The forerunner of dinosaurs like three-horned Triceratops was a bird-hipped creature the size of a turkey that lived in herds in South America and liked to munch on ferns, scientists said Wednesday.
Laquintasaura venezuelae, named after the country in which it was discovered, lived 201 million years ago in the earliest Jurassic period, soon after a major extinction at the end of the Triassic, said a paper in the journal Proceedings of the Royal Society B.
The early history of bird-hipped, beaked, plant-eating dinosaurs called Ornithischia, of which the newly-discovered lizard is a very old example, has thus far been sketchy, as so few have been found.
Ornithischia gave rise to famous beasts like Iguanodon, Stegosaurus and Triceratops, which have inspired childrens’ toys and cartoons.
The discovery of the remains of at least four Laquintasaura in Venezuela showed that dinosaurs bounced back quickly after the Triassic species wipeout, said study author Paul Barrett, a palaeontologist at the Natural History Museum in London.
Also, “it is fascinating and unexpected to see they lived in herds, something we have little evidence of so far in dinosaurs from this time,” he said in a statement.
“The fact that it is from a completely new and early taxon means we can fill in some of the gaps in our understanding of when different groups of dinosaurs evolved.”
The remains were found in the La Quinta geological formation in the Venezuelan Andes, an area previously thought to have been far too inhospitable for dinosaurs.
The fossilised evidence revealed that Laquintasaura walked on two hind legs, and was about a metre (3.3 feet) long with its tail, and about a quarter of that wide at the hips.
It is thought to have been largely a plant-eater, favouring ferns, but curved tips on some of its teeth suggest it may have also eaten insects and other small prey.
“It is always exciting to discover a new dinosaur species but there are many surprising firsts with Laquintasaura,” said Barrett.
“Not only does it expand the distribution of early dinosaurs, its age makes it important for understanding their early evolution and behaviour.”
It is the first new dinosaur species found in the north of South America.
The fossils’ age was determined with techniques that included analysing residual radioactivity of tiny crystals within the rock containing the ancient bones.
This is an artist’s conception of internal structure of the Moon based on this science result. Credit: Image courtesy of National Astronomical Observatory of Japan
An international research team, led by Dr. Yuji Harada from Planetary Science institute, China University of Geosciences, has found that there is an extremely soft layer deep inside the Moon and that heat is effectively generated in the layer by the gravity of Earth. These results were derived by comparing the deformation of the Moon as precisely measured by Kaguya (SELENE, Selenological and Engineering Explorer) and other probes with theoretically calculated estimates. These findings suggest that the interior of the Moon has not yet cooled and hardened, and also that it is still being warmed by the effect of Earth on the Moon. This research provides a chance to reconsider how both Earth and the Moon have been evolving since their births through mutual influence until now.
When it comes to clarifying how a celestial body like a planet or a natural satellite is born and grows, it is necessary to know as precisely as possible its internal structure and thermal state. How can we know the internal structure of a celestial body far away from us? We can get clues about its internal structure and state by thoroughly investigating how its shape changes due to external forces. The shape of a celestial body being changes by the gravitational force of another body is called tide. For example, the ocean tide on Earth is one tidal phenomenon caused by the gravitational force between the Moon and the Sun, and Earth. Sea water is so deformable that its desplacement can be easily observed. How much a celestial body can be deformed by tidal force, in this way, depends on its internal structure, and especially on the hardness of its interior. Conversely, it means that observing the degree of deformation enables us to learn about the interior, which is normally not directly visible to the naked eye.
The Moon is no exception; we can learn about the interior of our natural satellite from its deformation caused by the tidal force of Earth. The deformation has already been well known through several geodetic observations (*1). However, models of the internal structure of the Moon as derived from past research could not account for the deformation precisely observed by the above lunar exploration programs.
Therefore, the research team performed theoretical calculations to understand what type of internal structure of the Moon leads to the observed change of the lunar shape.
What the research team focused on is the structure deep inside the Moon. During the Apollo program, seismic observations (*2) were carried out on the Moon. One of the analysis results concerning the internal structure of the Moon based upon the seismic data indicates that the satellite is considered to consist mainly of two parts: the “core,” the inner portion made up of metal, and the “mantle,” the outer portion made up of rock. The research team has found that the observed tidal deformation of the Moon can be well explained if it is assumed that there is an extremely soft layer in the deepest part of the lunar mantle. The previous studies indicated that there is the possibility that a part of the rock at the deepest part inside the lunar mantle may be molten. This research result supports the above possibility since partially molten rock becomes softer. This research has proven for the first time that the deepest part of the lunar mantle is soft, based upon the agreement between observation results and the theoretical calculations.
Furthermore, the research team also clarified that heat is efficiently generated by the tides in the soft part, deepest in the mantle. In general, a part of the energy stored inside a celestial body by tidal deformation is changed to heat. The heat generation depends on the softness of the interior. Interestingly, the heat generated in the layer is expected to be nearly at the maximum when the softness of the layer is comparable to that which the team estimated from the above comparison of the calculations and the observations. This may not be a coincidence. Rather, the layer itself is considered to be maintained as the amount of the heat generated inside the soft layer is exquisitely well balanced with that of the heat escaping from the layer. Whereas previous research also suggests that some part of the energy inside the Moon due to the tidal deformation is changed to heat, the present research indicates that this type of energy conversion does not uniformly occur in the entire Moon, but only intensively in the soft layer. The research team believes that the soft layer is now warming the core of the Moon as the core seems to be wrapped by the layer, which is located in the deepest part of the mantle, and which efficiently generates heat. They also expect that a soft layer like this may efficiently have warmed the core in the past as well.
