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Mum and Dad Dinosaurs Shared the Work

Oviraptorid skeleton and eggs in the Senckenberg Museum in Frankfurt am Main. (Credit: EvaK via Wikimedia Commons, Creative Commons license)

A study into the brooding behaviour of birds has revealed their dinosaur ancestors shared the load when it came to incubation of eggs.

Research into the incubation behaviour of birds suggests the type of parental care carried out by their long extinct ancestors.

The study aimed to test the hypothesis that data from extant birds could be used to predict the incubation behaviour of Theropods, the group of carnivorous dinosaurs from which birds descended.

The paper, out today in Biology Letters, was co-authored by Dr Charles Deeming and Dr Marcello Ruta from the University of Lincoln’s School of Life Sciences and Dr Geoff Birchard from George Mason University, Virginia.

By taking into account factors known to affect egg and clutch size in living bird species, the authors — who started their investigation last summer at the University of Lincoln’s Riseholme campus — found that shared incubation was the ancestral incubation behaviour. Previously it had been claimed that only male Theropod dinosaurs incubated the eggs.

Dr Deeming said: “In 2009 a study in the journal Science suggested that it was males of the small carnivorous dinosaurs Troodon and Oviraptor that incubated their eggs. Irrespective of whether you accept the idea of Theropod dinosaurs sitting on eggs like birds or not, the analysis raised some concerns that we wanted to address. We decided to repeat the study with a larger data set and a better understanding of bird biology because other palaeontologists were starting to use the original results in Science in order to predict the incubation behaviour of other dinosaur species. Our analysis of the relationship between female body mass and clutch mass was interesting in its own right but also showed that it was not possible to conclude anything about incubation in extinct distant relatives of the birds.”

Palaeobiologist Dr Ruta was involved in mapping the parental behaviour in modern birds on to an evolutionary tree.

Dr Ruta said: “As always in any study involving fossils, knowledge of extant organisms helps us make inferences about fossils. Fossils have a unique role in shaping our knowledge of the Tree of Life and the dynamics of evolutionary processes. However, as is the case with our study, data from living organisms may augment and refine the potential of fossil studies and may shift existing notions of the biology and behaviour of long extinct creatures.”

Dr Birchard added: “The previous study was carried out to infer the type of parental care in dinosaurs that are closely related to birds. That study proposed that paternal care was present in these dinosaurs and this form of care was the ancestral condition for birds. Our new analysis based on three times as many species as in the previous study indicates that parental care cannot be inferred from simple analyses of the relationship of body size to shape, anatomy, physiologyand behaviour. Such analyses ought to take into account factors such as shared evolutionary history and maturity at hatching. However, our data does suggest that the dinosaurs used in the previous study were likely to be quite mature at birth.”

The project has helped in understanding the factors affecting the evolution of incubation in birds. More importantly it is hoped that the new analysis will assist palaeontologists in their interpretation of future finds of dinosaur reproduction in the fossil record.

Note : The above story is reprinted from materials provided by University of Lincoln. 

GPS Solution Provides Three-Minute Tsunami Alerts

Boat dragged inland in Akahama, Japan by the 2011 tsunami. (Credit: Stephen Vaughan)

Researchers have shown that, by using global positioning systems (GPS) to measure ground deformation caused by a large underwater earthquake, they can provide accurate warning of the resulting tsunami in just a few minutes after the earthquake onset.

For the devastating Japan 2011 event, the team reveals that the analysis of the GPS data and issue of a detailed tsunami alert would have taken no more than three minutes.The results are published on 17 May in Natural Hazards and Earth System Sciences, an open access journal of the European Geosciences Union (EGU).

Most tsunamis, including those in offshore Sumatra, Indonesia in 2004 and Japan in 2011, occur following underwater ground motion in subduction zones, locations where a tectonic plate slips under another causing a large earthquake. To a lesser extent, the resulting uplift of the sea floor also affects coastal regions. There, researchers can measure the small ground deformation along the coast with GPS and use this to determine tsunami information.

“High-precision real-time processing and inversion of these data enable reconstruction of the earthquake source, described as slip at the subduction interface. This can be used to calculate the uplift of the sea floor, which in turn is used as initial condition for a tsunami model to predict arrival times and maximum wave heights at the coast,” says lead-author Andreas Hoechner from the German Research Centre for Geosciences (GFZ).

In the new Natural Hazards and Earth System Sciences paper, the researchers use the Japan 2011 tsunami, which hit the country’s northeast coast in less than half an hour and caused significant damage, as a case study. They show that their method could have provided detailed tsunami alert as soon as three minutes after the beginning of the earthquake that generated it.

“Japan has a very dense network of GPS stations, but these were not being used for tsunami early warning as of 2011. Certainly this is going to change soon,” states Hoechner.

The scientists used raw data from the Japanese GPS Earth Observation Network (GEONET) recorded a day before to a day after the 2011 earthquake. To shorten the time needed to provide a tsunami alert, they only used data from 50 GPS stations on the northeast coast of Japan, out of about 1200 GEONET stations available in the country.

At present, tsunami warning is based on seismological methods. However, within the time limit of 5 to 10 minutes, these traditional techniques tend to underestimate the earthquake magnitude of large events. Furthermore, they provide only limited information on the geometry of the tsunami source (see note). Both factors can lead to underprediction of wave heights and tsunami coastal impact. Hoechner and his team say their method does not suffer from the same problems and can provide fast, detailed and accurate tsunami alerts.

The next step is to see how the GPS solution works in practice in Japan or other areas prone to devastating tsunamis. As part of the GFZ-lead German Indonesian Tsunami Early Warning System project, several GPS stations were installed in Indonesia after the 2004 earthquake and tsunami near Sumatra, and are already providing valuable information for the warning system.

“The station density is not yet high enough for an independent tsunami early warning in Indonesia, since it is a requirement for this method that the stations be placed densely close to the area of possible earthquake sources, but more stations are being added,” says Hoechner.

Note

Traditional tsunami early warning methods use hypocentre (the point directly beneath the epicentre where the seismic fault begins to rupture) and magnitude only, meaning the source of the earthquake and tsunami is regarded as a point source. However, especially in the case of subduction earthquakes, it can have a large extension: in Japan in 2011 the connection between the tectonic plates broke on a length of about 400km and the Sumatra event in 2004 had a length of some 1500km. To get a good tsunami prediction, it is important to consider this extension and the spatial slip distribution.

Note : The above story is reprinted from materials provided by European Geosciences Union. 

The Eloquence of Otoliths Seen in a 23-Million-Year-Old Fish Fossil

Osteology, scales and otolith of †Lepidocottus aries (Agassiz). (Credit: Christoph Gierl et al. An Extraordinary Gobioid Fish Fossil from Southern France. PLoS ONE, 2013; 8 (5): e64117 DOI: 10.1371/journal.pone.0064117)

Fish fossils that are about 23 million years old give unprecedented insight into the evolutionary history of the gobioid order, one of the most species-rich groups among the modern bony fishes.

Researchers led by paleontologist Professor Bettina Reichenbacher from the Division of Paleontology and Geobiology at the Department of Earth and Environmental Sciences at Ludwig-Maximilians-Universitaet (LMU) in Munich / Germany have completed a comprehensive analysis of fish fossils which they assign to the group of bony fishes that includes the gobies. Their results, which have just appeared in the journal PLOS ONE, provide new insights into the evolutionary history of these fish and also have implications for their taxonomy.

The fossil material examined is unusually well preserved. “This has allowed us to describe a gobioid fossil in greater detail than ever before,” says Reichenbacher. Indeed, the authors of the new study have been able to show that the fossil species concerned does not belong to the true gobies at all, in contrast to what earlier investigators had concluded. It is a member of an enigmatic family now known as the Butidae. Until very recently Butidae had been classified among the sleeper gobies. The family is now recognized as a separate clade, whose members are found in tropical river systems of Africa, Madagascar, Asia and Australia. Furthermore, no fossil specimens that could be attributed to this family have been identified until now. Indeed, datable gobioid fossils are comparatively rare in the fossil record. Since fossils of known age provide chronological markers of phylogeny, this has hampered understanding of the evolutionary history of this highly successful group of fishes.

The signature ear-stones

The new description published by the LMU team, in collaboration with a group of French researchers, is based on material that was discovered in the South of France and made available for study by the Cuvier Museum in Montbéliard. The specimens were excavated from sediments that had been laid down in a shallow lagoon near the coast of the Tethys Sea, the precursor of the modern Mediterranean, towards the end of the Oligocene epoch, around 23 million years ago. Among the many unusual features of the find is the fact that the otoliths (also known as ear-stones), which are small calcified particles that form part of the balance organs in the inner ear of bony fish, are perfectly preserved. Reichenbacher, who specializes in the analysis of fossil otoliths, explains the significance of this: “Otoliths are made up of the mineral aragonite, together with a minor fraction of organic material. What makes them of such interest for us is that they can be read like a genetic code. Otoliths allow us to deduce what sort of fish they belonged to, even if nothing else has survived,” she says. This is why the ear-stones play such a crucial role in studies of the paleontology, evolutionary history and biodiversity of the teleosts.

