tagged w/ Geology
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In a study published in the journal Geology, scientists at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science suggest that the large changes in the carbon isotopic composition of carbonates which occurred prior to the major climatic event more than 500 million years ago, known as 'Snowball Earth,' are unrelated to worldwide glacial events.
link:http://www.sciencedaily.com/releases/2012/01/120127140523.htmIn a study published in the journal Geology, scientists at the University of Miami... more
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This film and book project is a collaboration of evolutionary philosopher Brian Thomas Swimme and historian of religions Mary Evelyn Tucker. They weave a tapestry that draws together scientific discoveries in astronomy, geology, and biology with humanistic insights
concerning the nature of the universe.
PBS National Broadcast Premiere coming this December.
Click here for listings nationwide. WNET Ch. 13 in New York City will broadcast the film primetime on December 7th, 8:00pm.
More at the linkThis film and book project is a collaboration of evolutionary philosopher Brian Thomas... more
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_Thousands of people evacuated buildings across Washington, D.C., and New York City on Tuesday after a moderate earthquake in Virginia that was also felt as far south as Chapel Hill, N.C. No tsunami warning was issued for the East Coast.
..Parts of the Pentagon, White House and Capitol were among the areas evacuated.
At the Pentagon in northern Virginia, a low rumbling built and built to the point that the building was shaking. People ran into the corridors of the government's biggest building and as the shaking continued there were shouts of "Evacuate! Evacuate!"
Centered some 90 miles from the nation's capital, the quake was a magnitude 5.9, the U.S. Geological Survey said.
At the U.S. Capitol, light fixtures swung and the building shook for about 15 seconds while the tremor hit, NBC News reported.
At Reagan National Airport outside Washington, ceiling tiles fell during a few seconds of shaking. All flights were put on hold.
In New York City, NBC reported debris fell from the attorney general's office, causing a brief panic as people ran from the area.
Airport towers and government buildings in New York, including City Hall, were evacuated. The 26-story federal courthouse in lower Manhattan began swaying and hundreds of people were seen leaving the building.
A mild tremor was even felt by NBC reporters with President Barack Obama during his vacation on Martha's Vineyard, an island off Massachusetts.
In Charleston, W.Va., hundreds of workers left the state Capitol building and employees at other downtown office buildings were asked to leave temporarily."The whole building shook," said Jennifer Bundy, a spokeswoman for the state Supreme Court. "You could feel two different shakes. Everybody just kind of came out on their own."In Ohio, where office buildings swayed in Columbus and Cincinnati and the press box at the Cleveland Indians' Progressive Field shook. At least one building near the Statehouse was evacuated in downtown Columbus.In downtown Baltimore, Md., the quake sent office workers into the streets, where lamp posts swayed slightly as they called family and friends to check in.More about the quake at breakingnews.com
The earthquake’s epicenter was near Louisa, Va., the USGS reported. It was a very shallow quake, which would explain why it was so widely felt.
The D.C. area's previous record for an earthquake was on July 16, 2010, when a 3.6 magnitude quake was felt.
The East Coast gets earthquakes, but usually smaller ones than the West Coast and is less prepared for shaking.
This report will be updated as information becomes available.
Also see:
http://abcnews.go.com/Technology/earthquake-measured-59-magnitude-rattles-washington-york/story?id=14364643_Thousands of people evacuated buildings across Washington, D.C., and New York City on... more
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Does the position of geologic strata determine age?
In part one of this article, a reference to laboratory experiments that falsify the consensus view of sediment deposition mentioned that fossil ages could not be reliably determined based on the so-called "geologic column." The geologic column is defined as a series of depositional layers that form a chronological sequence. It is also called the "stratigraphical column."
Thus, the extinction of the dinosaurs is said to have taken place over 135 million years ago. However, the popular notion that the geologic column represents vast periods of time is being questioned by a number of geologists who realize that it most likely results from a series of catastrophic events.
