This Oct. 25, 2014 photo provided by the U.S. Geological Survey shows a Hawaii Volcano Observatory geologist standing on a partly cooled section of lava flow near the town of Pahoa on the Big Island of Hawaii. Note the thin red horizontal line of molten lava visible along the bottom third of the photo. The flow here is about one meter (three feet) thick, but slightly farther upslope where the lava has had more time to inflate the thickness was closer to two meters. Dozens of residents in this rural area of Hawaii were placed on alert as flowing lava continued to advance. Authorities on Sunday, Oct. 26, 2014 said lava had advanced about 250 yards since Saturday morning and was moving at the rate of about 10 to 15 yards an hour, consistent with its advancement in recent days. The flow front passed through a predominantly Buddhist cemetery, covering grave sites in the mostly rural region of Puna, and was roughly a half-mile from Pahoa Village Road, the main street of Pahoa. (AP Photo/U.S. Geological Survey)
A river of asphalt-black lava that has slowly snaked through unoccupied land for months has burned down a shed on residential property on Hawaii’s Big Island.
Lava burned the empty wooden shed Tuesday and came within 200 yards of two homes in Pahoa Village, the commercial center of the island’s agricultural Puna district.
Dozens of residents in the rural community have been told they might have to evacuate because of the slow-moving flow.
Meanwhile, officials say an elementary school in the molten stream’s projected path will be closed starting Wednesday.
Depending on which side of the flow students live on, they’ll either go to a newly built temporary facility or other area schools starting Nov. 7 and 10.
In this Oct. 27, 2014 photo provided by the U.S. Geological Survey, the lava flow from Kilauea Volcano that began on June 27 nears the town of Pahoa on the Big Island of Hawaii. Residents of the small town have had weeks to prepare for what’s been described as a slow-motion disaster. County officials are making arrangements for those living in the lava’s path to be able to watch the lava destroy their homes as a means of closure. (AP Photo/U.S. Geological Survey)This Oct. 26, 2014 photo provided by the U.S. Geological Survey a Hawaii Volcano Observatory geologist mapping the margin of the June 27 lava flow in the open field below Cemetery Road near the town of Pahoa on the Big Island of Hawaii. Dozens of residents in this rural area of Hawaii were placed on alert as flowing lava continued to advance. Authorities on Sunday, Oct. 26, 2014 said lava had advanced about 250 yards since Saturday morning and was moving at the rate of about 10 to 15 yards an hour, consistent with its advancement in recent days. The flow front passed through a predominantly Buddhist cemetery, covering grave sites in the mostly rural region of Puna, and was roughly a half-mile from Pahoa Village Road, the main street of Pahoa. (AP Photo/U.S. Geological Survey)In this Oct. 27, 2014 photo provided by the U.S. Geological Survey, lava flow from Kilauea Volcano that began on June 27 burns through thick vegetation below the pasture downslope of the Pahoa cemetery near the town of Pahoa on the Big Island of Hawaii. Residents of the small town have had weeks to prepare for what’s been described as a slow-motion disaster. County officials are making arrangements for those living in the lava’s path to be able to watch the lava destroy their homes as a means of closure. (AP Photo/U.S. Geological Survey)
Breakouts of lava from Hawaii’s Kilauea volcano are seen near the West end of Wilipe, Hawaii, on July 31, 2002
Smoldering lava from a slow-erupting volcano has reached within yards (several meters) of homes on Hawaii’s Big Island, emergency officials said Monday as villagers braced to evacuate.
The lava flow from the Kilauea volcano has been threatening nearby homes for weeks, and was 100 yards (91 meters) from the nearest house by early Monday. The lava front was moving at between 10-15 yards (9-14 m) an hour.
“Based on the current flow location, direction and advancement, residents in the flow path were placed on an evacuation advisory,” said the County of Hawaii’s Civil Defense force in an online update.
The slow-moving waves of lava, burning everything in its path, had advanced some 275 yards (251 m) in the past 24 hours towards Pahoa town, on the eastern tip of the island, officials said.
Hawaii County Mayor Billy Kenoi declared a state of emergency last month after the lava advanced to within a mile (1.6 km) of a residential area known as the Ka’ohe Homesteads.
Last week, Hawaii Governor Neil Abercrombie requested a Presidential Disaster Declaration to unlock federal resources to help local emergency protective measures.
As the lava threatens a main road in the area, measures needed include providing alternative routes and accommodating some 900 children that will be displaced by the lava, according to Abercrombie’s office.
Hawaii Island, or the Big Island, is the largest of the eight main islands which make up the Pacific US state—an archipelago that includes hundreds of smaller volcanic islands.
Controlled burning of surface oil slicks during the Deepwater Horizon event. Credit: David Valentine
Due to the environmental disaster’s unprecedented scope, assessing the damage caused by the 2010 Deepwater Horizon spill in the Gulf of Mexico has been a challenge. One unsolved puzzle is the location of 2 million barrels of submerged oil thought to be trapped in the deep ocean.
UC Santa Barbara’s David Valentine and colleagues from the Woods Hole Oceanographic Institute (WHOI) and UC Irvine have been able to describe the path the oil followed to create a footprint on the deep ocean floor. The findings appear today in the Proceedings of the National Academy of Sciences.
For this study, the scientists used data from the Natural Resource Damage Assessment process conducted by the National Oceanic and Atmospheric Administration. The United States government estimates the Macondo well’s total discharge — from the spill in April 2010 until the well was capped that July — to be 5 million barrels.
By analyzing data from more than 3,000 samples collected at 534 locations over 12 expeditions, they identified a 1,250-square-mile patch of the deep sea floor upon which 2 to 16 percent of the discharged oil was deposited. The fallout of oil to the sea floor created thin deposits most intensive to the southwest of the Macondo well. The oil was most concentrated within the top half inch of the sea floor and was patchy even at the scale of a few feet.
The investigation focused primarily on hopane, a nonreactive hydrocarbon that served as a proxy for the discharged oil. Researchers analyzed the spatial distribution of hopane in the northern Gulf of Mexico and found it was most concentrated in a thin layer at the sea floor within 25 miles of the ruptured well, clearly implicating Deepwater Horizon as the source.
“Based on the evidence, our findings suggest that these deposits come from Macondo oil that was first suspended in the deep ocean and then settled to the sea floor without ever reaching the ocean surface,” said Valentine, a professor of earth science and biology at UCSB. “The pattern is like a shadow of the tiny oil droplets that were initially trapped at ocean depths around 3,500 feet and pushed around by the deep currents. Some combination of chemistry, biology and physics ultimately caused those droplets to rain down another 1,000 feet to rest on the sea floor.”
Valentine and his colleagues were able to identify hotspots of oil fallout in close proximity to damaged deep-sea corals. According to the researchers, this data supports the previously disputed finding that these corals were damaged by the Deepwater Horizon spill.
“The evidence is becoming clear that oily particles were raining down around these deep sea corals, which provides a compelling explanation for the injury they suffered,” said Valentine. “The pattern of contamination we observe is fully consistent with the Deepwater Horizon event but not with natural seeps — the suggested alternative.”
While the study examined a specified area, the scientists argue that the observed oil represents a minimum value. They purport that oil deposition likely occurred outside the study area but so far has largely evaded detection because of its patchiness.
“This analysis provides us with, for the first time, some closure on the question ‘Where did the oil go and how?’ ” said Don Rice, program director in the National Science Foundation’s Division of Ocean Sciences. “It also alerts us that this knowledge remains largely provisional until we can fully account for the remaining 70 percent.”
“These findings should be useful for assessing the damage caused by the Deepwater Horizon spill as well as planning future studies to further define the extent and nature of the contamination,” Valentine concluded. “Our work can also help to assess the fate of reactive hydrocarbons, test models of oil’s behavior in the ocean and plan for future spills.”
Co-authors are G. Burch Fisher and Sarah C. Bagby, postdoctoral researchers in the Valentine Lab at UCSB; Robert K. Nelson, Christopher M. Reddy and Sean P. Sylva of WHOI; and Mary A. Woo of UC Irvine. The research was funded by the National Science Foundation.
