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Friend or Foe? Crows Never Forget a Face, It Seems
By MICHELLE NIJHUIS, The New York Times, August 26, 2008
Crows and their relatives — among them ravens, magpies and jays — are renowned for their intelligence and for their ability to flourish in human-dominated landscapes. That ability may have to do with cross-species social skills. In the Seattle area, where rapid suburban growth has attracted a thriving crow population, researchers have found that the birds can recognize individual human faces.
John M. Marzluff, a wildlife biologist at the University of Washington, has studied crows and ravens for more than 20 years and has long wondered if the birds could identify individual researchers. Previously trapped birds seemed more wary of particular scientists, and often were harder to catch. “I thought, ‘Well, it’s an annoyance, but it’s not really hampering our work,’ ” Dr. Marzluff said. “But then I thought we should test it directly.”
To test the birds’ recognition of faces separately from that of clothing, gait and other individual human characteristics, Dr. Marzluff and two students wore rubber masks. He designated a caveman mask as “dangerous” and, in a deliberate gesture of civic generosity, a Dick Cheney mask as “neutral.” Researchers in the dangerous mask then trapped and banded seven crows on the university’s campus in Seattle.
In the months that followed, the researchers and volunteers donned the masks on campus, this time walking prescribed routes and not bothering crows.
The crows had not forgotten. They scolded people in the dangerous mask significantly more than they did before they were trapped, even when the mask was disguised with a hat or worn upside down. The neutral mask provoked little reaction. The effect has not only persisted, but also multiplied over the past two years. Wearing the dangerous mask on one recent walk through campus, Dr. Marzluff said, he was scolded by 47 of the 53 crows he encountered, many more than had experienced or witnessed the initial trapping. The researchers hypothesize that crows learn to recognize threatening humans from both parents and others in their flock.
After their experiments on campus, Dr. Marzluff and his students tested the effect with more realistic masks. Using a half-dozen students as models, they enlisted a professional mask maker, then wore the new masks while trapping crows at several sites in and around Seattle. The researchers then gave a mix of neutral and dangerous masks to volunteer observers who, unaware of the masks’ histories, wore them at the trapping sites and recorded the crows’ responses.
The reaction to one of the dangerous masks was “quite spectacular,” said one volunteer, Bill Pochmerski, a retired telephone company manager who lives near Snohomish, Wash. “The birds were really raucous, screaming persistently,” he said, “and it was clear they weren’t upset about something in general. They were upset with me.”
Again, crows were significantly more likely to scold observers who wore a dangerous mask, and when confronted simultaneously by observers in dangerous and neutral masks, the birds almost unerringly chose to persecute the dangerous face. In downtown Seattle, where most passersby ignore crows, angry birds nearly touched their human foes. In rural areas, where crows are more likely to be viewed as noisy “flying rats” and shot, the birds expressed their displeasure from a distance.
Though Dr. Marzluff’s is the first formal study of human face recognition in wild birds, his preliminary findings confirm the suspicions of many other researchers who have observed similar abilities in crows, ravens, gulls and other species. The pioneering animal behaviorist Konrad Lorenz was so convinced of the perceptive capacities of crows and their relatives that he wore a devil costume when handling jackdaws. Stacia Backensto, a master’s student at the University of Alaska Fairbanks who studies ravens in the oil fields on Alaska’s North Slope, has assembled an elaborate costume — including a fake beard and a potbelly made of pillows — because she believes her face and body are familiar to previously captured birds.
Kevin J. McGowan, an ornithologist at the Cornell Laboratory of Ornithology who has trapped and banded crows in upstate New York for 20 years, said he was regularly followed by birds who have benefited from his handouts of peanuts — and harassed by others he has trapped in the past.
Why crows and similar species are so closely attuned to humans is a matter of debate. Bernd Heinrich, a professor emeritus at the University of Vermont known for his books on raven behavior, suggested that crows’ apparent ability to distinguish among human faces is a “byproduct of their acuity,” an outgrowth of their unusually keen ability to recognize one another, even after many months of separation.
