This image obtained on May 5, 2015 courtesy of the Institute of Vertebrate Paleontology and Paleoanthropology in Bejing, shows a computer generated image of an Ornithuromorph, a wading bird from the Early Cretaceous period in China. Credit: Institute of Vertebrate Paleontology and Paleoanthropology in Bejing
Modern birds may have evolved six million years earlier than thought, said Chinese palaeontologists Wednesday after analyzing the fossil remains of a previously unknown prehistoric relative.
The extinct species, of which two fossils were discovered in China’s northeastern Hebei province about two years ago, was the earliest known member of the Ornithuromorpha branch that also gave us Neornithes, or modern birds.
“The new fossil represents the oldest record (about 130.7 million years ago) of Ornithuromorpha,” study co-author Wang Min of the Chinese Academy of Sciences told AFP by email.
“It pushed back the origination date of Ornithuromorpha by at least five million years” and the divergence of modern birds by about the same margin.
The previous oldest known example of Ornithuromorpha lived about 125 million years ago.
According to an artist’s impression, the new bird, dubbed Archaeornithura meemannae, shared many features with its modern cousins, apart from tiny, sharp claws on its wings.
It stood about 15 centimetres (six inches) tall on two legs that had no feathers—suggesting it may have been a wader from a lake shore environment.
The fossils were not complete enough to determine whether the creature had teeth—a common feature of birds from the Early Cretaceous period, a sub-division of the Mesozoic era.
Like some modern birds, it may have used gastroliths, or stomach stones, to break down hard foods like seeds, and it was likely a plant-eater, said Wang.
In the artist’s recreation, it sports a striking, purple feather crown.
Ornithuromorpha are believed to have comprised about half of bird species that lived during the Mesozoic era, which lasted from about 252 million to 66 million years ago. Some evolved into living birds.
Other Mesozoic groups like Enantiornithes, which had teeth and clawed wings, are not thought to have left any living descendents.
Mesozoic bird fossils are rare, and very little is known about the early evolutionary history of birds.
The earliest known relative of birds is thought to be Archaeopteryx, considered a transitional species from non-avian dinosaurs with feathers which lived about 150 million years ago.
Note : The above story is based on materials provided by AFP.
Fig. 1 Tyrannosaurid tooth from the Nanxiong Formation of Jiangxi Province, in labial (A and B), lingual (C), mesial (D), distal (E), basal (F), and apical (G) views. Arrow indicates distal carina location. Scale bar equals 10 mm in A, and 20 mm in B-G. Credit: MO Jinyou
Large carnivorous dinosaurs, are common in the Late Cretaceous of Asia, but only some fragment teeth have been recovered from southern China. In a paper published in the latest issue of Vertebrata PalAsiatica, Dr. XU Xing, Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences, and MO Jinyou, Natural History Museum of Guangxi in Nanning reported two isolated, large predatory theropod teeth from the Upper Cretaceous of southern China. The smaller tooth is assigned to a tyrannosaurid, whereas the larger one is greatly distinct from other known Late Cretaceous theropods, probably represents a previously unrecognized large predatory dinosaur.
These large predatory theropod teeth were discovered for the first time from the Upper Cretaceous Nanxiong Formation of Jiangxi, helping better understand the known diversity of vertebrates from the Upper Cretaceous Nanxiong Formation, southern China.
The crown height of the smaller tooth is 76 mm. It is identified as a typical tooth of a large tyrannosaurid based on large and suboval in cross-section. The crown base ratio, about 0.72, is within the range seen in Tyrannosaurus rex, and the chisel-shaped distal denticles are similar to those of tyrannosaurids.
The larger tooth is moderately laterally compressed, with well defined longitudinal oriented enamel wrinkles at the basal halves of the mesial and distal margins. The crown height of the larger tooth is 91 mm. It probably represents a previously unknown large theropod inhabited Asia during the Late Cretaceous.
The Nanxiong Formation or its equivalents are exposed in several provinces of southeastern China and represented by a thick sequence of red mudstones, sandstones and conglomerates. In Jiangxi, these red beds have yielded dinosaurs and other vertebrate fossils since 1965, including turtles, lizards, dinosaur eggs, small theropods, and sauropods.
This work was supported by the National Natural Science Foundation of China.
Fig. 2 Large theropod tooth from the Nanxiong Formation of Jiangxi Province, in lingual (A, B), labial (C, D), basal (E), mesial (F, G), and distal (H, I) views. Arrow marks the end of mesial carina. The white frames in C, F, and H mark the tooth area displayed in enlarged form in images D, G, and I, respectively. Scale bars equal 10 mm in A, D, G, and I; 20 mm in B, C, E, F, and H. Credit: MO Jinyou
Capelatus prykei is so different from any of the world’s other diving beetles that it has been placed in a new genus all of its own. Credit: David Bilton/Plymouth University
A striking new species of beetle with no direct relatives has been identified by a scientist from Plymouth University living in wetlands on the outskirts of Cape Town.
Capelatus prykei is so different from any of the world’s other diving beetles that it has been placed in a new genus all of its own, with its nearest relations to be found around the Mediterranean and in New Guinea.
In a study, published in the journal Systematic Entomology, scientists used a combination of morphological and molecular data to study Capelatus, and establish it as a highly distinctive, and apparently endangered, member of the world fauna.
Capelatus prykei measures between 8-10mm, large in comparison to most copelatine diving beetles, and was discovered in areas of relatively dense vegetation within the Noordhoek Wetlands.
Dr David Bilton, Reader in Aquatic Biology at Plymouth University, said: “Capelatus prykei immediately looks odd, quite unlike any previously known diving beetle. It’s fairly common to find new species of beetle, but it’s much less usual to find things which are so different they have to be put in their own genus. Our study of DNA sequences shows that the closest relatives of Capelatus live thousands of miles away, and that they last shared a common ancestor around 30-40 million years ago.
“This beetle’s a real evolutionary relic, which only seems to have survived in a very small area close to Cape Town, probably because this region has had a relatively stable climate over the last few million years. Today Capelatus is extremely rare though – in fact we know of only one population, fortunately located inside Table Mountain National Park. We’ve also found old, unnamed specimens in the Natural History Museum in London, but the area where these were caught in the 1950s is now under the suburbs of the city.”
Dr Bilton first began sampling water beetles in the area as a result of annual field trips to South Africa by undergraduates on the BSc (Hons) in Marine Biology and Coastal Ecology, and has found dozens of new species in the area in the last five years. This study, written in conjunction with Plymouth entomologist Clive Turner and colleagues from the Museum of Zoology in Munich, really highlights the unique biological diversity of the region.
The Western Cape of South Africa hosts one of the world’s hottest biodiversity hotspots, and supports around 20 per cent of the plant species found in the whole of sub-Saharan Africa – most of which are restricted to the region.
The region is also home to a significant number of endemic reptiles, amphibians, freshwater fishes and insects and some of these, like Capelatus, lack close living relatives outside the region, making it one of the most biologically unique places on the planet.
The current study suggests that among such isolated species, Capelatus prykei is particularly under threat and that, as such, immediate action should be taken by conservation agencies.
“On the basis of available data, it is suggested that Capelatus prykei be afforded a provisional IUCN conservation status of Critically Endangered,” the authors say. “If the phylogenetic uniqueness of Capelatus prykei is also taken into consideration, it is clear that a better understanding of the range and requirements of this newly discovered taxon represents a priority for conservation, in both a regional and global context.”
Type specimen of Euanthus panii (L) and its reconstruction picture. Image Credit : CAS
The world’s first typical flower may date back to 162 million years ago, more than 37 million years earlier than previously thought, Chinese researchers reported in a new study.
The fossil flower, named Euanthus panii, was found in western Liaoning Province, according to the study, which was published in the recent edition of the UK-based Historical Biology, an international journal of paleobiology.
The findings were made by Wang Xin, a research fellow at the Nanjing Institute of Geology and Paleobiology of the Chinese Academy of Sciences, and Liu Zhongjian, a professor at the National Orchid Conservation Center.