Reference:
David L. Valentine, G. Burch Fisher, Sarah C. Bagby, Robert K. Nelson, Christopher M. Reddy, Sean P. Sylva, and Mary A. Woo. Fallout plume of submerged oil from Deepwater Horizon. PNAS, October 27, 2014 DOI: 10.1073/pnas.1414873111
Note : The above story is based on materials provided by University of California – Santa Barbara. The original article was written by Julie Cohen.
The researchers simulated earthquakes with magnitudes between 9.0 and 9.6 originating at different locations along the Aleutian-Alaska subduction zone, and found that the unique geometry of the eastern Aleutians would direct the largest post-earthquake tsunami energy directly toward the Hawaiian Islands. The red circles are centered on Kaua‘i and encircle the Big Island. Credit: Rhett Butler
A mass of marine debris discovered in a giant sinkhole in the Hawaiian islands provides evidence that at least one mammoth tsunami, larger than any in Hawaii’s recorded history, has struck the islands, and that a similar disaster could happen again, new research finds. Scientists are reporting that a wall of water up to nine meters (30 feet) high surged onto Hawaiian shores about 500 years ago. A 9.0-magnitude earthquake off the coast of the Aleutian Islands triggered the mighty wave, which left behind up to nine shipping containers worth of ocean sediment in a sinkhole on the island of Kauai.
The tsunami was at least three times the size of a 1946 tsunami that was the most destructive in Hawaii’s recent history, according to the new study that examined deposits believed to have come from the extreme event and used models to show how it might have occurred. Tsunamis of this magnitude are rare events. An earthquake in the eastern Aleutian Trench big enough to generate a massive tsunami like the one in the study is expected to occur once every thousand years, meaning that there is a 0.1 percent chance of it happening in any given year — the same probability as the 2011 Tohoku earthquake that struck Japan, according to Gerard Fryer, a geophysicist at the Pacific Tsunami Warning Center in Ewa Beach, Hawaii.
Nevertheless, the new research has prompted Honolulu officials to revise their tsunami evacuation maps to account for the possibility of an extreme tsunami hitting the county of nearly 1 million people. The new maps would more than double the area of evacuation in some locations, according to Fryer.
“You’re going to have great earthquakes on planet Earth, and you’re going to have great tsunamis,” said Rhett Butler, a geophysicist at the University of Hawaii at Manoa and lead author of the new study published online in Geophysical Research Letters, a journal of the American Geophysical Union. “People have to at least appreciate that the possibility is there.”
Hawaiians have told stories about colossal tsunamis hitting the islands for generations, but possible evidence of these massive waves was only first detected in the late 1990s when David Burney, a paleoecologist at the National Tropical Botanical Garden in Kalaheo, was excavating the Makauwahi sinkhole, a collapsed limestone cave on the south shore of Kauai.
Two meters (six and a half feet) below the surface he encountered a layer of sediment marked by coral fragments, mollusk shells and coarse beach sand that could only have come from the sea. But the mouth of the sinkhole was separated from the shore by 100 meters (328 feet) of land and seven-meter (23-foot) high walls. Burney speculated that the deposit could have been left by a massive tsunami, but he was unable to verify the claim.
The deposits remained a mystery until the Tohoku earthquake hit Japan in 2011. It caused water to surge inland like a rapidly rising tide, reaching heights up to 39 meters (128 feet) above the normal sea level. After that tsunami deluged the island nation, scientists began to question Hawaii’s current tsunami evacuation maps. The maps are based largely upon the 1946 tsunami, which followed a magnitude 8.6 earthquake in the Aleutian Islands and caused water to rise only two and a half meters (8 feet) up the side of the Makauwahi sinkhole.
“[The Japan earthquake] was bigger than almost any seismologist thought possible,” said Butler. “Seeing [on live TV] the devastation it caused, I began to wonder, did we get it right in Hawaii? Are our evacuation zones the correct size?”
To find out, the study’s authors used a wave model to predict how a tsunami would flood the Kauai coastline. They simulated earthquakes with magnitudes between 9.0 and 9.6 originating at different locations along the Aleutian-Alaska subduction zone, a 3,400-kilometer (2,113-mile) long ocean trench stretching along the southern coast of Alaska and the Aleutian Islands where the Pacific tectonic plate is slipping under the North American plate.
The researchers found that the unique geometry of the eastern Aleutians would direct the largest post-earthquake tsunami energy directly toward the Hawaiian Islands. Inundation models showed that an earthquake with a magnitude greater than 9.0 in just the right spot could produce water levels on the shore that reached eight to nine meters (26 to 30 feet) high, easily overtopping the Makauwahi sinkhole wall where the ocean deposits were found.
The authors used radiocarbon-dated marine deposits from Sedanka Island off the coast of Alaska and along the west coasts of Canada and the United States dating back to the same time period as the Makauwahi deposit to show that all three sediments could have come from the same tsunami and provide some evidence that the event occurred, according to the study.
“[The authors] stitched together geological evidence, anthropological information as well as geophysical modeling to put together this story that is tantalizing for a geologist but it’s frightening for people in Hawaii,” said Robert Witter, a geologist at the U.S. Geological Survey in Anchorage, Alaska who was not involved in the study.
According to Witter, it is possible that a massive tsunami hit Hawaii hundreds of years ago, based on the deposits found in the Kauai sinkhole, but he said it is difficult to determine if all three locations experienced the same event based on radiocarbon dating alone.
Radiocarbon dating only gives scientists a rough estimate of the age of a deposit, he said. All three locations offer evidence of a great tsunami occurring between 350 and 575 years ago, but it is hard to know if it was the same tsunami or ones that occurred hundreds of years apart.
“An important next thing to do is to look for evidence for tsunamis elsewhere in the Hawaiian island chain,” said Witter.
Fryer, of the Pacific Tsunami Warning Center, is confident that more evidence of the massive tsunami will be found, confirming that events of this magnitude have rocked the island chain in the not-so-distant past.
“I’ve seen the deposit,” said Fryer, who was not involved in the study. “I’m absolutely convinced it’s a tsunami, and it had to be a monster tsunami.”
Fryer is so convinced that he has worked with the city and county of Honolulu to update their tsunami evacuation maps to include the possibility of a massive tsunami the size of the one detailed in the new study hitting the islands. The county hopes to have the new maps distributed to residents by the end of the year, he said.
“We prepared ourselves for the worst tsunami that’s likely to happen in one hundred years,” Fryer said of the current tsunami evacuation maps based on the 1946 event. “What hit Japan was a thousand-year event … and this scenario [in the eastern Aleutians] is a thousand year event.”
Reference:
Rhett Butler, David Burney, David Walsh. Paleotsunami evidence on Kaua‘i and numerical modeling of a great Aleutian tsunami. Geophysical Research Letters, 2014; DOI: 10.1002/2014GL061232
Note : The above story is based on materials provided by American Geophysical Union.
The 67 million-year-old Edmontosaurus with fossilized skin was found in 1999 in south-western Dakota. Photograph: Townhall
Dakota the duckbilled dinosaur might have found permanent digs in Bismarck.
State Historical Society director Merl Paaverud said officials have reached a $3m deal to keep the rare mummified fossil on display at the North Dakota Heritage Center, where it will serve as a cornerstone for the facility’s $51m expansion.
The deal means the state can pursue fundraising from private sources, Paaverud said. While the $3m must be raised within four years “or the deal is off,” Paaverud said he’s optimistic.
“There is a lot of interest,” Paaverud said. “People feel strongly about keeping it here.”
The 67 million-year-old Edmontosaurus with fossilized skin was found in 1999 by high school student Tyler Lyson on his uncle’s ranch near Marmarth, in southwestern North Dakota. Lyson, who went on to earn a doctorate in paleontology from Yale University, is now a postdoctoral researcher at the Smithsonian.