Concerning the future outlook for this research, Dr. Yuji Harada, the principle investigator of the research team, said, “I believe that our research results have brought about new questions. For example, how can the bottom of the lunar mantle maintain its softer state for a long time? To answer this question, we would like to further investigate the internal structure and heat-generating mechanism inside the Moon in detail. In addition, another question has come up: how has the conversion from the tidal energy to the heat energy in the soft layer affected the motion of the Moon relative to the Earth, and also the cooling of the Moon? We would like to resolve those problems as well so that we can thoroughly understand how the Moon was born and has evolved.”
Another investigator, Prof. Junichi Haruyama of Institute of Space and Aeronautical Science, Japan Aerospace Exploration Agency, mentioned the significance of this research, saying, “A smaller celestial body like the Moon cools faster than a larger one like the Earth does. In fact, we had thought that volcanic activities on the Moon had already come to a halt. Therefore, the Moon had been believed to be cool and hard, even in its deeper parts. However, this research tells us that the Moon has not yet cooled and hardened, but is still warm. It even implies that we have to reconsider the question as follows: How have the Earth and the Moon influenced each other since their births? That means this research not only shows us the actual state of the deep interior of the Moon, but also gives us a clue for learning about the history of the system including both the Earth and the Moon.”
The scientific paper on which this article is based appears in the Nature Geoscience.
Strong tidal heating in an ultralow-viscosity zone at the core-mantle boundary of the Moon.
Note:
*1: Geodetic observation. (This is also called “selenodetic” observation as it is for the Moon.)
Observational results on gravity and rotation of the Moon are used in this research. Precise measurements of the lunar gravity and rotation enable us to know how our natural satellite is deformed by tidal forces.
The gravity of the Moon can be measured by tracking the motion of a satellite orbiting the Moon. This is because the motion of the satellite is influenced by lunar gravity. The motion of the satellite orbiting the Moon can be determined by using radio waves between the Earth and the satellite, and between multiple satellites around the Moon. The gravity of the Moon changes when it deforms due to tidal forces. The change in gravity caused by the lunar deformation due to the tidal force is extremely small, but when the change in location of the orbiter can be determined precisely enough, it is possible to accurately detect the change in lunar gravity caused by the deformation due to the tidal force. During the last several years, the degree of the lunar deformation caused by the tidal forces has been determined by several orbiters, for example, Kaguya from Japan, Chang’e-1 from China, and Lunar Reconnaissance Orbiter (LRO) and Gravity Recovery and Interior Laboratory (GRAIL) from the USA.
The rotation of the Moon can be observed by monitoring the change in position of a kind of mirror placed in several locations on the lunar surface. The same side of the Moon is almost always facing the Earth, but strictly speaking, it changes by a slight amount according to the lunar orbit around the Earth. This means that the locations of the mirrors with respect to the Earth also changes over time. If this change in position is precisely measured, it can also be determined how the direction of the lunar axis changes. This slight change of direction also depends on the deformation caused by the tidal force. It can be seen, therefore, how the Moon deforms due to the tidal force once the change in the axis is measured precisely. Some of the above-mentioned mirrors have been left on the surface of the Moon in the framework of the lunar exploration programs led by the USA or the former USSR several decades ago, such as the Apollo program. The degree of change in the location of each mirror on the Moon can be determined by using laser beams emitted from the Earth. This experiment still continues to be carried out even today.
*2: Seismic observation. (Quakes on the Moon are also called “moonquakes.” )
There are seismic activities not only on the Earth, but also on the Moon. As part of the Apollo program in the past, seismometers were placed on the lunar surface for seismological measurements. Waves induced by quakes measured with seismometers suggest what the internal structure of a celestial body is like. The behavior of the seismic waves is very important for understanding how the hardness inside the celestial body will change in accordance with the depth. In particular, the present research considered the following two previous analysis results in order to theoretically calculate the lunar deformation caused by the tidal force.
The first one is the existence of the area deep inside the Moon where the seismic waves become drastically weaker. It is generally known that the energy of the seismic waves tends to reduce more in softer solids, especially when they contain liquids. Therefore, the deepest part of the lunar mantle is softer than the shallower part. Also, a portion of the rocks is thought to be melted.
The second one is the existence of areas deep inside the Moon whose interfaces reflect the seismic waves. Three boundaries are considered to exist. Two of them are like the ones in the Earth: one separating the solid inner core and the liquid outer core, and the other one separating the outer core and the mantle. The last boundary is considered to correspond to the one in the mantle separating the solid area and the partially molten area mentioned above.
Note : The above story is based on materials provided by National Astronomical Observatory of Japan.
The middens are ancient dumping sites that typically contain a mix of mollusk shells, fish and bird bones, ceramics, cloth, charcoal, maize and other plants. Credit: M. Carré / Univ. of Montpellier
The planet’s largest and most powerful driver of climate changes from one year to the next, the El Niño Southern Oscillation in the tropical Pacific Ocean, was widely thought to have been weaker in ancient times because of a different configuration of the Earth’s orbit. But scientists analyzing 25-foot piles of ancient shells have found that the El Niños 10,000 years ago were as strong and frequent as the ones we experience today.
The results, from the University of Washington and University of Montpellier, question how well computer models can reproduce historical El Niño cycles, or predict how they could change under future climates. The paper is now online and will appear in an upcoming issue of Science.
“We thought we understood what influences the El Niño mode of climate variation, and we’ve been able to show that we actually don’t understand it very well,” said Julian Sachs, a UW professor of oceanography.
The ancient shellfish feasts also upend a widely held interpretation of past climate.
“Our data contradicts the hypothesis that El Niño activity was very reduced 10,000 years ago, and then slowly increased since then,” said first author Matthieu Carré, who did the research as a UW postdoctoral researcher and now holds a faculty position at the University of Montpellier in France.