“Euanthus demonstrates a typical flower organization, including sepals, petals, androecium of tetrasporangiate dithecate anthers and gynoecium with enclosed ovules, implying that flowers were already in place in the Jurassic period. Since enclosed ovules, tetrasporangiate dithecate anther and flower-like organisation are all seen in Euanthus, we place Euanthus among angiosperms with decent confidence,” the researchers wrote in the study.
Wang said his colleague Liu had collected tens of thousands of fossils in the 1970s and 1980s, including Euanthus, but relevant research did not begin until 2013, yangtse.com reported on Tuesday.
According to Wang, Euanthus is very small, only about 1 square centimeter, and may have relied on wind for pollination since there were no bees 162 million years ago. (ECNS)
In this artist’s rendering, the left image shows what Earth looked like more than 140 million years ago, when India was part of an immense supercontinent called Gondwana. The right image shows Earth today. Image: iStock (edited by MIT News)
In the history of continental drift, India has been a mysterious record-holder.
More than 140 million years ago, India was part of an immense supercontinent called Gondwana, which covered much of the Southern Hemisphere. Around 120 million years ago, what is now India broke off and started slowly migrating north, at about 5 centimeters per year. Then, about 80 million years ago, the continent suddenly sped up, racing north at about 15 centimeters per year — about twice as fast as the fastest modern tectonic drift. The continent collided with Eurasia about 50 million years ago, giving rise to the Himalayas.
For years, scientists have struggled to explain how India could have drifted northward so quickly. Now geologists at MIT have offered up an answer: India was pulled northward by the combination of two subduction zones — regions in the Earth’s mantle where the edge of one tectonic plate sinks under another plate. As one plate sinks, it pulls along any connected landmasses. The geologists reasoned that two such sinking plates would provide twice the pulling power, doubling India’s drift velocity.
The team found relics of what may have been two subduction zones by sampling and dating rocks from the Himalayan region. They then developed a model for a double subduction system, and determined that India’s ancient drift velocity could have depended on two factors within the system: the width of the subducting plates, and the distance between them. If the plates are relatively narrow and far apart, they would likely cause India to drift at a faster rate.
The group incorporated the measurements they obtained from the Himalayas into their new model, and found that a double subduction system may indeed have driven India to drift at high speed toward Eurasia some 80 million years ago.
“In earth science, it’s hard to be completely sure of anything,” says Leigh Royden, a professor of geology and geophysics in MIT’s Department of Earth, Atmospheric and Planetary Sciences. “But there are so many pieces of evidence that all fit together here that we’re pretty convinced.”
Royden and colleagues including Oliver Jagoutz, an associate professor of earth, atmospheric, and planetary sciences at MIT, and others at the University of Southern California have published their results this week in the journal Nature Geoscience.
What drives drift?
Based on the geologic record, India’s migration appears to have started about 120 million years ago, when Gondwana began to break apart. India was sent adrift across what was then the Tethys Ocean — an immense body of water that separated Gondwana from Eurasia. India drifted along at an unremarkable 40 millimeters per year until about 80 million years ago, when it suddenly sped up to 150 millimeters per year. India kept up this velocity for another 30 million years before hitting the brakes — just when the continent collided with Eurasia.
“When you look at simulations of Gondwana breaking up, the plates kind of start to move, and then India comes slowly off of Antarctica, and suddenly it just zooms across — it’s very dramatic,” Royden says.
In 2011, scientists believed they had identified the driving force behind India’s fast drift: a plume of magma that welled up from the Earth’s mantle. According to their hypothesis, the plume created a volcanic jet of material underneath India, which the subcontinent could effectively “surf” at high speed.
However, when others modeled this scenario, they found that any volcanic activity would have lasted, at most, for 5 million years — not nearly enough time to account for India’s 30 million years of high-velocity drift.
Squeezing honey
Instead, Royden and Jagoutz believe that India’s fast drift may be explained by the subduction of two plates: the tectonic plate carrying India and a second plate in the middle of the Tethys Ocean.
In 2013, the team, along with 30 students, trekked through the Himalayas, where they collected rocks and took paleomagnetic measurements to determine where the rocks originally formed. From the data, the researchers determined that about 80 million years ago, an arc of volcanoes formed near the equator, which was then in the middle of the Tethys Ocean.
A volcanic arc is typically a sign of a subduction zone, and the group identified a second volcanic arc south of the first, near where India first began to break away from Gondwana. The data suggested that there may have been two subducting plates: a northern oceanic plate, and a southern tectonic plate that carried India.
Back at MIT, Royden and Jagoutz developed a model of double subduction involving a northern and a southern plate. They calculated how the plates would move as each subducted, or sank into the Earth’s mantle. As plates sink, they squeeze material out between their edges. The more material that can be squeezed out, the faster a plate can migrate. The team calculated that plates that are relatively narrow and far apart can squeeze more material out, resulting in faster drift.
“Imagine it’s easier to squeeze honey through a wide tube, versus a very narrow tube,” Royden says. “It’s exactly the same phenomenon.”
Royden and Jagoutz’s measurements from the Himalayas showed that the northern oceanic plate remained extremely wide, spanning nearly one-third of the Earth’s circumference. However, the southern plate carrying India underwent a radical change: About 80 million years ago, a collision with Africa cut that plate down to 3,000 kilometers — right around the time India started to speed up.
The team believes the diminished plate allowed more material to escape between the two plates. Based on the dimensions of the plates, the researchers calculated that India would have sped up from 50 to 150 millimeters per year. While others have calculated similar rates for India’s drift, this is the first evidence that double subduction acted as the continent’s driving force.
“It’s a lucky coincidence of events,” says Jagoutz, who sees the results as a starting point for a new set of questions. “There were a lot of changes going on in that time period, including climate, that may be explained by this phenomenon. So we have a few ideas we want to look at in the future.”
Reference:
Oliver Jagoutz, Leigh Royden, Adam F. Holt, Thorsten W. Becker. Anomalously fast convergence of India and Eurasia caused by double subduction. Nature Geoscience, 2015; DOI: 10.1038/ngeo2418
Molten lava, rocks and gas went flying through the air on Hawaii’s Kilauea volcano after an explosion was caused by the partial collapse of a crater wall.
The collapse triggered a small explosion, spreading lava and debris around the rim of Kilauea’s Halemaumau Crater, the U.S. Geological Survey’s Hawaiian Volcano Observatory says.
Janet Babb, a geologist with the USGS, compared the blast on Sunday to taking a hammer to the top of a bottle of champagne.
“You look at the bottle and you see the liquid, but you don’t see the gas,” she said. “There’s a lot of gas in the lava. And so, when that rock fall hits the lava lake, it’s like the moment you knock the top of the champagne bottle off and that gas is released and it hurls molten lava and rock fragments.”
Rocks overhanging the lava lake are altered by gases coming from the lava, Babb said. The rocks eventually give way and collapse into the lava, causing an explosion.
The material was hurled about 280 feet skyward, she said.
Video of the event shows a wall of rocks sliding into a lava lake that last week rose to a record-high level. The slide caused an explosion that sent fist-size chunks of rock onto the closed Halemaumau visitor overlook, according to the Geological Survey. The area has been closed since 2008, when the lava lake formed, and no one was injured.
There could be fallout of ash and dust from this type of event, but it’s very unlikely that anyone could be injured, Babb said. Wind direction dictates the amount of debris that lands in visitor areas, and it is relatively common, she said.
The last time molten lava was visible in the crater was in 1982, when a fissure erupted. The last time there was a lake similar to this one was in 1974.
The vent within Halemaumau Crater has been rising and falling since it first opened, but it reached a record high last week. Even at its previous highest level in October 2012, the lake was too low for people to see. During the day, people could view the gas rising from the lake, and at night people could see the orange glow from the lava.
From the early 1800s up until 1924, there was a continuous lake of lava at Kilauea summit within Halemaumau. At that time, the crater was about half the diameter of what it is now.
In 1924, there was a huge eruption inside the volcano that doubled the size of the crater.