Lyson said in April that the money received for the fossil will be used to establish a Marmarth Research Foundation endowment fund “to be used to further vertebrate paleontology.” Money would be used to “fund public digs, build up research collections, train students and further the advancement of paleontology,” he said.
Researchers say Dakota is one of the more important dinosaur discoveries in recent times. It is one of only a few mummified dinosaurs in existence and may have the most and best-preserved skin, along with ligaments, tendons and possibly some internal organs. It has been the subject of a children’s book and an adult book, and National Geographic television programs. It was featured at a 2009 dinosaur exhibit in Japan.
“Keeping Dakota here is huge — a big deal,” Paaverud said.
The dinosaur itself is enormous. Dakota’s body, fossilized into stone, weighs about 8,500 pounds, and two other portions, including a tail and an arm, bring the total to about 10,000 pounds.
Dakota had been on loan to the North Dakota Heritage Center until July 2015.
The grand opening for the museum on the state Capitol grounds is slated for November 2, the 125th anniversary of North Dakota statehood.
Note : The above story is based on materials provided by Associated Press in Bismarck
Volcanism, driven by plate tectonics, built Earth’s atmosphere to make a habitable planet. Credit: Simon Redfern/University of Cambridge, Author provided
How is it that Earth developed an atmosphere that made the development of life possible? A study published in the journal Nature Geoscience links the origins of Earth’s nitrogen-rich atmosphere to the same tectonic forces that drive mountain-building and volcanism on our planet. It goes some way to explaining why, compared to our nearest neighbours, Venus and Mars, Earth’s air is richer in nitrogen.
The chemistry of the air we breathe is, at least partly, the result of billions of years of photosynthesis. Plant life has transformed our world from one cloaked in a carbon dioxide-rich atmosphere – as seen on Mars or Venus – to one with significant oxygen. About a fifth of the air is made up of oxygen, and almost all the rest is nitrogen. But the origins of the relatively high nitrogen content of Earth’s air have been something of a mystery.
Geoscientists Sami Mikhail and Dimitri Sverjensky of the Carnegie Institution of Washington have calculated what nitrogen is expected to do when it is cycled through the rocks of the deep Earth by the churning cycle of plate tectonics. Active volcanoes not only shower volcanic rock and superheated ash as they erupt molten rock into the air, they also vent huge amounts of gas from Earth’s depths. The latest eruptions in Iceland, for example, have been noted for the amounts of sulphurous fumes that they have emitted.
Alongside sulphur, steam and carbon dioxide, volcanoes next to active tectonic plate boundaries pump massive quantities of nitrogen into the air. Mikhail and Sverjensky explain this through the chemistry of what goes on beneath those volcanic roots.
Nitrogen bubbles up
As oceanic crust is subducted (that is, dragged down beneath continental crust) down into the depths of the Earth by the cycle of plate tectonics, it releases “volatile” elements into the rock above. These volatile elements contain nitrogen – and its fate could be to either end up locked in minerals or be released as gas into the atmosphere. The chemical composition of the overlying rocks decide the fate of the volatiles.
Nitrogen deep in the Earth’s crust will tend to form ammonium ions (NH4+) which get incorporated into solid silicate minerals easily. Silicate minerals are among the most abundant kind of minerals in Earth’s crust. This is presumed to occur to much of the nitrogen on Earth and pretty much all of the nitrogen on Venus and Mars. But when those silicate minerals react under certain conditions, such as in the presence of oxygen or oxygen-containing compounds, the ammonium molecules break down to a mixture of water (H2O) and nitrogen (N2). The latter then finds its way to the surface and the atmosphere through volcanic vents.
Mars and Venus have no plate tectonics and relatively little nitrogen. The nitrogen-rich atmosphere that made Earth a home for life thousands of millions of years ago appears to have its origin in the fact that the planet itself is a geologically active beast. Subduction, a driving force for plate tectonics, also creates the chemical reactor to make deep nitrogen. The same forces that drive the formation of mountains and continents, oceans and islands, are also responsible for our atmosphere and biosphere.
The findings suggest that nitrogen first started building in the atmosphere more than three billion years or so ago, and implies that plate tectonics was already active on Earth at that time. This fits in with other estimates for how long Earth has been an active planet, and it contrast starkly with the geologically stagnant picture we have of Mars and Venus. The results provide new insights into the pre-conditions guiding the likely character of life-hosting planets around distant stars, elsewhere in the universe. Note : The above story is based on materials provided by The Conversation This story is published courtesy of The Conversation (under Creative Commons-Attribution/No derivatives).
The history of sex may have to be rewritten thanks to a group of unsightly, long-extinct fish called placoderms. A careful study of fossils of these armour-plated creatures, which gave rise to all current vertebrates with jaws, suggests that their descendants — our ancient ancestors — switched their sexual practices from internal to external fertilization, an event previously thought to be evolutionarily improbable.
“This was totally unexpected,” says John Long, a palaeontologist at Flinders University in Adelaide, Australia, and lead author of the study, published in Nature. “Biologists thought that there could not be a reversion back from internal fertilization to external fertilization, but we have shown it must have happened this way.”
Go back far enough in your family tree — before placoderms — and your ancestors were rather ugly jawless fish who reproduced through external fertilization, in which sperm and eggs are expelled into the water to unite. Some of these distant relatives later gave rise to the jawless fish called lampreys that lurk in seas today and still use this method of reproduction.
Long’s team studied placoderms, one of the earliest groups of jawed animals, and found structures in fossils that they interpret as bony ‘claspers’ — male organs that penetrate the female and deliver sperm.
The researchers had previously shown in Nature that one placoderm species was the earliest animal known to have engaged in penetrative sex. But the latest paper shows that an even earlier group of placoderms, the antiarchs — specifically, a group of antiarchs called Microbrachius — also used this method of fertilization. The finding is significant because antiarchs are considered the most ‘basal’ jawed vertebrates (meaning those closest to the roots of the animal family tree), and so it suggests that all placoderms reproduced through internal fertilization using claspers.
But the implications of this finding are even more penetrating. Long says that the oldest bony fishes, which follow placoderms in the evolutionary tree, show no evidence for internal fertilization. Thus, at some point, early fishes must have lost the internal fertilization method seen in placoderms, before some of their descendants ‘re-invented’ organs with a similar function — ranging from similar claspers in sharks and rays today to the penises of modern humans, suggest the authors. (The claspers of modern sharks, however, are made of cartilage and develop from the pelvic fins, which makes them fundamentally different from the bone claspers of placoderms.)
“Our new paper suggests that after the first jawed vertebrates evolved internal fertilization, then it was lost at the point close to where the last common ancestor of modern jawed fishes evolved,” Long told Nature.
Evolutionary conundrum
The paper is also likely to strongly influence an ongoing debate about placoderms’ place in evolutionary history. Until a few years ago, placoderms were considered to be a ‘monophyletic’ group — a coherent group that includes all its descendants, a kind of evolutionary ‘dead end’. By this interpretation, other vertebrates would have shared a common ancestor with this group rather than descending from them.
But more recently, researchers including Martin Brazeau, a vertebrate palaeontologist at Imperial College London’s Silwood Park campus in Berkshire, have suggested that placoderms may not be a single coherent group, on the basis of evidence from their cranial structures. This would mean that rather than humans sharing a common ancestor with placoderms, placoderms are themselves humans’ ancestors.
The latest paper complicates this debate, and offers two uncomfortable options. According to Brazeau, the work convincingly makes the case that all placoderms were internal fertilizers, leading to a conclusion once seen as highly improbable: that some of the living fishes that practise external fertilization had ancestors that fertilized internally. But the fact that all placoderms had bony claspers could be taken as evidence that they were a unified, monophyletic group, and this would contradict the cranial evidence that puts placoderms near the top of the jawed-vertebrate evolutionary tree.
Brazeau says that he is now “increasingly agnostic” about these two options. “This work will certainly make people sit down and consider this more seriously than in the past,” he says. “It is pretty exciting because of that. It raises more questions than it answers.”