The otoliths revealed to the researchers that the fossils did not actually belong among the true gobies, but should be assigned to either the sleeper gobies or the butids. “Among the skeletal elements of the fossils, we then identified other traits that confirmed this assessment and enabled us to place the species among the butids,” says doctoral student Christoph Gierl, who analyzed the structural anatomy of the skull and the dorsal and pelvic fins.

This is the first butid fossil to be found anywhere. Interestingly, no members of the Butidae are found in European waters today. The new findings show that, back in the Oligocene, butids were distributed in estuaries and lagoons around the Tethys and the Paratethys (the remnant sea to the northeast that was cut off from the rest of the Tethys Sea, today’s Mediterranean, when the Alps were formed), which were then located in subtropical latitudes. The family vanished from these waters during the Early Miocene, about 22 million years ago. “They were probably displaced by true gobies that were more adaptable,” says Reichenbacher.

The researchers expect that their study will lead to a better picture of the evolutionary history of the gobioids as a whole. “Our results also demonstrate that otoliths can play a much greater role in the classification of gobioids than has previously been appreciated,” Bettina Reichenbacher concludes.

Note : The above story is reprinted from materials provided by Ludwig-Maximilians-Universitaet Muenchen (LMU). 

Actor Johnny Depp Immortalized in Ancient Fossil Find

Kootenichela reconstruction. (Credit: Image courtesy of Imperial College London)

A scientist has discovered an ancient extinct creature with ‘scissor hand-like’ claws in fossil records and has named it in honour of his favourite movie star.

 

The 505 million year old fossil called Kooteninchela deppi (pronounced Koo-ten-ee-che-la depp-eye), which is a distant ancestor of lobsters and scorpions, was named after the actor Johnny Depp for his starring role as Edward Scissorhands — a movie about an artificial man named Edward, an unfinished creation, who has scissors for hands.
Kooteninchela deppi is helping researchers to piece together more information about life on Earth during the Cambrian period when nearly all modern animal types emerged.

David Legg, who carried out the research as part of his PhD in the Department of Earth Science and Engineering at Imperial College London, says:

“When I first saw the pair of isolated claws in the fossil records of this species I could not help but think of Edward Scissorhands. Even the genus name, Kootenichela, includes the reference to this film as ‘chela’ is Latin for claws or scissors. In truth, I am also a bit of a Depp fan and so what better way to honour the man than to immortalise him as an ancient creature that once roamed the sea?”

Kooteninchela deppi lived in very shallow seas, similar to modern coastal environments, off the cost of British Columbia in Canada, which was situated much closer to the equator 500 million years ago. The sea temperature would have been much hotter than it is today and although coral reefs had not yet been established, Kooteninchela deppi would have lived in a similar environment consisting of sponges.

The researcher believes that Kooteninchela deppi would have been a hunter or scavenger. Its large Edward Scissorhands-like claws with their elongated spines may have been used to capture prey, or they could have helped it to probe the sea floor looking for sea creatures hiding in sediment.

Kooteninchela deppi was approximately four centimetres long with an elongated trunk for a body and millipede-like legs, which it used to scuttle along the sea floor with the occasional short swim.

It also had large eyes composed of many lenses like the compound eyes of a fly. They were positioned on top of movable stalks called peduncles to help it more easily search for food and look out for predators.

The researcher discovered that Kooteninchela deppi belongs to a group known as the ‘great-appendage’ arthropods, or megacheirans, which refers to the enlarged pincer-like frontal claws that they share. The ‘great-appendage’ arthropods are an early relation of arthropods, which includes spiders, scorpions, centipedes, millipedes, insects and crabs.

David Legg adds: “Just imagine it: the prawns covered in mayonnaise in your sandwich, the spider climbing up your wall and even the fly that has been banging into your window and annoyingly flying into your face are all descendants of Kooteninchela deppi. Current estimates indicate that there are more than one million known insects and potentially 10 million more yet to be categorised, which potentially means that Kooteninchela Deppi has a huge family tree.”

In the future, David Legg intends to further his research and study fossilised creatures from the Ordovician, the geological period that saw the largest increase in diversity of species on the planet. He hopes to understand why this happened in order to learn more about the current diversity of species on Earth.

The research was published in the Journal of Palaeontology 2 May 2013.

Note : The above story is reprinted from materials provided by Imperial College London. The original article was written by Colin Smith.

World’s Biggest Ice Sheets Likely More Stable Than Previously Believed

Icebergs off the coast of Greenland. (Credit: © kavring / Fotolia)

For decades, scientists have used ancient shorelines to predict the stability of today’s largest ice sheets in Greenland and Antarctica. Markings of a high shoreline from three million years ago, for example — when Earth was going through a warm period — were thought to be evidence of a high sea level due to ice sheet collapse at that time.

This assumption has led many scientists to think that if the world’s largest ice sheets collapsed in the past, then they may do just the same in our modern, progressively warming world.However, a new groundbreaking study now challenges this thinking.

Using the east coast of the United States as their laboratory, a research team led by David Rowley, CIFAR Senior Fellow and professor at the University of Chicago, has found that Earth’s hot mantle pushed up segments of ancient shorelines over millions of years, making them appear higher now than they originally were millions of years ago.

“Our findings suggest that the previous connections scientists made between ancient shoreline height and ice volumes are erroneous and that perhaps our ice sheets were more stable in the past than we originally thought,” says Rowley. “Our study is telling scientists that they can no longer ignore the effect of Earth’s interior dynamics when predicting historic sea levels and ice volumes.”

The study, published online in Science on May 16, was a collaboration that included CIFAR Senior Fellows Alessandro Forte (Université du Québec à Montréal) and Jerry Mitrovica (Harvard), and a former CIFAR-supported post-doctoral fellow Rob Moucha (Syracuse).

“This study was the culmination of years of work and deep collaboration by researchers in CIFAR’s program in Earth System Evolution,” explains Rowley. “For this study, each of us brought our individual expertise to the table: Rob and Alex worked on simulations of Earth’s mantle dynamics, Jerry provided calculations on how glaciers warp Earth’s surface, and I shaped our understanding of the geology of the landscape we were looking at. This study would not have been possible without CIFAR.”

The team studied the coast from Virginia to Florida, which has an ancient scarp tens of metres above present-day sea level. Until now, many research groups have studied this shoreline and concluded that during a warm period three million years ago, the Greenland, West Antarctic and a fraction of East Antarctic ice sheets collapsed, raising the sea level at least 35 metres. But the new findings by Rowley and his team suggest that these ice sheets, particularly the East Antarctic Ice Sheet (the world’s largest), were probably more stable.

To do their study, the team used computer simulations to follow the movement of mantle and tectonic plates that occurred over time. Their prediction of how the ancient shoreline would have developed over millions of years matched what geologists mapping this ancient coast have observed. The next steps for the team are to try to make accurate predictions in other locations around the world.

“The paper is important because it shows that no prediction of ancient ice volumes can ever again ignore the Earth’s interior dynamics,” explains Rowley. “It also provides a novel bridge between two disciplines in Earth science that rarely intersect: mantle dynamics and long-term climate. It is the kind of study that changes how people think about our past climate and what our future holds.”

Note : The above story is reprinted from materials provided by Canadian Institute for Advanced Research. 

International Chronostratigraphic Chart 2013

chronostratchart2013-01

International Chronostratigraphic Chart, latest version (January of 2013)

Click here (PDF or JPG) to download the latest version (January of 2013) of the International Chronostratigraphic Chart.

Translations of the chart: Chinese  (v2013-01: PDF or JPG), Spanish (v2013-01), Portuguese (v2013-01: PDF or JPG), Norwegian (v2013-01: PDF or JPG), Basque (v2013-01: PDF or JPG), Catalan (v2013-01: PDF or JPG), French (v2012) and Japanese (v2012).
The old versions can be download at the following links: 2008 (PDF or JPG), 2009 (PDF or JPG), 2010 (PDF or JPG), 2012 (PDF or JPG).

© 2013 International Commission on Stratigraphy – ALL RIGHTS RESERVED 

Clam Fossils Divulge Secrets of Ecologic Stability

Clam fossils from the Devonian Sea, which are now found in the Finger Lakes region of New York, bear the scars from attackers some 380 million years ago. (Credit: Image courtesy of Cornell University)

Clam fossils from the middle Devonian era — some 380 million years ago — now yield a better paleontological picture of the capacity of ecosystems to remain stable in the face of environmental change, according to research published today (May 15) in the online journal PLOS ONE.