In 2007, while at the UW-based Joint Institute for the Study of the Atmosphere and Ocean, Carré accompanied archaeologists to seven sites in coastal Peru. Together they sampled 25-foot-tall piles of shells from Mesodesma donacium clams eaten and then discarded over centuries into piles that archaeologists call middens.
While in graduate school, Carré had developed a technique to analyze shell layers to get ocean temperatures, using carbon dating of charcoal from fires to get the year, and the ratio of oxygen isotopes in the growth layers to get the water temperatures as the shell was forming.
The shells provide 1- to 3-year-long records of monthly temperature of the Pacific Ocean along the coast of Peru. Combining layers of shells from each site gives water temperatures for intervals spanning 100 to 1,000 years during the past 10,000 years.
The new record shows that 10,000 years ago the El Niño cycles were strong, contradicting the current leading interpretations. Roughly 7,000 years ago the shells show a shift to the central Pacific of the most severe El Niño impacts, followed by a lull in the strength and occurrence of El Niño from about 6,000 to 4,000 years ago.
One possible explanation for the surprising finding of a strong El Niño 10,000 years ago was that some other factor was compensating for the dampening effect expected from cyclical changes in Earth’s orbit around the sun during that period.
“The best candidate is the polar ice sheet, which was melting very fast in this period and may have increased El Niño activity by changing ocean currents,” Carré said.
Around 6,000 years ago most of the ice age floes would have finished melting, so the effect of Earth’s orbital geometry might have taken over then to cause the period of weak El Niños.
In previous studies, warm-water shells and evidence of flooding in Andean lakes had been interpreted as signs of a much weaker El Niño around 10,000 years ago.
The new data is more reliable, Carré said, for three reasons: the Peruvian coast is strongly affected by El Niño; the shells record ocean temperature, which is the most important parameter for the El Niño cycles; and the ability to record seasonal changes, the timescale at which El Niño can be observed.
“Climate models and a variety of datasets had concluded that El Niños were essentially nonexistent, did not occur, before 6,000 to 8,000 years ago,” Sachs said. “Our results very clearly show that this is not the case, and suggest that current understanding of the El Niño system is incomplete.”
The research was funded by the U.S. National Science Foundation, the U.S. National Oceanic and Atmospheric Administration and the French National Research Agency.
Other co-authors are Sara Purca at the Marine Institute of Peru; Andrew Schauer, a UW research scientist in Earth and space sciences; Pascale Braconnot at France’s Climate and Environment Sciences Laboratory; Rommel Angeles Falcón at Peru’s Minister of Culture; and Michèle Julien and Danièle Lavallée at France’s René Ginouvès Institute for Archaeology and Anthropology.
InSAR image showing volcanic uplift in the Great Rift Valley
Little known volcanoes in one of Africa’s most stunning locations are to be explored in a bid to understand the threat they pose to life, livelihood and the landscape. Researchers are to assess largely uncharted volcanoes in the East African Rift Valley, home to vast mammal migrations, mountain gorillas, spectacular peaks and fertile plains.
The region’s volcanoes, numbering more than 100, are shrouded in mystery. Dates of their last eruptions are mostly unknown and very few have detectors in place to highlight early signs of activity.
The human and financial cost could be huge if any of the volcanoes in the densely-populated and economically crucial area of Ethiopia’s main rift become active.
Researchers aim to understand past volcanic behaviour, search for signs of current activity and make a long-range eruptive forecast for the region. A recent report for the World Bank ranked 49 of Ethiopia’s 65 volcanoes in the highest category of hazard uncertainty.
The eruption of Nabro volcano on the Ethiopia-Eritrea border in 2011 was a reminder of the potential threat to the region. Despite lying in a remote and sparsely populated location and with no historical record of eruption, it claimed the lives of 32 people and displaced 5,000 more. Prior to its eruption, the volcano was believed to be dormant.
The five-year project, focusing on the volcanoes of the Main Ethiopian Rift, will be led by researchers from the Universities of Edinburgh and Bristol, in collaboration with the Universities of Cambridge, Leeds, Oxford and Southampton, the British Geological Survey, Addis Ababa University and the Geological Survey of Ethiopia. Overseas partners include Reykjavik Geothermal, which is part of a multi-billion dollar investment to develop the infrastructure to exploit this rich source of geothermal power.
The multi-disciplinary team will collect samples, map the geological record of previous eruptions and deploy geophysical instruments before analysing the data and creating models of the eruptive history, current states of unrest, and computing the likelihood of future eruptions. The team will also work on the best way of communicating their results to the relevant authorities and communities.
The £3.7million project, known as RiftVolc, is funded by the Natural Environment Research Council and begins in September. It will build on previous successful studies collaborating with Addis Ababa University and the Geological Survey of Ethiopia in the region.
RiftVolc co-leader Dr Juliet Biggs, of the University of Bristol’s School of Earth Sciences said; “The East African Rift is a fascinating place, full of exciting scientific challenges. We’re thrilled to establish a major project to study the past, present and future behaviour of these little-known volcanoes, and to be able work with our Ethiopian partners on such a societally relevant project.”
Note : The above story is based on materials provided by University of Bristol
A site at Pitch Lake where liquid oil ascends to the surface. Credit: Rainer Meckenstock
An international team of researchers has found extremely small habitats that increase the potential for life on other planets while offering a way to clean up oil spills on our own.
Looking at samples from the world’s largest natural asphalt lake, they found active microbes in droplets as small as a microliter, which is about 1/50th of a drop of water.
“We saw a huge diversity of bacteria and archaea,” said Dirk Schulze-Makuch, a professor in Washington State University’s School of the Environment and the only U.S. researcher on the team. “That’s why we speak of an ‘ecosystem,’ because we have so much diversity in the water droplets.”