Mount Ontake, a week after the 27 September eruption. Alpsdake/Wikimedia Commons (CC BY-SA 4.0)
Can volcanic eruptions be predicted?
The question has been very much in the news in Japan since the 27 September eruption of Mount Ontake. Despite 24/7 monitoring of the mountain for telltale warning signs, the Japan Meteorological Agency (JMA) failed to predict the eruption. It surprised several hundred hikers enjoying a glorious autumn day on the 3067-meter mountain, leaving 56 confirmed dead and seven still missing—the country’s deadliest eruption in nearly 90 years.
On Monday, a popular TV show asked whether the country could do better. Each week, Beat Takeshi’s TV Tackle features a group of celebrities quizzing experts on topics in the news. The most recent program brought together a panel of earth scientists and others concerned about volcanoes (on YouTube in Japanese here). “There is no way to precisely predict eruptions,” said Robert Geller, a geophysicist at the University of Tokyo famous for his criticism of Japan’s earthquake prediction efforts. He added that prediction efforts might succeed once in a thousand tries. “If society recognizes that, then warnings are surely possible,” he added. Hideki Shimamura, a geophysicist at Musashino Gakuin University in Sayama, agreed. “I’m rather critical about the idea of eruption prediction,” he said.
Today at a briefing for journalists, Toshitsugu Fujii, who chairs the JMA Coordinating Committee for Prediction of Volcanic Eruptions, got a chance for rebuttal. Fujii, a volcanologist and professor emeritus of the University of Tokyo, pointed to nine successful predictions since the program started in 1974. The most impressive example may be the case of Mount Unzen near Nagasaki. In late May 1991, after noting small eruptions and the formation of a lava dome, JMA convinced local authorities to evacuate 12,000 nearby residents. The mountain erupted on 3 June, sending a pyroclastic flow 4.5 kilometers from the crater. It killed 43 journalists and volcanologists who had entered the no-go zone to take pictures and gather data. “But not a single resident of the area died,” Fujii says.
Still, he agrees that eruption prediction “is not very reliable yet.”
It is not for lack of trying. Japan has 110 active volcanoes, including those on remote islands and beneath the ocean. JMA monitors 47 of those around the clock for seismic activity and ground deformation, and for some mountains it also watches gas and smoke emissions. At one time, human observers were stationed on certain mountains. Now, all the data are relayed to four observation centers.
Those centers, however, are largely staffed by civil servants and not trained scientists, Fujii explained. And because volcanic activity in Japan has been rather quiet in recent decades, they’ve had little on-the-job training.
Another weakness of Japan’s eruption prediction efforts is the split of responsibilities. JMA does not directly carry out volcanic research, which is left to universities and certain national institutes. In contrast, the U.S. Geological Survey has more than 100 volcanologists involved in a comprehensive research effort. The coordinating committee he chairs has “no legal authority, power, or budget,” Fujii explains.
Communications is also a weak link. Even among the nine cases where JMA recognized a coming eruption, warnings reached local authorities in time for action in only three cases. A new committee charged with investigating how to speed up the flow of information will hold its first meeting this month. A separate committee will examine the specifics of the Mount Ontake eruption to see if warning signs were missed.
After the TV program, Geller wrote to ScienceInsider that he is not saying eruption prediction shouldn’t be tried. But he objects to JMA’s five volcanic alert levels, which range from normal (Level 1) to stay off the mountain (Level 3) to evacuating nearby residents (Level 5). He thinks this implies a degree of precision beyond the current state of the art. The five-level system “is misleading the public to overestimate the accuracy and reliability of what’s now possible,” he wrote.
Note : The above story is based on materials provided by Dennis Normile ” American Association for the Advancement of Science. All Rights Reserved.”
A large bipedal dinosaur once known only from fossils of its long arms and a few isolated bone fragments turns out to be a hump-backed, big-bellied beast almost the size of Tyrannosaurus rex, suggest Mongolian fossils newly described in Nature1. Few scientists could have imagined the behemoth’s distinctive combination of features from the smattering of bones previously in hand.
“This is an entirely new body plan” for such dinosaurs, says Stephen Brusatte, a vertebrate palaeontologist at the University of Edinburgh, UK.
Fossils of Deinocheirus mirificus — a pastiche of Greek and Latin meaning ‘unusual horrible hand’ — were first unearthed in the summer of 1965 in the Gobi Desert in southern Mongolia. Along with a few rib and vertebra fragments, the remains included a remarkable set of shoulder girdles and 2.4-metre-long forelimbs, the longest yet found for a bipedal animal of any era (although some flying animals, notably pterosaurs, had longer wings).
Eventually, scientists placed Deinocheirus in a subgroup of theropod dinosaurs known as ornithomimosaurs (‘bird-mimicking lizards’) — which makes them relatively close kin to fierce predators such as T. rex and Allosaurus, says Yuong-Nam Lee, a vertebrate palaeontologist at the Korea Institute of Geoscience and Mineral Resources in Daejeon, South Korea, and a co-author of the study.
In expeditions to the Gobi Desert in the past decade, Lee and his colleagues have unearthed the 70-million-year-old fossils of two more individuals of the species from sites near to where the original 1965 specimen was discovered. Together, those remains — along with some bones stolen by poachers before Lee and his team found the fossils, but since recovered from a private collection — account for about 95% of the creature’s skeleton, he notes.
The newer-found bones differ from those of other ornithomimosaurs in several unexpected ways. Most of the spinal vertebrae have blade-like projections that extended upward and served as anchors for a network of ligaments that probably helped to support the immense weight of the creature’s abdomen. The researchers estimate that Deinocheirus was about 11 metres long and tipped the scales at more than 6.3 tonnes.
“This is definitely an unusual animal,” says Thomas Holtz, Jr., a vertebrate palaeontologist at the University of Maryland in College Park, who wrote an accompanying News & Views piece2. “It had more of a ‘beer belly’ than your typical ornithomimosaur,” he suggests.
No teeth
Deinocheirus had a skull more than a metre long. Although the creature lacked teeth, it had a keratinous beak that could be used to nip at tender vegetation. A deep lower jaw probably housed an immense tongue that could have helped to suck up plants from the bottoms of rivers and lakes. Stomach contents preserved in the fossils, including fish vertebrae and scales, suggest that Deinocheirus also consumed large quantities of aquatic prey.
As well as its wide hips and big feet, Deinocheirus had broad toes, which helped to prevent it from sinking into soft sediments while foraging, suggest the researchers. The last bone in each of its toes was flattened and had a blunt tip, unlike the tapered tips seen in the toes of all other theropod dinosaurs.
Using data gleaned from the fossils, Lee and his colleagues have created a video that shows how Deinocheirus might have looked and, more amusingly, how it may have walked.
“This creature wasn’t built for speed,” says Brusatte. “That’s pretty obvious.”
Note : The above story is based on materials provided by Nature doi:10.1038/nature.2014.16203
Holuhraun fissure eruption on the flanks of the Bárðarbunga volcano in central Iceland on Oct. 4, 2014, showing the development of a lava lake in the foreground. Vapor clouds over the lava lake are caused by degassing of volatile-rich basaltic magma. Credit: Morten S. Riishuus, Nordic Volcanological Institute
Spectacular eruptions at Bárðarbunga volcano in central Iceland have been spewing lava continuously since Aug. 31. Massive amounts of erupting lava are connected to the destruction of supercontinents and dramatic changes in climate and ecosystems.
New research from UC Davis and Aarhus University in Denmark shows that high mantle temperatures miles beneath the Earth’s surface are essential for generating such large amounts of magma. In fact, the scientists found that the Bárðarbunga volcano lies directly above the hottest portion of the North Atlantic mantle plume.
The study, published online Oct. 5 and appearing in the November issue of Nature Geoscience, comes from Charles Lesher, professor of Earth and Planetary Science at UC Davis and a visiting professor at Aarhus University, and his former PhD student, Eric Brown, now a post-doctoral scholar at Aarhus University.
