The Prophecy is much more than seeing into the future. For the Prophecy sees without the element of time. For the Prophecy sees what is, what was, and what always shall be. 11:11 LLC
History of earthquakes in Lower Hudson ValleySwapna Venugopal Ramaswamy 9:05 a.m. ET Feb. 7, 2018 At around 6:14 a.m. this morning, a 2.2-magnitude earthquake was reported about three miles northwest of Mohegan Lake in Yorktown, according to the United States Geological Survey. The epicenter of the quake was in Putnam Valley. Social media was rife with posts on the quake with people from Chappaqua, Cortlandt, Lewisboro, Mahopac and Putnam Valley chiming in with their rattling experiences, though it wasn’t nearly as strong as the 5.0 earthquake our forefathers experienced here in 1783. Lower Hudson Valley earthquakes through the years: 1783 — The epicenter of a magnitude 5.0 earthquake may have been the Westchester-Putnam county line and was felt as far south as Philadelphia. 1884 — A magnitude 5.2 earthquake was centered off Rockaway, Queens, causing property damage but no injuries to people. A dead dog was reported. 1970 to 1987 — Between these years, instruments at the Lamont-Doherty Observatory in Rockland County recorded 21 quakes in Westchester and two in Manhattan. October 1985 — A magnitude 4.0 earthquake was centered in an unincorporated part of Greenburgh between Ardsley and Yonkers. Tremors shook the metropolitan area and were felt in Philadelphia, southern Canada and Long Island. November 1988 — A quake 90 miles north of Quebec City in eastern Canada registered magnitude 6.0 with tremors felt in the Lower Hudson Valley and New York City. June 1991 — A 4.4-magnitude quake struck west of Albany, rattling homes. April 1991 — A quake registering between magnitude 2.0 and 2.6 struck Westchester and Fairfield, Conn. It lasted just five seconds and caused no damage. https://tpc.googlesyndication.com/safeframe/1-0-15/html/container.html January 2003 — Two small earthquakes struck the area surrounding Hastings-on-Hudson. One was a magnitude of 1.2, the other 1.4. March 2006 — Two earthquakes struck Rockland. The first, at 1.1 magnitude, hit 3.3 miles southwest of Pearl River; the second, 1.3 magnitude, was centered in the West Nyack-Blauvelt-Pearl River area. July 2014 — “Micro earthquake” struck, 3.1 miles beneath the Appalachian Trail in a heavily wooded area of Garrison. January 2016 — A 2.1 magnitude earthquake occurred at 12:58 a.m. northwest of Ringwood, N.J., and the earthquake was felt in the western parts of Ramapo, including the Hillburn and Sloatsburg areas. April 2017 — A 1.3 magnitude quake rumbled in Pawling on April 10. Putnam County residents in Brewster, Carmel, Patterson and Putnam Valley, as well as Dutchess County residents in Wingdale felt the earthquake. Twitter: @SwapnaVenugopal
America’s Next Big QuakeDoug 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.
47 km (29 mi) ESE of New Rochelle (New York) (pop: 79,800) | Show on map | Quakes nearby 53 km (33 mi) SE of Scarsdale (New York) (pop: 17,900) | Show on map | Quakes nearby 53 km (33 mi) SE of White Plains (New York) (pop: 58,500) | Show on map | Quakes nearby 56 km (35 mi) E of Brooklyn (New York) (pop: 2,300,700) | Show on map | Quakes nearby 57 km (35 mi) ESE of Yonkers (New York) (pop: 201,100) | Show on map | Quakes nearby 58 km (36 mi) SE of Greenburgh (New York) (pop: 86,800) | Show on map | Quakes nearby 60 km (38 mi) E of New York (pop: 8,175,100) | Show on map | Quakes nearby 379 km (235 mi) NE of Washington (District of Columbia) (pop: 601,700) | Show on map | Quakes nearby
Sloshing of Earth’s core may spike major earthquakesBy 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
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.