Writing in the journal Science, the researchers report they also found the microbes were actively degrading oil in the asphalt, suggesting a similar phenomenon could be used to clean up oil spills.
“For me, the cool thing is I got into it from an astrobiology viewpoint, as an analog to Saturn’s moon, Titan, where we have hydrocarbon lakes on the surface,” said Schulze-Makuch. “But this shows astrobiology has also great environmental applications, because of the biodegradation of oil compounds.”
Schulze-Makuch and his colleagues in 2011 found that the 100-acre Pitch Lake, on the Caribbean island of Trinidad, was teeming with microbial life, which is also thought to increase the likelihood of life on Titan.
The new paper adds a new, microscopic level of detail to how life can exist in such a harsh environment.
“We discovered that there are additional habitats where we have not looked at where life can occur and thrive,” said Schulze-Makuch.
Analyzing the droplets’ isotopic signatures and salt content, the researchers determined that they were not coming from rain or groundwater, but ancient sea water or a brine deep underground.
Eat dirt. Ancient seafloor diggers, like the extinct worm Ancalagon minor depicted here, may have altered planetary chemistry. Obsidian Soul/Creative Commons
You can credit your existence to tiny wormlike creatures that lived 500 million years ago, a new study suggests. By tunneling through the sea floor, scientists say, these creatures kept oxygen concentrations at just the right level to allow animals and other complex life to evolve. The finding may help answer an enduring mystery of Earth’s past.
At the dawn of the Cambrian period about 570 million years ago, multicellular organisms were just beginning to appear, largely in the oceans. But for animals to evolve, the concentration of oxygen in the ocean and atmosphere had to be just right. Too little oxygen, and nascent animals would have suffocated. Too much, and lightning strikes would have created catastrophic fires, torching the primordial land vegetation. “How come oxygen levels didn’t crash or double?” says Tais Dahl, a geochemist at the University of Southern Denmark (SDU), Odense. “Something [regulated] oxygen in relatively narrow limits.”
A key moment in the evolution of the new study was when Dahl met Richard Boyle, a geochemical modeler who was then at the University of Exeter in the United Kingdom. Dahl was puzzled by data he and others had collected from rock outcroppings that were once on the floor of the ocean. For 30 million years, beginning 530 million years ago, the oxygen levels of the ocean dropped steadily, four different sets of chemical measurements suggested.
Boyle, now at SDU, had developed a hypothesis that might explain why. By burrowing, he reasoned, seafloor creepy-crawlies that lived at the start of the Cambrian kick-started a complex chain of events that altered the chemical composition of Earth. In the new study, the two scientists and their colleagues use a simple model to spell out their proposed mechanism. The idea is that as they dug and wiggled, these early multicellular creatures—some were likely worms as long as 40 cm—exposed new layers of seafloor sediment to the ocean’s water. Each new batch of sediment that settles onto the sea floor contains bacteria; as those bacteria were exposed to the oxygen in the water, they began storing a chemical called phosphate in their cells. So as the creatures churned up more sediment layers, more phosphate built up in ocean sediments and less was found in seawater.
Because algae and other photosynthetic ocean life require phosphate to grow, removing phosphate from seawater reduced their growth. Less photosynthesis, in turn, meant less oxygen released into the ocean. In this way, the system formed a negative feedback loop that automatically slowed the rise in oxygen levels as the levels increased. What kept the oxygen levels from getting too low? Less oxygen in the water also meant fewer worms, so less oxygen-reducing digging, the researchers explain. “We think these animals may have completely transformed geochemical cycles,” says Dahl, whose team reported its work online this week in Nature Geoscience.
“Although we are still far from knowing to what extent worms and their ilk influenced the geochemical history of our planet, this is a novel and testable hypothesis, which will inspire novel thinking,” writes Filip Meysman, a biogeochemist at the Royal Netherlands Institute for Sea Research in Yerseke, in a commentary on the research in Nature Geoscience. But he cautions that the rapid increase in the extent of worms’ burrowing modeled in the new study may have been limited to some areas of the ancient ocean and has yet to be shown to be a global phenomenon.
“In hindsight, the result isn’t particularly surprising or counterintuitive,” adds biogeochemist Lee Kump of Pennsylvania State University, University Park, in an e-mail to Science. Still, he says, “I wish I’d thought of that.”
Note : The above story is based on materials provided by Eli Kintisch “American Association for the Advancement of Science”
The second main type of faults found in extensional regimes, listric faults can be defined as curved normal faults in which the fault surface in concave upwards; its dip decreases with depth. These faults also occur in extension zones where there is a main detachment fracture following a curved path rather than a planar path. Hanging wall blocks may either rotate and slide along the fault plane (eg slumps), or they may pull away from the main fault, slipping instead only along the low dipping part of the fault. Roll-over anticlines will often form between bedding planes and the main fault plane as a result of the flexing between the two.
Fossil of burrow activity in sediment, 530 million years old. Credit: Martin Brasier, University of Oxford
Around 540 million years ago, the first burrowing animals evolved. When these worms began to mix up the ocean floor’s sediments (a process known as bioturbation), their activity came to significantly influence the ocean’s phosphorus cycle and as a result, the amount of oxygen in Earth’s atmosphere.
“Our research is an attempt to place the spread of animal life in the context of wider biogeochemical cycles, and we conclude that animal activity had a decreasing impact on the global oxygen reservoir and introduced a stabilizing effect on the connection between the oxygen and phosphorus cycles,” says lead author Dr. Richard Boyle from the Nordic Center for Earth Evolution (NordCEE) at the University of Southern Denmark.
The computer modelling study by Dr. Richard Boyle and colleagues from Denmark, Germany, China and the UK, published in Nature Geoscience, links data from the fossil record to well established connections between the phosphorus and oxygen cycles.