Dr. McGowan and Dr. Marzluff believe that this ability gives crows and their brethren an evolutionary edge. “If you can learn who to avoid and who to seek out, that’s a lot easier than continually getting hurt,” Dr. Marzluff said. “I think it allows these animals to survive with us — and take advantage of us — in a much safer, more effective way.”
Study Maps Faults for New York Quakes
By KENNETH CHANG, The New York Times, August 26, 2008
New York City may seem immune to earthquakes, at least compared with its West Coast megacity counterpart, Los Angeles. But there is some danger.
A new analysis of 383 quakes in a 15,000-square-mile area around New York City estimates that a magnitude-5 earthquake in or around the city occurs on average once a century, and a magnitude-6 or larger quake occurs once every 670 years. An even larger magnitude-7 is estimated at once every 3,400 years.
Researchers at the Lamont-Doherty Earth Observatory at Columbia University analyzed earthquakes that occurred from 1677 to 2007 as well as data gathered by seismic instruments in the past 34 years and mapped out a family of faults responsible for most of the earthquakes. Their report appears in the current issue of the Bulletin of the Seismological Society of America.
“We now have some way to look at the geology and use it to map the hazards,” said Leonardo Seeber, a senior researcher at Lamont-Doherty and one of the study authors.
The historical record includes three earthquakes of magnitude-5 or larger, the most recent in 1884. That quake originated offshore near Coney Island and toppled chimneys in the city.
While earthquakes in the northeast United States are smaller and less frequent than in places like California or Japan, the risks still warrant attention from officials, the researchers said.
“New York City is a major concentration of people and buildings, so if you combine the rate of earthquakes with what is there to be damaged, that combination becomes relatively high,” said John Armbruster, another study author. “There’s a lot to be damaged. A magnitude-5 earthquake under Queens is going to be much more damaging than a magnitude-5 earthquake in upstate New York.”
Lynn R. Sykes, an emeritus professor of earth and environmental sciences at Columbia and the lead author of the study, said critical facilities needed the most attention. That includes schools, fire stations, bridges — and the Indian Point nuclear power plant 24 miles north of the city. The study found a previously unidentified boundary, likely a fault, that runs 25 miles to Peekskill, N.Y., from Stamford, Conn., passing within a mile of Indian Point.
With the new data, engineers could better analyze what types of forces the plant might experience in an earthquake along that fault. The owner, Entergy, is seeking to extend its operating licenses of the two reactors at Indian Point by 20 years.
Even a modest earthquake could wreak millions of dollars of damage on Manhattan. And, surprisingly, the lack of large earthquakes makes the smaller earthquakes potentially more damaging. In places like California, the many earthquakes have weakened the top layers of crust, making for less buildup of strain and less powerful quakes near the surface. Thus, the most damaging earthquakes usually originate 5 to 10 miles underground.
In the New York area, most earthquakes are much shallower, within three miles of the surface. A shallow earthquake shakes the surface more violently than a deep one of the same magnitude. Mr. Seeber said a recent magnitude-2.3 earthquake near Warwick, N.Y., shook items off shelves, and there were reports of damaged foundations.
Stiffer rocks in the New York area also transmit farther the higher-frequency vibrations that shake objects harder. “These very shallow earthquakes can deliver a big punch even though very small,” Mr. Seeber said.
The Appalachians Mountains were first pushed up several hundred million years ago, and those ancient large faults, including the Ramapo fault that also passes near Indian Point, have been quiet. The earthquakes have instead occurred along smaller faults running perpendicular to the older faults.
Israel to Display the Dead Sea Scrolls on the Internet
By ETHAN BRONNER, The New York Times, August 27, 2008
JERUSALEM — In a crowded laboratory painted in gray and cooled like a cave, half a dozen specialists embarked this week on a historic undertaking: digitally photographing every one of the thousands of fragments of the Dead Sea Scrolls with the aim of making the entire file — among the most sought-after and examined documents on earth — available to all on the Internet.