Since 1924, lava lakes have been present at different times. In 1967 and 1968, the entire crater was filled with molten lava. You can still see a “bathtub ring” on the walls of the crater where the lava had risen to at that time.
A magnitude 3.6 earthquake was felt in the area early Monday morning, according to the Geological Survey.
This photo shows a spectacular sigmoidal jointing within a very thick lava flow from the Ambenali formation in the Western Ghats area of India. See related open-access article by M.A. Richards et al. Credit: M.A. Richards and colleagues, and GSA Bulletin
In a new paper published online by GSA Bulletin on 30 April, researchers Mark Richards and colleagues address the “uncomfortably close” occurrence of the Chicxulub impact in the Yucatán and the most voluminous phase of the Deccan Traps flood basalt eruptions in India. Specifically, the researchers argue that the impact likely triggered most of the immense eruptions of lava in India — that indeed, this was not a coincidence, but a cause-and-effect relationship.
Knowledge and study of the Deccan Traps eruptions have consistently cast a shadow of doubt on the theory that the Chicxulub impact was the sole cause of the end-Cretaceous mass extinction, most infamous for killing off Earth’s dinosaurs. But Richards and colleagues write that historical evidence for the triggering of volcanoes by large earthquakes, coupled with a wide range of data, show that the massive outpouring of Deccan lavas are likely to have been triggered by the Chicxulub impact — and thus following on as a secondary disaster.
“The chances of that occurring at random are minuscule,” says Richards. “It’s not a very credible coincidence.”
Several of the authors visited India in April 2014 to obtain lava samples for dating, and noticed that there are pronounced weathering surfaces, or terraces, marking the onset of the huge Wai subgroup flows. This geological evidence likely indicates a period of quiescence in Deccan volcanism prior to the Chicxulub impact, which, says Richards, “gave this thing a shake,” thus mobilizing a huge amount of magma over a short period of time.
Richards and colleagues write that while the Deccan eruptions probably spewed massive amounts of carbon dioxide and other noxious, climate-modifying gases into the atmosphere, “It’s still unclear if this contributed to the demise of most of life on Earth at the end of the Age of Dinosaurs.”
This article is open access online. Co-authors of the paper are Paul Renne, Michael Manga, Stephen Self, and Courtney Sprain, all from UC-Berkeley; Walter Alvarez, a UC-Berkeley professor emeritus and the co-originator of the dinosaur-killing asteroid theory; Leif Karlstrom of the University of Oregon; Jan Smit of Vrije Universeit in Amsterdam; Loÿc Vanderkluysen of Drexel University in Philadelphia; and Sally A. Gibson of the University of Cambridge, UK. Learn more about this team’s research via the UC-Berkeley newsroom.
Reference:
M. A. Richards, W. Alvarez, S. Self, L. Karlstrom, P. R. Renne, M. Manga, C. J. Sprain, J. Smit, L. Vanderkluysen, S. A. Gibson. Triggering of the largest Deccan eruptions by the Chicxulub impact. Geological Society of America Bulletin, 2015; DOI: 10.1130/B31167.1
Cold seeps, the sites on the ocean floor where the bubbles of the methane gas rise up, are a home for a varied communities of bacteria, bivalves and other associated life forms. Credit: NOAA-OER/BOEM/USGS
Offshore the Svalbard archipelago, methane gas is seeping out of the seabed at the depths of several hundred meters. These cold seeps are a home to communities of microorganisms that survive in a chemosynthetic environment — where the fuel for life is not the sun, but the carbon rich greenhouse gas.
There is a large, and relatively poorly understood, community of methane-consuming bacteria in this environment. They gorge on the gas, control its concentration in the ocean, and stop it from reaching the ocean surface and released into the atmosphere.
In the atmosphere methane is a much more potent climate gas than CO2 and it can amplify current global warming.
However, a new study published in Nature Geoscience shows that ocean currents can have a strong impact on this bacterial methane filter.
Varies drastically
Oceanographer Benedicte Férré, who is a team leader at CAGE, is a co-author of the study. It shows that the level of activity of the methane-consuming bacteria varied drastically over very short time spans.
The international team of scientists behind this study was able to detect that the fluctuations in bacterial communities changed at the whim of the West Spitsbergen Current that carries warm water from Norwegian Sea to Arctic Ocean. Important oceanographic factors such as water temperature and salinity changed.
The warm and salty current swept over the methane seeping sites, and carried bacteria communities away, thus disturbing methane filtration processes.
Important for the future release
This bacteria filter could become even more important in the future, because environmental change can cause bottom water warming in the Arctic Ocean.
As a consequence methane rich gas hydrates in the ocean floor dissociate, and release even more gas to the water column. This could increase food supply for bacteria. But whether bacteria are able to consume the methane depends on ocean current dynamics as documented by Ferre and her team.
Future methane release from the ocean to the atmosphere will depend on ocean currents.
“We were able to show that strength and variability of ocean currents control the prevalence of methanotrophic bacteria,” says Lea Steinle from University of Basel and the lead author of the study, “therefore, large bacteria populations cannot develop in a strong current, which consequently leads to less methane consumption.”
Reference:
Lea Steinle, Carolyn A. Graves, Tina Treude, Bénédicte Ferré, Arne Biastoch, Ingeborg Bussmann, Christian Berndt, Sebastian Krastel, Rachael H. James, Erik Behrens, Claus W. Böning, Jens Greinert, Célia-Julia Sapart, Markus Scheinert, Stefan Sommer, Moritz F. Lehmann, Helge Niemann. Water column methanotrophy controlled by a rapid oceanographic switch. Nature Geoscience, 2015; 8 (5): 378 DOI: 10.1038/ngeo2420
Given the importance of water in Australia, surprisingly, there is relatively little information about the past variability of rainfall on this continent. Although there is a good annual record of the past 100 years in Australia, there is nothing much before that period and no known cave deposit records exist for New South Wales.
The Australian Nuclear Science and Technology Organisation (ANSTO), University of New South Wales (UNSW) Australia and the National Parks and Wildlife Service (NPWS) have collaborated on research, which appears in the Journal of Hydrology (Markowska et al. 2015). The group is interested in interpreting the rainfall record of the past 2000 years in Australia, because understanding past climate can help predict the availability of water resources in the future.
The study is taking place in the Snowy Mountains, which are an important study site as the area provides an important source of water for the Murrumbidgee and Murray River systems, two major waterways in southeast Australia. The limestone deposit contains a system of about 400 caves managed by the NPWS. Geologists suggest that the caves were formed about 440 million years ago.
Researchers working in underground caves studying when rainfall reaches the subsurface (groundwater recharge) at Yarrangobilly Caves in the Snowy Mountains have found new information that will help reconstruct past climates and groundwater recharge from cave deposits. Cave deposits, or speleothems, are mineral accumulations formed by calcium-rich water in underground caverns. They are important because they can be used to establish a record of past environmental changes, such as rainfall variability.
Lead author, Institute of Environmental Research scientist Monika Markowska and colleagues have been monitoring dripping water, which forms stalagmites, for fifteen months in the cave system, which is located in Kosciuszko National Park.
“Monitoring the water movement from the surface to the cave is important because it carries the majority of the climate and environmental information from the surface,” according to Prof Andy Baker of UNSW Australia, a co-author on the paper.
In this study researchers found that the soil moisture content may be more important than the amount of rainfall in the formation of stalagmites. “Although rainfall is essential for groundwater recharge, at Harrie Wood Cave it was the antecedent soil moisture saturation (i.e. wet or dry preconditions) that controlled whether water from individual rainfall events reached the underground cave system.” said Markowska.
The research team came to this conclusion after a detailed analysis of drip water flow at 14 sites within the Harrie Wood Cave taken at 15-minute intervals and weather data from the surface above the cave. By monitoring drip rates, researchers can determine how long it took the water to get into the cave. They also monitored precipitation, temperature, barometric pressure and soil moisture.
In the cave, dripping water was automatically recorded using Stalagmate® drip logger, devices similar to a miniature, watertight, plastic drum that records each drip from the vibration measured each time a water droplet hits its surface. The data from 14 sites reported in the paper are part of a network of fifty devices placed in the cave, one of the largest such studies in the world. Interpreting the data provided by the Stalagmate® loggers provided a unique way to classify and understand water flow from the surface to the cave.