Marine organic carbon burial is a source of oxygen to the atmosphere, and its rate is proportional to the amount of phosphate in the oceans. This means that (over geologic timescales) anything that decreases the size of the ocean phosphate reservoir also decreases oxygen. The study focuses on one such removal process, burial of phosphorus in the organic matter in ocean sediments.
The authors hypothesize the following sequence of events: Around 540 million years ago, the evolution of the first burrowing animals significantly increased the extent to which oxygenated waters came into contact with ocean sediments. Exposure to oxygenated conditions caused the bacteria that inhabit such sediments to store phosphate in their cells (something that is observed in modern day experiments). This caused an increase in phosphorus burial in sediments that had been mixed up by burrowing animals. This in turn triggered decreases in marine phosphate concentrations, productivity, organic carbon burial and ultimately oxygen. Because an oxygen decrease was initiated by something requiring oxygen (i.e. the activity burrowing animals) a net negative feedback loop was created.
Boyle states: “It has long been appreciated that organic phosphorus burial is greater from the kind of well oxygenated, well-mixed sediments that animals inhabit, than from poorly mixed, low oxygen “laminated” sediments. The key argument we make in this paper is that this difference is directly attributable to bioturbation. This means that (1) animals are directly involved in an oxygen-regulating cycle or feedback loop that has previously been overlooked, and (2) we can directly test the idea (despite the uncertainties associated with looking so far back in time) by looking for a decrease in ocean oxygenation in conjunction with the spread of bioturbation. My colleague, Dr Tais Dahl from University of Copenhagen, compiled data on ocean metals with oxygen-sensitive burial patterns, which does indeed suggest such an oxygen decrease as bioturbation began — confirming the conclusions of the modelling. It is our hope that wider consideration of this feedback loop and the timing of its onset, will improve our understanding of the extent to which Earth’s atmosphere-ocean oxygen reservoir is regulated.”
Co-author Professor Tim Lenton of the University of Exeter adds: “We already think this cycle was key to helping stabilise atmospheric oxygen during the Phanerozoic (the last 542 million years) — and that oxygen stability is a good thing for the evolution of plants and animals. What is new in this study is it attributes the oxygen stabilisation to biology — the presence or absence of animals stirring up the ocean sediments.”
Earlier this year, researchers from the Nordic Center for Earth Evolution showed that early animals may have needed surprisingly little oxygen to grow, supporting the theory that rising oxygen levels were not crucial for animal life to evolve on Earth.
Journal Reference:
R. A. Boyle, T. W. Dahl, A. W. Dale, G. A. Shields-Zhou, M. Zhu, M. D. Brasier, D. E. Canfield, T. M. Lenton. Stabilization of the coupled oxygen and phosphorus cycles by the evolution of bioturbation. Nature Geoscience, 2014; DOI: 10.1038/ngeo2213
Note : The above story is based on materials provided by University of Southern Denmark.
A controlled burn of central marine chaparral conducted by the U.S. Army Corps of Engineers at Fort Ord, Cal., on October 14, 2013. Credit: U.S. Army
Fire season has arrived in California with vengeance in this third year of extended drought for the state. A series of large fires east of Redding and Fresno, in Yosemite, and on the Oregon border prompted Gov. Jerry Brown to declare a state of emergency on Sunday, August 3rd.
As force of destruction and renewal, fire has a long and intimate history with the ecology of California. Ecological scientists will discuss aspects of that history in detail at the upcoming 99th Annual Meeting of the Ecological Society of America on August 10 — 15th, 2014.
“Big fires today are not outside the range of historical variation in size,” said Jon Keeley, an ecologist based in Three Rivers, Cal., with the U.S. Geological Survey’s Western Ecological Research Center, and a Fellow of the Ecological Society.
Keeley will present research on the “association of megafires and extreme droughts in California” at the Annual Meeting as part of a symposium on understanding and adapting to extreme weather and climate events.
He will synthesize his research on the history of wildfire across the entire state, contrasting historical versus contemporary and forested versus non-forested patterns of wildfire incidence. He and his colleagues reviewed Forest Service records dating to 1910, as well as a wealth of newspaper clippings, compiled by a Works Progress Administration archival project, that stretch back to the middle of the last century.
Understanding historical fire trends, Keeley said, means recognizing that when we talk about wildfire in California we are talking about two very different fire regimes in two different ecosystems: the mountain forests and the lower elevation chaparral, oak woodlands, and grasslands.
The chaparral shrublands of southern California, and similar sagebrush ecosystems in the Great Basin, are not adapted to the kind of frequent fire typical of the mountain conifer forests in California. Fires in the lower elevation ecosystems are always crown fires, which kill most of the vegetation. In the millennia before humans arrived, these ecosystems burned at intervals of 100 to 130 years.
These lower elevation ecosystems experienced unprecedented fire frequency in the last century, with fire returning to the same area every 10 to 20 years, altering the ecology of the landscape.
“In Southern California, lower elevation ecosystems have burned more frequently than ever before. I think it’s partly climate, but also people starting fires during bad conditions,” Keeley said. Bad conditions include extended droughts and dry fall days when the Santa Ana winds blow through the canyons.
In high elevation conifer forests, spring temperatures and drought are strongly correlated with fire, and Keeley thinks climate change and management choices are likely playing a role in current trends. But in the hotter, drier valleys and foothills cloaked in grass, oak, and chaparral, human behavior dominates. Through arson or accident, in southern California, over 95% of fires are started by people, according to Cal Fire.
“Climate change is certainly important on some landscapes. But at lower elevation, we should not be thinking just about climate change,” said Keeley. “We should be thinking about all global change.” Land use change and population growth create more opportunities for fires to start.
The high frequency of fire has instigated a persistent switch from chaparral to grass in some areas. Frequent fire favors quick germination and spread of forbs and grasses. Most grasslands in California are not native.
