.
Tuesday’s quake was centered about 40 miles northwest of Richmond, 90 miles south of Washington and 3.7 miles underground. In the nearby town of Mineral, Va., Michael Leman knew his Main Street Plumbing & Electrical Supply business would need – at best – serious and expensive repairs.
At worst, it could be condemned. The facade had become detached from the rest of the building, and daylight was visible through a 4- to 6-inch gap that opened between the front wall and ceiling.
“We’re definitely going to open back up,” Leman said. “I’ve got people’s jobs to look out for.”
Leman said he is insured, but some property owners might not be so lucky.
The Insurance Information Institute said earthquakes are not covered under standard U.S. homeowners or business insurance policies, although supplemental coverage is usually available.
The institute says coverage for other damage that may result from earthquakes, such as fire and water damage from burst gas or water pipes, is provided by standard homeowners and business insurance policies in most states. Cars and other vehicles with comprehensive insurance would also be protected.
The U.S. Geological Survey classified the quake as Alert Level Orange, the second-most serious category on its four-level scale. Earthquakes in that range lead to estimated losses between $100 million and $1 billion.
In Culpeper, Va., about 35 miles from the epicenter, walls had buckled at the old sanctuary at St. Stephen’s Episcopal Church, which was constructed in 1821 and drew worshippers including Confederate Gens. Robert E. Lee and J.E.B. Stuart. Heavy stone ornaments atop a pillar at the gate were shaken to the ground. A chimney from the old Culpeper Baptist Church built in 1894 also tumbled down.
At the Washington National Cathedral, spokesman Richard Weinberg said the building’s overall structure remains sound and damage was limited to “decorative elements.”
Massive stones atop three of the four spires on the building’s central tower broke off, crashing onto the roof. At least one of the spires is teetering badly, and cracks have appeared in some flying buttresses.
Repairs were expected to cost millions of dollars – an expense not covered by insurance.
“Every single portion of the exterior is carved by hand, so everything broken off is a piece of art,” Weinberg said. “It’s not just the labor, but the artistry of replicating what was once there.”
The building will remain closed as a precaution. Services to dedicate the memorial honoring Rev. Martin Luther King Jr. were moved.
Other major cities along the East Coast that felt the shaking tried to gauge the risk from another quake.
A few hours after briefly evacuating New York City Hall, Mayor Michael Bloomberg said the city’s newer buildings could withstand a more serious earthquake. But, he added, questions remain about the older buildings that are common in a metropolis founded hundreds of years ago.
“We think that the design standards of today are sufficient against any eventuality,” he said. But “there are questions always about some very old buildings. … Fortunately those tend to be low buildings, so there’s not great danger.”
An earthquake similar to the one in Virginia could do billions of dollars of damage if it were centered in New York, said Barbara Nadel, an architect who specializes in securing buildings against natural disasters and terrorism.
The city’s 49-page seismic code requires builders to prepare for significant shifting of the earth. High-rises must be built with certain kinds of bracing, and they must be able to safely sway at least somewhat to accommodate for wind and even shaking from the ground, Nadel said.
Buildings constructed in Boston in recent decades had to follow stringent codes comparable to anything in California, said Vernon Woodworth, an architect and faculty member at the Boston Architectural College. New construction on older structures also must meet tough standards to withstand severe tremors, he said.
It’s a different story with the city’s older buildings. The 18th- and 19th-century structures in Boston’s Back Bay, for instance, were often built on fill, which can liquefy in a strong quake, Woodworth said. Still, there just aren’t many strong quakes in New England.
The last time the Boston area saw a quake as powerful as the one that hit Virginia on Tuesday was in 1755, off Cape Ann, to the north. A repeat of that quake would likely cause deaths, Woodworth said. Still, the quakes are so infrequent that it’s difficult to weigh the risks versus the costs of enacting tougher building standards regionally, he said.