“From time to time the Earth’s mantle belches out huge quantities of magma on a scale unlike anything witnessed in historic times,” Lesher said. “These events provide unique windows into the internal working of our planet.”
Such fiery events have produced large igneous provinces throughout Earth’s history. They are often attributed to upwelling of hot, deeply sourced mantle material, or “mantle plumes.”
Recent models have dismissed the role of mantle plumes in the formation of large igneous provinces, ascribing their origin instead to chemical anomalies in the shallow mantle.
Based on the volcanic record in and around Iceland over the last 56 million years and numerical modeling, Brown and Lesher show that high mantle temperatures are essential for generating the large magma volumes that gave rise to the North Atlantic large igneous provinces bordering Greenland and northern Europe.
Their findings further substantiate the critical role of mantle plumes in forming large igneous provinces.
“Our work offers new tools to constrain the physical and chemical conditions in the mantle responsible for large igneous provinces,” Brown said. “There’s little doubt that the mantle is composed of different types of chemical compounds, but this is not the dominant factor. Rather, locally high mantle temperatures are the key ingredient.”
Colorized transmission electron micrograph (TEM) of the Ebola virus. Credit: Frederick A. Murphy, via the Centers for Disease Control and Prevention
A new study is helping to rewrite Ebola’s family history. The research shows that filoviruses — a family to which Ebola and its similarly lethal relative, Marburg, belong — are at least 16-23 million years old.
Filoviruses likely existed in the Miocene Epoch, and at that time, the evolutionary lines leading to Ebola and Marburg had already diverged, the study concludes.
The research was published in the journal PeerJ in September. It adds to scientists’ developing knowledge about known filoviruses, which experts once believed came into being some 10,000 years ago, coinciding with the rise of agriculture. The new study pushes back the family’s age to the time when great apes arose.
“Filoviruses are far more ancient than previously thought,” says lead researcher Derek Taylor, PhD, a University at Buffalo professor of biological sciences. “These things have been interacting with mammals for a long time, several million years.”
According to the PeerJ article, knowing more about Ebola and Marburg’s comparative evolution could “affect design of vaccines and programs that identify emerging pathogens.”
The research does not address the age of the modern-day Ebolavirus. Instead, it shows that Ebola and Marburg are each members of ancient evolutionary lines, and that these two viruses last shared a common ancestor sometime prior to 16-23 million years ago.
Taylor and co-author Jeremy Bruenn, UB professor of biological sciences, research viral “fossil genes” — chunks of genetic material that animals and other organisms acquire from viruses during infection.
In the new study, the authors report finding remnants of filovirus-like genes in various rodents. One fossil gene, called VP35, appeared in the same spot in the genomes of four different rodent species: two hamsters and two voles. This meant the material was likely acquired in or before the Miocene Epoch, prior to when these rodents evolved into distinct species some 16-23 million years ago.
In other words: It appears that the known filovirus family is at least as old as the common ancestor of hamsters and voles.
“These rodents have billions of base pairs in their genomes, so the odds of a viral gene inserting itself at the same position in different species at different times are very small,” Taylor says. “It’s likely that the insertion was present in the common ancestor of these rodents.”
The genetic material in the VP35 fossil was more closely related to Ebola than to Marburg, indicating that the lines leading to these viruses had already begun diverging from each other in the Miocene.
The new study builds on Taylor’s previous work with Bruenn and other biologists, which used viral fossil genes to estimate that the entire family of filoviruses was more than 10 million years old. However, those studies used fossil genes only distantly related to Ebola and Marburg, which prevented the researchers from drawing conclusions about the age of these two viral lines.
The current PeerJ publication fills this viral “fossil gap,” enabling the scientists to explore Ebola’s historical relationship with Marburg.
Possible relevance to disease prevention
The first Ebola outbreak in humans occurred in 1976, and scientists still know little about the virus’ history. The same dearth of information applies to Marburg, which was recognized in humans in 1967 and implicated in the death of a Ugandan health worker this month.
Understanding the virus’ ancient past could aid in disease prevention, Taylor says. He notes that if a researcher were trying to create a single vaccine effective against both Ebola and Marburg, it could be helpful to know that their evolutionary lineages diverged so long ago.
Knowing more about filoviruses in general could provide insight into which host species might serve as “reservoirs” that harbor undiscovered pathogens related to Ebola and Marburg, Taylor says.
“When they first started looking for reservoirs for Ebola, they were crashing through the rainforest, looking at everything — mammals, insects, other organisms,” Taylor says. “The more we know about the evolution of filovirus-host interactions, the more we can learn about who the players might be in the system.”
Taylor and Bruenn’s co-authors on the PeerJ study include UB students Matthew Ballinger, Laura Hanzly and Jack Zhan, all in the UB Department of Biological Sciences.
Note : The above story is based on materials provided by University at Buffalo. The original article was written by Charlotte Hsu.
In this Oct. 22, 2014 photo provided by the U.S. Geological Survey, a geologist marks the coordinates of the Kilauea lava flow front with a GPS unit. A 13-mile finger of lava from Kilauea Volcano has started to again move quickly, and could hit a secondary road sometime Friday, Oct. 24, 2014. Officials on Hawaii’s Big Island won’t start evacuating people until the lava flow is within three to five days of affecting Pahoa residents. (AP Photo/U.S. Geological Survey)
A growing lava stream threatening homes on Hawaii’s Big Island is expanding as it heads toward a small rural town.
The narrow, leading edge of the lava flow is now just 250 yards from a country road, which has been closed. Crews are working on an alternate route for remote communities in the rural Puna district in case the lava crosses a major thoroughfare.
Officials say the lava advanced nearly 460 yards from Thursday morning to Friday. It sped up over the past few days but slowed again Friday morning.
No evacuations have been ordered, and residents of a home that is nearest to the flow already have left voluntarily.
The Hawaii County Civil Defense is planning to go door-to-door Saturday to find out how many people might need shelter if the eruption continues.
In this Oct. 22, 2014 photo provided by the U.S. Geological Survey, geologists walk over the surface of the flow to track surface breakouts along a portion of the flow margin, about a kilometer upslope of the flow front. A 13-mile finger of lava from Kilauea Volcano has started to again move quickly, and could hit a secondary road sometime Friday, Oct. 24, 2014. Officials on Hawaii’s Big Island won’t start evacuating people until the lava flow is within three to five days of affecting Pahoa residents. (AP Photo/U.S. Geological Survey)
The Saint Louis River (abbreviated St. Louis River) is a river in the U.S. states of Minnesota and Wisconsin that flows into Lake Superior. The largest U.S. river to flow into the lake, it is 192 miles (309 km) in length and starts 13 miles (21 km) east of Hoyt Lakes, Minnesota. The river’s watershed covers 3,634 square miles (9,410 km2). Near the Twin Ports of Duluth, Minnesota and Superior, Wisconsin, the river becomes a freshwater estuary.
According to Warren Upham, the Ojibwe name of the river is Gichigami-ziibi (Great-lake River). He notes
“The river was probably so named by Pierre Gaultier de Varennes, sieur de La Vérendrye (1685–1749), who was a very active explorer, in the years 1731 and onward, of the vast country from Pigeon River and Rainy Lake to the Saskatchewan and Missouri Rivers, establishing trading posts and missions. The king of France in 1749, shortly before the death of La Vérendrye, conferred on him the cross of Saint Louis as a recognition of the importance of his discoveries, and thence the name of the Saint Louis River appears to have come. On Jean-Baptiste-Louis Franquelin’s map (1688) and Philippe Buache’s map (1754), it is called the Rivière du Fond du Lac, and the map by Gilles Robert de Vaugondy (1755) and Jonathan Carver’s map (1778) are the earliest to give the present name.”