The researchers identified five different types of drip water responses to surface climate and were surprised to see different flow patterns in drips in close proximity to each other.
The five types of response are due to the many possible water flow paths from the surface to the cave, with water potentially stored in both the soil and in fractures and solution pockets in the limestone, before reaching the cave.
Most importantly, the research demonstrates that speleothems can have very individual relationships to the surface climate due to the specific water flow route. This information has allowed researchers to identify which speleothems can be used to obtain a rainfall record for the past 2000 years.
Stalagmites, a speleothem, are important because they can be analysed using mass spectroscopy to determine records of past climate. The decay of uranium-234 into thorium from the calcite in a stalagmite can be measured to determine age. The ratio of oxygen-18 and oxygen-16 can provide information about rainfall.
Reference:
“Unsaturated zone hydrology and cave drip discharge water response: Implications for speleothem paleoclimate record variability,” Journal of Hydrology, DOI: 10.1016/j.jhydrol.2014.12.044
While fjords are celebrated for their beauty, these ecosystems are also major carbon sinks that likely play an important role in the regulation of the planet’s climate, new research reveals. Credit: Candida Savage
While fjords are celebrated for their beauty, these ecosystems are also major carbon sinks that likely play an important role in the regulation of the planet’s climate, new research reveals.
The finding is newly published in the international journal Nature Geoscience.
After studying sediment data from worldwide fjord systems, the researchers, who include Dr Candida Savage of New Zealand’s University of Otago, estimate that about 18 million tonnes of organic carbon (OC) is buried in fjords each year, equivalent to 11% of annual marine carbon burial globally.
Dr Savage and colleagues calculated that per unit area, fjord organic carbon burial rates are twice as large as the ocean average.
“Therefore, even though they account for only 0.1% of the surface area of oceans globally, fjords act as hotspots for organic carbon burial,” Dr Savage says.
Fjords are long, deep and narrow estuaries formed at high latitudes during glacial periods as advancing glaciers incise major valleys near the coast. They are found in North Western Europe, Greenland, North America, New Zealand, and Antarctica.
As deep and often low oxygen marine environments, fjords provide stable sites for carbon-rich sediments to accumulate, Dr Savage says.
Carbon burial is an important natural process that provides the largest carbon sink on the planet and influences atmospheric carbon dioxide (CO2) levels at multi-thousand-year time scales.
In the Nature Geoscience article, the researchers suggest that fjords may play an especially important role as a driver of atmospheric CO2 levels during times when ice sheets are advancing or retreating.
Earth is currently in an interglacial period after ice sheets receded around 11,700 years ago.
During glacial retreats, fjords would trap and prevent large volumes of organic carbon flowing out to the continental shelf, where chemical processes would have caused CO2 to be produced, says Dr Savage.
Once glaciers started advancing again this material would likely then be pushed out onto the shelf and CO2 production would increase.
“In essence, fjords appear to act as a major temporary storage site for organic carbon in between glacial periods. This finding has important implications for improving our understanding of global carbon cycling and climate change,” she says.
The research involved fieldwork in Fiordland and analysing data from 573 surface sediment samples and 124 sediment cores from fjords around the world.
Reference:
Richard W. Smith, Thomas S. Bianchi, Mead Allison, Candida Savage, Valier Galy. High rates of organic carbon burial in fjord sediments globally. Nature Geoscience, 2015; DOI: 10.1038/ngeo2421
NASA data and expertise are providing valuable information for the ongoing response to the April 25, 2015, magnitude 7.8 Gorkha earthquake in Nepal. The quake has caused significant regional damage and a humanitarian crisis. Credit: NASA/JPL/Ionosphere Natural Hazards Team
NASA and its partners are gathering the best available science and information on the April 25, 2015, magnitude 7.8 earthquake in Nepal, referred to as the Gorkha earthquake, to assist in relief and humanitarian operations. Organizations using these NASA data products and analyses include the U.S. Geological Survey, United States Agency for International Development (USAID)/Office of U.S. Foreign Disaster Assistance, World Bank, American Red Cross, and the United Nations Children’s Fund.
NASA and its collaborators are pulling optical and radar satellite data from international and domestic partners and compiling them into a variety of products. The products include “vulnerability maps,” used to determine risks that may be present; and “damage proxy maps,” used to determine the type and extent of existing damage. Such products can be used to better direct response efforts.
The satellite data will be used to compile maps of ground surface deformation and to create risk models. NASA and its partners are also contributing to assessments of damage to infrastructure. They are tracking remote areas that may be a challenge for relief workers to reach, as well as areas that could be at risk for landslides, river damming, floods and avalanches. The data will contribute to ongoing investigations of our restless Earth and its impacts on society.
NASA is helping get satellite data into the hands of government officials in Nepal where Internet bandwidth is limited. The joint NASA-USAID SERVIR project is supporting disaster response mapping efforts through the SERVIR-Himalaya office at the International Centre for Integrated Mountain Development in Kathmandu. SERVIR staff at NASA’s Marshall Space Flight Center, Huntsville, Alabama, are coordinating image tasking, processing, compression, and distribution efforts with colleagues from Goddard Space Flight Center in Greenbelt, Maryland, and the Jet Propulsion Laboratory in Pasadena, California.
NASA technology that can locate people trapped beneath collapsed buildings is being deployed to Nepal. A remote-sensing radar technology called FINDER (Finding Individuals for Disaster and Emergency Response), developed by JPL in conjunction with the U.S. Department of Homeland Security’s Science and Technology Directorate, can locate individuals buried as deep as 30 feet (9.1 meters) in crushed materials, hidden behind 20 feet (6 meters) of solid concrete, and from a distance of 100 feet (30.5 meters) in open spaces. This technology, licensed by the private entity R4 Incorporated of Edgewood, Maryland, has been taken to Nepal to assist with recovery efforts.
NASA uses the vantage point of space to increase our understanding of our home planet, improve lives and safeguard our future. NASA develops new ways to observe and study Earth’s interconnected natural systems with long-term data records. The agency freely shares this unique knowledge and works with institutions around the world to gain new in-sights into how our planet is changing.
Note : The above story is based on materials provided by NASA.
Full Moon photograph taken 10-22-2010 from Madison, Alabama, USA. Photographed with a Celestron 9.25 Schmidt-Cassegrain telescope.
With an estimated 1.6 billion tonnes of water ice at its poles and an abundance of rare-earth elements hidden below its surface, the Moon is rich ground for mining.
In this month’s issue of Physics World, science writer Richard Corfield explains how private firms and space agencies are dreaming of tapping into these lucrative resources and turning the Moon’s grey, barren landscape into a money-making conveyer belt.
Since NASA disbanded its manned Apollo missions to the Moon over 40 years ago, unmanned spaceflight has made giant strides and has identified a bountiful supply of water ice at the north and south poles of the Moon.
“It is this, more than anything else,” Cornfield writes, “that has kindled interest in mining the Moon, for where there is ice, there is fuel.”
Texas-based Shackleton Energy Company (SEC) plans to mine the vast reserves of water ice and convert it into rocket propellant in the form of hydrogen and oxygen, which would then be sold to space partners in low Earth orbit.
As the company’s chief executive officer, Dale Tietz, explains, the plan is to build a “gas station in space” in which rocket propellant will be sold at prices significantly lower than the cost of sending fuel from Earth.
SEC plans to extract the water ice by sending humans and robots to mine the lunar poles, and then use some of the converted products to power mining hoppers, lunar rovers and life support for its own activities.
Moon Express, another privately funded lunar-resources company, is also interested in using water ice as fuel — but in a different form. It plans to fuel its operations and spacecraft using “high-test peroxide” (HTP), which has a long and illustrious history as a propellant.
As for mining the rare-earth elements on the Moon, China is making the most noticeable headway. The Jade Rabbit lander successfully touched down on the Moon in December 2013 and the Chinese space agency has publicly suggested establishing a “base on the Moon as we did in the South Pole and the North Pole.”