History of earthquakes in Lower Hudson ValleySwapna Venugopal Ramaswamy 9:05 a.m. ET Feb. 7, 2018 At around 6:14 a.m. this morning, a 2.2-magnitude earthquake was reported about three miles northwest of Mohegan Lake in Yorktown, according to the United States Geological Survey. The epicenter of the quake was in Putnam Valley. Social media was rife with posts on the quake with people from Chappaqua, Cortlandt, Lewisboro, Mahopac and Putnam Valley chiming in with their rattling experiences, though it wasn’t nearly as strong as the 5.0 earthquake our forefathers experienced here in 1783. Lower Hudson Valley earthquakes through the years: 1783 — The epicenter of a magnitude 5.0 earthquake may have been the Westchester-Putnam county line and was felt as far south as Philadelphia. 1884 — A magnitude 5.2 earthquake was centered off Rockaway, Queens, causing property damage but no injuries to people. A dead dog was reported. 1970 to 1987 — Between these years, instruments at the Lamont-Doherty Observatory in Rockland County recorded 21 quakes in Westchester and two in Manhattan. October 1985 — A magnitude 4.0 earthquake was centered in an unincorporated part of Greenburgh between Ardsley and Yonkers. Tremors shook the metropolitan area and were felt in Philadelphia, southern Canada and Long Island. November 1988 — A quake 90 miles north of Quebec City in eastern Canada registered magnitude 6.0 with tremors felt in the Lower Hudson Valley and New York City. June 1991 — A 4.4-magnitude quake struck west of Albany, rattling homes. April 1991 — A quake registering between magnitude 2.0 and 2.6 struck Westchester and Fairfield, Conn. It lasted just five seconds and caused no damage. https://tpc.googlesyndication.com/safeframe/1-0-15/html/container.html January 2003 — Two small earthquakes struck the area surrounding Hastings-on-Hudson. One was a magnitude of 1.2, the other 1.4. March 2006 — Two earthquakes struck Rockland. The first, at 1.1 magnitude, hit 3.3 miles southwest of Pearl River; the second, 1.3 magnitude, was centered in the West Nyack-Blauvelt-Pearl River area. July 2014 — “Micro earthquake” struck, 3.1 miles beneath the Appalachian Trail in a heavily wooded area of Garrison. January 2016 — A 2.1 magnitude earthquake occurred at 12:58 a.m. northwest of Ringwood, N.J., and the earthquake was felt in the western parts of Ramapo, including the Hillburn and Sloatsburg areas. April 2017 — A 1.3 magnitude quake rumbled in Pawling on April 10. Putnam County residents in Brewster, Carmel, Patterson and Putnam Valley, as well as Dutchess County residents in Wingdale felt the earthquake. Twitter: @SwapnaVenugopal
Sloshing of Earth’s core may spike major earthquakesBy 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
Northern New Jersey, which straddles a significant ancient crack in the Earth’s crust known as the Ramapo Fault, recorded 16 earthquakes last year, an unusually high number for the area.
It had been relatively quiet this year, until geologists recorded a 1.3 magnitude quake last weekend in Morris Plains, and then a 1.0 magnitude quake Saturday in Morristown.
Last weekend’s tremor was reported by Columbia University’s Lamont-Doherty Observatory to the Morris Plains Police Department, which issued an advisory to residents on Monday morning.
Lamont-Doherty spokesman Kevin Krajick said the quake was pinpointed to a shallow depth of 6 kilometers just north of Grannis Avenue, between Mountain and Sun Valley ways, about 500 feet southeast of Mountain way School.
“To date (there) were no reported injuries or damage related to the earthquake and no Morris Plains residents reported any activity to this agency,” according to Morris Plains police Chief Jason Kohn.
On the other hand, Butler Police Lt. Mike Moeller said his department received “a bunch of calls about it, between 9:30 and 10:30 p.m.”
Saturday’s earthquake was so minor that Morristown police said they received no calls from residents.
Earthquakes are generally less frequent and less intense in the Northeast compared to the U.S. Pacific Coast, according to the New Jersey Department of Environmental Protection. But due to geological differences between the regions, earthquakes of similar magnitude affect an area 10 times larger in the Northeast compared to the West Coast.
The 16 tremors recorded in 2016 were minor, generally 1 or 2 magnitude, often misinterpreted as explosions, said Alexander Gates, geology professor at Rutgers University Newark campus.
“A lot of people in Butler felt them over the course of the last year, but a lot of them didn’t know it was an earthquake,” Gates said.
Butler is the borough, but also the name of the fault that sits at the end of a series of others belonging to the Ramapo Fault, Gates said.
The Ramapo fault, Gates said, is the longest in the Northeast and runs from Pennnsylvania through New Jersey, snaking northeast through Hunterdon, Somerset, Morris, Passaic, and Bergen counties before coming to an end in New York’s Westchester County, not far from the Indian Point Energy Center, a nuclear power plant.
The small area, Gates said, is considered the most seismically active region east of the Mississippi based on data gathered since 1974, when seismographs were installed.
“I’d be willing to bet that you’d have to go all the way to Canada and all the way to South Carolina before you’d get one that active,” Gates said of the area which runs from the New York state line in the Ringwood and Mahwah area down to Butler and central Passaic County, Gates said.
Butler Councilman Ray Verdonik said area residents are well aware of the frequency of earthquakes and agrees they are often difficult to discern.