Equipped with high-powered cameras with resolution and clarity many times greater than those of conventional models, and with lights that emit neither heat nor ultraviolet rays, the scientists and technicians are uncovering previously illegible sections and letters of the scrolls, discoveries that could have significant scholarly impact.
The 2,000-year-old scrolls, found in the late 1940s in caves near the Dead Sea east of Jerusalem, contain the earliest known copies of every book of the Hebrew Bible (missing only the Book of Esther), as well as apocryphal texts and descriptions of rituals of a Jewish sect at the time of Jesus. The texts, most of them on parchment but some on papyrus, date from the third century B.C. to the first century A.D.
Only a handful of the scrolls exist in large pieces, with several on permanent exhibit at the Israel Museum here in its dimly lighted Shrine of the Book. Most of what was found is separated into 15,000 fragments that make up about 900 documents, fueling a longstanding debate on how to order the fragments as well as the origin and meaning of what is written on them.
The scrolls’ contemporary history has been something of a tortured one because they are among the most important sources of information on Jewish and early Christian life. After their initial discovery they were tightly held by a small circle of scholars. In the last 20 years access has improved significantly, and in 2001 they were published in their entirety. But debate over them seems only to grow.
Scholars continually ask the Israel Antiquities Authority, the custodian of the scrolls, for access to them, and museums around the world seek to display them. Next month, the Jewish Museum of New York will begin an exhibition of six of the scrolls.
The keepers of the scrolls, people like Pnina Shor, head of the conservation department of the antiquities authority, are delighted by the intense interest but say that each time a scroll is exposed to light, humidity and heat, it deteriorates. She says even without such exposure there is deterioration because of the ink used on some of the scrolls as well as the residue from the Scotch tape used by the 1950s scholars in piecing together fragments.
The entire collection was photographed only once before — in the 1950s using infrared — and those photographs are stored in a climate-controlled room because they show things already lost from some of the scrolls. The old infrared pictures will also be scanned in the new digital effort.
“The project began as a conservation necessity,” Ms. Shor explained. “We wanted to monitor the deterioration of the scrolls and realized we needed to take precise photographs to watch the process. That’s when we decided to do a comprehensive set of photos, both in color and infrared, to monitor selectively what is happening. We realized then that we could make the entire set of pictures available online to everyone, meaning that anyone will be able to see the scrolls in the kind of detail that no one has until now.”
The process will probably take one to two years — more before it is available online — and is being led by Greg Bearman, who retired from the NASA Jet Propulsion Laboratory. Data collection is directed by Simon Tanner of Kings College London.
Jonathan Ben-Dov, a professor of biblical studies at the University of Haifa, is taking part in the digitalization project. Watching the technicians gingerly move a fragment into place for a photograph, he said that it had long been very difficult for senior scholars to get access.
Once this project is completed, he said with wonder, “every undergraduate will be able to have a detailed look at them from numerous angles.”

Green Roofs Offer More Than Color for the Skyline
By KEN BELSON, The New York Times, August 28, 2008
The thousands of recently planted green and purple shrublike sedum lining the roof of Con Edison’s training center in Long Island City look a bit out of place in the shadow of Manhattan’s skyline.
But the tiny absorbent leaves and modest but hardy roots of the sedum — typically found in desert climates — are at the center of a growing effort to reduce greenhouse gases, rainwater runoff and electricity demand in New York.
This month, Gov. David A. Paterson approved tax abatements to developers and building owners who install green roofs, or a layer of vegetation and rock that absorbs rainwater, insulates buildings and extends the lives of roofs. Sedum, which soaks up water quickly and releases it slowly, is an ideal plant for the job.