Since the more recent arrival of immigrants from Europe and Asia, several of the exotic grasses they brought with them from the Old World have been quick to capitalize on the opportunities presented by fires to spread invasively throughout roughly a quarter of chaparral country. To Keeley, this means that prescribed fires in lower elevation ecosystems now have entirely different consequences for the regional ecology than they did when native Californian peoples set fires to manipulate resources.
“When the Native Americans did it, they did not affect native species so much, because native perennial bunchgrass and other herbaceous species grew in,” said Keeley. “Once the aliens got here, it completely changed.”
Note : The above story is based on materials provided by Ecological Society of America.
The Yukon River is a major watercourse of northwestern North America. The source of the river is located in British Columbia, Canada. The next portion lies in, and gives its name to Yukon. The lower half of the river lies in the U.S. state of Alaska. The river is 3,190 kilometres (1,980 mi) long and empties into the Bering Sea at the Yukon-Kuskokwim Delta. The average flow is 6,430 m³/s (227,000 ft³/s). The total drainage area is 832,700 km² (321,500 mi²), of which 323,800 km² (126,300 mi²) is in Canada. By comparison, the total area is more than 25% larger than Texas or Alberta.
The longest river in Alaska and Yukon, it was one of the principal means of transportation during the 1896–1903 Klondike Gold Rush. A portion of the river in Yukon—”The Thirty Mile” section, from Lake Laberge to the Teslin River—is a national heritage river and a unit of Klondike Gold Rush International Historical Park. Paddle-wheel riverboats continued to ply the river until the 1950s, when the Klondike Highway was completed. After the purchase of Alaska by the United States in 1867, the Alaska Commercial Company acquired the assets of the Russian-American Company and constructed several posts at various locations on the Yukon River.
The Russians named the Yukon River, believing that “yuk-khana” was a Deg Xinag phrase meaning big river. However, “yuk-khana” is not a Deg Xinag phrase meaning big river. Probably, the Deg Hit’an borrowed the name from an upriver language and borrowed the “big river” meaning from the Central Yup’ik name. Most likely, Yukon was derived from an obsolete Gwich’in word, which included the concept of long water or wide water, but did not mean “big” river or “great” river. The Lewes River is the former name of the upper course of the Yukon, from Marsh Lake to the confluence of the Pelly River at Fort Selkirk.
The Yukon River has had a history of pollution from gold mining, military installations, dumps, wastewater, and other sources. However, the Environmental Protection Agency does not list the Yukon River among its impaired watersheds, and water quality data from the U.S. Geological Survey shows relatively good levels of turbidity, metals, and dissolved oxygen.
The Yukon River Inter-Tribal Watershed Council, a cooperative effort of 70 First Nations and tribes in Alaska and Canada, has the goal of making the river and its tributaries safe to drink from again by supplementing and scrutinizing Government data.
The generally accepted source of the Yukon River is the Llewellyn Glacier at the southern end of Atlin Lake in British Columbia. Others suggest that the source is Lake Lindeman at the northern end of the Chilkoot Trail. Either way, Atlin Lake flows into Tagish Lake (via the Atlin River), as eventually does Lake Lindeman after flowing into Bennett Lake. Tagish Lake then flows into Marsh Lake (via the Tagish River). The Yukon River proper starts at the northern end of Marsh Lake, just south of Whitehorse. Some argue that the source of the Yukon River should really be Teslin Lake and the Teslin River, which has a larger flow when it reaches the Yukon at Hootalinqua. The upper end of the Yukon River was originally known as the Lewes River until it was established that it actually was the Yukon. North of Whitehorse, the Yukon River widens into Lake Laberge, made famous by Robert W. Service’s “The Cremation of Sam McGee”. Other large lakes that are part of the Yukon River system include Kusawa Lake (into the Takhini River) and Kluane Lake (into the Kluane and then White River).
The river passes through the communities of Whitehorse, Carmacks, (just before the Five Finger Rapids) and Dawson City in Yukon, and crossing Alaska into Eagle, Circle, Fort Yukon, Stevens Village, Rampart, Tanana, Ruby, Galena, Nulato, Grayling, Holy Cross, Russian Mission, Marshall, Pilot Station, St. Marys (which is accessible from the Yukon at Pitkas Point), and Mountain Village. After Mountain Village, the main Yukon channel frays into many channels, sprawling across the delta. There are a number of communities after the “head of passes,” as the channel division is called locally: Nunum Iqua, Alakanuk, Emmonak, and Kotlik. Of those delta communities, Emmonak is the largest with roughly 760 people in the 2000 census. Emmonak’s gravel airstrip is the regional hub for flights.
Geography and ecology
Some of the upper slopes of this watershed (e.g. Nulato Hills) are forested by Black Spruce. This locale near the Seward Peninsula represents the near westernmost limit of the Black Spruce, Picea mariana, one of the most widespread conifers in northern North America.
Note : The above story is based on materials provided by Wikipedia
Humans have left many kinds of mark on the planet, but some of the most remarkable and enduring are in the subterranean ‘underworld’ of rocks, hidden deep below our feet.
It’s a world that’s usually out of sight and out of mind — but it’s one where humans have created true geological novelties that have been studied extensively by Dr Jan Zalasiewicz and Professor Mark Williams of the University of Leicester, together with Dr Colin Waters of the British Geological Survey in a new paper published in the academic journal Anthropocene.
Among these observable novelties are the effects of human drilling on the geological ‘underworld’ that exists underfoot.
Dr Zalasiewicz explained: “Human drilling into the Earth’s crust to extract minerals or store wastes may be regarded as ‘anthroturbation’, comparable to the burrows made by worms and other animals but on a vastly greater scale.