With a near-monopoly on the dwindling terrestrial rare-earth elements, which are vital for everything from mobile phones to computers and car batteries, it is no surprise that China may want to cast its net wider.
“All interested parties agree that the Moon — one step from Earth — is the essential first toehold for humankind’s diaspora to the stars,” Corfield concludes.
The structural engineer strides through Kathmandu’s old city, past buildings reduced to rubble, buildings whose facades are cracked in dozens of places, like the fractured shell of a hardboiled egg. But it’s the many buildings that made it unscathed through the earthquake that amaze Kit Miyamoto.
“It could have been so much worse,” said Miyamoto, head of a global earthquake and structural engineering firm, who flew to Nepal soon after he heard about last weekend’s 7.8- magnitude quake. He shakes his head, topped by a white hardhat. Before landing, he’d envisioned a flattened moonscape of dust and debris. He thought as many as 40,000 people could be dead.
That the reality has turned out to be far less destructive has a lot to do with the vagaries of geology, geography and construction decisions. Not to mention sheer luck.
The danger, however, may not be over. Dozens of mostly small aftershocks have hit Nepal since the quake. A more powerful aftershock a bit closer to the capital could cause immense damage.
“If a magnitude 6 or 6.5 quake happens within 20 kilometers of Kathmandu, it’s going to be a nightmare,” said Sandeep Donald Shah, a structural engineer with Miyamoto International, during the walk through Kathmandu. “The probability is pretty high that this may happen because we just had a (huge) earthquake, and the fault line has been activated.”
The general state of Kathmandu’s buildings—with their ancient soot-and-exhaust-stained concrete, their uneven bricks, their drooping facades and crooked balconies—raises questions about how so many still stand after such a big quake.
Remaining upright depended on a combination of factors, including age, size, building material and strength, location and the underlying soil. But the simplest explanation is that Kathmandu largely sits outside the danger zone of last week’s quake.
Because the epicenter was about 80 kilometers (50 miles) from the capital, the quake’s power had partially dissipated by the time it got to Kathmandu, said Miyamoto, who is also a seismic safety commissioner for the state of California.
Even so, some of Kathmandu’s remaining buildings look “very bad, seismically speaking,” with weak foundations and structures, Miyamoto said. They’ve also been “softened up” by the quake, making them more likely to collapse or be seriously damaged if another, closer quake hits.
The region will likely see aftershocks for another year, including some big ones, Miyamoto said, but it’s impossible to predict where or when they will occur. The two biggest aftershocks so far have been more than 60 kilometers (38 miles) from Kathmandu.
A direct or even a near hit on Kathmandu by the April 25 quake would have meant a massive death toll.
The Nepal quake released 16 times the energy of the 2010 Haiti earthquake, where death estimates ranged from 100,000 to 300,000, yet the death toll in Nepal now stands at more than 6,600. This is a huge loss of life, but far less than recent estimates that 100,000 people might die in Nepal’s next major earthquake.
Driving through the city, the juxtaposition of what crumbled and what survived is striking.
At some big hotel compounds it’s almost as if the quake never happened: honking geese wander over manicured lawns and foreign guests start their days with hot showers before lining up at brimming breakfast buffets, eyes locked on phones connected to Wi-Fi.
Outside the gates, even many of those whose homes weren’t ruined slept out in the open for days after the quake because of fears of aftershocks. In some closely packed quarters, there is spectacular damage, with tall buildings leaning against their neighbors like tipped dominoes. Many villages in the countryside, outside the capital, have been virtually flattened.
Generally, the older and bigger the building, the worse off it fared. So the so-called old city, home to many of Kathmandu’s precious world heritage buildings, is obliterated in places. All over the city, destroyed brick walls spill into the streets like ocean waves breaking on beaches.
In much of Kathmandu, however, roads are choked with traffic, and businesses have begun to reopen. You can go blocks sometimes without seeing any obvious earthquake damage.
“It’s getting back to normal, but … it still doesn’t feel safe,” said Prabhu Dutta, a 27-year-old banker in Kathmandu.
He has started sleeping again inside his home, which has some cracks in the walls but is still standing. However, the dozens of aftershocks he has felt since the quake make him uneasy. Many people in Kathmandu have been leaving for the countryside because of fears of a big aftershock.
In the final equation, buildings collapse, or stand, because of the power and length of a quake’s shaking.
The strength of the shaking depends on the magnitude of the earthquake, the distance from the epicenter, the depth of the earthquake—shallower quakes do more damage than deeper ones—and the type of soil, according to Susan Cutter, director of the Hazards and Vulnerability Research Institute at the University of South Carolina.
While both the Haiti and Nepal quakes were shallow—10 kilometers (6 miles) deep for Nepal, 13 kilometers (8 miles) for Haiti—the soil in Haiti made the shaking more severe and longer, Cutter said. Port-au-Prince was also much closer to the epicenter than Kathmandu—25 kilometers (15 miles) rather than 80 kilometers (50 miles).
Old or unreinforced masonry normally fares poorly in an earthquake, though much depends on the quality of the materials and the building methods, as well as on building codes and their enforcement. If Nepal is far below most Western nations in terms of construction quality and code enforcement, most experts also believe it is better than Haiti.
Miyamoto, the structural engineer, called the damage in Nepal’s capital, and the possibility that aftershocks could cause much more, a wakeup call. The government and outside nations, he said, should begin work to strengthen existing buildings and construct stronger new ones.
But that may prove difficult for Nepal’s leaders.
After the quake, as he stood outside a multi-story home where emergency teams were pulling out the body of a 12-year-old girl, Transport Minister Tek Bahadur Garung said that while Nepal does issue building regulations and licenses, there’s no monitoring or enforcement.
Officials, he said, were simply overwhelmed.
“In this situation, what to do?” he said. “It’s a big problem for our government to solve.”
Now extinct, woolly mammoths lived during the last ice age. Credit: Natural History Museum, London/SPL
Unlike their elephant cousins, woolly mammoths were creatures of the cold, with long hairy coats, thick layers of fat and small ears that kept heat loss to a minimum. For the first time, scientists have comprehensively catalogued the hundreds of genetic mutations that gave rise to these differences.
The research reveals how woolly mammoths (Mammuthus primigenius) evolved from the ancestor they share with Asian elephants (Elephas maximus). It could even serve as a recipe for engineering elephants that are able to survive in Siberia.
“These are genes we would need to alter in an elephant genome to create an animal that was mostly an elephant, but actually able to survive somewhere cold,” says Beth Shapiro, an evolutionary geneticist at the University of California, Santa Cruz who was not involved in the latest research. As fanciful as it sounds, such an effort is at a very early stage in a research lab in Boston, Massachusetts.
The first woolly mammoth genome was published in 2008 (ref. 2), but it contained too many errors to reliably distinguish how the mammoth genome differs from those of elephants. Other studies singled out individual mammoth genes for close inspection, identifying mutations that would have endowed the animals with light coats3 and oxygen-carrying haemoglobin proteins that work in the cold4.
Fatty secrets
In the latest study, Vincent Lynch, an evolutionary geneticist at the University of Chicago in Illinois, and his team describe how they sequenced the genomes of three Asian elephants and two woolly mammoths (one died 20,000 years ago, another 60,000 years ago) to a very high quality. They found about 1.4 million DNA letters that differ between mammoths and elephants, which altered the sequence of more than 1,600 protein-coding genes. The study was posted on the biology preprint server bioRxiv.org on 23 April1.
Combing the literature for information about what those proteins do in other organisms revealed dozens of genes implicated in skin and hair development, fat storage and metabolism, temperature sensation and other aspects of biology potentially relevant to life in the Arctic.
For instance, several of the genes with changes unique to the mammoths were involved in setting the circadian clock, a potential adaptation to living in a world with dark winters and 24 hours of daylight in summer. Other Arctic animals such as some reindeer have similar mutations.
The mammoth genomes also contained extra copies of a gene that controls the production of fat cells and variations in genes linked to insulin signalling, which are in turn linked to diabetes and diabetes prevention. And several of the genes that differ between mammoths and elephants are involved in sensing heat and transmitting that information to the brain.
