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

         Sloshing of Earth’s core may spike major earthquakes

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

Preparing for the Sixth Seal (Revelation 6:12)

          

Scenario Earthquakes for Urban Areas Along the Atlantic Seaboard of the United States
NYCEM

The Sixth Seal: NY City Destroyed

If today a magnitude 6 earthquake were to occur centered on New York City, what would its effects be? Will the loss be 10 or 100 billion dollars? Will there be 10 or 10,000 fatalities? Will there be 1,000 or 100,000 homeless needing shelter? Can government function, provide assistance, and maintain order?

At this time, no satisfactory answers to these questions are available. A few years ago, rudimentary scenario studies were made for Boston and New York with limited scope and uncertain results. For most eastern cities, including Washington D.C., we know even less about the economic, societal and political impacts from significant earthquakes, whatever their rate of occurrence.

Why do we know so little about such vital public issues? Because the public has been lulled into believing that seriously damaging quakes are so unlikely in the east that in essence we do not need to consider them. We shall examine the validity of this widely held opinion.

Is the public’s earthquake awareness (or lack thereof) controlled by perceived low Seismicity, Seismic Hazard, or Seismic Risk? How do these three seismic features differ from, and relate to each other? In many portions of California, earthquake awareness is refreshed in a major way about once every decade (and in some places even more often) by virtually every person experiencing a damaging event. The occurrence of earthquakes of given magnitudes in time and space, not withstanding their effects, are the manifestations of seismicity. Ground shaking, faulting, landslides or soil liquefaction are the manifestations of seismic hazard. Damage to structures, and loss of life, limb, material assets, business and services are the manifestations of seismic risk. By sheer experience, California’s public understands fairly well these three interconnected manifestations of the earthquake phenomenon. This awareness is reflected in public policy, enforcement of seismic regulations, and preparedness in both the public and private sector. In the eastern U.S., the public and its decision makers generally do not understand them because of inexperience. Judging seismic risk by rates of seismicity alone (which are low in the east but high in the west) has undoubtedly contributed to the public’s tendency to belittle the seismic loss potential for eastern urban regions.

Let us compare two hypothetical locations, one in California and one in New York City. Assume the location in California does experience, on average, one M = 6 every 10 years, compared to New York once every 1,000 years. This implies a ratio of rates of seismicity of 100:1. Does that mean the ratio of expected losses (when annualized per year) is also 100:1? Most likely not. That ratio may be closer to 10:1, which seems to imply that taking our clues from seismicity alone may lead to an underestimation of the potential seismic risks in the east. Why should this be so?

To check the assertion, let us make a back-of-the-envelope estimate. The expected seismic risk for a given area is defined as the area-integrated product of: seismic hazard (expected shaking level), assets ($ and people), and the assets’ vulnerabilities (that is, their expected fractional loss given a certain hazard – say, shaking level). Thus, if we have a 100 times lower seismicity rate in New York compared to California, which at any given point from a given quake may yield a 2 times higher shaking level in New York compared to California because ground motions in the east are known to differ from those in the west; and if we have a 2 times higher asset density (a modest assumption for Manhattan!), and a 2 times higher vulnerability (again a modest assumption when considering the large stock of unreinforced masonry buildings and aged infrastructure in New York), then our California/New York ratio for annualized loss potential may be on the order of (100/(2x2x2)):1. That implies about a 12:1 risk ratio between the California and New York location, compared to a 100:1 ratio in seismicity rates.

From this example it appears that seismic awareness in the east may be more controlled by the rate of seismicity than by the less well understood risk potential. This misunderstanding is one of the reasons why earthquake awareness and preparedness in the densely populated east is so disproportionally low relative to its seismic loss potential. Rare but potentially catastrophic losses in the east compete in attention with more frequent moderate losses in the west. New York City is the paramount example of a low-probability, high-impact seismic risk, the sort of risk that is hard to insure against, or mobilize public action to reduce the risks.