Europe has had green roofs for decades, and cities like Chicago and Seattle have added many of them in recent years. But there are fewer in New York because of the cost of installing them compared with the benefits, which can be hard to quantify. The new one-year abatements, though, can cut as much as $100,000 a year from a building’s taxes, and are expected to turn what has largely been a hidden luxury into a standard feature of a little-seen part of the city’s landscape.
“This is just the beginning,” said Kari Elwell Katzander, a partner in Mingo Design, a landscape design firm in Manhattan that works on green roofs. “It’s not just about the green roof. This transcends into various ways to make buildings more green.”
There are few accurate reckonings of how much of the 944 million square feet of rooftops across New York City — 11.5 percent of the total building area — has gone green, or how much more could be cultivated. But clearly there is plenty of space available. Just in Long Island City, there are 667 acres of empty, flat roofs suitable for vegetation, according to Balmori Associates, an urban design company. That is the equivalent of 80 percent of Central Park.
The best locations for green roofs are buildings with large, flat tops well exposed to the sun. That is why many of the city’s green roofs are in industrial neighborhoods in the Bronx and Queens.
One of the largest installations was completed in 2005 at Silvercup Studios in Long Island City, where parts of the HBO series “The Sopranos” were filmed. About 1,500 plants, in 20 different species of red, yellow and green, cover 35,000 square feet.
Because of high labor and transportation prices in New York, green roofs can cost as much as $30 a square foot to install in the city, up to three times more than in other places. While the environmental benefits of green roofs are real, builders have had a hard time justifying the extra cost when it is unclear how it will affect their bottom line.
Green roofs, for instance, absorb as much as 70 percent of the rain that might otherwise overwhelm the city’s sewage system during heavy downfalls and run directly in the East River, the Hudson River and New York Harbor. By diverting the runoff, the city could prevent millions of gallons of polluted water from reaching waterways.
But while runoff is a big problem for the city, it is a negligible one for individual building owners. Lawmakers and environmental activists, though, say that the new financial credits — worth $4.50 per square foot of vegetation — should prompt building owners to install green roofs that, over time, will help the city grapple with the growing problem of runoff.
“Essentially, cities are going to benefit more than any individuals will benefit because it will save with infrastructure costs,” said Diana Balmori of Balmori Associates, which helped install the green roof at Silvercup Studios. “It’s a modest help, what individuals receive, but it changes the way we think about infrastructure.”
When sunshine hits a blacktop roof, it heats the building beneath it as well as the area nearby. When it hits plants on a roof, in contrast, the plants not only absorb the sunshine, but cool the air when the water in their leaves evaporates.
Temperatures on buildings with green roofs are up to 30 percent lower during the daytime in the summer than they are on those with conventional roofs, which means that tenants on the floors below do not have to run their air-conditioning as much.
The savings can vary, though, depending on how well the windows are insulated and other variables.
And the average life of a typical roof can be doubled when a layer of plants rests on top. Con Ed’s 10,000-square-foot green roof, which was installed in July and is the first at one of its buildings, is more advanced than most projects. The company spent $200,000 to install 1,350 trays filled with 21,000 plants, including 15 varieties of sedum. The plants, which were cultivated at a nursery in Connecticut, sit in a mixture of volcanic rock, sandstone and other light stone capable of absorbing water.
The bottoms of the trays look like egg cartons; they allow a small amount of water to pool beneath the plants. The trays can easily be moved to provide access to the roof if there are leaks that have to be plugged. Con Ed chose sedum not only because it can absorb rainwater quickly, but also because it is not indigenous to New York, making it unlikely to attract potential pests. The plants also require very little maintenance.
Con Ed has teamed up with Columbia University’s Center for Climate Systems Research to evaluate the benefits, using rooftop sensors to measure the temperature, wind and water runoff. Con Edison said it hoped to use the findings to encourage customers to install green roofs themselves.
David Westman, the resource conservation coordinator at Con Edison, said, “It’s not only the right thing to do, but it can make economic sense.”