“Anthroturbation has created textures and structures underground that are unique within the animal world. No other organism has made igneous and metamorphic rocks — and yet we have made many tons of these in underground nuclear tests, in shock-fracturing and by melting the rock around the blast.”
Anthroturbation commonly extends to several kilometres depth, as compared to the few centimetres or metres that non-human organisms achieve.
Examining the effects of human drilling shows how humans have left their mark on Earth both above the surface and deep below in the subterranean network of human-made tunnels in ways that will have a long-standing impact in the future.
Professor Williams added: “Many of these underground transformations, being beyond the reach of surface erosion, will effectively last forever. They can be preserved for millions and even billions of years into the future, and thus may form our most enduring — and most puzzling — legacy, for any intelligent creatures that may inherit the Earth from us.”
Journal Reference:
Jan Zalasiewicz, Colin N. Waters, Mark Williams. Human bioturbation, and the subterranean landscape of the Anthropocene. Anthropocene, 2014; DOI: 10.1016/j.ancene.2014.07.002
Note : The above story is based on materials provided by University of Leicester.
Low-level clouds along the California coast are visible in this July 26, 2014 image from the NOAA/NASA Geostationary Operational Environmental Satellite (GOES)-15 satellite. A new NASA/Caltech study examines how changes in aerosol levels affect this key type of cloud that helps cool our planet. Credit: NASA-Goddard Space Flight Center, data from NOAA GOES
Of all the factors that influence Earth’s changing climate, the effect that tiny particles in Earth’s atmosphere called aerosols have on clouds is the least well understood. Aerosols scatter and absorb incoming sunlight and affect the formation and properties of clouds. Among all cloud types, low-level clouds over the ocean, which cover about one-third of the ocean’s surface, have the biggest impact on the albedo, or reflectivity, of Earth’s surface, reflecting solar energy back to space and cooling our planet.
Now a new, comprehensive global analysis of satellite data led by Yi-Chun Chen, a postdoctoral fellow at NASA’s Jet Propulsion Laboratory, Pasadena, California, and a joint team of researchers from JPL and the California Institute of Technology in Pasadena, has quantified how changes in aerosol levels affect these warm clouds over the ocean. The findings appeared Aug. 3 in the advance online version of the journal Nature Geoscience.
Changes in aerosol levels have two main effects — they alter the amount of clouds in the atmosphere and change their properties. Water vapor condenses on aerosol particles into cloud droplets or cloud ice particles, so higher levels of aerosols mean more clouds. With regard to cloud properties, increased aerosol levels can either increase or decrease the amount of liquid water in clouds, depending on whether the clouds are raining or not, the stability of the atmosphere and humidity levels in the upper troposphere. The team analyzed 7.3 million individual data points from multiple satellites in the international constellation of Earth observing satellites known as the Afternoon Constellation, or A-Train, from August 2006 to April 2011 to provide the first real estimate of both effects.
The researchers found each effect to be of similar magnitude — that is, changing the amount of the clouds and changing their internal properties are both equally important in their contribution to cooling our planet. Moreover, they found that the total impact from the influence of aerosols on this type of cloud is almost double that estimated in the latest report of the United Nations’ Intergovernmental Panel on Climate Change.
“These results offer unique guidance on how warm cloud processes should be incorporated in climate models with changing aerosol levels,” said John Seinfeld, the Louis E. Nohl professor and professor of chemical engineering at Caltech.
The study is funded by NASA and the Office of Naval Research.
NASA monitors Earth’s vital signs from land, air and space with a fleet of satellites and ambitious airborne and ground-based observation campaigns. NASA develops new ways to observe and study Earth’s interconnected natural systems with long-term data records and computer analysis tools to better see how our planet is changing. The agency shares this unique knowledge with the global community and works with institutions in the United States and around the world that contribute to understanding and protecting our home planet.
How long does it take for natural Earth processes to form hydraulic fractures? Is the formation driven by sediment compaction, oil and gas generation, or something else? What role do these natural fractures play in modern hydraulic fracturing production? A new GSA BULLETIN study by András Fall and colleagues from The University of Texas at Austin, Virginia Tech, and ExxonMobil addresses these questions, and the article is open-access online.
The process of fracture formation by a natural increase in pore-fluid pressure has previously been referred to as natural hydraulic fracturing. Researchers work to understand these fractures through examination of fluid inclusions trapped in minerals within the fractures. In this study, Fall and colleagues conclude that natural hydraulic fractures formed over time spans of 33 to 35 million years, driven by the slow generation of natural gas.
Natural fractures provide important pathways for the flow of water, natural gas, and oil in geologic formations, including unconventional tight-gas sandstone oil and gas reservoirs targeted for production by hydraulic fracturing. These fractures play an essential role during well completion and production by connecting pores in the reservoir rock storing oil and gas to the hydraulic fracture and wellbore that allow production. “Sweet spots,” or zones of higher than average permeability, have been attributed to the presence of these open fractures.
Successful prediction of zones of increased fracture abundance provides an opportunity to minimize drilling and completion costs as well as the environmental footprint of production. Successful prediction of natural fracture occurrence and their hydraulic properties requires models of fracture formation that are based on realistic mechanical, hydraulic, and chemical principles that can be tested against core, well-log, and production data.
Journal Reference:
A. Fall, P. Eichhubl, R. J. Bodnar, S. E. Laubach, J. S. Davis. Natural hydraulic fracturing of tight-gas sandstone reservoirs, Piceance Basin, Colorado. Geological Society of America Bulletin, 2014; DOI: 10.1130/B31021.1
Note : The above story is based on materials provided by Geological Society of America.
Aerial photo of the San Andreas Fault in the Carrizo Plain, northwest of Los Angeles. Credit: Wikipedia.