People in several of the affected states won’t have much time to reflect before confronting another potential emergency. Hurricane Irene is approaching the East Coast and could skirt the Mid-Atlantic region by the weekend and make landfall in New England after that.
In North Carolina, officials were inspecting an aging bridge that is a vital evacuation route for people escaping the coastal barrier islands as the storm approaches.
Speaking at an earthquake briefing Wednesday, Washington Mayor Vincent Gray inadvertently mixed up his disasters.
“Everyone knows, obviously, that we had a hurricane,” he said before realizing his mistake.
“Hurricane,” he repeated sheepishly as reporters and staffers burst into laughter. “I’m getting ahead of myself!”
___
Associated Press writers Sam Hananel in Washington; Alex Dominguez in Baltimore; Bob Lewis in Mineral, Va.; Samantha Gross in New York City; and Jay Lindsay in Boston contributed to this report.

Columbia University Warns Of Sixth Seal (Revelation 6:12)

           

Earthquakes May Endanger New York More Than Thought, Says Study
A study by a group of prominent seismologists suggests that a pattern of subtle but active faults makes the risk of earthquakes to the New York City area substantially greater than formerly believed. Among other things, they say that the controversial Indian Point nuclear power plants, 24 miles north of the city, sit astride the previously unidentified intersection of two active seismic zones. The paper appears in the current issue of the Bulletin of the Seismological Society of America.
Many faults and a few mostly modest quakes have long been known around New York City, but the research casts them in a new light. The scientists say the insight comes from sophisticated analysis of past quakes, plus 34 years of new data on tremors, most of them perceptible only by modern seismic instruments. The evidence charts unseen but potentially powerful structures whose layout and dynamics are only now coming clearer, say the scientists. All are based at Columbia University’s Lamont-Doherty Earth Observatory, which runs the network of seismometers that monitors most of the northeastern United States.
Lead author Lynn R. Sykes said the data show that large quakes are infrequent around New Yorkcompared to more active areas like California and Japan, but that the risk is high, because of the overwhelming concentration of people and infrastructure. “The research raises the perception both of how common these events are, and, specifically, where they may occur,” he said. “It’s an extremely populated area with very large assets.” Sykes, who has studied the region for four decades, is known for his early role in establishing the global theory of plate tectonics.
The authors compiled a catalog of all 383 known earthquakes from 1677 to 2007 in a 15,000-square-mile area around New York City. Coauthor John Armbruster estimated sizes and locations of dozens of events before 1930 by combing newspaper accounts and other records. The researchers say magnitude 5 quakes—strong enough to cause damage–occurred in 1737, 1783 and 1884. There was little settlement around to be hurt by the first two quakes, whose locations are vague due to a lack of good accounts; but the last, thought to be centered under the seabed somewhere between Brooklyn and Sandy Hook, toppled chimneys across the city and New Jersey, and panicked bathers at Coney Island. Based on this, the researchers say such quakes should be routinely expected, on average, about every 100 years. “Today, with so many more buildings and people, a magnitude 5 centered below the city would be extremely attention-getting,” said Armbruster. “We’d see billions in damage, with some brick buildings falling. People would probably be killed.”
Starting in the early 1970s Lamont began collecting data on quakes from dozens of newly deployed seismometers; these have revealed further potential, including distinct zones where earthquakes concentrate, and where larger ones could come. The Lamont network, now led by coauthor Won-Young Kim, has located hundreds of small events, including a magnitude 3 every few years, which can be felt by people at the surface, but is unlikely to cause damage. These small quakes tend to cluster along a series of small, old faults in harder rocks across the region. Many of the faults were discovered decades ago when subways, water tunnels and other excavations intersected them, but conventional wisdom said they were inactive remnants of continental collisions and rifting hundreds of millions of years ago. The results clearly show that they are active, and quite capable of generating damaging quakes, said Sykes.