By MICHELLE NIJHUIS, The New York Times, August 26, 2008
Crows and their relatives — among them ravens, magpies and jays — are renowned for their intelligence and for their ability to flourish in human-dominated landscapes. That ability may have to do with cross-species social skills. In the Seattle area, where rapid suburban growth has attracted a thriving crow population, researchers have found that the birds can recognize individual human faces.
John M. Marzluff, a wildlife biologist at the University of Washington, has studied crows and ravens for more than 20 years and has long wondered if the birds could identify individual researchers. Previously trapped birds seemed more wary of particular scientists, and often were harder to catch. “I thought, ‘Well, it’s an annoyance, but it’s not really hampering our work,’ ” Dr. Marzluff said. “But then I thought we should test it directly.”
To test the birds’ recognition of faces separately from that of clothing, gait and other individual human characteristics, Dr. Marzluff and two students wore rubber masks. He designated a caveman mask as “dangerous” and, in a deliberate gesture of civic generosity, a Dick Cheney mask as “neutral.” Researchers in the dangerous mask then trapped and banded seven crows on the university’s campus in Seattle.
In the months that followed, the researchers and volunteers donned the masks on campus, this time walking prescribed routes and not bothering crows.
The crows had not forgotten. They scolded people in the dangerous mask significantly more than they did before they were trapped, even when the mask was disguised with a hat or worn upside down. The neutral mask provoked little reaction. The effect has not only persisted, but also multiplied over the past two years. Wearing the dangerous mask on one recent walk through campus, Dr. Marzluff said, he was scolded by 47 of the 53 crows he encountered, many more than had experienced or witnessed the initial trapping. The researchers hypothesize that crows learn to recognize threatening humans from both parents and others in their flock.
After their experiments on campus, Dr. Marzluff and his students tested the effect with more realistic masks. Using a half-dozen students as models, they enlisted a professional mask maker, then wore the new masks while trapping crows at several sites in and around Seattle. The researchers then gave a mix of neutral and dangerous masks to volunteer observers who, unaware of the masks’ histories, wore them at the trapping sites and recorded the crows’ responses.
The reaction to one of the dangerous masks was “quite spectacular,” said one volunteer, Bill Pochmerski, a retired telephone company manager who lives near Snohomish, Wash. “The birds were really raucous, screaming persistently,” he said, “and it was clear they weren’t upset about something in general. They were upset with me.”
Again, crows were significantly more likely to scold observers who wore a dangerous mask, and when confronted simultaneously by observers in dangerous and neutral masks, the birds almost unerringly chose to persecute the dangerous face. In downtown Seattle, where most passersby ignore crows, angry birds nearly touched their human foes. In rural areas, where crows are more likely to be viewed as noisy “flying rats” and shot, the birds expressed their displeasure from a distance.
Though Dr. Marzluff’s is the first formal study of human face recognition in wild birds, his preliminary findings confirm the suspicions of many other researchers who have observed similar abilities in crows, ravens, gulls and other species. The pioneering animal behaviorist Konrad Lorenz was so convinced of the perceptive capacities of crows and their relatives that he wore a devil costume when handling jackdaws. Stacia Backensto, a master’s student at the University of Alaska Fairbanks who studies ravens in the oil fields on Alaska’s North Slope, has assembled an elaborate costume — including a fake beard and a potbelly made of pillows — because she believes her face and body are familiar to previously captured birds.
Kevin J. McGowan, an ornithologist at the Cornell Laboratory of Ornithology who has trapped and banded crows in upstate New York for 20 years, said he was regularly followed by birds who have benefited from his handouts of peanuts — and harassed by others he has trapped in the past.
Why crows and similar species are so closely attuned to humans is a matter of debate. Bernd Heinrich, a professor emeritus at the University of Vermont known for his books on raven behavior, suggested that crows’ apparent ability to distinguish among human faces is a “byproduct of their acuity,” an outgrowth of their unusually keen ability to recognize one another, even after many months of separation.