There are basically two ways to respond. One is to do little and wait until one or more disastrous events occur. Then react to these – albeit disastrous – “windows of opportunity.” That is, pay after the unmitigated facts, rather than attempt to control their outcome. This is a high-stakes approach, considering the evolved state of the economy. The other approach is to invest in mitigation ahead of time, and use scientific knowledge and inference, education, technology transfer, and combine it with a mixture of regulatory and/or economic incentives to implement earthquake preparedness. The National Earthquake Hazard Reduction Program (NEHRP) has attempted the latter while much of the public tends to cling to the former of the two options. Realistic and reliable quantitative loss estimation techniques are essential to evaluate the relative merits of the two approaches.

The current efforts in the eastern U.S., including New York City, to start the enforcement of seismic building codes for new constructions are important first steps in the right direction. Similarly, the emerging efforts to include seismic rehabilitation strategies in the generally needed overhaul of the cities’ aged infrastructures such as bridges, water, sewer, power and transportation is commendable and needs to be pursued with diligence and persistence. But at the current pace of new construction replacing older buildings and lifelines, it will take many decades or a century before a major fraction of the stock of built assets will become seismically more resilient than the current inventory is. For some time, this leaves society exposed to very high seismic risks. The only consolation is that seismicity on average is low, and, hence with some luck, the earthquakes will not outpace any ongoing efforts to make eastern cities more earthquake resilient gradually. Nevertheless, M = 5 to M = 6 earthquakes at distances of tens of km must be considered a credible risk at almost any time for cities like Boston, New York or Philadelphia. M = 7 events, while possible, are much less likely; and in many respects, even if building codes will have affected the resilience of a future improved building stock, M = 7 events would cause virtually unmanageable situations. Given these bleak prospects, it will be necessary to focus on crucial elements such as maintaining access to cities by strengthening critical bridges, improving the structural and nonstructural performance of hospitals, and having a nationally supported plan how to assist a devastated region in case of a truly severe earthquake. No realistic and coordinated planning of this sort exists at this time for most eastern cities.

The current efforts by the Federal Emergency Management Administration (FEMA) via the National Institute of Building Sciences (NIBS) to provide a standard methodology (RMS, 1994) and planning tools for making systematic, computerized loss estimates for annualized probabilistic calculations as well as for individual scenario events, is commendable. But these new tools provide only a shell with little regional data content. What is needed are the detailed data bases on inventory of buildings and lifelines with their locally specific seismic fragility properties. Similar data are needed for hospitals, shelters, firehouses, police stations and other emergency service providers. Moreover, the soil and rock conditions which control the shaking and soil liquefaction properties for any given event, need to be systematically compiled into Geographical Information System (GIS) data bases so they can be combined with the inventory of built assets for quantitative loss and impact estimates. Even under the best of conceivable funding conditions, it will take years before such data bases can be established so they will be sufficiently reliable and detailed to perform realistic and credible loss scenarios. Without such planning tools, society will remain in the dark as to what it may encounter from a future major eastern earthquake. Given these uncertainties, and despite them, both the public and private sector must develop at least some basic concepts for contingency plans. For instance, the New York City financial service industry, from banks to the stock and bond markets and beyond, ought to consider operational contingency planning, first in terms of strengthening their operational facilities, but also for temporary backup operations until operations in the designated facilities can return to some measure of normalcy. The Federal Reserve in its oversight function for this industry needs to take a hard look at this situation.

A society, whose economy depends increasingly so crucially on rapid exchange of vast quantities of information must become concerned with strengthening its communication facilities together with the facilities into which the information is channeled. In principle, the availability of satellite communication (especially if self-powered) with direct up and down links, provides here an opportunity that is potentially a great advantage over distributed buried networks. Distributed networks for transportation, power, gas, water, sewer and cabled communication will be expensive to harden (or restore after an event).

In all future instances of major capital spending on buildings and urban infrastructures, the incorporation of seismically resilient design principles at all stages of realization will be the most effective way to reduce society’s exposure to high seismic risks. To achieve this, all levels of government need to utilize legislative and regulatory options; insurance industries need to build economic incentives for seismic safety features into their insurance policy offerings; and the private sector, through trade and professional organizations’ planning efforts, needs to develop a healthy self-protective stand. Also, the insurance industry needs to invest more aggressively into broadly based research activities with the objective to quantify the seismic hazards, the exposed assets and their seismic fragilities much more accurately than currently possible. Only together these combined measures may first help to quantify and then reduce our currently untenably large seismic risk exposures in the virtually unprepared eastern cities. Given the low-probability/high-impact situation in this part of the country, seismic safety planning needs to be woven into both the regular capital spending and daily operational procedures. Without it we must be prepared to see little progress. Unless we succeed to build seismic safety considerations into everyday decision making as a normal procedure of doing business, society will lose the race against the unstoppable forces of nature. While we never can entirely win this race, we can succeed in converting unmitigated catastrophes into manageable disasters, or better, tolerable natural events.