The river was a vital link connecting the Mississippi River waterways to the west with the Great Lakes to the east. Jay Cooke State Park is located near the mouth of the river and is the site of a canoe portage used by Native Americans, European explorers, fur traders, Voyageurs, coureurs des bois, and missionaries of the 18th and 19th centuries. It was a rough trail of steep hills and swamps that began at the foot of the rapids above the neighborhood of Fond du Lac (“head of the lake”) and climbed some 450 feet (140 m) to the present day city of Carlton. Above Carlton travelers proceeded upstream and continued on to Lake Vermillion and the Rainy River. Or they may have traveled southwest up the East Savanna River, portaged the grueling 6 mile long Savanna Portage (now a state park), and then paddled on to the Mississippi River.
By the mid 20th century, the lower Saint Louis River became one of the most heavily polluted waterways in the state. Holling Clancy Holling, in his 1941 book Paddle-to-the-Sea, illustrated the polluted state of the Saint Louis River. By 1975, the river became an Environmental Protection Agency Area of Concern. The Western Lake Superior Sanitary District (WLSSD) was established in 1971 to address serious pollution problems in the lower Saint Louis River Basin. WLSSD’s regional wastewater treatment plant began operating in 1978. Within two years, fish populations rebounded and anglers began returning to the river. Through the 1980s and 1990s, additional cleanups took place, but the river remains polluted. In 2013 the State of Minnesota abruptly pulled out of a project intended to research the mercury problem in the river. The cooperating agencies including Wisconsin DNR and the Fond du Lac Tribe were not in agreement with the ending of the study. The level of mercury is so high that strong limitations on consumption of the fish are in effect by the Minnesota Department of Health which for example limit consumption of walleye for a 50 pound child to 1/6 of a pound per month or no more than one pound every six months. https://www.fish.state.pa.us/images/fisheries/fcs/pcb_fishtech.pdfhttp://www.health.state.mn.us/divs/eh/fish/eating/genpoprivers.pdf
The river is fished for walleye, northern pike, smallmouth bass, largemouth bass, bluegill, black crappie, and channel catfish populations. Other species of rough fish include Shorthead Redhorse and White Sucker. Attempts to introduce sturgeon are under way; sturgeon, if caught, are to be returned. The river is frequented by those traveling the Minnesota DNR Saint Louis River Water Trail, which has campsites and angling.
The Saint Louis River Trail Association is planning construction of a long-distance hiking trail along more than half the length of the river. Construction of the first 36-mile segment began in early 2012, with cooperation from the Minnesota DNR; the trail association hopes to have this section completed in 2015.
Note : The above story is based on materials provided by Wikipedia
Ferns are believed to be ‘old’ plant species — some of them lived alongside the dinosaurs, over 200 million years ago. However, a group of Andean ferns evolved much more recently: their completely new form and structure (morphology) arose and diversified within the last 2 million years. This novel morphology seems to have been advantageous when colonising the extreme environment of the high Andes.
Dr Patricia Sanchez-Baracaldo (Bristol) and Dr Gavin Thomas (Sheffield) used molecular and morphological data to study a group of ferns which grow in a unique ecosystem of the Andean mountains.
This ecosystem, known as the páramo, was created relatively recently (around 3 to 5 million years ago), when the Andes underwent a major uplifting event. This provided new ecological opportunities for plants to exploit and flourish in. Other plants from North America and temperate southern regions were also able to colonise these new páramo environments.
In contrast to the archetypal tropical rainforest, where trees are tall and some plants have huge leaves, the páramos are more exposed, tundra-like biomes where plants are short and have much smaller leaves, some of which are very hairy.
Higher altitudes near the equator experience extreme environmental fluctuations every twenty-four hours, with very cold nights and very hot days. In order to grow there, some plants have evolved new adaptions, in form and in leaf structure, which allow them to cope with the paramos’ freezing nights and high solar radiation at midday.
The Bristol and Sheffield team found that one group of páramo ferns evolved highly modified leaves, which retain the furled fronds of a young fern yet are sexually mature. Some páramo species were found to have over 300 pairs of leaflets per frond — this is in contrast to their closest relatives in the more sheltered habitat of the cloud forest, lower down the mountains, which have no more than 12 pairs of leaflets per frond. In addition, the length of these leaflets declines rapidly with the increase in altitude.
The researchers also found that the rate by which new biological species arise (speciation) is significantly higher among páramo than non-páramo ferns.
Dr Sanchez-Baracaldo of Bristol’s School of Geographical Sciences said: “These ferns are remarkable because, in geological terms, they quickly evolved a new morphology as a response to new and extreme environmental conditions. It’s fascinating to notice that, by a process known as convergent evolution, whereby similar features evolve independently in species of different lineages, cloud forest ferns arrived at the same ‘solution’ in response to the same environmental pressures.”
Note : The above story is based on materials provided by University of Bristol.
Japan could be nearly destroyed by a massive volcanic eruption over the next century, putting almost all of the country’s 127 million-strong population at risk, according to a new study
Japan could be nearly destroyed by a massive volcanic eruption over the next century, putting almost all of the country’s 127 million-strong population at risk, according to a new study.
“It is not an overstatement to say that a colossal volcanic eruption would leave Japan extinct as a country,” Kobe University earth sciences professor Yoshiyuki Tatsumi and associate professor Keiko Suzuki said in a study publicly released on Wednesday.
The experts said they analysed the scale and frequency of volcanic eruptions in the archipelago nation over the past 120,000 years and calculated that the odds of a devastating eruption at about one percent over the next 100 years.
The chance of a major earthquake striking the city of Kobe within 30 years was estimated at about one percent just a day before a 7.2-magnitude quake destroyed the Japanese port city in 1995, killing 6,400 people and injuring nearly 4,400 others, the study noted.
“Therefore, it would be no surprise if such a colossal eruption occurs at any moment,” it added.
The new research comes weeks after Japan’s Mount Ontake erupted without warning—killing 57 people and leaving at least six others missing in the country’s deadliest volcanic eruption in almost 90 years.
The Kobe University researchers said their study was critical because Japan is home to about seven percent of the volcanoes that have erupted over the past 10,000 years.
A disaster on the southernmost main island of Kyushu, which has been struck by seven massive eruptions over the past 120,000 years, would see an area with seven million people buried by flows of lava and molten rock in just two hours, they said.
Volcanic ash would also be carried by westerly winds toward the main island of Honshu, making almost all of the country “unliveable” as it strangled infrastructure, including key transport systems, they said.
It would be “hopeless” trying to save about 120 million living in major cities and towns across Honshu, the study said.
This prediction was based on geological findings from the eruption of a gigantic crater, 23 kilometres (14 miles) across, in southern Kyushu about 28,000 years ago.
The study called for new technology to accurately grasp the state of “magma reservoirs” which are spread across the earth’s crust in layers a few kilometres deep.
Hima Hassenruck-Gudipati (BS ’14) on a backpacking trip along the Tour de Mont Blanc, one of the most popular long distance walks in Europe. Hassenruck-Gudipati, a Waston Fellowship recipient, is a few months into a yearlong, worldwide quest to understand past, present, and future climate change. Credit: Hima Hassenruck-Gudipati
This past summer, not long after collecting her degree from Caltech and thanks to the support of a Watson Fellowship, Hima Hassenruck-Gudipati (BS ’14) found herself walking alone along a creek near the northern Italian town of Feltre, about 50 miles north of Venice. She was not vacationing, but instead was on the hunt for the site of a particular type of rock that offers clues about the most rapid and dramatic climate change in Earth’s history.
Normally, Hassenruck-Gudipati would have tracked her quarry using its GPS coordinates. But on this day, confident that she would find the site easily, Hassenruck-Gudipati only had a map and a field guide with pictures of the rocks. It was not the wisest of decisions, she realized after discovering that the area had no trails. Although unsure of which direction to go, she continued upstream and hiked for hours, searching. Surprisingly, instead of exasperation, she felt exhilaration. “I felt like an explorer,” she recalls.