Dr. McGowan and Dr. Marzluff believe that this ability gives crows and their brethren an evolutionary edge. “If you can learn who to avoid and who to seek out, that’s a lot easier than continually getting hurt,” Dr. Marzluff said. “I think it allows these animals to survive with us — and take advantage of us — in a much safer, more effective way.”
Study Maps Faults for New York Quakes
By KENNETH CHANG, The New York Times, August 26, 2008
New York City may seem immune to earthquakes, at least compared with its West Coast megacity counterpart, Los Angeles. But there is some danger.
A new analysis of 383 quakes in a 15,000-square-mile area around New York City estimates that a magnitude-5 earthquake in or around the city occurs on average once a century, and a magnitude-6 or larger quake occurs once every 670 years. An even larger magnitude-7 is estimated at once every 3,400 years.
Researchers at the Lamont-Doherty Earth Observatory at Columbia University analyzed earthquakes that occurred from 1677 to 2007 as well as data gathered by seismic instruments in the past 34 years and mapped out a family of faults responsible for most of the earthquakes. Their report appears in the current issue of the Bulletin of the Seismological Society of America.
“We now have some way to look at the geology and use it to map the hazards,” said Leonardo Seeber, a senior researcher at Lamont-Doherty and one of the study authors.
The historical record includes three earthquakes of magnitude-5 or larger, the most recent in 1884. That quake originated offshore near Coney Island and toppled chimneys in the city.
While earthquakes in the northeast United States are smaller and less frequent than in places like California or Japan, the risks still warrant attention from officials, the researchers said.
“New York City is a major concentration of people and buildings, so if you combine the rate of earthquakes with what is there to be damaged, that combination becomes relatively high,” said John Armbruster, another study author. “There’s a lot to be damaged. A magnitude-5 earthquake under Queens is going to be much more damaging than a magnitude-5 earthquake in upstate New York.”
Lynn R. Sykes, an emeritus professor of earth and environmental sciences at Columbia and the lead author of the study, said critical facilities needed the most attention. That includes schools, fire stations, bridges — and the Indian Point nuclear power plant 24 miles north of the city. The study found a previously unidentified boundary, likely a fault, that runs 25 miles to Peekskill, N.Y., from Stamford, Conn., passing within a mile of Indian Point.
With the new data, engineers could better analyze what types of forces the plant might experience in an earthquake along that fault. The owner, Entergy, is seeking to extend its operating licenses of the two reactors at Indian Point by 20 years.
Even a modest earthquake could wreak millions of dollars of damage on Manhattan. And, surprisingly, the lack of large earthquakes makes the smaller earthquakes potentially more damaging. In places like California, the many earthquakes have weakened the top layers of crust, making for less buildup of strain and less powerful quakes near the surface. Thus, the most damaging earthquakes usually originate 5 to 10 miles underground.
In the New York area, most earthquakes are much shallower, within three miles of the surface. A shallow earthquake shakes the surface more violently than a deep one of the same magnitude. Mr. Seeber said a recent magnitude-2.3 earthquake near Warwick, N.Y., shook items off shelves, and there were reports of damaged foundations.
Stiffer rocks in the New York area also transmit farther the higher-frequency vibrations that shake objects harder. “These very shallow earthquakes can deliver a big punch even though very small,” Mr. Seeber said.
The Appalachians Mountains were first pushed up several hundred million years ago, and those ancient large faults, including the Ramapo fault that also passes near Indian Point, have been quiet. The earthquakes have instead occurred along smaller faults running perpendicular to the older faults.
Israel to Display the Dead Sea Scrolls on the Internet
By ETHAN BRONNER, The New York Times, August 27, 2008
JERUSALEM — In a crowded laboratory painted in gray and cooled like a cave, half a dozen specialists embarked this week on a historic undertaking: digitally photographing every one of the thousands of fragments of the Dead Sea Scrolls with the aim of making the entire file — among the most sought-after and examined documents on earth — available to all on the Internet.