During one earthquake, the councilman said he and his neighbors rushed from their homes.
“We thought it was from Picatinny Arsenal or a sonic boom.” he said.
Won-Young Kim, director of the Lamont-Doherty Cooperative Seismographic Network, which monitors earthquakes in the Northeast, said often very shallow, the low magnitude quakes’ waves cause much ground motion. He said even though the waves don’t travel very far, they can seem more intense than the magnitude suggests.
They may not topple chimneys, he said but can crack foundations and frighten residents.
There are 30,000 that measure between 2.5 and 5.4, and these are often felt, but cause minor damage.
About 500 quakes worldwide are recorded between 5.5 and 6 magnitude per year and cause slight damage to buildings and structures.
The 100 that fall within 6.1 and 6.9 may cause lots of damage in populated areas.
The 20 or so which fall within the 7 and 7.9 magnitude per year are considered major and cause serious damage.
Those that measure at 8 or greater can totally destroy communities near the epicenter and average one every five to 10 years.
The earthquake recorded in Mexico last week measured 7.1 magnitude.
Gates said he has identified most of the region’s numerous faults, but has yet to name them all. Among the unnamed include the faults responsible for last year’s quakes in the region.
Earthquakes in this region are intraplate ones, Gates said, meaning they occur within the plates. Earthquakes of this type account for more than 90 percent of the total seismic energy released around the world.
The plate North America rides upon runs from the Mid Atlantic Ridge to the Pacific Coast. The theory is that as plates interact with one another, they create stress within the plate. Faults occur where the crust is weak, Gates said. Earthquakes relieve the built up pressure.
Boston College Geophysics Professor John Ebel said he and a Virginia Tech colleague, believe the seismically active areas in New York and South Carolina are where some 200 million years ago, the plates tried to break off but failed. This led to a weakening of the earth’s crust which makes them susceptible to quakes.
While not predictable, the data collected seem to suggest earthquakes occur somewhat periodically, 40 active years followed by 40 less active, Gates said.
“We are over due for a 3 or 4” magnitude, Gates said. “A 4 you’d feel. It would shake the area. Everybody would be upset.”
Ebel does not fully agree. He said saying “overdue” might be somewhat misleading. Earthquakes happen through a slow process of rising stress, “like dropping individual grains of sand on the table.”
You never know which grain will cause the table to break, he said.
Still all three experts say statistically it is only a matter time before a magnitude 5 quake is recorded in the northern New Jersey area.
The scientists said quakes in the Northeastern part of the United States tend to come 100 years apart and the last one was recorded in 1884 believed to be centered south of Brooklyn. It toppled chimneys and moved houses from their foundations across the city and as far as Rahway.
Washington D.C. experienced a 5.8 magnitude quake in 2011, which was felt in the Northeast, Gates said. That quake cracked the Washington Monument.
A similar quake was recorded in 1737 in Weehawken, Gates noted.
“Imagine putting a 5.5 magnitude earthquake in Weehawken, New Jersey next to the Bridge, next to the tunnel,” Gates said. “Boy that would be a dangerous one.”
In 2008 Columbia University’s The Earth Institute posted an article titled: “Earthquakes May Endanger New York More Than Thought, Says Study.”
“Today, with so many more buildings and people, a magnitude 5 centered below the city would be extremely attention-getting,” the article’s co-author John Armbruster wrote. “We’d see billions in damage, with some brick buildings falling.”
The threat though, is not tangible to many, Armbruster wrote.
“There is no one now alive to remember that last one, so people tend to forget. And having only a partial 300-year history, we may not have seen everything we could see. There could be surprises — things bigger than we have ever seen,” Armbruster wrote.
The Earth Institute’s article did note New York City added earthquake-resistant building codes in 1995.
The issue, Gates said, is that many of the buildings were built before these codes went into effect. A “sizable” earthquake could cause much damage.
Then there’s the prediction that every 3,400 years this area can expect a quake at 7 magnitude.
According to the Earth Institute article, a 2001 analysis for Bergen County estimates a magnitude 7 quake would destroy 14,000 buildings and damage 180,000 in that area alone. Likewise, in New York City the damage could easily hit hundreds of billions of dollars.
Ebel noted that depending on the depth and power of a severe quake, damage could be also be wide ranging. In 2011, Washington D.C., 90 miles away from the epicenter, which was located in central Virginia, suffered significant damage. Cities like Philadelphia fall within that radius.
Then again North Jersey is more likely to be hit by hurricane in the next three years, Gates added.
Email: Fagan@NorthJersey.com
Staff Writer William Westhoven contributed to this report.
