Quakeland: On the Road to America’s Next Devastating Earthquake in NYC: 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 Quakes Preceding the Sixth Seal: Revelation 6:12

               

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.

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

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: NEW YORK CITY (MARCH 3, 2026)

       

Earthquake activity in the New York City area

Wikipedia

Although the eastern United States is not as seismically active as regions near plate boundaries, large and damaging earthquakes do occur there. Furthermore, when these rare eastern U.S. earthquakes occur, the areas affected by them are much larger than for western U.S. earthquakes of the same magnitude. Thus, earthquakes represent at least a moderate hazard to East Coast cities, including New York City and adjacent areas of very high population density.

Seismicity in the vicinity of New York City. Data are from the U.S. Geological Survey (Top, USGS) and the National Earthquake Information Center (Bottom, NEIC). In the top figure, closed red circles indicate 1924-2006 epicenters and open black circles indicate locations of the larger earthquakes that occurred in 1737, 1783 and 1884. Green lines indicate the trace of the Ramapo fault.

As can be seen in the maps of earthquake activity in this region(shown in the figure), seismicity is scattered throughout most of the New York City area, with some hint of a concentration of earthquakes in the area surrounding Manhattan Island. The largest known earthquake in this region occurred in 1884 and had a magnitude of approximately 5.For this earthquake, observations of fallen bricks and cracked plaster were reported from eastern Pennsylvania to central Connecticut, and the maximum intensity reported was at two sites in western Long Island (Jamaica, New York and Amityville, New York). Two other earthquakes of approximately magnitude 5 occurred in this region in 1737 and 1783. The figure on the right shows maps of the distribution of earthquakes of magnitude 3 and greater that occurred in this region from 1924 to 2010, along with locations of the larger earthquakes that occurred in 1737, 1783 and 1884.

Background

The NYC area is part of the geologically complex structure of the Northern Appalachian Mountains. This complex structure was formed during the past half billion years when the Earth’s crust underlying the Northern Appalachians was the site of two major geological episodes, each of which has left its imprint on the NYC area bedrock. Between about 450 million years ago and about 250 million years ago, the Northern Appalachian region was affected by a continental collision, in which the ancient African continent collided with the ancient North American continent to form the supercontinent Pangaea. Beginning about 200 million years ago, the present-day Atlantic ocean began to form as plate tectonic forces began to rift apart the continent of Pangaea. The last major episode of geological activity to affect the bedrock in the New York area occurred about 100 million years ago, during the Mesozoic era, when continental rifting that led to the opening of the present-day Atlantic ocean formed the Hartford and Newark Mesozoic rift basins.

Earthquake rates in the northeastern United States are about 50 to 200 times lower than in California, but the earthquakes that do occur in the northeastern U.S. are typically felt over a much broader region than earthquakes of the same magnitude in the western U.S.This means the area of damage from an earthquake in the northeastern U.S. could be larger than the area of damage caused by an earthquake of the same magnitude in the western U.S. The cooler rocks in the northeastern U.S. contribute to the seismic energy propagating as much as ten times further than in the warmer rocks of California. A magnitude 4.0 eastern U.S. earthquake typically can be felt as far as 100 km (60 mi) from its epicenter, but it infrequently causes damage near its source. A magnitude 5.5 eastern U.S. earthquake, although uncommon, can be felt as far as 500 km (300 mi) from its epicenter, and can cause damage as far away as 40 km (25 mi) from its epicenter. Earthquakes stronger than about magnitude 5.0 generate ground motions that are strong enough to be damaging in the epicentral area.

At well-studied plate boundaries like the San Andreas fault system in California, scientists can often make observations that allow them to identify the specific fault on which an earthquake took place. In contrast, east of the Rocky Mountains this is rarely the case.  The NYC area is far from the boundaries of the North American plate, which are in the center of the Atlantic Ocean, in the Caribbean Sea, and along the west coast of North America. The seismicity of the northeastern U.S. is generally considered to be due to ancient zones of weakness that are being reactivated in the present-day stress field. In this model, pre-existing faults that were formed during ancient geological episodes persist in the intraplate crust, and the earthquakes occur when the present-day stress is released along these zones of weakness. The stress that causes the earthquakes is generally considered to be derived from present-day rifting at the Mid-Atlantic ridge.