Equipped with high-powered cameras with resolution and clarity many times greater than those of conventional models, and with lights that emit neither heat nor ultraviolet rays, the scientists and technicians are uncovering previously illegible sections and letters of the scrolls, discoveries that could have significant scholarly impact.
The 2,000-year-old scrolls, found in the late 1940s in caves near the Dead Sea east of Jerusalem, contain the earliest known copies of every book of the Hebrew Bible (missing only the Book of Esther), as well as apocryphal texts and descriptions of rituals of a Jewish sect at the time of Jesus. The texts, most of them on parchment but some on papyrus, date from the third century B.C. to the first century A.D.
Only a handful of the scrolls exist in large pieces, with several on permanent exhibit at the Israel Museum here in its dimly lighted Shrine of the Book. Most of what was found is separated into 15,000 fragments that make up about 900 documents, fueling a longstanding debate on how to order the fragments as well as the origin and meaning of what is written on them.
The scrolls’ contemporary history has been something of a tortured one because they are among the most important sources of information on Jewish and early Christian life. After their initial discovery they were tightly held by a small circle of scholars. In the last 20 years access has improved significantly, and in 2001 they were published in their entirety. But debate over them seems only to grow.
Scholars continually ask the Israel Antiquities Authority, the custodian of the scrolls, for access to them, and museums around the world seek to display them. Next month, the Jewish Museum of New York will begin an exhibition of six of the scrolls.
The keepers of the scrolls, people like Pnina Shor, head of the conservation department of the antiquities authority, are delighted by the intense interest but say that each time a scroll is exposed to light, humidity and heat, it deteriorates. She says even without such exposure there is deterioration because of the ink used on some of the scrolls as well as the residue from the Scotch tape used by the 1950s scholars in piecing together fragments.
The entire collection was photographed only once before — in the 1950s using infrared — and those photographs are stored in a climate-controlled room because they show things already lost from some of the scrolls. The old infrared pictures will also be scanned in the new digital effort.
“The project began as a conservation necessity,” Ms. Shor explained. “We wanted to monitor the deterioration of the scrolls and realized we needed to take precise photographs to watch the process. That’s when we decided to do a comprehensive set of photos, both in color and infrared, to monitor selectively what is happening. We realized then that we could make the entire set of pictures available online to everyone, meaning that anyone will be able to see the scrolls in the kind of detail that no one has until now.”
The process will probably take one to two years — more before it is available online — and is being led by Greg Bearman, who retired from the NASA Jet Propulsion Laboratory. Data collection is directed by Simon Tanner of Kings College London.
Jonathan Ben-Dov, a professor of biblical studies at the University of Haifa, is taking part in the digitalization project. Watching the technicians gingerly move a fragment into place for a photograph, he said that it had long been very difficult for senior scholars to get access.
Once this project is completed, he said with wonder, “every undergraduate will be able to have a detailed look at them from numerous angles.”

Green Roofs Offer More Than Color for the Skyline
By KEN BELSON, The New York Times, August 28, 2008
The thousands of recently planted green and purple shrublike sedum lining the roof of Con Edison’s training center in Long Island City look a bit out of place in the shadow of Manhattan’s skyline.
But the tiny absorbent leaves and modest but hardy roots of the sedum — typically found in desert climates — are at the center of a growing effort to reduce greenhouse gases, rainwater runoff and electricity demand in New York.
This month, Gov. David A. Paterson approved tax abatements to developers and building owners who install green roofs, or a layer of vegetation and rock that absorbs rainwater, insulates buildings and extends the lives of roofs. Sedum, which soaks up water quickly and releases it slowly, is an ideal plant for the job.