Nicolaus Steno is often said to be the father of geology. His "principle of superposition" influences geologists to this day, even though it was formulated in the late 1600s. In many ways it seems to be completely straight forward, but only now is it recognized that it was not based on experiments but on field observation.
"At the time when any given stratum was being formed, all the matter resting upon it was fluid, and, therefore, at the time when the lower stratum was being formed, none of the upper strata existed."
In February 2000, Guy Berthault wrote a paper in which he described several experiments that analyzed the hydraulic processes involved with sedimentary layering. His conclusions were subsequently published in Lithology and Mineral Resources, Vol. 37, No. 5. Under conditions of constant flow rate and a continuous supply of particles, he discovered that a mixture of coarse and fine particles would separate into thin laminations.
Material flowing through a flume under simulated flood conditions created a downstream deposit that sorted into several horizontal strata that continued to build up on the advancing face. The unusual aspect to the deposition of particles is that each layer was composed of laminations younger than those farther back. Rather than top stratum being younger than the bottom, all strata were deposited simultaneously in a horizontal fashion. As the paper states: "Superposed strata are not, therefore, necessarily identical to successive sedimentary layers."
Another problem with the superposed strata theory is speed of erosion. The current weathering rate for the continental shelves is thought to be six centimeters per thousand years. Therefore, in less than 10 million years today's continental shelves will erode away. The difficulty with that assessment is that sediments hundreds of millions of years old are on top of all the continental shelves. How can this be when that material should have all washed away in the Cenozoic era?
Since rock layers are often dated by the type of fossil contained within them, and experiments reveal that the deposition of sediments containing pre-fossil skeletons can no longer be based on the principle of superposition, then rock layers can no longer be dated in that way.
Another problem with gradualism in geology is the radiometric dating of rocks. Rocks are typically dated using the principle of constant radioactive isotope decay rates and an assumption of the estimated original isotope ratios. The oldest rocks are dated using the uranium/lead half-life ratios.
When rocks form, they contain a certain percentage of elements. Zircon contains uranium and thorium atoms, but no lead. Therefore, the assumption is that all the lead in zircon must be radiogenic. This idea depends on a uniform, gradual process free of sudden alteration. If the decay rates of various elements can be altered by external influences, then the percentage formulae that indicate a sample's age are unreliable.
"There has been in recent years the horrible realization that radiodecay rates are not as constant as previously thought, nor are they immune to environmental influences. And this could mean that the atomic clocks are reset during some global disaster, and events which brought the Mesozoic to a close may not be 65 million years ago but, rather, within the age and memory of man." Fred Jueneman, FAIC, Industrial Research & Development, p.21, June 1982.
A foundation of Electric Universe theory is the flow of electricity through space and the catastrophic influence it had on planets and moons in the recent past. Whatever phenomenon it was, within the recorded history of humanity a great cataclysm engulfed the Earth. Canyons were blasted out, mountains raised, ocean basins shifted, and great swathes of plants, animals, and people obliterated in the blink of an eye.
Those enormous energies, the rearrangement of the topography, and the intense radiation make it impossible to assign any measure of antiquity. Repeated and rapid sedimentation that hardened to stone in mere minutes, fossilizing its burden of organic detritus, means that what is visible on the surface might be the same age as what lies beneath.
Stephen Smith
Apr 29, 2011
Hat tip to Mel AchesonDoes the position of geologic strata determine age?
In part one of this article, a... more
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Did the terrain we see around us take millions of years to form? Some recent experiments suggest otherwise.
As mentioned in past articles, Electric Universe proponents think that something is wrong with the "long, slow" view of geology. Fossils are dated based on the rock layers in which they are found, so a uniformitarian view of geology influences the understanding of how life began and evolved on Earth. If the rock ages are wrong, fossil ages are wrong.