New Jersey’s top earthquakes
Dec. 19, 1737 — Weehawken, believed to be a 5-plus magnitude quake, could be very serious if occurred in same spot today.
Nov. 29, 1783 — Western New Jersey. Geologists are not exactly sure where it happened because area was sparsely populated. Estimated magnitude varies from 4.8 to 5.3. Felt from Pennsylvania to New England.
Aug. 10, 1884 — A 5.2 earthquake occurred somewhere near Jamaica Bay near Brooklyn. The quake toppled chimneys and moved houses off their foundations as far Rahway.
The biggest earthquake in the last 45 years of data available form USGS was a 3.8 quake centered in Carneys Point in Salem County on the morning of Feb.28, 1973
New Jersey has never recorded a fatality due to an earthquake, according to the DEP.
A geologist heads to the hills to study precariously perched boulders, which could provide clues to the frequency of the rare major quakes that shake the region.
Every now and then, the ground trembles, in some places more often and more dramatically than in others. New York is no California. Still, Brooklyn chimneys toppled and windows shattered in the summer of 1884, when a quake struck near Coney Island: magnitude 5, or thereabouts. (Seismometers were not then in wide circulation.) Anything larger, amid today’s infrastructure, would cause quite a bit of damage. But we have scant records about how frequently such a quake occurs. “Every thousand years, every ten thousand years, every million years?,” William Menke, a seismologist at Columbia’s Lamont-Doherty observatory, wondered recently, with the potential destruction of the metropolitan region in mind. “It makes a difference!” Many major earthquakes have occurred on the East Coast, he explained. We just don’t know when.
Menke was hiking up a mountain in Harriman State Park, beside the Ramapo Fault, to try to fill in the gaps. He was in search of rocks whose shape and placement gave him a sense of existential comfort instead of dread. “That was the one that started me thinking about this,” he said, arriving at a bobsled-size boulder perched near the edge of a shallow cliff. “That must say something important about the amount of shaking that occurred since it was put up there. If there was a lot of shaking, it would have fallen.” A hiking companion couldn’t resist a futile push. The boulder was deposited there, of course, by a glacier. “Everything here reeks of the Ice Age,” Menke said. The last of the glaciers melted in these parts around fifteen thousand years ago. Auspicious.
The two continued climbing, in search of ever more precariously perched boulders. Some were too small to rule out human intervention. “You can see somebody moved those hefty rocks into a bench configuration,” Menke noted of one arrangement, near the remains of a campfire. Another boulder, intriguingly top-heavy, sat in a crack, making it harder to dislodge, and therefore unworthy of scrutiny. Menke crouched beside others to sketch their contours in a notebook and measure the slopes of the underlying bedrock, using a carpenter’s level and an inclinometer, for which he’d paid eight dollars at Lowe’s. “Most of the stuff I do is pretty low tech,” he said. “I have occasionally lost things in the field and then found them six months later, a little rusty.”
Menke’s gray hair was untrimmed and, like some of the stones he examined, in seeming defiance of gravity. His fixation on the geology was such that he failed to notice a buck galloping past, though he called attention to a small discoloration in the bedrock at one point. “See the surface here? Something was protecting this from erosion. Was there a boulder there that rolled off? Where is it?” Using some back-of-the-envelope physics, he estimated the amount of gravitational acceleration required to send various candidates in his notebook sliding downhill. “The last one we did was on a more gentle slope, and it was about point three of gravity,” he said. “So that would be about a seven-and-a-half magnitude.” By contrast, a giant sea-turtle-shaped rock on a steeper slope seemed likely to ski with a magnitude 7. “So that, actually, is an interesting number,” Menke said. “If you can rule out that there have been any earthquakes of magnitude 7 since the end of the Ice Age, that actually is pretty important in terms of New York’s seismic risk.”
Proper science would require his following up with sophisticated camera technology, for photogrammetry and 3-D computer modelling. “I’ll tell you a funny story about a Greek dude,” Menke said, referring to the astronomer Aristarchus, who attempted to estimate the distance from the earth to the sun. “He did a pretty good job, but there was a critical piece of info he needed to know, and that was the angular diameter of the sun. It’s half a degree, and he guessed that it was two degrees. Had he been careful to measure things, he would have gotten the right number.” For now, though, Menke took comfort in what the naked eye was telling him. Then again, a magnitude 7 earthquake is a thousand times more powerful than a magnitude 5. Think of Haiti in 2010, instead of Coney Island in 1884.
Pausing for a water break before beginning his descent, Menke ran his hand over another boulder and broke off a piece of crusty rock tripe, or lichen. “Very low nutritional value,” he said. “But if faced with a choice between eating rock tripe and dying, you eat rock tripe.” ♦
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.
The Prophecy Blog 