One major previously known feature, the Ramapo Seismic Zone, runs from eastern Pennsylvania to the mid-Hudson Valley, passing within a mile or two northwest of Indian Point. The researchers found that this system is not so much a single fracture as a braid of smaller ones, where quakes emanate from a set of still ill-defined faults. East and south of the Ramapo zone—and possibly more significant in terms of hazard–is a set of nearly parallel northwest-southeast faults. These include Manhattan’s 125th Street fault, which seems to have generated two small 1981 quakes, and could have been the source of the big 1737 quake; the Dyckman Street fault, which carried a magnitude 2 in 1989; the Mosholu Parkway fault; and the Dobbs Ferry fault in suburban Westchester, which generated the largest recent shock, a surprising magnitude 4.1, in 1985. Fortunately, it did no damage. Given the pattern, Sykes says the big 1884 quake may have hit on a yet-undetected member of this parallel family further south.
The researchers say that frequent small quakes occur in predictable ratios to larger ones, and so can be used to project a rough time scale for damaging events. Based on the lengths of the faults, the detected tremors, and calculations of how stresses build in the crust, the researchers say that magnitude 6 quakes, or even 7—respectively 10 and 100 times bigger than magnitude 5–are quite possible on the active faults they describe. They calculate that magnitude 6 quakes take place in the area about every 670 years, and sevens, every 3,400 years. The corresponding probabilities of occurrence in any 50-year period would be 7% and 1.5%. After less specific hints of these possibilities appeared in previous research, a 2003 analysis by The New York City Area Consortium for Earthquake Loss Mitigation put the cost of quakes this size in the metro New York area at $39 billion to $197 billion. A separate 2001 analysis for northern New Jersey’s Bergen County estimates that a magnitude 7 would destroy 14,000 buildings and damage 180,000 in that area alone. The researchers point out that no one knows when the last such events occurred, and say no one can predict when they next might come.
“We need to step backward from the simple old model, where you worry about one large, obvious fault, like they do in California,” said coauthor Leonardo Seeber. “The problem here comes from many subtle faults. 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. We need to take a very close look.” Seeber says that because the faults are mostly invisible at the surface and move infrequently, a big quake could easily hit one not yet identified. “The probability is not zero, and the damage could be great,” he said. “It could be like something out of a Greek myth.”
The researchers found concrete evidence for one significant previously unknown structure: an active seismic zone running at least 25 miles from Stamford, Conn., to the Hudson Valley town of Peekskill, N.Y., where it passes less than a mile north of the Indian Point nuclear power plant. The Stamford-Peekskill line stands out sharply on the researchers’ earthquake map, with small events clustered along its length, and to its immediate southwest. Just to the north, there are no quakes, indicating that it represents some kind of underground boundary. It is parallel to the other faults beginning at 125th Street, so the researchers believe it is a fault in the same family. Like the others, they say it is probably capable of producing at least a magnitude 6 quake. Furthermore, a mile or so on, it intersects the Ramapo seismic zone.
Sykes said the existence of the Stamford-Peekskill line had been suggested before, because the Hudson takes a sudden unexplained bend just ot the north of Indian Point, and definite traces of an old fault can be along the north side of the bend. The seismic evidence confirms it, he said. “Indian Point is situated at the intersection of the two most striking linear features marking the seismicity and also in the midst of a large population that is at risk in case of an accident,” says the paper. “This is clearly one of the least favorable sites in our study area from an earthquake hazard and risk perspective.”
The findings comes at a time when Entergy, the owner of Indian Point, is trying to relicense the two operating plants for an additional 20 years—a move being fought by surrounding communities and the New York State Attorney General. Last fall the attorney general, alerted to the then-unpublished Lamont data, told a Nuclear Regulatory Commission panel in a filing: “New data developed in the last 20 years disclose a substantially higher likelihood of significant earthquake activity in the vicinity of [Indian Point] that could exceed the earthquake design for the facility.” The state alleges that Entergy has not presented new data on earthquakes past 1979. However, in a little-noticed decision this July 31, the panel rejected the argument on procedural grounds. A source at the attorney general’s office said the state is considering its options.