It is commonly believed that fossils are created when an animal or plant dies and is subsequently entombed in mud or silt before decay and dissolution. After millions of years, the sediments in which it is buried harden because of pressure from the overlying accumulation of other later deposits.
Tectonic forces then break or bend the ocean bottom (or lakebed), causing it to rise above the waterline and dry out, hardening the sediments into stone. Those layers of stone around the world are used to determine when the fossils were alive, since it is assumed that the top layers are younger than the bottom layers. The layers of hardened sediments are called "the geologic column."
Prevailing theories state that it took millions, if not billions, of years to arrange the scenery on our planet. Mountains rise in response to mechanisms that are so slow as to be undetectable: the Himalayas, the Alps, and the Rocky Mountains retain the same shapes that ancient nomadic tribes saw.
The seas, it is said, have not left their basins in time spans that have no meaning to the human mind. The Atlantic Ocean has bridged the distance between Africa, Europe, and the Americas for a period greater than the human species has existed on Earth.
Rivers, deserts, canyons—all appear to our modern eyes just as they would have appeared to Alexander the Great, Goyathlay, Sargon, or Khufu. The cyclic processes of erosion or sediment deposition are the same today as they were long ago. Most of the current methods for dating artifacts, geologic layers, or fossils are dependent on that presumed gradual, uniform action.
What if the uniformitarian hypothesis is incorrect? What if the topography of Earth was created in a time so short that ancient civilizations were able to record it? What meaning would the Neolithic, or the Jurassic, or the Precambrian eras have? Would evolutionary theory suffer for the lack of a chronological map?
Electric Universe theorists postulate that between 5000 and 10,000 years ago (perhaps sooner), the Earth and its sister planets were engulfed in a catastrophic interplay of celestial forces that have not been seen since. Clouds of electrified plasma and electric arcs described by the ancients as "thunderbolts of the gods" dissected the continental geography, creating what traditional theories say are ages-old structures in an instant of time.
"Evolutionary theory is based upon the belief that a succession of fossil species in a scale of geological time demonstrates that evolutionary progress has taken place... As we have shown in the laboratory, layers of incoming sediment have been wrongly identified as being strata. The scale of geological time and the chronological succession of fossils have been calculated on this mistaken belief: that strata are successive layers of sediment. So the position of fossils, rather than sharing evolution, merely indicates the distribution of marine species which lived at different depths." (Guy Berthault: Fundamental Experiments in Stratification)
Stephen Smith
Hat tip to Mel AchesonDid the terrain we see around us take millions of years to form? Some recent... more
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Summary: Dan Fagre, a research ecologist at the Northern Rocky Mountain Science Center of the United States Geological Survey, speaks with Earthjustice staffer Jessica Knoblauch. Over the past 15 years, Fagre has worked to understand how climate change will affect mountain ecosystems such as Glacier National Park, the cornerstone of the Crown of the Continent ecosystem and a major focus of Earthjustice's litigation. Scientists like Fagre predict that, due to rising temperatures, Glacier National Park will be glacier free by 2030.
Click on link to read everything imaginable... and prepare to perhaps cry.Summary: Dan Fagre, a research ecologist at the Northern Rocky Mountain Science Center... more
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Japan has been shaken due to an earthquake of 8.9 magnitudes. This earthquake has done huge scale damage to infrastructure of Japan. Simultaneously, it has been reported that tsunami waves will strike vast areas of Pacific Ocean. Countries what may come under affect of these tsunami waves are Russia, Philippines, Taiwan, Colombia, Ecuador, Chile, Peru, Fiji, Papua New Guinea, Guatemala, El Salvador, Nicaragua, Costa Rica, Honduras and Panama.Japan has been shaken due to an earthquake of 8.9 magnitudes. This earthquake has done... more
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An earthquake hit Honshu, Japan today. This quake did not create tsunami. Other areas of Japan what came in quake struck regions are Morioka, Sendai and Fukushima. The intensity of quake on Richter scale was told 7.2. This quake shakes buildings up to Tokyo. However, according to statements of Alaska and West Coast’s warning centres, this quake did no produce a tsunami. But the areas of Alaska coast, British Columbia, Washington, Oregon and California are not in danger due to the tsunami.An earthquake hit Honshu, Japan today. This quake did not create tsunami. Other areas... more
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Latest Complete News Updates This time of year we see lots of pictures of our favorite celebrities sunning themselves and their families on the beaches of Hawaii. A small earthquake hit Hawaii on Thursday, with a jolt felt across Honolulu.Latest Complete News Updates This time of year we see lots of pictures of our favorite... more
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The New York Times
December 21, 2010
A Scientist, His Work and a Climate Reckoning
By JUSTIN GILLIS
PART ONE…
MAUNA LOA OBSERVATORY, Hawaii — Two gray machines sit inside a pair of utilitarian buildings here, sniffing the fresh breezes that blow across thousands of miles of ocean.