Eventually, Hassenruck-Gudipati found the site, an outcrop that formed the tall channel bank of the river along which she walked. The outcrop tells the story of the Paleocene-Eocene Thermal Maximum, or PETM, an ancient climate event that occurred some 55 million years ago. During the PETM, the planet’s temperature suddenly spiked as much as nine degrees Celsius over just a few thousand years—a blip of time on the geologic scale. The PETM is one of the best known examples of past climate change, on a par with the Permian-Triassic mass extinction 250 million years ago, when the globe warmed by as much as eight degrees, wiping out about 90 percent of marine species and 70 percent of the animals on land. Studying such dramatic climate shifts in the past can help scientists better understand today’s warming world.
It’s a topic of particular interest to Hassenruck-Gudipati, who majored in mechanical engineering but minored in geology at Caltech. During her time at Caltech, she was keenly interested in green technology and how engineering solutions can mitigate the effects of climate change. But she also developed a fascination with the complex ways Earth responds to a shifting climate. An introduction to the PETM during her junior year left her intrigued; she wanted to learn more, and thought it could be a great topic for a Watson. The fellowship, established by the Thomas J. Watson Foundation in 1968, offers graduating seniors of “unusual promise” a $28,000 stipend to support independent study and travel outside the United States.
One of 44 students awarded the fellowship for the 2014–2015 academic year, Hassenruck-Gudipati is now a few months into a yearlong, worldwide quest to understand the past, present, and future of climate change. She spent the beginning of the summer in Italy and is now in Spain. Her itinerary is constantly in flux. “It’s how the fellowship is set up,” she explains. “They encourage you to shape your itinerary based on what inspires you in the different places and take advantage of new opportunities as they arise.” Currently, she plans to visit Australia in November and then to head to New Zealand, Nepal, Norway, and possibly South Africa.
At each location, Hassenruck-Gudipati has identified geologic sites that will offer insight into the PETM or Earth’s response to a shifting climate. In New Zealand, for example, she will collect fossilized pollen to probe how plants responded to the PETM. In Nepal, she will focus on how climate reshapes mountain landscapes by studying the effect of melting glaciers on erosion. On a Norwegian island called Svalbard, located close to the North Pole, she will study the extremes of both past and present climate change.
Hassenruck-Gudipati often teams up with geologists from local institutions, but for the most part, she is on her own, traveling via bus, bike, or her own two feet, as conditions require. Near the Italian town of Gubbio, a woman camping nearby commended Hassenruck-Gudipati for her bravery, for traveling alone. “It was news to me,” she says. “I never thought of myself as courageous before.”
Note : The above story is based on materials provided by California Institute of Technology
Artist rendering: entry view. Credit: TCF Architecture
Washington’s coast is so close to the seismically active Cascadia Subduction Zone that if a megathrust earthquake were to occur, a tsunami would hit the Washington shoreline in just 25 minutes.
One coastal community is preparing for such a disaster by starting construction on the nation’s first tsunami evacuation refuge, large enough to shelter more than 1,000 people who are within 20-minute walking distance.
The vertical evacuation-refuge will be the roof of the gym of the new school in Grays Harbor County, Washington. The Ocosta Elementary School and Tsunami Safe Haven will be the first of its kind in the nation and will be the culmination of 18 years of effort, said Tim Walsh, who is a Chief Hazard Geologist at the Department of Natural Resources and has been working on this project since The National Tsunami Hazard Mitigation Program was formed in 1995.
Walsh will present the project design for the school and structure, along with the detailed tsunami modeling used to find the best location for the refuge, at the Annual Meeting for the Geological Society of America in Vancouver, Canada, on 21 October.
The Cascadia subduction zone is a 700-mile-long (over 1,000 kilometers) fault along the West Coast, where the Juan de Fuca Plate is being forced under the North American Plate. The subduction zone is capable of producing massive earthquakes; scientists have calculated that magnitude-9 earthquakes along this fault line could generate a massive tsunami that would hit the coastlines of British Columbia, Washington, Oregon, and California within 20 to 30 minutes.
“It used to be thought that Cascadia was not an active fault,” said Walsh. Not only has Cascadia been found to be an active fault, it has a 10 percent chance that it will cause an earthquake in the next 50 years, he said.
“It is more than 10 times more likely than the chance you will be killed in a traffic accident,” said Walsh. “But you aren’t looking at the statistics of a single person, but an earthquake that would have an effect on thousands of miles of shoreline.”
The biggest challenge was at the very beginning, trying to come up with a location that could be effective and accessible to people, said Walsh. “It was difficult in the beginning to go to the public meetings in these communities and present the hazards, but have no solution for them,” he said.
Project Safe Haven brought together structural engineers, oceanographers, geographers, and scientists from many other disciplines to create a safe and accessible refuge.
Walsh and his colleagues used a model called GeoClaw to research the risk a tsunami, factoring in and any potential landslides caused by the wave or megaquake. Using this model in the community for Grays Harbor County, the scientists determined the best place for the school, and what how much force the structure would have to withstand to protect refugees.
The school will be built on a dune ridge, so the roof of the evacuation shelter will be about 55 feet (almost 17 meters) above sea-level. The structure is designed to withstand earthquakes and the impact of a storm surge, with reinforced concrete cores at each corner of the gym and staircases leading to the room. The school, and refuge, is expected to be finished and operating for the 2015-2016 academic year.
Walsh would like to see other scientists and community groups working together to create novel solutions for tsunami risk, he said. Currently the Washington coast has very few tall buildings, and barely any are taller than three stories, leaving thousands of people at risk in the event of a tsunami, he said.
Note : The above story is based on materials provided by Geological Society of America.
Streamline visualisation provides a 2D generalised representation of recorded electromagnetic fields within deep oceans. Credit: IBM Research
A study involving the use of streamline visualisation has found the technology can help guide electromagnetic transmitter and receiver placements, thereby aiding the search for oil and gas on the seafloor.
Curtin University geophysics experts and co-authors Dr Andrew Pethick and Associate Professor Brett Harris used Dr Pethick’s visualisation software to determine its impact on the design stages of marine controlled source electromagnetic methods (MCSEM).
The resulting designs may ultimately improve the representation of subsurface geology including oil and gas deposits.
“To understand what’s going on very quickly for survey planning, it’s really handy because it enables you to see what is physically happening with the direction of currents,” Dr Pethick says.
“For a person that knows very little about EM, it’s very important.
“It actually bridges an enormous conceptual gap that people have in understanding how the technology works.
“Until they see the streamlines they really don’t have a clue about what’s happening under the ground.”
Dr Harris says his colleague’s software is used by people all over the world.
“You can go to his website and people have been able to download it and be able to visualise and understand streamlines in a way that there is no ready possibility without it.”
Software improves receiver targets
Electromagnetic fields generated during a marine EM survey engulf thousands of cubic kilometres of ocean and sub-ocean geology.
Streamline visualisation provides a 2D generalised representation of recorded electromagnetic fields within deep oceans.
This representation aids the placement of receivers that are dropped into the ocean and sink to the bottom during surveying and are subsequently recovered for data harvesting.
“[Streamline visualisation] was part of my PhD,” Dr Pethick says.
“I had written a pretty comprehensive EM modelling and computation visualisation framework from scratch and it was just a matter of coding it up.
“The greater size and density the receiver network is, the better we can resolve the underlying geology.
“All of the technology does exist already but no one had really tried to apply streamlines in this case.
“The next step is perhaps moving towards a towing system.
“Right now they’re actually towing near the air but just beneath the water. Our research may indicate alternative locations.”
A towed system consists of a transmitter and EM receivers, which are dragged behind a vessel within the ocean.
More information:
“Bathymetry, electromagnetic streamlines and the marine controlled source electromagnetic method.” Exploration Geophysics 45(3) 208-215 dx.doi.org/10.1071/EG13050
Note : The above story is based on materials provided by Science Network WA
The wound found in the allosaur fits well with what would result from a stegosaur striking under and upwards with its spiked tail. Fossil’s of contemporaneous stegosaurs appear to have had unusually flexible and agile tails. Credit: Robert Bakker
Stegosaurs might be portrayed as lumbering plant eaters, but they were lethal fighters when necessary, according to paleontologists who have uncovered new evidence of a casualty of stegosaurian combat. The evidence is a fatal stab wound in the pubis bone of a predatory allosaur. The wound — in the conical shape of a stegosaur tail spike — would have required great dexterity to inflict and shows clear signs of having cut short the allosaur’s life.