Resurrected gene
The team ‘resurrected’ the mammoth version of one of the heat-sensing genes, which encodes a protein called TRPV3 that is expressed in skin and also regulates hair growth. They inserted the gene sequence into the genomes of human cells in the lab and exposed them to different temperatures, revealing that the mammoth TRPV3 protein is less responsive to heat than the elephant version is. The result chimes with a previous finding that mice with a deactivated version of TRPV3 are more likely to spend time in colder parts of their cage compared with normal rodents, and boast wavier hair.
The next step, says Lynch, is to insert the same gene into elephant cells that have been chemically programmed to behave like embryonic cells, and so can be turned into a variety of cell types. Such induced pluripotent stem (iPS) cells could then be used to examine expression of mammoth proteins in different tissues. Lynch’s team also plans to test the effects of other mammoth mutations in iPS cells.
Mammoth task
Similar work is already being carried out in the lab of George Church, a geneticist at Harvard Medical School in Boston. Using a technology known as CRISPR/Cas9 that allows genes to be easily edited, his team claims to have engineered elephant cells that contain the mammoth version of 14 genes potentially involved in cold tolerance — although the team has not yet tested how this affects the elephant cells. Church plans to do these experiments in “organoids” created from elephant iPS cells.
The work, says Church, is a preamble to editing an entire woolly mammoth genome — and perhaps even resurrecting the woolly mammoth, or at least giving an Asian elephant enough mammoth genes to survive in the Arctic. The second option would be easier to do because it would require fewer mutations than the first option. A 16-square-kilometre reserve in north Siberia, known as Pleistocene Park, has even been proposed as a potential home for such a population of cold-tolerant elephants.
However, whether anyone would want to do such a thing is a different question, says Lynch, and Shapiro agrees. In her book How to Clone a Mammoth (Princeton University Press, 2015), she outlines the innumerable hurdles that stand in the way of breeding genetically modified ‘woolly elephants’ — from the ethics of applying reproductive technologies to an endangered species to the fact that the field of elephant reproductive biology is still immature.
“I probably should have called the book How One Might Go About Cloning a Mammoth (Should It Become Technically Possible, And If It Were, In Fact, a Good Idea, Which It’s Probably Not),” Shapiro says. “But that was a much less compelling title.”
Note : The above story is based on materials provided by Nature. The original article was written by Ewen Callaway.
This custom-built precise pressure sensor detects the seafloor’s rise and fall as magma, or molten rock, moves in and out of the underlying magma chamber. Three are installed on the caldera of the underwater volcano. Credit: NSF-OOI/UW/CSSF
If a volcano erupts at the bottom of the sea, does anybody see it? If that volcano is Axial Seamount, about 300 miles offshore and 1 mile deep, the answer is now: yes.
Thanks to a set of high-tech instruments installed last summer by the University of Washington to bring the deep sea online, what appears to be an eruption of Axial Volcano on April 23 was observed in real time by scientists on shore.
“It was an astonishing experience to see the changes taking place 300 miles away with no one anywhere nearby, and the data flowed back to land at the speed of light through the fiber-optic cable connected to Pacific City—and from there, to here on campus by the Internet, in milliseconds,” said John Delaney, a UW professor of oceanography who led the installation of the instruments as part of a larger effort sponsored by the National Science Foundation.
Delaney organized a workshop on campus in mid-April at which marine scientists discussed how this high-tech observatory would support their science. Then, just before midnight on April 23 until about noon the next day, the seismic activity went off the charts.
The gradually increasing rumblings of the mountain were documented over recent weeks by William Wilcock, a UW marine geophysicist who studies such systems.
During last week’s event, the earthquakes increased from hundreds per day to thousands per day, and the center of the volcanic crater dropped by about 6 feet (2 meters) over the course of 12 hours.
“The only way that could have happened was to have the magma move from beneath the caldera to some other location,” Delaney said, “which the earthquakes indicate is right along the edge of the caldera on the east side.”
The seismic activity was recorded by eight seismometers that measure shaking up to 200 times per second around the caldera and at the base of the 3,000-foot seamount. The height of the caldera was tracked by the bottom pressure tilt instrument, which measures the pressure of the water overhead and then removes the effect of tides and waves to calculate its position.
The depth instrument was developed by Bill Chadwick, an oceanographer at Oregon State University and the National Oceanic and Atmospheric Administration who has also been tracking the activity at Axial Volcano and predicted that the volcano would erupt in 2015.
The most recent eruptions were in 1998 and 2011.
The volcano is located about 300 miles west of Astoria, Oregon, on the Juan de Fuca Ridge, part of the globe-girdling mid-ocean ridge system—a continuous, 70,000 km (43,500 miles) long submarine volcanic mountain range stretching around the world like the strings on a baseball, and where about 70 percent of the planet’s volcanic activity occurs. The highly energetic Axial Seamount, Delaney said, is viewed by many scientists as being representative of the myriad processes operating continuously along the powerful subsea volcanic chain that is present in every ocean.
“This exciting sequence of events documented by the OOI-Cabled Array at Axial Seamount gives us an entirely new view of how our planet works,” said Richard Murray, division director for ocean sciences at the National Science Foundation. “Although the OOI-Cabled Array is not yet fully operational, even with these preliminary observations we can see how the power of innovative instrumentation has the potential to teach us new things about volcanism, earthquakes and other vitally important scientific phenomena.”
The full set of instruments in the deep-sea observatory is scheduled to come online this year. A first maintenance cruise leaves from the UW in early July, and will let researchers and students further explore the aftermath of the volcanic activity.
Did you feel that? Credit: Brian Collins/USFWS/flickr, CC BY
The recent earthquake in Nepal demonstrated yet again how difficult it is to reliably predict natural disasters. While we have a good knowledge of the various earthquakes zones on the planet, we have no way of knowing exactly when a big quake like the 7.8-magnitude event in Nepal will happen.
But we know that many animals seem able to sense the onset of such events. We could use powerful computers to monitor herds of animals and make use of their natural instincts to provide forewarning of natural disasters.
Immediately before an earthquake, herds of animals often start to behave strangely – for example suddenly leaving their homes to seek shelter. This could be because they detect small, fast-travelling waves or because they sense chemical changes in ground water from an impending earthquake.
Although there are possibilities here, we certainly need more studies – because it’s difficult to find statistically significant links between unusual animal behaviour and impending disasters. This is because natural disasters occur relatively rarely and it’s hard to reliably interpret animal behaviour after the fact. In fact, this uncertainty was quoted by the Chinese government after reports that zoo animals behaved strangely before the Wenchuan earthquake a few years ago.
Animal whispering software is needed
There are areas where we know beyond doubt that animals have accurate detection ability, for example the way dogs can spot signs of cancer that we otherwise have difficulty recognising. We also know that by giving them animal-centred interfaces we can provide them the means to express what they detect, for example by hitting the right buttons according to their judgement.
This is an example of providing animals with accessible technology that supports their natural behaviour, while also translating their behaviour into something we can understand.
Of course, a key difference between a dog who is detecting cancer and a swarm of birds that is responding to the early signs of an imminent quake is in the numbers involved. We would expect an upcoming earthquake to affect many individuals at the same time, which would amplify the effect.
Collecting data in large quantities – while at the same time being able to recognise and filter background noise – requires efficient and elastic cloud computation. However, we already have technology that can do this, something we’ve previously suggested could be used to track the course of large numbers of aircraft.
So the bigger question is how to record data from large groups of animals, capitalising on advances in the Internet of Things, without affecting the welfare of the animals and without interfering with their natural behaviour.
Research has shown that putting sensors such as biotelemetric devices on animals can have seriously detrimental effects on their welfare, change their behaviour and, by doing so, invalidate whatever data is collected. Of course, trying to fit sensors to large numbers of animals for generation after generation would be highly impractical.
A better option would be to monitor changes in the animals’ behaviour around their habitats via ambient sensors such as motion detectors. The data could be used to automatically detect any deviation from normal behavioural patterns.