They make no noise. But once an hour, they spit out a number, and for decades, it has been rising relentlessly.
The first machine of this type was installed on Mauna Loa in the 1950s at the behest of Charles David Keeling, a scientist from San Diego. His resulting discovery, of the increasing level of carbon dioxide in the atmosphere, transformed the scientific understanding of humanity’s relationship with the earth. A graph of his findings is inscribed on a wall in Washington as one of the great achievements of modern science.
Yet, five years after Dr. Keeling’s death, his discovery is a focus not of celebration but of conflict. It has become the touchstone of a worldwide political debate over global warming.
When Dr. Keeling, as a young researcher, became the first person in the world to develop an accurate technique for measuring carbon dioxide in the air, the amount he discovered was 310 parts per million. That means every million pints of air, for example, contained 310 pints of carbon dioxide.
By 2005, the year he died, the number had risen to 380 parts per million. Sometime in the next few years it is expected to pass 400. Without stronger action to limit emissions, the number could pass 560 before the end of the century, double what it was before the Industrial Revolution.
The greatest question in climate science is: What will that do to the temperature of the earth?
Scientists have long known that carbon dioxide traps heat at the surface of the planet. They cite growing evidence that the inexorable rise of the gas is altering the climate in ways that threaten human welfare.
Fossil fuel emissions, they say, are like a runaway train, hurtling the world’s citizens toward a stone wall — a carbon dioxide level that, over time, will cause profound changes.
The risks include melting ice sheets, rising seas, more droughts and heat waves, more flash floods, worse storms, extinction of many plants and animals, depletion of sea life and — perhaps most important — difficulty in producing an adequate supply of food. Many of these changes are taking place at a modest level already, the scientists say, but are expected to intensify.
Reacting to such warnings, President George Bush committed the United States in 1992 to limiting its emissions of greenhouse gases, especially carbon dioxide. Scores of other nations made the same pledge, in a treaty that was long on promises and short on specifics.
But in 1998, when it came time to commit to details in a document known as the Kyoto Protocol, Congress balked. Many countries did ratify the protocol, but it had only a limited effect, and the past decade has seen little additional progress in controlling emissions.
Many countries are reluctant to commit themselves to tough emission limits, fearing that doing so will hurt economic growth. International climate talks in Cancún, Mexico, this month ended with only modest progress. The Obama administration, which came into office pledging to limit emissions in the United States, scaled back its ambitions after climate and energy legislation died in the Senate this year.
Challengers have mounted a vigorous assault on the science of climate change. Polls indicate that the public has grown more doubtful about that science. Some of the Republicans who will take control of the House of Representatives in January have promised to subject climate researchers to a season of new scrutiny.
One of them is Representative Dana Rohrabacher, Republican of California. In a recent Congressional hearing on global warming, he said, “The CO2 levels in the atmosphere are rather undramatic.”
But most scientists trained in the physics of the atmosphere have a different reaction to the increase.