“A massive infection ate away a baseball-sized sector of the bone,” reports Houston Museum of Natural Science paleontologist Robert Bakker and his colleagues, who present a poster on the discovery on Tuesday at the meeting of the Geological Society of America in Vancouver, B.C. “Probably this infection spread upwards into the soft tissue attached here, the thigh muscles and adjacent intestines and reproductive organs.” The lack of any signs of healing strongly suggests the allosaur died from the infection.
Similar wounds are seen in rodeo cowboys or horses when they are gored by longhorns, Bakker said. And since large herbivores — like longhorn cattle, rhinos and buffalo — today defend themselves with horns, it’s reasonable to assume spiky herbivorous dinos did the same. A big difference is that stegosaurs wielded their weapon on their tails rather than their heads. Skeletal evidence from fossil stegosaurs suggests their tails were more dextrous than most dinosaur tails.
The size and conical shape of the allosaur bone injury closely fits that of the spikes on a stegosaur tail. The stegosaur wouldhave had to wield its tale with great skill to make the deadly blow. Credit: Robert Bakker
“They have no locking joints, even in the tail,” Bakker explained. “Most dinosaur tails get stiffer towards the end.” But stegosaurs had massive muscles at the base of the tails, flexibility and fine muscle control all the way to the tail tip. “The joints of a stegosaur tail look like a monkey’s tail. They were built for 3-dimensional combat.”
In order to deliver the mortal wound to the allosaur, a stegosaur would have had to sweep its tail under the allosaur and twist the tail tip, because normally the spikes point outward and backward. That would have been well within the ability of a stegosaur, Bakker said.
The fighting style and skill of stegosaurs should come as no surprise to anyone familiar with the dinosaur battle scene in the 1940 Disney animated film Fantasia, said Bakker. That segment of the movie shows a beefed up allosaur attacking a stegosaur. The stegosaur delivers a number of well aimed tail blows at the predator, but loses the fight. The Fantasia stegosaur tail dexterity appears to be accurate, he said. But he questions the stegosaur’s loss in the end. “I think the stegosaur threw the fight,” he said. On the other hand, he points out stegosaurs had among the smallest brains for its body size of any large animal, ever.
Note: The above story is based on materials provided by Geological Society of America.
Scientists are using volcanic gases to understand how volcanoes work, and as the basis of a hazard-warning forecast system.
When the USA’s Mount St Helens erupted in 1980, just two months after showing signs of reawakening, its blast was equivalent to 1,600 times the energy of the atomic bomb dropped on Hiroshima. It remains the most economically destructive volcanic event in the USA’s history.
When Eyjafjallajӧkull erupted in 2010 in Iceland, the ash cloud it emitted stranded around half of the world’s air traffic, with an estimated global economic cost of US $5 billion. Recently, magma has been on the move again, this time under and beyond Iceland’s Bárðarbunga volcano.
Volcanoes are the vents through which our planet exhales. Yet, not all volcanoes experience spectacular releases of energy, or even erupt at all: of the 500 or so volcanoes that are currently active worldwide, 20 might be expected to erupt in any one year. But, when volcanoes do erupt, they can cause almost total destruction in the immediate vicinity and the ash clouds they release can affect areas thousands of kilometres away.
Fortunately, the ability to monitor volcanoes has dramatically improved in recent years, thanks in part to the work of scientists like Dr Marie Edmonds in Cambridge’s Department of Earth Sciences.
Studying the behaviour of volcanoes such as Soufrière Hills in Montserrat, which caused the displacement of two-thirds of the island’s population (over 8,000 people) when it erupted in 1995, Edmonds and colleagues have accumulated huge datasets on everything from the type and quantity of gas belched from volcanoes, to the bulging and deformation of the volcanoes’ shape, to the altitude and quantity of ash thrown up into the stratosphere.
“About 600 million people live close enough to an active volcano to have their lives disturbed or threatened, so there’s a clear need for hazard assessment,” Edmonds said. “We knew that gas monitoring data could be essential for this, but monitoring depended on the use of cumbersome instruments that had to be driven around the crater’s edge.”
In the early 2000s, with funding from the Natural Environment Research Council (NERC), she and Dr Clive Oppenheimer from the Department of Geography developed a new gas sensor – one that is cheap, miniaturised and can be left long term on the volcano, relaying the data back to the observatory by radio modem. Today, sensors like these are used by scientists worldwide for monitoring volcanoes.
“Previous studies had shown that changes in the emission rate of gases correlated with volcanic activity but, because we have such a long dataset, we began to see another pattern emerging,” said Edmonds. “What you see at the volcano surface is really only the end part of the story.”
The intense temperatures and pressures deep in the earth find release through fissures and cracks, which carry dissolved gases such as carbon dioxide (CO2), sulphur dioxide (SO2), hydrogen chloride (HCl) and steam up through the mantle to the crust.
As the magma begins its journey to the surface, the pressure lowers and dissolved gases form tiny bubbles, which start to expand. Close to the surface, the expansion can be so great that it fuels an explosive burst of lava, shooting volcanic gases tens of kilometres into the earth’s atmosphere.
Because each species of gas dissolves at different pressures, the scientists can measure what is released at the surface and use this to work out the depth at which the gases separated from the magma to form bubbles. “The gases are like messages that tell you how the volcano is ‘plumbed’ and what shape that plumbing is in,” explained Edmonds.
“One intriguing pattern to emerge in Soufrière Hills is that the time series for the magma eruption and that for the SO2 gas eruption are completely unrelated to one another. There have been three big episodes of lava extrusion in the past 15 years and, although HCl flux seems to be a proxy for eruption rate, SO2 emission is uncoupled from what is happening in the eruption. We think the SO2 flux is telling us about something much deeper in the system.”
When these results were combined with a study of the rocks spewed from the volcano, Edmonds and colleagues began to piece together an idea of the physics and chemistry happening within.
They believe that a hot magnesium- and iron-rich ‘mafic’ magma is intruding from depth into the shallower magma chamber where it meets a silica- and crystal-rich ‘andesite’ magma that forms the main part of the eruption. However, it is the gas-rich mafic magma that Edmonds and colleagues believe triggers and fuels the eruption, and it is this that surface SO2 levels are a proxy for.
“This is far from the traditional view of how a magma chamber works,” said Edmonds. “It was thought to be balloon-like but now we think it’s vertically protracted, with different types of magma at different levels.”
“The surface SO2 is telling us about long-scale processes, of the order of months to years,” explained Edmonds. “Even though there may be no evidence of lava at the summit, if SO2 is still outgassing then there’s potential for the eruption to resume. We can to an extent use it to forecast a volcanic eruption.”
Recently, Edmonds and colleagues joined forces with researchers at other universities to understand how best to monitor volcanoes and earthquakes in two new NERC-funded projects. The £2.8 million Centre for the Observation and Modelling of Earthquakes, Volcanoes and Tectonics (COMET+) programme run by the University of Leeds will provide new understanding of geohazards to underpin national risk capabilities; and the £3.7 million RiftVolc project will create a long-range eruptive forecast for the largely uncharted volcanoes in the East African Rift Valley.
For Soufrière Hills, monitoring is providing a key input to the risk assessments by the UK government’s Scientific Advisory Committee for Montserrat, a British Overseas Territory. “All the surface signs indicate the volcanic activity is decaying away but, from the SO2 emissions, the volcano remains active at depth. We think there’s a huge magma reservoir – tens of cubic kilometres beneath the island, much bigger than the island itself. We know from looking at older ash deposits on the island that this volcano is capable of much larger eruptions than we have seen in recent years, perhaps even as large as the Mount St Helens blast.”
Note : The above story is based on materials provided by University of Cambridge