Trained to examine species abundance — the head counts of specimens — paleontologists test the stability of Earth’s past ecosystems. The research shows that factors such as predation and organism body size from epochs-gone-by can now be considered in such detective work.

Back 380 million years ago, New York was under the Devonian sea. Today, the fossils found in the rocks of this region have become well known for documenting long-term stability in species composition — that is, the same species have been found to persist with little change over a 5 million year period. But research has found that species abundance in this ancient ecosystem went up and down, generating debate among paleontologists whether the fauna, as a whole, was also stable in terms of its ecology.

A team of Cornell, Paleontological Research Institution (PRI) — an affiliate of Cornell — and University of Cincinnati researchers revisited this debate by examining the ecological stability of the Devonian clam fauna.

“To understand how these species fared in the Devonian, you have to look at how they interacted with other

Clam fossils from the Finger Lakes region of New York bear the scars from attackers some 380 million years ago.

species. There is more to ecology than just the abundance and distribution of species,” said Gregory Dietl, Cornell adjunct professor, earth and atmospheric sciences, and a paleontologist at PRI.

The research, “Abundance Is Not Enough: The Need for Multiple Lines of Evidence in Testing for Ecological Stability in the Fossil Record,” was written by Judith Nagel-Myers, paleontologist, PRI; John Handley, PRI; Carlton Brett, University of Cincinnati professor of geology; and Dietl.

The scientists took a new approach to testing ecological stability: In addition to counting numbers of clams, they examined repair scars on fossil clams that were left by the unsuccessful attacks from shell-crushing predators, and the body size of the clam assemblage as it yields biological information on the structure of food webs.

“Surprisingly, predation pressure and the body size structure of the clams remained stable, even as abundance varied,” said Nagel-Myers. Possible mechanisms that explain the clam assemblage’s stability are related to the dynamics of food webs — the same mechanisms operating in food webs today. In one mechanism, predators switched between feeding on different clam species as their abundance varied.

The ancient Devonian ecosystem was more complex than previously thought, as it cautions scientists against basing conclusions on a single factor. Said Dietl: “Our results thus raise serious doubt as to whether ecological stability can be tested meaningfully, solely based upon the abundance of taxa, which has been the standard metric used to test for ecological stability in paleoecology.”

Note : The above story is reprinted from materials provided by Cornell University. The original article was written by Blaine Friedlander.

Fossil Saved from Mule Track Revolutionizes Understanding of Ancient Dolphin-Like Marine Reptile

Malawania, the Jurassic-style Cretaceous ichthyosaur from Iraq. (Credit: Illustration by Robert Nicholls ; coloring by C. M. Kosemen .)

An international team of scientists have revealed a new species of ichthyosaur (a dolphin-like marine reptile from the age of dinosaurs) from Iraq, which revolutionises our understanding of the evolution and extinction of these ancient marine reptiles.
The results, produced by a collaboration of researchers from universities and museums in Belgium and the UK and published today (May 15) in Biology Letters, contradict previous theories that suggest the ichthyosaurs of the Cretaceous period (the span of time between 145 and 66 million years ago) were the last survivors of a group on the decline.

Ichthyosaurs are marine reptiles known from hundreds of fossils from the time of the dinosaurs. “They ranged in size from less than one to over 20 metres in length. All gave birth to live young at sea, and some were fast-swimming, deep-diving animals with enormous eyeballs and a so-called warm-blooded physiology,” says lead author Dr Valentin Fischer of the University of Liege in Belgium.

Until recently, it was thought that ichthyosaurs declined gradually in diversity through multiple extinction events during the Jurassic period. These successive events were thought to have killed off all ichthyosaurs except those strongly adapted for fast-swimming life in the open ocean. Due to this pattern, it has been assumed that ichthyosaurs were constantly and rapidly evolving to be ever-faster open-water swimmers; seemingly, there was no ‘stasis’ in their long evolutionary history.

However, an entirely new ichthyosaur from the Kurdistan region of Iraq substantially alters this view of the group. The specimen concerned was found during the 1950s by British petroleum geologists. “The fossil – a well-preserved partial skeleton that consists of much of the front half of the animal – wasn’t exactly being treated with the respect it deserves. Preserved within a large, flat slab of rock, it was being used as a stepping stone on a mule track,” says co-author Darren Naish of the University of Southampton. “Luckily, the geologists realized its potential importance and took it back to the UK, where it remains today,” adds Dr Naish, who is based at the National Oceanography Centre, Southampton.

Study of the specimen began during the 1970s with ichthyosaur expert Robert Appleby, then of University College, Cardiff. “Robert Appleby recognised that the specimen was significant, but unfortunately died before resolving the precise age of the fossil, which he realised was critical,” says Jeff Liston of National Museums Scotland and manager of the research project. “So continuation of the study fell to a new generation of researchers.”

In the new study (which properly includes Appleby as an author), researchers name it Malawania anachronus, which means ‘out of time swimmer’. Despite being Cretaceous in age, Malawania represents the last-known member of a kind of ichthyosaur long believed to have gone extinct during the Early Jurassic, more than 66 million years earlier. Remarkably, this kind of archaic ichthyosaur appears characterised by an evolutionary stasis: they seem not to have changed much between the Early Jurassic and the Cretaceous, a very rare feat in the evolution of marine reptiles.

“Malawania’s discovery is similar to that of the coelacanth in the 1930s: it represents an animal that seems ‘out of time’ for its age. This ‘living fossil’ of its time demonstrates the existence of a lineage that we had never even imagined. Maybe the existence of such Jurassic-style ichthyosaurs in the Cretaceous has been missed because they always lived in the Middle-East, a region that has previously yielded only a single, very fragmentary ichthyosaur fossil,” adds Dr Fischer.

Thanks to both their study of microscopic spores and pollen preserved on the same slab as Malawania, and to their several analyses of the ichthyosaur family tree, Fischer and his colleagues retraced the evolutionary history of Cretaceous ichthyosaurs. In fact, the team was able to show that numerous ichthyosaur groups that appeared during the Triassic and Jurassic ichthyosaur survived into the Cretaceous. It means that the supposed end of Jurassic extinction event did not ever occur for ichthyosaurs, a fact that makes their fossil record quite different from that of other marine reptile groups..

When viewed together with the discovery of another ichthyosaur by the same team in 2012 and named Acamptonectes densus, the discovery of Malawania constitutes a ‘revolution’ in how we imagine ichthyosaur evolution and extinction. It now seems that ichthyosaurs were still important and diverse during the early part of the Cretaceous. The final extinction of the ichthyosaurs – an event that occurred about 95 million years ago (long before the major meteorite-driven extinction event that ended the Cretaceous) – is now even more confusing than previously assumed.

Note : The above story is reprinted from materials provided by University of Southampton, via AlphaGalileo. 

Tropical air circulation drives fall warming on Antarctic Peninsula

A German research vessel, Polarstern, is shown off the Rothera station on the west coast of the Antarctic Peninsula. Rothera is one of eight stations that provided temperature data for this research. (Credit: Hannes Grobe/Alfred Wegener Institute for Polar and Marine Research)

The eastern side of the Antarctic Peninsula, a finger of the southern polar continent that juts toward South America, has experienced summer warming of perhaps a half-degree per decade — a greater rate than possibly anywhere else on Earth — in the last 50 years, and that warming is largely attributed to human causes.

But new University of Washington research shows that the Southern Hemisphere’s fall months — March, April and May — are the only time when there has been extensive warming over the entire peninsula, and that is largely governed by atmospheric circulation patterns originating in the tropics.

The autumn warming also brings a notable reduction in sea ice cover in the Bellingshausen Sea off the peninsula’s west coast, and more open water leads to warmer temperatures on nearby land in winter and spring (June through November), said Qinghua Ding, a UW research associate in Earth and space sciences. In fact, the most significant warming on the west side of the peninsula in recent decades has occurred during the winter.

“Local northerly wind pushes warmer air from midlatitudes of the Southern Ocean to the peninsula, and the northern wind favors warming of the land and sea ice reduction,” said Ding.

He is the lead author of a paper explaining the findings, published online this month in the Journal of Climate. Eric Steig, a UW professor of Earth and space sciences, is co-author. The work was funded by the National Science Foundation.

The scientists analyzed temperature data gathered from 1979 through 2009 at eight stations on the Antarctic Peninsula. The stations were selected because each has reliable monthly data for at least 95 percent of the study period. They also used two different sets of data, one from Europe and the other from NASA, that combine surface observations, satellite temperature data and modeling.