“I find it shocking,” said Pieter P. Tans, who runs the government monitoring program of which the Mauna Loa Observatory is a part. “We really are in a predicament here, and it’s getting worse every year.”
As the political debate drags on, the mute gray boxes atop Mauna Loa keep spitting out their numbers, providing a reality check: not only is the carbon dioxide level rising relentlessly, but the pace of that rise is accelerating over time.
“Nature doesn’t care how hard we tried,” Jeffrey D. Sachs, the Columbia University economist, said at a recent seminar. “Nature cares how high the parts per million mount. This is running away.”
CONTINUED…The New York Times
December 21, 2010
A Scientist, His Work and a Climate Reckoning... more
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Death toll climbs to 54 in Indonesia volcano's latest eruption
From Kathy Quiano, CNN
November 5, 2010 12:28 a.m. EDT
Photo: The air is thick with volcanic ash as residents flee on motorcycle in Klaten district, central Java.
STORY HIGHLIGHTS
* NEW: 78 others have been severely burned
* Mount Merapi started its recent eruptions on October 26
* Friday's victims bring the total to 93 killed
* The volcano has not stopped erupting since Thursday
Jakarta, Indonesia (CNN) -- The latest eruption of Indonesia's Mount Merapi volcano, on Friday, killed at least 54 people and severely burned 78, hospital officials said.
Bodies recovered from a village about 16 kilometers (9.9 miles) from the volcano were badly burned, Commissioner Tjiptono of the Yogyakarta police told a local station, TV One.
Mount Merapi began its latest eruptions on October 26. Friday's victims bring the total to 93 killed.
The volcano has not stopped erupting since Thursday, the Volcanology and Geological Disaster Management Office said. An explosion Thursday night could be heard 30 kilometers (18 miles) away, and it continued to spew ash clouds.
Earlier, Mount Merapi had belched a steady stream of gas and ash, unleashing a pair of powerful eruptions into the morning sky on Thursday.
The hot clouds hovered over central Java, rising up to 2.5 kilometers (1.5 miles) and then drifting to the south toward Kali Gendol, Kali Kuning, Kali Boyong, Kali Krasak and Kali Bedok, according to the Indonesian Volcanology and Geological Disaster Mitigation Disaster Agency.
Those affected by the latest eruption lived outside the 15-kilometer (9-mile) evacuation radius that had been established. The danger zone was expanded to 20 kilometers (12 miles) after Friday's eruption.
Residents of a village 12 kilometers (7.5 miles) from the volcano were ordered to move for safety, said Sutopo Purwo Nugroho, head of risk disaster reduction.
Nearly 75,000 people have been evacuated, according to Indonesia's National Disaster Management Board.
Residents on the volcano have repeatedly evacuated, but then returned to check on their houses and farm animals and fled anew with each fresh eruption.
Because of rains, geological officials are warning residents and evacuees not to go to areas within the danger zone or near rivers.
Rainfall can convert volcanic ash to lahar, or mudflow.
There have been reports of mudflow headed down riverbeds on Merapi's slopes.
The 3,000-meter (9,800-foot) Merapi is famously unpredictable. An eruption killed two people in 2006 and another killed more than 60 villagers in 1994. About 1,300 people died when Merapi erupted in 1930.
In addition, last week, a 7.7-magnitude earthquake hit Indonesia's coast, triggering a tsunami and killing at least 449 people. Hundreds more were injured.SCROLL DOWN FOR NEWEST UPDATES
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Death toll climbs... more
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10/31/10 Updates: Updates: 449 Dead, 270 Injured, 96 Missing after 7.7 Earthquake Triggers Tsunami, Followed by Two Volcano Eruptions, In Indonesia | Videos | Photos
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ORIGINAL NEWS STORY...