Europe has had green roofs for decades, and cities like Chicago and Seattle have added many of them in recent years. But there are fewer in New York because of the cost of installing them compared with the benefits, which can be hard to quantify. The new one-year abatements, though, can cut as much as $100,000 a year from a building’s taxes, and are expected to turn what has largely been a hidden luxury into a standard feature of a little-seen part of the city’s landscape.
“This is just the beginning,” said Kari Elwell Katzander, a partner in Mingo Design, a landscape design firm in Manhattan that works on green roofs. “It’s not just about the green roof. This transcends into various ways to make buildings more green.”
There are few accurate reckonings of how much of the 944 million square feet of rooftops across New York City — 11.5 percent of the total building area — has gone green, or how much more could be cultivated. But clearly there is plenty of space available. Just in Long Island City, there are 667 acres of empty, flat roofs suitable for vegetation, according to Balmori Associates, an urban design company. That is the equivalent of 80 percent of Central Park.
The best locations for green roofs are buildings with large, flat tops well exposed to the sun. That is why many of the city’s green roofs are in industrial neighborhoods in the Bronx and Queens.
One of the largest installations was completed in 2005 at Silvercup Studios in Long Island City, where parts of the HBO series “The Sopranos” were filmed. About 1,500 plants, in 20 different species of red, yellow and green, cover 35,000 square feet.
Because of high labor and transportation prices in New York, green roofs can cost as much as $30 a square foot to install in the city, up to three times more than in other places. While the environmental benefits of green roofs are real, builders have had a hard time justifying the extra cost when it is unclear how it will affect their bottom line.
Green roofs, for instance, absorb as much as 70 percent of the rain that might otherwise overwhelm the city’s sewage system during heavy downfalls and run directly in the East River, the Hudson River and New York Harbor. By diverting the runoff, the city could prevent millions of gallons of polluted water from reaching waterways.
But while runoff is a big problem for the city, it is a negligible one for individual building owners. Lawmakers and environmental activists, though, say that the new financial credits — worth $4.50 per square foot of vegetation — should prompt building owners to install green roofs that, over time, will help the city grapple with the growing problem of runoff.
“Essentially, cities are going to benefit more than any individuals will benefit because it will save with infrastructure costs,” said Diana Balmori of Balmori Associates, which helped install the green roof at Silvercup Studios. “It’s a modest help, what individuals receive, but it changes the way we think about infrastructure.”
When sunshine hits a blacktop roof, it heats the building beneath it as well as the area nearby. When it hits plants on a roof, in contrast, the plants not only absorb the sunshine, but cool the air when the water in their leaves evaporates.
Temperatures on buildings with green roofs are up to 30 percent lower during the daytime in the summer than they are on those with conventional roofs, which means that tenants on the floors below do not have to run their air-conditioning as much.
The savings can vary, though, depending on how well the windows are insulated and other variables.
And the average life of a typical roof can be doubled when a layer of plants rests on top. Con Ed’s 10,000-square-foot green roof, which was installed in July and is the first at one of its buildings, is more advanced than most projects. The company spent $200,000 to install 1,350 trays filled with 21,000 plants, including 15 varieties of sedum. The plants, which were cultivated at a nursery in Connecticut, sit in a mixture of volcanic rock, sandstone and other light stone capable of absorbing water.
The bottoms of the trays look like egg cartons; they allow a small amount of water to pool beneath the plants. The trays can easily be moved to provide access to the roof if there are leaks that have to be plugged. Con Ed chose sedum not only because it can absorb rainwater quickly, but also because it is not indigenous to New York, making it unlikely to attract potential pests. The plants also require very little maintenance.
Con Ed has teamed up with Columbia University’s Center for Climate Systems Research to evaluate the benefits, using rooftop sensors to measure the temperature, wind and water runoff. Con Edison said it hoped to use the findings to encourage customers to install green roofs themselves.
David Westman, the resource conservation coordinator at Con Edison, said, “It’s not only the right thing to do, but it can make economic sense.”