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.

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

The Sixth Seal by Nostradamus (Revelation 6:12)

         

The Sixth Seal by Nostradamus

To Andrew the Prophet
Completed February 5, 2008

Nostradamus and the New City

Les Propheties
(Century 1 Quatrain 27)

Michel de Nostredame Earth-shaking fire from the center of the earth.Will cause the towers around the New City to shake,Two great rocks for a long time will make war, And then Arethusa will color a new river red.(And then areth USA will color a new river red.) Earth-shaking fire from the center of the earth.Will cause the towers around the New City to shake,Two great rocks for a long time will make war

There is recent scientific evidence from drill core sampling in Manhattan, that the southern peninsula is overlapped by several tectonic plates. Drill core sampling has been taken from regions south of Canal Street including the Trade Towers’ site. Of particular concern is that similar core samples have been found across the East River in Brooklyn. There are also multiple fault lines along Manhattan correlating with north-northwest and northwest trending neo-tectonic activity. And as recently as January and October of 2001, New York City has sustained earthquakes along these plates. For there are “two great rocks” or tectonic plates that shear across Manhattan in a northwestern pattern. And these plates “for a longtime will make war”, for they have been shearing against one other for millions of years. And on January 3 of 2010, when they makewar with each other one last time, the sixth seal shall be opened, and all will know that the end is near.

And then Arethusa will color a new river red.

Arethusa is a Greek mythological figure, a beautiful huntress and afollower of the goddess Artemis. And like Artemis, Arethusa would have nothing to do with me; rather she loved to run and hunt in the forest. But one day after an exhausting hunt, she came to a clear crystal stream and went in it to take a swim. She felt something from beneath her, and frightened she scampered out of the water. A voice came from the water, “Why are you leaving fair maiden?” She ran into the forest to escape, for the voice was from Alpheus, the god of the river. For he had fallen in love with her and became a human to give chase after her. Arethusa in exhaustion called out to Artemis for help, and the goddess hid her by changing her into a spring.But not into an ordinary spring, but an underground channel that traveled under the ocean from Greece to Sicily. But Alpheus being the god of the river, converted back into water and plunged downthe same channel after Arethusa. And thus Arethusa was captured by Artemis, and their waters would mingle together forever. And of great concern is that core samples found in train tunnels beneath the Hudson River are identical to those taken from southern Manhattan. Furthermore, several fault lines from the 2001 earthquakes were discovered in the Queen’s Tunnel Complex, NYC Water Tunnel #3. And a few years ago, a map of Manhattan drawn up in 1874 was discovered, showing a maze of underground waterways and lakes. For Manhattan was once a marshland and labyrinth of underground streams. Thus when the sixth seal is broken, the subways of the New City shall be flooded be Arethusa:the waters from the underground streams and the waters from the sea. And Arethusa shall be broken into two. And then Arethusa will color a new river red.

And then areth USA will color a new river red.

For Arethusa broken into two is areth USA. For areth (αρετη) is the Greek word for values. But the values of the USA are not based on morality, but on materialism and on wealth. Thus when the sixth seal is opened, Wall Street and our economy shall crash and “arethUSA”, the values of our economy shall fall “into the red.” “Then the kings of the earth and the great men and the commanders and the rich and the strong and every slave and free man hid themselves in the caves and among the rocks of the mountains; and they said to the mountains and to the rocks, ‘Fall on us and hide us from the presence of Him who sits on the throne, and from the wrath of the Lamb; for the great day of their wrath has come, and who is able to stand?’” (Revelation 6:15-17)

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.

New York Subways at the Sixth Seal (Revelation 6)

                      How vulnerable are NYC’s underwater subway tunnels to flooding?

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