112 dead, 500 missing after 7.7 quake triggers tsunami
http://www.cnn.com/2010/WORLD/asiapcf/10/26/indonesia.quake/index.html?hpt=T1
At least 112 dead, more than 500 missing after Indonesia quake
From Andy Saputra, CNN
October 26, 2010 1:29 p.m. EDT
Indonesian resorts destroyed
Jakarta, Indonesia (CNN) -- At least 112 people were killed and 502 others were missing after a 7.7-magnitude earthquake struck off Sumatra on Monday and triggered a tsunami, Indonesian officials said Tuesday.
The Pacific Tsunami Warning Center said the quake generated a "significant" tsunami. Some of the missing may include people who are unaccounted for after fleeing to higher ground, said Henri Dori Satoko, the head of the Mentawai Islands parliament.
Although communication with remote areas was difficult, some witnesses in West Sumatra reported seeing a wave 6 meters (nearly 20 feet) high. Other reports described the tsunami as being about 3 meters (almost 10 feet) high.
Satoko said at least one village with a population of about 200 people was swept away, with only 40 people recovered.
Eight to 10 Australians on board a tourist vessel who had been feared missing were reported to be safe, Satoko said. "All foreign tourists are safe.".
The numbers of dead and injured were in flux because information was trickling in from remote parts of Indonesia, a country made up of myriad islands. The area believed hardest-hit was the Mentawai Islands, a popular surfing destination. In particular, Pagai Island was thought to have been affected, said Ita Balanda, a program manager for World Vision in Padang.
Large waves were keeping rescue crews and aid workers from reaching the area. An Indonesian Red Cross assessment team had set out for the island but was forced to turn back because of high seas and debris in the water, said Gayat, spokeswoman for the agency, who like many Indonesians only uses one name. She said the team will try again Wednesday morning.
The trip takes 10 hours, even under good conditions, Balanda said.
The quake struck at 9:42 p.m. Monday, triggering a tsunami warning that was later lifted when sea level readings indicated the threat had diminished or was over for most areas. Its epicenter was 240 kilometers (150 miles) south of Padang, at a depth of 20.6 kilometers (12.8 miles), according to the U.S. Geological Survey. The magnitude was revised upward from a preliminary magnitude of 7.5.
"Big, slow, long earthquake last night, and a couple tremblers afterward," WavePark Mentawai Surfing Resort said on its website. "Turns out it was a 7.5 about 70 [kilometers] south of us." The resort said it saw "about six waves on the beach after about 20 minutes" but none was higher than usually seen during high tide.
"No damage here, but reports of damage to other resorts and charter boats further south," the posting said.
"The local residents in the Mentawai Islands reported seeing a tsunami as high as 3 meters [that] reached as far as 600 meters inland," said Mujiharto of the Indonesian Health Ministry.
The Perfect Wave, a surf travel company that said it had 32 clients in the area, also described the wave in a statement as about 3 meters (10 feet) high, and said it washed through a bay where two boats with clients on board were docked. One boat hit the other, which caught on fire, and all the guests jumped overboard. Nine guests and five crew members were washed into the jungle and took more than an hour to make their way to safety, the company said.
All those aboard were picked up by a third boat and were safe "apart from suffering some smoke inhalation and minor scratches," the statement said.
A surf guide aboard the third boat reported "there was a lot of debris floating in the water including bar stools and other pieces of furniture from Macaronis Resort," the company said. "No news on the state of the village at Silabu."
The resort, where six clients were staying, is "all but gone," the statement said.
"It's very difficult to access the coast right now because the sea is quite bad," said Gilles Bordessoule, owner of the Siloinak Surf Resort. He said his property was unaffected, but his staff was attempting to help the Macaronis Resort, which was "completely destroyed" along with two others. Two of the Macaronis guests are missing, he said.
He said the only means of communication with the affected area is by satellite phone, which is how he found out about the resort and received some other information. The fate of the other 130 kilometers (80 miles) of coastline is unknown, he said.
Bordessoule said he had been in contact with authorities and residents of the area and was told between 150 and 180 people are dead and body bags are needed.