The researchers concluded that the nonsummer Antarctic Peninsula warming is being driven by large-scale atmospheric circulation originating in the equatorial Pacific Ocean. There, the warm sea surface generates an atmospheric phenomenon called a Rossby wave train, which reaches the Antarctic Peninsula and alters the local circulation to warm the region.

The sea-surface temperature trend in the tropical Pacific is related to natural phenomena such as the El Niño Southern Oscillation (El Niño and La Niña) and cycles that occur on longer timescales, sometimes decades. But it is not clear whether human causes play a role in that trend.

“We still lack a very clear understanding of the tropical natural variability, of what that dynamic is,” Ding said.

He said that in the next two or three decades it is quite possible that natural variability and forcing from human factors will play equivalent roles in temperature changes on the Antarctic Peninsula, but after that the forcing from human causes will likely play a larger role.

“If these trends continue, we will continue to see warming in the peninsular region, there is no doubt,” Ding said.

Note : The above story is reprinted from materials provided by University of Washington. The original article was written by Vince Stricherz. 

Could Carbon Dioxide Be Injected in Sandstone?

Sandstone can crack if it is filled with too much CO2. To be certain that this will not happen, NTNU Professors Martin Landrø and Ole Torsæter take X-rays of sandstone while it is being pumped full of CO2. (Credit: Ole Morten Melgård)

As CO2 levels in Earth’s atmosphere top 400 parts per million, options such as storing the greenhouse gas in porous sandstone rock formations found in abundance on the sea floor are of increasing interest. But how do we know if CO2 can be safely injected into spongy sandstone, and that once it is there, that it will stay there?

Two petroleum engineering and applied geophysics professors at the Norwegian University of Science and Technology (NTNU) are using X-rays and CAT scanners to probe the secrets of undersea rock formations and their ability to store CO2 safely in perpetuity. Their results are promising.

Earth has a fever

CO2 is formed when any kind of organic material or fossil fuel, such as natural gas, petroleum, coal or gasoline, is burned. A cozy bonfire or a little fire in the wood stove on a cold winter’s day will add to the amount of CO2 in the atmosphere.
At the same time, if you were in an area with a CO2 leak, you’d die of CO2 poisoning before you’d die from a lack of oxygen.

CO2 has another important characteristic: too much of it in the atmosphere is causing global temperatures to rise. The last time the average atmospheric CO2 levels were around 400 ppm, as they are now, was 3 million years ago. Earth has a fever, and by burning fossil fuels, we are causing it.

Checking for leaks

“I think it is important to remember that CO2 isn’t radioactive, but part of the air that we all exhale,” says Martin Landrø, a professor of petroleum engineering and applied geophysics at NTNU, and one of the world’s leading seismic experts — that is, in geophysical surveys of bedrock. Landrø has been engaged in monitoring underwater CO2 storage areas for more than ten years.

The goal of storing CO2 is to deposit it deep enough so that it becomes liquid. The gas needs to be buried under so many layers of sand and clay that it can’t escape, and stay encapsulated in a bubble under the sea forever.

But sometimes it doesn’t go according to plan. After a few years, the CO2 may begin to seep up and out. Sometimes small amounts manage to escape completely, appearing as small bubbles on the sea floor. This is one of the reasons that the petroleum professors at NTNU have acquired a giant X-ray machine — a CAT scanner.

This particular X-ray machine has previously served its duty at St Olavs Hospital in Trondheim, working steadily to reveal bone fractures and joint injuries. At NTNU it is being used to determine how much CO2 can be stored in various rock formations found under the sea. But taking X-rays of CO2 is not all that the professors are doing — they’re also measuring the speed of sound in different types of stone.

Patient — and pill

“This is our X-ray patient,” says Ole Torsæter, who is also a professor of petroleum engineering and applied geophysics at NTNU, and holds up a small piece of sandstone.

But this patient contains its own medicine — Earth’s own fever-reducing pill. This porous stone, found in abundance at the bottom of the sea, can store large amounts of CO2. Sandstone is porous, like a sponge — a sponge that oil companies can fill with CO2.

“Some sandstone can be filled with as much as 80 per cent CO2, while others can only hold about 30 per cent. These variations in capacity are exactly what we’re trying to figure out,” says Torsæter.

And here’s how they do it: they take sandstone and put it in water, so that all the pores are filled. They then put the stone into a thin, condom-like plastic cover. The cover has several holes in it that are sealed using microphones.

The entire thing is then placed in a box that simulates the pressure in the seabed, which is then placed in the X-ray machine. As the X-ray scanner is on, the researchers inject CO2 into the rock, filling the porous stone with it and pressing out the water.

The X-ray images show how much CO2 has penetrated the rock’s pores. Since CO2 has a different density than water, the speed of sound will be slower when the rock is saturated with CO2. Therefore, the researchers measure the speed of sound in the rocks, watching how it changes as CO2 enters the pores. The goal is to fill up the stone without cracking it.

Two years of CO2 emissions

“If the pressure in the stone is too high, it can crack. To relieve the pressure we need to remove the water, the same way a doctor would drain fluid from a patient’s cyst. We do that too. When CO2 is injected into the seabed, sometimes we need to remove the water being pressed out of the rocks through a new well,” say Landrø and Torsæter.
 
It has now been 14 years since the first CO2 was injected into a seabed formation in the North Sea. Since then, Statoil has stored more than 12 million tons of CO2 in such formations. In 2011, the Norwegian Petroleum Directorate presented an atlas showing that Norway may be able to store as much as 50 gigatons of CO2 in geological formations under the sea.

Annual global CO2 emissions are usually about 30 gigatons, meaning that Norway may be able to store almost two years of global emissions under the North Sea.

Norway is responsible for 0.17 per cent of global CO2 emissions. China accounts for 23 per cent.

Consumers are key

“I think it’s important to look at it from a practical standpoint. Storing CO2 in geological formations under the sea may be a good alternative to sending it straight into the atmosphere. If we do that, some of it is absorbed by the ocean anyway, so it is better store it under the sea, even though small quantities may still seep out,” says Landrø.

Consumers account for the largest emissions worldwide, he says: Heating and electricity generation account for about 40 per cent of global CO2 emissions, while transportation accounts for 25 per cent. “This means we as consumers can help to determine how much CO2 is emitted,” Landrø says. “That’s one reason why I bike to work every day.”

Note : The above story is reprinted from materials provided by The Norwegian University of Science and Technology (NTNU).

Climate record from bottom of Russian lake shows Arctic was warmer millions of years ago

The Lake El’gygytgyn drilling rig is shown at night. – The Lake El’gygytgyn Drilling Project

The Arctic was very warm during a period roughly 3.5 to 2 million years ago–a time when research suggests that the level of carbon dioxide in the atmosphere was roughly comparable to today’s–leading to the conclusion that relatively small fluctuations in carbon dioxide levels can have a major influence on Arctic climate, according to a new analysis of the longest terrestrial sediment core ever collected in the Arctic.

“One of our major findings is that the Arctic was very warm in the middle Pliocene and Early Pleistocene–roughly 3.6 to 2.2 million years ago–when others have suggested atmospheric carbon dioxide was not much higher than levels we see today,” said Julie Brigham-Grette, of the University of Massachusetts Amherst.

Brigham-Grette is a National Science Foundation- (NSF) funded researcher on the sediment core project and a lead author of a new paper published this week in the journal Science that describes the results.

She added that “this could tell us where we are going in the near future. In other words, the Earth system response to small changes in carbon dioxide is bigger than suggested by earlier climate models.”

The data come from the analysis of a continuous cylinder of sediments collected by NSF-funded researchers from the bottom of ice-covered Lake El’gygytgyn, pronounced El-Guh-Git-Kin, the oldest deep lake in the northeast Russian Arctic, located 100 kilometers (62 miles) north of the Arctic Circle. The drilling was an international project.

Drilling took place in the early months of 2009. The Earth Sciences and Polar Programs divisions of NSF’s Geosciences Directorate funded the drilling and analysis.

Analysis of the sediment core provides “an exceptional window into environmental dynamics” never before possible, noted Brigham-Grette.

“While existing geologic records from the Arctic contain important hints about this time period, what we are presenting is the most continuous archive of information about past climate change from the entire Arctic borderlands,” she said. “Like reading a detective novel, we can go back in time and reconstruct how the Arctic evolved with only a few pages missing here and there.”

Results of the core analysis, according to Brigham-Grette, have “major implications for understanding how the Arctic transitioned from a forested landscape without ice sheets to the ice- and snow-covered land we know today.”