Earthquakes and geologically mapped faults in the Northeastern U.S.

The northeastern U.S. has many known faults, but virtually all of the known faults have not been active for perhaps 90 million years or more. Also, the locations of the known faults are not well determined at earthquake depths. Accordingly, few (if any) earthquakes in the region can be unambiguously linked to known faults. Given the current geological and seismological data, it is difficult to determine if a known fault in this region is still active today and could produce a modern earthquake. As in most other areas east of the Rocky Mountains, the best guide to earthquake hazard in the northeastern U.S. is probably the locations of the past earthquakes themselves.

The Ramapo fault and other New York City area faults

The Ramapo Fault, which marks the western boundary of the Newark rift basin, has been argued to be a major seismically active feature of this region,but it is difficult to discern the extent to which the Ramapo fault (or any other specific mapped fault in the area) might be any more of a source of future earthquakes than any other parts of the region. The Ramapo Fault zone spans more than 185 miles (300 kilometers) in New York, New Jersey, and Pennsylvania. It is a system of faults between the northern Appalachian Mountains and Piedmont areas to the east. This fault is perhaps the best known fault zone in the Mid-Atlantic region, and some small earthquakes have been known to occur in its vicinity. Recently, public knowledge about the fault has increased – especially after the 1970s, when the fault’s proximity to the Indian Point nuclear plant in New York was noticed.

There is insufficient evidence to unequivocally demonstrate any strong correlation of earthquakes in the New York City area with specific faults or other geologic structures in this region. The damaging earthquake affecting New York City in 1884 was probably not associated with the Ramapo fault because the strongest shaking from that earthquake occurred on Long Island (quite far from the trace of the Ramapo fault). The relationship between faults and earthquakes in the New York City area is currently understood to be more complex than any simple association of a specific earthquake with a specific mapped fault.

A 2008 study argued that a magnitude 6 or 7 earthquake might originate from the Ramapo fault zone, which would almost definitely spawn hundreds or even thousands of fatalities and billions of dollars in damage. Studying around 400 earthquakes over the past 300 years, the study also argued that there was an additional fault zone extending from the Ramapo Fault zone into southwestern Connecticut. As can be seen in the above figure of seismicity, earthquakes are scattered throughout this region, with no particular concentration of activity along the Ramapo fault, or along the hypothesized fault zone extending into southwestern Connecticut.

Just off the northern terminus of the Ramapo fault is the Indian Point Nuclear Power Plant, built between 1956 and 1960 by Consolidated Edison Company. The plant began operating in 1963, and it has been the subject of a controversy over concerns that an earthquake from the Ramapo fault will affect the power plant. Whether or not the Ramapo fault actually does pose a threat to this nuclear power plant remains an open question.

New York is America’s Next Major Quake (Revelation 6)

  America’s Next Big Quake

Doug Fabrizio
The devastation wrought in Mexico City by a recent massive earthquake may have rattled more than a few nerves along the Wasatch Front. Salt Lake City is, of course, overdue for a significant seismic event. So are other places in the United States, such as Los Angeles, the Pacific Northwest, even New York City. In a new book, science writer Kathryn Miles tours the country in search of the latest research on America’s next big earthquake and what’s being done to address the threat. She joins us Wednesday to talk about it.
Kathryn Miles is the author of several books, including her newest, Quakeland: On the Road to America’s Next Devastating Earthquake [Independent bookstores|Amazon|Audible].
Learn more about predicting earthquakes in Utah and how well the state’s buildings could stand-up to a great shake from KUER’s news team.

Conclusion to Economic Consequences of the Sixth Seal (Revelation 6:15)

  

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

NYCEM.org

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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.

Economic Consequences of the Sixth Seal (Revelation 6:12)

   

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

NYCEM.org

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.
This paper tries to bring into focus some of the seismological factors which are but one set of variables one needs for quantifying the earthquake loss potential in eastern U.S. urban regions. We use local and global analogs for illustrating possible scenario events in terms of risk. We also highlight some of the few local steps that have been undertaken towards mitigating against the eastern earthquake threat; and discuss priorities for future actions.

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.