World Vision's Balanda said her organization is working with the Indonesian government and the United Nations to figure out how to get to the hardest-hit area. Indonesian government resources have been sent to central Java, where Mount Merapi was erupting, she said, but said her group hopes one or two helicopters will be freed up to help with the quake and tsunami response. She said she is receiving information from a local nongovernmental organization as well as others in the region.
The Perfect Wave said it was working to obtain replacement passports for its clients and organize flights home.
The city of Padang and the Mentawai Islands are at the meeting place of two tectonic plates, making them vulnerable to earthquakes and tsunamis.
On December 26, 2004, a 9.1-magnitude earthquake struck off northern Sumatra. A tsunami generated by that earthquake killed more than 225,000 people in 14 countries -- mainly India, Indonesia, Maldives, Sri Lanka and Thailand. The Indonesian region of Banda Aceh was hard-hit: About 150,000 died there.
CNN's Sarita Harilela and Brian Walker contributed to this report.10/31/10 Updates: Updates: 449 Dead, 270 Injured, 96 Missing after 7.7 Earthquake... more
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Study shakes up scientists' view of San Andreas earthquake risk
Researchers find major quakes on the southern section, on average, every 88 years — three times as often as previously thought. It's the strongest evidence yet that we're overdue for a massive quake.
San Andreas fault study
Photo: Sarah Robinson, 23, a graduate student at Arizona State University, runs along a trench at the Bidart Fan sector of the San Andreas fault in June 2009. She is on a team of geologists trying to construct a history of earthquakes on the San Andreas fault by reading lines of sediment in the earth. (Ricardo DeAratanha / Los Angeles Times / June 1, 2009)
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By Rong-Gong Lin II, Los Angeles Times
August 21, 2010
Southern California is long overdue for a major earthquake along the San Andreas fault, according to a landmark study of historic seismic activity released Friday.
The study, produced after several years of field studies in the Carrizo Plain area about 100 miles northwest of Los Angeles, found that earthquakes along the San Andreas fault have occurred far more often than previously believed.
For years, scientists have said major earthquakes occurred every 250 to 450 years along this part of the San Andreas. The new study found big temblors on the fault every 88 years, on average.
The last massive earthquake on that part of the fault was in 1857, leading scientists to warn that another such temblor is likely in Southern California.
"The next earthquake could be sooner than later," said Lisa Grant Ludwig, a UC Irvine earthquake expert and co-author of the study, which was published online in the journal Geology. "It was thought that we weren't at risk of having another large one any time soon. Well, now, it might be ready to rupture."
Other seismic experts described the revelation as a major change in the way they think about earthquake risks along the southern San Andreas fault.
Thomas Jordan, director of the Southern California Earthquake Center, said the fault is "locked and loaded. It's been a long time since an earthquake has occurred on that fault — over 150 years."
To reach the new conclusion, scientists dug trenches deep into the Carrizo Plain. They used carbon dating and sophisticated imaging technology known as lidar to find signs of earth movements. They were able to detect earthquakes dating back to the 15th century, creating a far more complete record than had previously been known.
The research found that earlier examinations of the San Andreas had badly undercounted the number of major earthquakes. Those were based on observations made in the 1970s when scientists used measuring tape to look for evidence of past earthquakes.
"Now we have better techniques," Grant Ludwig said. "We can see there's actually more earthquakes."
Scientists now estimate that earthquakes occurred on that section of the fault in 1417, 1462, 1565, 1614 and 1713.
The finding adds weight to the view of many seismologists that the San Andreas has been in a quiet period and that a major rupture is possible. A 2009 study, which Grant Ludwig also participated in, suggested that the San Andreas was overdue for a rupture. But Friday's report offers a much more grim estimate of how frequently quakes have occurred on that segment of the fault.
The San Andreas fault is considered one of the most dangerous in Southern California, partly because it is so long that its southern section is capable of producing a temblor as large as magnitude 8.1.