“Lake E,” as it is often called, was formed 3.6 million years ago when a meteorite, perhaps a kilometer in diameter, hit the Earth and blasted out an 18-kilometer (11-mile) wide crater. The lake bottom has been accumulating layers of sediment ever since the initial impact.

The lake also is situated in one of the few areas of the Arctic that was not eroded by continental ice sheets during ice ages. So a thick, continuous sediment record was left remarkably undisturbed. Cores from Lake E reach back in geologic time nearly 25 times farther than Greenland ice cores that span only the past 140,000 years.

Important to the story are the fossil pollen found in the core, including Douglas fir and hemlock, clearly not found in this part of the Arctic today. The pollen allows the reconstruction of the vegetation living around the lake in the past, which in turn paints a picture of past temperatures and precipitation.

Another significant finding is documentation of sustained warmth in the Middle Pliocene, with summer temperatures of about 15 to 16 degrees Celsius (59 to 61 degrees Fahrenheit), about 8 degrees Celsius (14.4 degrees Fahrenheit) warmer than today, and regional precipitation three times higher.

“We show that this exceptional warmth well north of the Arctic Circle occurred throughout both warm and cold orbital cycles and coincides with a long interval of 1.2 million years when other researchers from the ANDRILL project have shown the West Antarctic Ice Sheet did not exist,” the authors point out.

Hence both poles share some common history, but the pace of change differed.

Along with Brigham-Grette, her co-authors Martin Melles of the University of Cologne, Germany, and Pavel Minyuk of Russia’s Northeast Interdisciplinary Scientific Research Institute, Magadan, led research teams on the project. Robert DeConto, also at the University of Massachusetts, led the climate-modeling efforts. These data were compared with ecosystem reconstructions performed by collaborators at University of Berlin and University of Cologne.

The Lake E cores provide a terrestrial perspective on the stepped pacing of several portions of the climate system through the transition from a warm, forested Arctic to the first occurrence of land ice, Brigham-Grette says, and the eventual onset of major glacial-interglacial cycles.

“It is very impressive that summer temperatures during warm intervals even as late as 2.2 million years ago were always warmer than in our pre-Industrial reconstructions,” she added.

Minyuk notes that they also observed a major drop in Arctic precipitation at around the same time large Northern Hemispheric ice sheets first expanded and ocean conditions changed in the North Pacific. This has major implications for understanding what drove the onset of the ice ages.

The sediment core also reveals that even during the first major “cold snap” to show up in the record 3.3 million years ago, temperatures in the western Arctic were similar to recent averages of the past 12,000 years. “Most importantly, conditions were not ‘glacial,’ raising new questions as to the timing of the first appearance of ice sheets in the Northern Hemisphere,” the authors add.

This week’s paper is the second article published in Science by these authors using data from the Lake E project. Their first in July 2012 covered the period from the present to 2.8 million years ago, while the current work addresses the record from 2.2 to 3.6 million years.

“This latest paper completes our goal of providing an overview of new knowledge of the evolution of Arctic change across the Western borderlands back to 3.6 million years and places this record into a global context with comparisons to records in the Pacific, the Atlantic and Antarctica,” Melles points out.

The Lake E paleoclimate reconstructions and climate modeling are consistent with estimates made by other research groups that support the idea that Earth’s climate sensitivity to carbon dioxide may well be higher than suggested by the 2007 report of the Intergovernmental Panel on Climate Change.

Note: This story has been adapted from a news release issued by the National Science Foundation

Western Indian Ocean Earthquake and Tsunami Hazard Potential Greater Than Previously Thought

Makran map earthquakes. (Credit: Image courtesy of National Oceanography Centre)

Earthquakes similar in magnitude to the 2004 Sumatra earthquake could occur in an area beneath the Arabian Sea at the Makran subduction zone, according to recent research published in Geophysical Research Letters.

The primary tectonic plates and plate boundaries in the Arabian Sea region

The research was carried out by scientists from the University of Southampton based at the National Oceanography Centre Southampton (NOCS), and the Pacific Geoscience Centre, Natural Resources Canada.

The study suggests that the risk from undersea earthquakes and associated tsunami in this area of the
Western Indian Ocean — which could threaten the coastlines of Pakistan, Iran, Oman, India and potentially further afield — has been previously underestimated. The results highlight the need for further investigation of pre-historic earthquakes and should be fed into hazard assessment and planning for the region.

Subduction zones are areas where two of Earth’s tectonic plates collide and one is pushed beneath the other. When an earthquake occurs here, the seabed moves horizontally and vertically as the pressure is released, displacing large volumes of water that can result in a tsunami.

The Makran subduction zone has shown little earthquake activity since a magnitude 8.1 earthquake in 1945 and magnitude 7.3 in 1947. Because of its relatively low seismicity and limited recorded historic earthquakes it has often been considered incapable of generating major earthquakes.

Plate boundary faults at subduction zones are expected to be prone to rupture generating earthquakes at temperatures of between 150 and 450 °C. The scientists used this relationship to map out the area of the potential fault rupture zone beneath the Makran by calculating the temperatures where the plates meet. Larger fault rupture zones result in larger magnitude earthquakes.

“Thermal modelling suggests that the potential earthquake rupture zone extends a long way northward, to a width of up to 350 kilometres which is unusually wide relative to most other subduction zones,” says Gemma Smith, lead author and PhD student at University of Southampton School of Ocean and Earth Science, which is based at NOCS.

The team also found that the thickness of the sediment on the subducting plate could be a contributing factor to the magnitude of an earthquake and tsunami there.

“If the sediments between the plates are too weak then they might not be strong enough to allow the strain between the two plates to build up,” says Smith. “But here we see much thicker sediments than usual, which means the deeper sediments will be more compressed and warmer. The heat and pressure make the sediments stronger. This results in the shallowest part of the subduction zone fault being potentially capable of slipping during an earthquake.

“These combined factors mean the Makran subduction zone is potentially capable of producing major earthquakes, up to magnitude 8.7-9.2. Past assumptions may have significantly underestimated the earthquake and tsunami hazard in this region.”

Note : The above story is reprinted from materials provided by National Oceanography Centre.

The effect of climate change on iceberg production by Greenland glaciers

Image Caption: Natural-color satellite image of the ice island that calved off the glacier on August 5, 2010. Credit: Jesse Allen & Robert Simmon, NASA Earth Observatory

While the impact of climate change on the surface of the Greenland ice sheet has been widely studied, a clear understanding of the key process of iceberg production has eluded researchers for many yearsWhile the impact of climate change on the surface of the Greenland ice sheet has been widely studied, a clear understanding of the key process of iceberg production has eluded researchers for many years. Published in Nature this week, a new study presents a sophisticated computer model that provides a fresh insight into the impact of climate change on the production of icebergs by Greenland glaciers, and reveals that the shape of the ground beneath the ice has a strong effect on its movement.

Over the past decade, ice-loss from the Greenland Ice Sheet has been accelerating, raising concerns about runaway losses and consequent sea-level rise. But research into the four major Greenland fast-flowing glaciers has enabled scientists to show that while these glaciers may show several bursts of retreat and periods of high iceberg formation in future, the rapid acceleration seen in recent years is unlikely to continue unchecked.

This is a crucial step forward in understanding how Greenland’s glaciers will contribute to sea-level rise in the future and indicates, say the scientists, how important a more detailed knowledge of such glaciers is. The scientists first investigated the current behaviour of the four glaciers and found that the rate at which they lose ice depends critically on the shape of the fjords in which they sit, and the topography of the rock below them.

A computer model for fast-flowing outlet glaciers was then specifically designed from their investigations. It gave a projected sea-level-rise contribution from these glaciers of 2cm to 5cm by the year 2200, which is lower than estimates based solely on the extrapolation of current trends.

Lead author Dr Faezeh Nick, of the Université Libre de Bruxelles, says,

“I am excited by the way we have managed to create a detailed picture of the workings of the glaciers. It turns out that if the fjord a glacier sits in is wide or narrow it really affects the way the glacier reacts. The important role of the terrain below the ice shows we need to get a much clearer picture of the rest of Greenland’s glaciers before we have the whole story.”

The scientists chose the four glaciers, Petermann, Kangerdlugssuaq, Helheim and Jakobshavn Isbræ, as together these drain around 20 per cent of the Greenland ice sheet. The model, which was developed within the EU funded ice2sea programme, predicts that, together these glaciers will lose on average, 30Gt of ice per year to 47Gt per year over the 21st century. A Gigaton (Gt) is the equivalent of 1 cubic kilometre (km3) of water. For comparison Lake Geneva contains about 90Gt of water.