Herdsourcing
The “wisdom of crowds” has been put to use through the practice of crowdsourcing, where the internet is used to bring together a large, diverse range of users in order to undertake a certain task. For example, analysing Wikipedia documents, conducting citizen science projects, or generating cash through crowd-sourcing.
This is exactly that kind of concept we need to extend to animals in order to watch for collective changes in their behaviour. The technology of cloud computing, which can elastically scale to the amount of computation needed for such a project, is already commercially available.
The groundwork for the kind of system we need has been carried out as part of an ongoing security research programme. This project designs cloud-based software systems to recognise and adapt to changes that may have safety and security consequences.
Applied to the task of monitoring collective animal behaviour, the system could use sensors to detect big groups of animals in specific areas, monitor the speed and shape of their movement, or detect variations in their calls or cries. Of course, a major consideration would have to be to ensure the data is secure, so that for example it couldn’t be used to cause the animals harm (for example, through poaching).
We could apply approaches typically used for human-computer interfaces to animals; designing the means to do so for animals might shed light on how to predict earthquakes – not only that but it could show that there are plenty of other things we can find out from animals too, if only we can learn how to do it.
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).
Axial Seamount, an active underwater volcano located about 300 miles off the coast of Oregon and Washington, appears to be erupting – after two scientists had forecast that such an event would take place there in 2015.
Geologists Bill Chadwick of Oregon State University and Scott Nooner of the University of North Carolina Wilmington made their forecast last September during a public lecture and followed it up with blog posts and a reiteration of their forecast just last week at a scientific workshop.
They based their forecast on some of their previous research – funded by the National Science Foundation (NSF) and the National Oceanic and Atmospheric Administration (NOAA), which showed how the volcano inflates and deflates like a balloon in a repeatable pattern as it responds to magma being fed into the seamount.
Since last Friday, the region has experienced thousands of tiny earthquakes – a sign that magma is moving toward the surface – and the seafloor dropped by 2.4 meters, or nearly eight feet, also a sign of magma being withdrawn from a reservoir beneath the summit. Instrumentation recording the activity is part of the NSF-funded Ocean Observatories Initiative. William Wilcock of the University of Washington first observed the earthquakes.
“It isn’t clear yet whether the earthquakes and deflation at Axial are related to a full-blown eruption, or if it is only a large intrusion of magma that hasn’t quite reached the surface,” said Chadwick, who works out of OSU’s Hatfield Marine Science Center in Newport and also is affiliated with NOAA’s Pacific Marine Environmental Laboratory. “There are some hints that lava did erupt, but we may not know for sure until we can get out there with a ship.”
In any case, the researchers say, such an eruption is not a threat to coastal residents. The earthquakes at Axial Seamount are small and the seafloor movements gradual and thus cannot cause a tsunami.
“I have to say, I was having doubts about the forecast even the night before the activity started,” Chadwick admitted. “We didn’t have any real certainty that it would take place – it was more of a way to test our hypothesis that the pattern we have seen was repeatable and predictable.”
Axial Seamount provides scientists with an ideal laboratory, not only because of its close proximity to the Northwest coast, but for its unique structure.
“Because Axial is on very thin ocean crust, its ‘plumbing system’ is simpler than at most volcanoes on land that are often complicated by other factors related to having a thicker crust,” said Chadwick, who is an adjunct professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences. “Thus Axial can give us insights into how volcano magma systems work – and how eruptions might be predicted.”
Axial Seamount last erupted in 2011 and that event was loosely forecast by Chadwick and Nooner, who had said in 2006 that the volcano would erupt before 2014. Since the 2011 eruption, additional research led to a refined forecast that the next eruption would be in 2015 based on the fact that the rate of inflation had increased by about 400 percent since the last eruption.
“We’ve learned that the supply rate of magma has a big influence on the time between eruptions,” Nooner said. “When the magma rate was lower, it took 13 years between eruptions. But now when the magma rate is high, it took only four years.”
Chadwick and Nooner are scheduled to go back to Axial in August to gather more data, but it may be possible for other researchers to visit the seamount on an expedition as early as May. They hope to confirm the eruption and, if so, measure the volume of lava involved.
Evidence that was key to the successful forecast came in the summer of 2014 via measurements taken by colleagues Dave Caress and Dave Clague of Monterey Bay Aquarium Research Institute and Mark Zumberge and Glenn Sasagawa of Scripps Oceanographic Institution. Those measurements showed the high rate of magma inflation was continuing.
The fourth largest gold producer in Africa is on target to reach 10 percent of its country’s Gross Domestic Product by 2025
Silica dust hazards in large gold mines have been well documented, but the situation is far worse in small-scale gold mining according to a new study.
The new research in the article “Silica Exposures in Artisanal Small-Scale Gold Mining in Tanzania and Implications for Tuberculosis Prevention” shows that exposures to silica are more than two hundred times greater in small-scale artisanal mines than in larger mines. Hundreds of thousands of miners have already come down with silicosis and rates of tuberculosis (TB) among miners in Africa are approximately 5-6 times higher than in the general population.
This first ever study to measure silica exposures in small-scale gold mining operations was published online in the Journal of Occupational and Environmental Health.
Researchers found that the average airborne crystalline silica levels in underground gold mining operations were 337 times greater than the recommended limit set by the U.S. National Institute of Occupational Safety and Health. Even miners working above ground had exposures that are four times the limit. Silica dust is a known cause of silicosis and lung cancer, and is strongly linked to TB and other lung diseases.
An estimated 15 million artisanal miners worldwide — many times more than are employed in formal sector mines — are working without any dust control measures.
Perry Gottesfeld, Executive Director of Occupational Knowledge International and the lead author of the study said, “Silica dust hazards are being ignored while thousands of miners die each year due to silicosis and the alarmingly high rates of TB in these mining communities.”
“A recent global treaty has emphasized reducing mercury exposures among these gold miners, while silica dust hazards are overlooked although they are likely to cause much more death and disease,” Gottesfeld added.
In sub-Saharan Africa, mining communities are experiencing an epidemic of TB due to the combination of silica exposures and higher background rates of people with HIV. These factors work together to multiply the risk.
“While we did the study in Tanzania, the risk for TB and silicosis is similar in artisanal mining around the world. Many times more people work in artisanal mining than in formal sector mines.” Gottesfeld added.
Globally, more than $3 billion a year is spent on diagnosing and treating TB.
Damian Andrew, an author of the study said that “The use of low cost methods to control airborne dust could significantly reduce exposures and the risk of TB and silicosis in these communities.”
“Simple measures including water misting would be an effective method to greatly reduce silica dust exposures,” he added.
The study also pointed out that more than half of all small-scale gold mining takes place in 18 of the 22 countries with the highest rates of TB. The World Health Organization (WHO) has prioritized these 18 countries as they account for 46% of all TB cases worldwide.
The authors conclude that ongoing efforts by governments and international aid agencies to address mercury hazards in small-scale gold mining should incorporate silica dust controls.
Reference:
Perry Gottesfeld, Damian Andrew, Jeffrey Dalhoff. Silica Exposures in Artisanal Small-Scale Gold Mining in Tanzania and Implications for Tuberculosis Prevention. Journal of Occupational and Environmental Hygiene, 2015; 00 DOI: 10.1080/15459624.2015.1029617
Note: The above story is based on materials provided by Taylor & Francis.
Illustration of a hot mantle plume “head” pancaked beneath the Indian Plate. The theory by Richards and his colleagues suggests that existing magma within this plume head was mobilized by strong seismic shaking from the Chicxulub asteroid impact, resulting in the largest of the Deccan Traps flood basalt eruptions. Credit: Mark Richards et al, UC Berkeley
The asteroid that slammed into the ocean off Mexico 66 million years ago and killed off the dinosaurs probably rang the Earth like a bell, triggering volcanic eruptions around the globe that may have contributed to the devastation, according to a team of University of California, Berkeley, geophysicists.