The characteristics of New York’s geology and human footprint may increase the problem. Unlike in California, many New York quakes occur near the surface—in the upper mile or so—and they occur not in the broken-up, more malleable formations common where quakes are frequent, but rather in the extremely hard, rigid rocks underlying Manhattan and much of the lower Hudson Valley. Such rocks can build large stresses, then suddenly and efficiently transmit energy over long distances. “It’s like putting a hard rock in a vise,” said Seeber. “Nothing happens for a while. Then it goes with a bang.” Earthquake-resistant building codes were not introduced to New York City until 1995, and are not in effect at all in many other communities. Sinuous skyscrapers and bridges might get by with minimal damage, said Sykes, but many older, unreinforced three- to six-story brick buildings could crumble.
Art Lerner-Lam, associate director of Lamont for seismology, geology and tectonophysics, pointed out that the region’s major highways including the New York State Thruway, commuter and long-distance rail lines, and the main gas, oil and power transmission lines all cross the parallel active faults, making them particularly vulnerable to being cut. Lerner-Lam, who was not involved in the research, said that the identification of the seismic line near Indian Point “is a major substantiation of a feature that bears on the long-term earthquake risk of the northeastern United States.” He called for policymakers to develop more information on the region’s vulnerability, to take a closer look at land use and development, and to make investments to strengthen critical infrastructure.
“This is a landmark study in many ways,” said Lerner-Lam. “It gives us the best possible evidence that we have an earthquake hazard here that should be a factor in any planning decision. It crystallizes the argument that this hazard is not random. There is a structure to the location and timing of the earthquakes. This enables us to contemplate risk in an entirely different way. And since we are able to do that, we should be required to do that.”
New York Earthquake Briefs and Quotes:
Existing U.S. Geological Survey seismic hazard maps show New York City as facing more hazard than many other eastern U.S. areas. Three areas are somewhat more active—northernmost New York State, New Hampshire and South Carolina—but they have much lower populations and fewer structures. The wider forces at work include pressure exerted from continuing expansion of the mid-Atlantic Ridge thousands of miles to the east; slow westward migration of the North American continent; and the area’s intricate labyrinth of old faults, sutures and zones of weakness caused by past collisions and rifting.
Due to New York’s past history, population density and fragile, interdependent infrastructure, a 2001 analysis by the Federal Emergency Management Agency ranks it the 11th most at-risk U.S. city for earthquake damage. Among those ahead: Los Angeles, San Francisco, Seattle and Portland. Behind: Salt Lake City, Sacramento, Anchorage.
New York’s first seismic station was set up at Fordham University in the 1920s. Lamont-Doherty Earth Observatory, in Palisades, N.Y., has operated stations since 1949, and now coordinates a network of about 40.
Dozens of small quakes have been felt in the New York area. A Jan. 17, 2001 magnitude 2.4, centered  in the Upper East Side—the first ever detected in Manhattan itself–may have originated on the 125th Street fault. Some people thought it was an explosion, but no one was harmed.
The most recent felt quake, a magnitude 2.1 on July 28, 2008, was centered near Milford, N.J. Houses shook and a woman at St. Edward’s Church said she felt the building rise up under her feet—but no damage was done.
Questions about the seismic safety of the Indian Point nuclear power plant, which lies amid a metropolitan area of more than 20 million people, were raised in previous scientific papers in 1978 and 1985.
Because the hard rocks under much of New York can build up a lot strain before breaking, researchers believe that modest faults as short as 1 to 10 kilometers can cause magnitude 5 or 6 quakes.
In general, magnitude 3 quakes occur about 10 times more often than magnitude fours; 100 times more than magnitude fives; and so on. This principle is called the Gutenberg-Richter relationship.