Professor David Vaughan, who works at the British Antarctic Survey in Cambridge and is head of the ice2sea programme says,

“We know that the breaking off of icebergs from glaciers is influenced by climate, but this is the first time we’ve been able make projections of how the most important glaciers in Greenland will be affected by future climate change. The ice2sea research led by Dr Nick shows how a truly international programme can make it possible for scientists to work together across different institutions to make significant steps forward.”

Note : This story has been adapted from a news release issued by the British Antarctic Survey

Dying Trees Set Stage For Erosion And Water Loss

Image Caption: Pinyon pine forests near Los Alamos, N.M., had already begun to turn brown from drought stress in the image at left, in 2002, and another photo taken in 2004 from the same vantage point, at right, show them largely grey and dead. (Photo by Craig Allen, U.S. Geological Survey)

New research concludes that a one-two punch of drought and mountain pine beetle attacks are the primary forces that have killed more than 2.5 million acres of pinyon pine and juniper trees in the American Southwest during the past 15 years, setting the stage for further ecological disruption.

The widespread dieback of these tree species is a special concern, scientists say, because they are some of the last trees that can hold together a fragile ecosystem, nourish other plant and animal species, and prevent serious soil erosion.

The major form of soil erosion in this region is wind erosion. Dust blowing from eroded hills can cover snowpacks, cause them to absorb heat from the sun and melt more quickly, and further reduce critically-short water supplies in the Colorado River basin.

The findings were published in the journal Ecohydrology by scientists from the College of Forestry at Oregon State University and the Conservation Biology Institute in Oregon. NASA supported the work.

“Pinyon pine and juniper are naturally drought-resistant, so when these tree species die from lack of water, it means something pretty serious is happening,” said Wendy Peterman, an OSU doctoral student and soil scientist with the Conservation Biology Institute. “They are the last bastion, the last trees standing and in some cases the only thing still holding soils in place.”

“These areas could ultimately turn from forests to grasslands, and in the meantime people are getting pretty desperate about these soil erosion issues,” she said. “And anything that further reduces flows in the Colorado River is also a significant concern.”

It’s not certain whether or not the recent tree die-offs are related to global warming, Peterman said. However, the 2007 report of the Intergovernmental Panel on Climate Change projected that while most of the United States was getting warmer and wetter, the Southwest will get warmer and drier. Major droughts have in fact occurred there, and the loss of pinyon pine and juniper trees would be consistent with the climate change projections, Peterman said.

Pinyon pine and juniper are the dominant trees species in much of the Southwest, routinely able to withstand a year or two of drought, and able to grow in many mountainous areas at moderate elevation. The trees are common in Utah, Colorado, New Mexico and Arizona, and may have expanded their range in the past century during conditions that were somewhat wetter than normal.

In some places up to 90 percent of these trees have now died, many of them during a major drought in 2003 and 2004. The new research concluded that most of the mortality occurred in shallow soils having less than four inches of available water in about the top five feet of the soil column.

Most of the tree mortality, the scientists said, was caused by trees being sufficiently weakened by drought that opportunistic bark beetle epidemics were able to kill the pinyon pine, and the vascular system of the juniper ceased to function.

Traditionally, pinyon pine and juniper were not considered trees of significant value. They were occasionally used for firewood, but otherwise small and not particularly impressive.

They perform key ecosystem functions, however, not the least of which is stabilizing soils and preventing erosion. They also provide some food in the form of pine nuts and juniper berries, and store carbon in their biomass, and in the soils beneath their canopies.

Note : The above story is reprinted from materials provided by Oregon State University

Sediment Cores From Russian Lake Hint At A Future Ice-free Arctic

Image Caption: Lake El’gygytgyn in Russia. Credit: NASA

An international team of scientists, led by Julie Brigham-Grette of the University of Amherst, has analyzed the longest continental sediment core ever collected in the Arctic to provide “absolutely new knowledge” of Arctic climate from 2.2 million to 3.6 million years ago.

“While existing geologic records from the Arctic contain important hints about this time period, what we are presenting is the most continuous archive of information about past climate change from the entire Arctic borderlands. As if reading a detective novel, we can go back in time and reconstruct how the Arctic evolved with only a few pages missing here and there,” says Brigham-Grette.

The results of this study, published in Science, provide “an exceptional window into environmental dynamics” never before possible. Brigham-Grette claims that their findings have “major implications for understanding how the Arctic transitioned from a forested landscape without ice sheets to the ice- and snow-covered land we know today.”

The sediment cores used in this study were collected in the winter of 2009 from ice-covered Lake El’gygytgyn, the oldest deep lake in the northeast Russian Arctic. “Lake E”, located 62 miles north of the Arctic Circle, was formed 3.6 million years ago when a meteorite of approximately a half mile in diameter hit the Earth, blasting out an 11-mile wide crater. Fortunately for geologists, the lake lies in one of the few Arctic areas not eroded by continental ice sheets during the ice ages. This leaves a thick, continuous sediment record remarkably undisturbed along the lake bed. Cores obtained from Lake E reach nearly 25 times farther back in geologic time than the Greenland ice cores, which only span the past 140,000 years.

“One of our major findings is that the Arctic was very warm in the middle Pliocene and Early Pleistocene [~ 3.6 to 2.2 million years ago] when others have suggested atmospheric CO2 was not much higher than levels we see today. This could tell us where we are going in the near future. In other words, the Earth system response to small changes in carbon dioxide is bigger than suggested by earlier climate models,” stated Brigham-Grette.

The team also found that the cores supplied documentation of sustained warmth in the middle Pliocene, with summer temperatures of about 59 to 61 degrees Fahrenheit – approximately 14.4 degrees Fahrenheit warmer than today. Regional precipitation was about three times higher than now, as well.

“We show that this exceptional warmth well north of the Arctic Circle occurred throughout both warm and cold orbital cycles and coincides with a long interval of 1.2 million years when other researchers have shown the West Antarctic Ice Sheet did not exist,” Brigham-Grette notes. This indicates that while both poles share some common history, the pace of change differed between them.

Research teams on the project were led by Martin Melles of the University of Cologne and Pavel Minyuk of Russia’s Northeast Interdisciplinary Scientific Research Institute, Magadan, while the modeling efforts were led by Robert DeConto, at UMass Amherst. Collaborators at the universities of Bern and Cologne performed ecosystem reconstructions which were compared to the data of both the research teams and the modeling team.

Brigham-Grette says the Lake E cores provide a terrestrial perspective on the stepped pacing of several portions of the climate system. The cores demonstrate the transition from a warm, forested Arctic to the first occurrence of land ice and the eventual onset of major glacial/interglacial cycles. “It is very impressive that summer temperatures during warm intervals even as late as 2.2 million years ago were always warmer than in our pre-Industrial reconstructions.”

The team also observed a major drop in Arctic precipitation at around the same time large Northern Hemispheric ice sheets first expanded, according to Minyuk, and ocean conditions changed in the North Pacific. These findings have major implications for understanding what drove the onset of the ice ages.

During the first major “cold snap” to show up in the record 3.3 million years ago, the sediment core also revealed that temperatures in the western Arctic were similar to recent averages of the past 12,000 years. “Most importantly, conditions were not ‘glacial,’ raising new questions as to the timing of the first appearance of ice sheets in the Northern Hemisphere,” the authors add.

This is the second article published by the team based on the Lake E project. The first covered the time period from the present to 2.8 million years ago. The most recent paper covers the record from 2.2 to 3.6 million years ago.

Melles says, “This latest paper completes our goal of providing an overview of new knowledge of the evolution of Arctic change across the western borderlands back to 3.6 million years and places this record into a global context with comparisons to records in the Pacific, the Atlantic and Antarctica.”

The findings of the Lake E paleoclimate reconstructions and climate modeling are consistent with estimates made by other research groups, supporting the idea that Earth’s climate sensitivity to CO2 might be higher than suggested by the 2007 Intergovernmental Panel on Climate Change (IPCC). Much of the funding for this project was obtained from the National Science Foundation (NSF).

 Note : The above story is reprinted from materials provided by April Flowers for redOrbit

Moon and Earth Have Common Water Source

The Moon’s water did not come from comets but was already present on Earth 4.5 billion years ago, when a giant collision sent material from Earth to form the Moon, new research shows. (Credit: NASA/JPL)

Researchers used a multicollector ion microprobe to study hydrogen-deuterium ratios in lunar rock and on Earth. Their conclusion: The Moon’s water did not come from comets but was already present on Earth 4.5 billion years ago, when a giant collision sent material from Earth to form the Moon.
Water inside the Moon’s mantle came from primitive meteorites, new research finds, the same source thought to have supplied most of the water on Earth. The findings raise new questions about the process that formed the Moon.