Specifically, the researchers argue that the impact likely triggered most of the immense eruptions of lava in India known as the Deccan Traps, explaining the “uncomfortably close” coincidence between the Deccan Traps eruptions and the impact, which has always cast doubt on the theory that the asteroid was the sole cause of the end-Cretaceous mass extinction.
“If you try to explain why the largest impact we know of in the last billion years happened within 100,000 years of these massive lava flows at Deccan … the chances of that occurring at random are minuscule,” said team leader Mark Richards, UC Berkeley professor of earth and planetary science. “It’s not a very credible coincidence.”
Richards and his colleagues marshal evidence for their theory that the impact reignited the Deccan flood lavas in a paper to be published in The Geological Society of America Bulletin, available online today (April 30) in advance of publication.
While the Deccan lava flows, which started before the impact but erupted for several hundred thousand years after re-ignition, probably spewed immense amounts of carbon dioxide and other noxious, climate-modifying gases into the atmosphere, it’s still unclear if this contributed to the demise of most of life on Earth at the end of the Age of Dinosaurs, Richards said.
“This connection between the impact and the Deccan lava flows is a great story and might even be true, but it doesn’t yet take us closer to understanding what actually killed the dinosaurs and the ‘forams,'” he said, referring to tiny sea creatures called foraminifera, many of which disappeared from the fossil record virtually overnight at the boundary between the Cretaceous and Tertiary periods, called the KT boundary. The disappearance of the landscape-dominating dinosaurs is widely credited with ushering in the age of mammals, eventually including humans.
He stresses that his proposal differs from an earlier hypothesis that the energy of the impact was focused around Earth to a spot directly opposite, or antipodal, to the impact, triggering the eruption of the Deccan Traps. The “antipodal focusing” theory died when the impact crater, called Chicxulub, was found off the Yucatán coast of Mexico, which is about 5,000 kilometers from the antipode of the Deccan traps.
Flood basalts
Richards proposed in 1989 that plumes of hot rock, called “plume heads,” rise through Earth’s mantle every 20-30 million years and generate huge lava flows, called flood basalts, like the Deccan Traps. It struck him as more than coincidence that the last four of the six known mass extinctions of life occurred at the same time as one of these massive eruptions.
“Paul Renne’s group at Berkeley showed years ago that the Central Atlantic Magmatic Province is associated with the mass extinction at the Triassic/Jurassic boundary 200 million years ago, and the Siberian Traps are associated with the end Permian extinction 250 million years ago, and now we also know that a big volcanic eruption in China called the Emeishan Traps is associated with the end-Guadalupian extinction 260 million years ago,” Richards said. “Then you have the Deccan eruptions — including the largest mapped lava flows on Earth — occurring 66 million years ago coincident with the KT mass extinction. So what really happened at the KT boundary?”
Richards teamed up with experts in many areas to try to discover faults with his radical idea that the impact triggered the Deccan eruptions, but instead came up with supporting evidence. Renne, a professor in residence in the UC Berkeley Department of Earth and Planetary Science and director of the Berkeley Geochronology Center, re-dated the asteroid impact and mass extinction two years ago and found them essentially simultaneous, but also within approximately 100,000 years of the largest Deccan eruptions, referred to as the Wai subgroup flows, which produced about 70 percent of the lavas that now stretch across the Indian subcontinent from Mumbai to Kolkata.
Michael Manga, a professor in the same department, has shown over the past decade that large earthquakes — equivalent to Japan’s 9.0 Tohoku quake in 2011 — can trigger nearby volcanic eruptions. Richards calculates that the asteroid that created the Chicxulub crater might have generated the equivalent of a magnitude 9 or larger earthquake everywhere on Earth, sufficient to ignite the Deccan flood basalts and perhaps eruptions many places around the globe, including at mid-ocean ridges.
“It’s inconceivable that the impact could have melted a whole lot of rock away from the impact site itself, but if you had a system that already had magma and you gave it a little extra kick, it could produce a big eruption,” Manga said.
Similarly, Deccan lava from before the impact is chemically different from that after the impact, indicating a faster rise to the surface after the impact, while the pattern of dikes from which the supercharged lava flowed — “like cracks in a soufflé,” Renne said — are more randomly oriented post-impact.
“There is a profound break in the style of eruptions and the volume and composition of the eruptions,” said Renne. “The whole question is, ‘Is that discontinuity synchronous with the impact?'”
Reawakened volcanism
Richards, Renne and graduate student Courtney Sprain, along with Deccan volcanology experts Steven Self and Loÿc Vanderkluysen, visited India in April 2014 to obtain lava samples for dating, and noticed that there are pronounced weathering surfaces, or terraces, marking the onset of the huge Wai subgroup flows. Geological evidence suggests that these terraces may signal a period of quiescence in Deccan volcanism prior to the Chicxulub impact. Apparently never before noticed, these terraces are part of the western Ghats, a mountain chain named after the Hindu word for steps.
“This was an existing massive volcanic system that had been there probably several million years, and the impact gave this thing a shake and it mobilized a huge amount of magma over a short amount of time,” Richards said. “The beauty of this theory is that it is very testable, because it predicts that you should have the impact and the beginning of the extinction, and within 100,000 years or so you should have these massive eruptions coming out, which is about how long it might take for the magma to reach the surface.”
Reference:
Mark A. Richards, Walter Alvarez, Stephen Self, Leif Karlstrom, Paul R. Renne, Michael Manga, Courtney J. Sprain, Jan Smit, Loÿc Vanderkluysen, and Sally A. Gibson. Triggering of the largest Deccan eruptions by the Chicxulub impact. Geological Society of America Bulletin, April 30, 2015 DOI: 10.1130/B31167.1
Tropical marine ecosystems have been found to be most at risk from human impact. Credit: Andrew Baird
An international team of scientists has used the fossil record during the past 23 million years to predict which marine animals and ecosystems are at greatest risk of extinction from human impact.
In a paper published in the journal Science, the researchers found those animals and ecosystems most threatened are predominantly in the tropics.
“Marine species are under threat from human impacts, but knowledge of their vulnerabilities is limited,” says study co-author, Professor John Pandolfi from the ARC Centre of Excellence for Coral Reef Studies at the University of Queensland.
The researchers found that the predictors of extinction vulnerability, geographic range size and the type of organism, have remained consistent over the past 23 million years.
As such, they were able to use fossil records to assess the baseline extinction risk for marine animals, including sharks, whales and dolphins, as well as small sedentary organisms such as snails, clams and corals.
They then mapped the regions where those species with a high intrinsic risk are most affected today by human impact and climate change.
“Our goal was to diagnose which species are vulnerable in the modern world, using the past as a guide” says study lead author, Assistant Professor Seth Finnegan from the University of California Berkeley.
“We used these estimates to map natural extinction risk in modern oceans, and compare it with recent human pressures on the ocean such as fishing, and climate change to identify the areas most at risk,” says Professor Pandolfi.
“These regions are disproportionately in the tropics, raising the possibility that these ecosystems may be particularly vulnerable to future extinctions.”
The scientists say that identifying the regions and species at greatest risk means conservation efforts can be better targeted.
“We believe the past can inform the way we plan our conservation efforts. However there is a lot more work that needs to be done to understand the causes underlying these patterns and their policy implications,” says Asst. Professor, Seth Finnegan
Co-author, Dr Sean Anderson from Simon Fraser University in Burnaby, British Columbia adds, “It’s very difficult to detect extinctions in the modern oceans but fossils can help fill in the gaps.”
“Our findings can help prioritize areas and species that might be at greater risk of extinction and that might require extra attention, conservation or management — protecting vulnerable species in vulnerable places.”
Reference:
Seth Finnegan, Sean C. Anderson, Paul G. Harnik, Carl Simpson, Derek P. Tittensor, Jarrett E. Byrnes, Zoe V. Finkel, David R. Lindberg, Lee Hsiang Liow, Rowan Lockwood, Heike K. Lotze, Craig R. McClain, Jenny L. McGuire, Aaron O’Dea, and John M. Pandolfi. Paleontological baselines for evaluating extinction risk in the modern oceans. Science, April 2015 DOI: 10.1126/science.aaa6635