By contrast, earthquake experts consider 1994's destructive 6.7-magnitude Northridge quake, which occurred on a different fault, to be a medium-sized quake.
The San Andreas is a sleeping giant. It's hard to imagine the power of a huge quake on the southern section because the last one occurred more than a century ago when the area was sparsely populated. Just 4,000 people lived in Los Angeles at the time.
The 1857 temblor, with an estimated magnitude of 7.9, is known as the Fort Tejon quake, but that's a bit of a misnomer because it is thought to have started farther north, way up in Parkfield in Monterey County. The quake then barreled south on the San Andreas for about 200 miles, through Fort Tejon near the northern edge of what is now Los Angeles County, then east toward the Cajon Pass in San Bernardino County, near what is now the 15 Freeway.
The quake was so powerful that the soil liquefied, causing trees as far away as Stockton to sink. Trees were also uprooted west of Fort Tejon. The shaking lasted 1 to 3 minutes.
The study was conducted by scientists at UC Irvine and Arizona State University. As preliminary data went out for peer review, other earthquake scientists immediately took note.
The U.S. Geological Survey was so concerned that it dispatched its own team of investigators to the Carrizo Plain to look over the initial findings and review the evidence in the trenches.
"These investigators really were challenged by their scientific peers," said Ken Hudnut, a geophysicist at the U.S. Geological Survey. "And they made it through. They ran the gantlet and came through with a really solid paper."
Hudnut said the "Big One" wouldn't compare to most quakes Californians have endured. Such a large quake on the San Andreas, generally above a magnitude 7, would send enormous V-shape energy waves spreading out from the fault. If the earthquake energy hit the Los Angeles Basin, the soft sediment underneath it could actually amplify the waves, making the shaking worse.
Hudnut said the study offers both "bad news and good news," noting that it also concluded future earthquakes along that section of the San Andreas could be smaller than the 1857 quake.
"It's not the kind of news that ought to make people crawl into the fetal position. Rather, it's the kind of information that ought to once remind people about basic earthquake preparedness," Hudnut said.
Grant Ludwig said her research should motivate people to prepare.
"If you're waiting for someone to tell you when we're close to the next San Andreas earthquake, just look at the data," she said. "If we look at the only data we have, it's not very comforting. I'm preparing for that possibility."Study shakes up scientists' view of San Andreas earthquake risk
Researchers... more
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A Texas woman says she spotted the image of the Virgin Mary holding baby Jesus in rocks.
Stephanie Madden, a Granbury resident, says she saw the holy image in two oddly shaped rocks on a walk during a break at work.“It looks like Mary holding baby Jesus to me,” she told CBS 11 News. “You can see the cape or shawl or whatever it is she covers her head with and wraps around him.” She added: “And you can see her face looking down at him.”
But don’t call it a coincidence–Madden believes it is a divine sign. “Coincidence is when God chooses to remain anonymous,” she says. “I was showing them to people at church Sunday morning and one of the members said ‘hey do you know in the bible it says, in Luke 19:40, ‘If my people become silent that even the rocks will cry out’.”
“That hit me as confirmation that I’m supposed to say something,” she says.
And now, Madden has taken to the Internet to share her rocks and hopes it will resonate with others.
“Some people see it, some people don’t,” she says. “I don’t really care if people think I’m crazy.”
http://www.tabloidprodigy.com/?p=17263A Texas woman says she spotted the image of the Virgin Mary holding baby Jesus in... more
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Zircons are tiny crystals with a big story to tell. Some of these minerals are the oldest Earth materials ever discovered, and therefore yield clues about what the planet was like after it formed 4.5 billion years ago. In this new Science Bulletins video, travel to a remote island off Greenland's coast and a zircon-making lab in New York State to learn how geologists are using these time capsules to build new hypotheses about the early Earth.Zircons are tiny crystals with a big story to tell. Some of these minerals are the... more
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