The Moon is thought to have formed from a disc of debris left when a giant object hit Earth 4.5 billion years ago, very early in Earth’s history. Scientists have long assumed that the heat from an impact of that size would cause hydrogen and other volatile elements to boil off into space, meaning the Moon must have started off completely dry. But recently, NASA spacecraft and new research on samples from the Apollo missions have shown that the Moon actually has water, both on its surface and beneath.

By showing that water on the Moon and on Earth came from the same source, this new study offers yet more evidence that the Moon’s water has been there all along.

“The simplest explanation for what we found is that there was water on the proto-Earth at the time of the giant impact,” said Alberto Saal, associate professor of Geological Sciences at Brown University and the study’s lead author. “Some of that water survived the impact, and that’s what we see in the Moon.”

The research was co-authored by Erik Hauri of the Carnegie Institution of Washington, James Van Orman of Case Western Reserve University, and Malcolm Rutherford from Brown and published online in Science Express.

To find the origin of the Moon’s water, Saal and his colleagues looked at melt inclusions found in samples brought back from the Apollo missions. Melt inclusions are tiny dots of volcanic glass trapped within crystals called olivine. The crystals prevent water escaping during an eruption and enable researchers to get an idea of what the inside of the Moon is like.

Research from 2011 led by Hauri found that the melt inclusions have plenty of water — as much water in fact as lavas forming on Earth’s ocean floor. This study aimed to find the origin of that water. To do that, Saal and his colleagues looked at the isotopic composition of the hydrogen trapped in the inclusions. “In order to understand the origin of the hydrogen, we needed a fingerprint,” Saal said. “What is used as a fingerprint is the isotopic composition.”

Using a Cameca NanoSIMS 50L multicollector ion microprobe at Carnegie, the researchers measured the amount of deuterium in the samples compared to the amount of regular hydrogen. Deuterium is an isotope of hydrogen with an extra neutron. Water molecules originating from different places in the solar system have different amounts of deuterium. In general, things formed closer to the sun have less deuterium than things formed farther out.

Saal and his colleagues found that the deuterium/hydrogen ratio in the melt inclusions was relatively low and matched the ratio found in carbonaceous chondrites, meteorites originating in the asteroid belt near Jupiter and thought to be among the oldest objects in the solar system. That means the source of the water on the Moon is primitive meteorites, not comets as some scientists thought.

Comets, like meteorites, are known to carry water and other volatiles, but most comets formed in the far reaches of the solar system in a formation called the Oort Cloud. Because they formed so far from the sun, they tend to have high deuterium/hydrogen ratios — much higher ratios than in the Moon’s interior, where the samples in this study came from.

“The measurements themselves were very difficult,” Hauri said, “but the new data provide the best evidence yet that the carbon-bearing chondrites were a common source for the volatiles in the Earth and Moon, and perhaps the entire inner solar system.”

Recent research, Saal said, has found that as much as 98 percent of the water on Earth also comes from primitive meteorites, suggesting a common source for water on Earth and water on Moon. The easiest way to explain that, Saal says, is that the water was already present on the early Earth and was transferred to the Moon.

The finding is not necessarily inconsistent with the idea that the Moon was formed by a giant impact with the early Earth, but presents a problem. If the Moon is made from material that came from Earth, it makes sense that the water in both would share a common source. However, there’s still the question of how that water was able to survive such a violent collision.

“The impact somehow didn’t cause all the water to be lost,” Saal said. “But we don’t know what that process would be.”

It suggests, the researchers say, that there are some important processes we don’t yet understand about how planets and satellites are formed.

“Our work suggests that even highly volatile elements may not be lost completely during a giant impact,” said Van Orman. “We need to go back to the drawing board and discover more about what giant impacts do, and we also need a better handle on volatile inventories in the Moon.”

Funding for the research came from NASA’s Cosmochemistry and LASER programs and the NASA Lunar Science Institute.

 Note : The above story is reprinted from materials provided by Brown University. 

Geologists Study Mystery of ‘Eternal Flames’

A gas-fired flame shines through a waterfall at Chestnut Ridge Park in Erie County, N.Y. (Credit: Indiana University)

“Eternal flames” fueled by hydrocarbon gas could shine a light on the presence of natural gas in underground rock layers and conditions that let it seep to the surface, according to research by geologists at the Department of Geological Sciences and the Indiana Geological Survey at Indiana University Bloomington.

 

A little-known but spectacular flame in Erie County, N.Y., is the focus of an article in the journal Marine and Petroleum Geology, co-authored by Agnieszka Drobniak, research scientist with the Indiana Geological Survey, and Arndt Schimmelmann, senior scientist in the Department of Geological Sciences in the College of Arts and Sciences.

The article results from a U.S. Department of Energy research grant to Schimmelmann and Maria Mastalerz, senior scientist with the Indiana Geological Survey and graduate faculty member at the Department of Geological Sciences. The project seeks to identify natural gas seeps in Indiana and nearby states and assess their contributions to atmospheric concentrations of greenhouse gases.

The researchers said much remains to be learned about the passage of gas from underground rock layers to Earth’s surface — occasionally in “macro seeps” strong and abundant enough to produce a continuous flame like the one in western New York.

“The story is developing,” Schimmelmann said.

Giuseppe Etiope of the National Institute of Geophysics and Volcanology in Italy is lead author of the Marine and Petroleum Geology article, “Natural seepage of shale gas and the origin of ‘eternal flames’ in the Northern Appalachian Basin, USA.” Etiope, who has studied eternal flames around the world, said the New York flame, behind a waterfall in Chestnut Ridge Park, is the most beautiful he has seen.

Not only that, but it may feature the highest concentrations of ethane and propane of any known natural gas seep. Approximately 35 percent of the gas is ethane and propane, as opposed to methane, the dominant constituent in natural gas. Ethane and propane can be valuable byproducts in the processing of natural gas.

By analyzing the gases and comparing them with gas well records from the region, the researchers concluded the gas fueling the Chestnut Ridge Park flame originates from Rhinestreet Shale, an Upper Devonian formation about 400 meters deep. It reaches the surface through passages associated with faulting caused by tectonic activity.

At the New York site, the researchers identified numerous “micro seeps” of gas, apparently from the same source that fuels the eternal flame. This suggests that such seeps, if they are numerous and widespread, could make a significant contribution to atmospheric concentrations of greenhouse gases and other pollutants.

The researchers also studied a larger eternal flame at Cook Forest State Park in northwestern Pennsylvania. They determined that flame, in a continuously burning fire pit, is not a natural seep but a leak from an abandoned gas well. The source is thought to be a conventional gas reservoir, not shale.

Mastalerz said naturally occurring methane sources are believed to account for about 30 percent of the total methane emissions in Earth’s atmosphere. Natural gas seeps are thought to be the second most significant source of naturally occurring methane emissions, after wetlands.

But finding seeps is like searching for a needle in a haystack. Last year, the researchers surveyed a region of Kentucky that is geologically similar to western New York — and where “burning springs” figure in local history and folklore — but turned up no evidence of escaping natural gas.

Schimmelmann said researchers have found elevated levels of carbon dioxide in caves, possibly resulting from methane that is converted by microorganisms to carbon dioxide gas as it seeps slowly toward the surface. Carbon dioxide is also a greenhouse gas, but it is 20 times less effective at trapping heat than methane.

The findings suggest natural gas seeps occur in areas that have experienced tectonic activity, and it may be easier to find them in caves, which capture and concentrate gas when it reaches the surface. A next step in the research, planned for this summer, is to continue the search in areas of Pennsylvania, West Virginia and Virginia where gas-bearing shale underlies cave systems.

Funding for the research comes from the U.S. Department of Energy.

Note : The above story is reprinted from materials provided by Indiana University, via Newswise. 

Four New Dinosaur Species Identified

CMN 0210 is the holotype of Euoplocephalus tutus, CMN 8530 is the holotype of Anodontosaurus lambei, MOR 433 is the holotype of Oohkotokia horneri, and ROM 784 is the holotype of Dyoplosaurus acutosquameus. AMNH 5337, AMNH 5405, CMN 0210, ROM 784, ROM 1930, TMP 1979.14.74, TMP 1991.127.1, TMP 1997.132.1, and UALVP 31 are from the Dinosaur Park Formation. AMNH 5238 and UALVP 47977 are of uncertain stratigraphic position within Dinosaur Provincial Park. AMNH 5223, CMN 8530, ROM 832, and TMP 1997.59.1 are from the Horseshoe Canyon Formation. NHMUK R4947 is from an unknown stratigraphic position in Alberta. MOR 433, TMP 2001.42.9 (much of the anterior rostrum in heavily reconstructed), and USNM 11892 are from the Upper Two Medicine Formation in Montana. Scale equals 10 cm. (Credit: Victoria M. Arbour, Philip J. Currie; Photograph of ROM 832 by C. Brown, and of ROM 1930 by J. Arbour)

Just when dinosaur researchers thought they had a thorough knowledge of ankylosaurs, a family of squat, armour plated, plant eaters, along comes University of Alberta graduate student, Victoria Arbour.

 

Arbour visited dinosaur fossil collections from Alberta to the U.K. examining skull armour and comparing those head details with other features of the fossilized ankylosaur remains. She made a breakthrough that resurrected research done more than 70 years ago.

Arbour explains that between 1900 and 1930 researchers had determined that small variations in the skull armour and the tail clubs in some ankylosaurs constituted four individual species of the dinosaurs.

“In the 1970s the earlier work was discarded and those four species were lumped into one called species Euoplocephalus,” said Arbour.

“I examined many fossils and found I could group some fossils together because their skull armour corresponded with a particular shape of their tail club,” said Arbour.

Finding common features in fossils that come from the same geologic time is evidence that the original researchers were right says Arbour. “There were in fact four different species represented by what scientists previously thought was only one species, Euoplocephalus.”

The four species span a period of about 10 million years. Arbour’s research shows three of those ankylosaurs species lived at the same time in what is now Dinosaur Provincial Park in southern Alberta.

Arbour says this opens the door to new questions.

“How did these three species shared their habitat, how did they divide food resources and manage to survive?” said Arbour.

Arbour will also look into how slight differences in skull ornamentation and tail shape between the species influenced the animals’ long reign on Earth.

Arbour’s research was published May 8, in the journal PLOS ONE.

Note : The above story is reprinted from materials provided by University of Alberta, via EurekAlert!, a service of AAAS. 

Bone-Headed Dinosaur Hinting at Higher Diversity of Small Dinosaurs

Life reconstruction of Acrotholus audeti in its environment. (Credit: © Julius Csotonyi)

Scientists have named a new species of bone-headed dinosaur (pachycephalosaur) from Alberta, Canada. Acrotholus audeti (Ack-RHO-tho-LUS) was identified from both recently discovered and historically collected fossils. Approximately six feet long and weighing about 40 kilograms in life, the newly identified plant-eating dinosaur represents the oldest bone-headed dinosaur in North America, and possibly the world.

 

Dr. Michael Ryan, curator of vertebrate paleontology at The Cleveland Museum of Natural History, co-authored research describing the new species, which was published May 7, 2013 in the journal Nature Communications.

Acrotholus means “high dome,” referring to its dome-shaped skull, which is composed of solid bone over 10 centimeters (two inches) thick. The name Acrotholus audeti also honors Alberta rancher Roy Audet, on whose land the best specimen was discovered in 2008. Acrotholus walked on two legs and had a greatly thickened, domed skull above its eyes, which was used for display to other members of its species, and may have also been used in head-butting contests. Acrotholus lived about 85 million years ago.

The new dinosaur discovery is based on two skull ‘caps’ from the Milk River Formation of southern Alberta. One of these was collected by the Royal Ontario Museum (ROM) more than 50 years ago. However, a better specimen was found in 2008 by University of Toronto graduate student Caleb Brown during a field expedition organized by Dr. David Evans of the Royal Ontario Museum and University of Toronto, and Ryan.

“Acrotholus provides a wealth of new information on the evolution of bone-headed dinosaurs. Although it is one of the earliest known members this group, its thickened skull dome is surprisingly well-developed for its geological age,” said lead author Evans, ROM curator, vertebrate palaeontology. “More importantly, the unique fossil record of these animals suggests that we are only beginning to understand the diversity of small-bodied plant-eating dinosaurs.”

Small mammals and reptiles can be very diverse and abundant in modern ecosystems, but small dinosaurs (less than 100 kg) are considerably less common than large ones in the fossil record. Whether this pattern is a true reflection of dinosaur communities, or is related to the greater potential for small bones to be destroyed by carnivores and natural decay, has been debated. The massively constructed skull domes of pachycephalosaurs are resistant to destruction, and are much more common than their relatively delicate skeletons — which resemble those of other small plant-eating dinosaurs. Therefore, the researchers suggest that the pachycephalosaur fossil record can provide valuable insights into the diversity of small, plant-eating dinosaurs as a whole.

“We can predict that many new small dinosaur species like Acrotholus are waiting to be discovered by researchers willing to sort through the many small bones that they pick up in the field,” said co-author Ryan of The Cleveland Museum of Natural History. “This fully domed and mature individual suggests that there is an undiscovered, hidden diversity of small-bodied dinosaurs. So when we look back, we need to reimagine the paleoenvironment. There is an evolutionary history that we just don’t know because the fossil record is incomplete. This discovery also highlights the importance of landowners, like Roy Audet, who grant access to their land and allow scientifically important finds to be made.”

This dinosaur is the latest in a series of new finds being made by Evans and Ryan as part of their Southern Alberta Dinosaur Project, which aims to fill in gaps in of the record of Late Cretaceous dinosaurs and study their evolution. This project focuses on the palaeontology of some of the oldest dinosaur-bearing rocks in Alberta, which have been studied less intensely than those of the famous badlands of Dinosaur Provincial Park and Drumheller.

Acrotholus was identified by a team comprising of palaeontologists Evans, of the Royal Ontario Museum; and Ryan, of The Cleveland Museum of Natural History; as well as Ryan Schott, Caleb Brown, and Derek Larson, all graduate students at the University of Toronto who studied under Evans.

Note : The above story is reprinted from materials provided by Cleveland Museum of Natural History. 

Landsat Thermal Sensor Lights Up from Volcano’s Heat

An ash plume drifts from Paluweh volcano in Indonesia in this image, taken April 29, 2013 from the Landsat Data Continuity Misison’s Operational Land Imager instrument. (Credit: Robert Simmon, NASA’s Earth Observatory, using data from USGS and NASA)

As the Landsat Data Continuity Mission satellite flew over Indonesia’s Flores Sea April 29, it captured an image of Paluweh volcano spewing ash into the air. The satellite’s Operational Land Imager detected the white cloud of smoke and ash drifting northwest, over the green forests of the island and the blue waters of the tropical sea. The Thermal Infrared Sensor on LDCM picked up even more.By imaging the heat emanating from the 5-mile-wide volcanic island, TIRS revealed a hot spot at the top of the volcano where lava has been oozing in recent months.

The two LDCM instruments, working together, illustrate a quote from Aristotle: The whole is greater than the sum of its parts, said Betsy Forsbacka, TIRS instrument manager at NASA’s Goddard Space Flight Center in Greenbelt, Md.

“Each instrument by itself is magnificent,” she said. “When you put them together, with the clues that each give you on what you’re seeing on Earth’s surface, it’s greater than either could do by themselves.”

The image of Paluweh also illuminates TIRS’ abilities to capture the boundaries between the hot volcanic activity and the cooler volcanic ash without the signal from the hot spot bleeding over into pixels imaging the cooler surrounding areas. TIRS engineers tested and refined the instrument pre-launch to ensure each pixel correctly represents the heat source it images on Earth’s surface. Otherwise, Forsbacka said, it would be like shining a flashlight in your eyes — the bright light can leave you seeing spots and halos where it should be dark. The same effect can occur with detectors. But the contrast is sharp on the Paluweh image.

“We can image the white, representing the very hot lava, and right next to it we image the gray and black from the cooler surrounding ash,” Forsbacka said. “It’s exciting that we’re imaging such diverse thermal activity so well.”

The TIRS instrument can also pick up subtle shifts of temperatures, within a 10th of a degree Celsius. And, with two different thermal bands instead of the one band on previous Landsat satellites, LDCM is poised to make it easier for scientists to subtract out the effects of the atmosphere on the signal, obtaining a more accurate temperature of Earth’s surface.

Taking Earth’s temperature from space can be difficult because the atmosphere gets in the way and alters the thermal signals, Forsbacka said. Scientists looking to estimate surface temperatures with the single thermal band on previous Landsat instruments needed measurements or assumptions about atmospheric conditions.

TIRS has two thermal bands, however. The atmosphere affects each band slightly differently, resulting in one thermal image that’s a hair darker than the other. By measuring that difference, and plugging it into algorithms, scientists can better address atmospheric effects and create a more accurate temperature record of Earth’s surface.

The Landsat program is a joint mission of NASA and the U.S. Geological Survey. Once LDCM completes its onboard calibration and check-out phase in late May, the satellite will be handed over to the USGS and renamed Landsat 8. Data from TIRS and OLI will be processed, archived and distributed from the USGS Earth Resources and Observation Science Center in Sioux Falls, S.D., for free over the Internet.

Note : The above story is reprinted from materials provided by NASA/Goddard Space Flight Center. 

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