Gary Griggs began studying sediment deposits on the deep-sea floor off the Oregon coast in 1965 as a graduate student in oceanography at Oregon State University. Now, almost 50 years later, Griggs is a distinguished professor of Earth and planetary sciences and director of the Institute of Marine Sciences at UC Santa Cruz, and the sediment cores he collected as a grad student have led geologists to rethink their ideas about earthquake hazards in the Pacific Northwest.
It wasn’t until 1990 that the distinctive sediment layers Griggs and his colleagues observed were recognized as evidence of massive earthquakes that occurred centuries ago. A new study published July 29 in Geology reexamines that evidence and its implications.
“Science has come a long way in the past half century. When I was a graduate student we didn’t have the benefit of plate tectonics and no understanding of the potential for big earthquakes in that area,” said Griggs, a coauthor of the new paper.
The report focuses on the Cascadia subduction zone—a giant active fault that slants eastward beneath the Pacific coast of southern British Columbia, Washington, Oregon, and northern California. The lead author is Brian Atwater of the U.S. Geological Survey, an expert on Cascadia earthquakes who contacted Griggs several years ago to learn more about the sediment cores he had collected as a graduate student.
Geologic studies in the past three decades have provided increasingly specific estimates of Cascadia earthquake sizes and repeat times. The estimates affect public safety through seismic provisions in building design and tsunami limits on evacuation maps. At issue is not whether the Cascadia subduction zone produces enormous earthquakes repeatedly. It is widely held, for instance, that the zone last ruptured along most of its 700-mile length in January 1700, in an earthquake of estimated magnitude 9. The new report does not question this consensus. What the report asks instead is how much geologists can say, with confidence, about Cascadia earthquake history before 1700.
“The question is whether we get magnitude 8 earthquakes every 300 years or magnitude 9 earthquakes every 500 years, and that’s important because it’s been over 300 years since the last very large quake and tsunami,” Griggs said. “It may be more complicated than people once thought to determine exactly when those past earthquakes occurred.”
The new report reappraises sediment cores that were collected near the foot of the continental slope offshore Washington. Several cores from this area underpin influential estimates of Cascadia earthquake size and recurrence that were published in 2012. The new report points to confounding evidence from a much larger suite of cores that were collected and first analyzed in the late 1960s and early 1970s, including those collected by Griggs.
At that time, plate tectonics was such a new idea that scientists were just beginning to recognize the Cascadia subduction zone as a tectonic plate boundary. The sediment cores were collected to learn about turbidites—beds of sand and mud laid down by bottom-hugging, sediment-driven currents that infrequently emerged from submarine canyons onto the deep ocean floor. Not until a 1990 report would turbidites be reinterpreted as clues to Cascadia earthquake history.
The new report asks how well geologists have managed to read this earthquake history. Which earthquakes represent long ruptures and which represent sequential, shorter breaks? Do earthquakes happen more often here than there? The report concludes that extracting such details from turbidites at Cascadia is more complicated than was previously thought.
For Griggs, the new developments show how important it is to keep good research records. “Even if you don’t have the answer at the time, if you do careful work others can come along later and reevaluate the evidence in the light of new models and understanding,” he said.
Note : The above story is based on materials provided by University of California – Santa Cruz
A wrack line high on a rock outcrop and dunes at Anketell, west of Port Samson. Credit: Tanya Stul
Evidence showing tsunamis or other waves caused by cyclones have previously reached more than 10m above sea level in WA, has raised questions about the capacity of coastal infrastructure according to a study of the Pilbara coast.
The study used historic deposits of shells and other skeletal material—called wrack lines because they occur in distinct bands—to identify high water levels up to 2500 years ago.
The research team examined wrack lines at 26 sites spread over 375km of coast and found six sites had shell deposits more than 8m above sea level. Three reached 10m above sea level.
Damara WA coastal engineer and paper co-author Matt Eliot, says it is unclear whether the biggest waves were tsunamis or were caused by tropical cyclones.
Generally, high water marks less than 4.5m above sea level are attributed to moderate storm surges and high tides, high water marks between 4.5m and 7.5m are attributed to extreme tropical cyclones combined with a high tide, and high water marks above 7.5m are attributed to tsunamis.
But Matt Eliot says the nature of tropical cyclones means they can also cause massive waves.
“We were really interested in trying to use the physical patterns of the wrack lines because a cyclone should have a directional focus and be spatially less coherent than a tsunami,” he says.
“What we’ve found is that the nature of the wrack lines and their reworking actually means that even if a tsunami was far more coherent, the signature is decayed sufficiently over time or by the landforms themselves that it will resemble a cyclone anyhow.”
Shell clusters at various sites across the Pilbara coast, indicated high water level events up to 2500 years ago. Credit: John Collins
Matt Eliot, his father Ian Eliot (also from Damara WA) and their colleague John Dodson initially discovered the wrack lines while they were working on a contract for an oil and gas company.
Much of the infrastructure in the Pilbara, including Karratha and Port Hedland, is built on low-lying plains or close to shore and the study reported that the implications of extreme high water events may have not been fully considered in the design of this infrastructure.
Ian Eliot says a giant wave could have a huge economic impact on WA.
“You could use Varanus Island as a model—a gas explosion on the island cost a large part of the WA economy at the time and therefore had a big impact on the rest of Australia,” he says.
“Imagine one of these extremely high waves directly hitting a highly vulnerable part of the Pilbara coast.”
More information:
John Dodson, Ian Eliot, Matthew Eliot, Catherine Chagué-Goff, James Goff, “Wrack line signatures of high-magnitude water-level events on the northwest Australian coast,” Marine Geology, Volume 355, 1 September 2014, Pages 310-317, ISSN 0025-3227, dx.doi.org/10.1016/j.margeo.2014.06.013.
Note : The above story is based on materials provided by Science Network WA
The dinosaur lineage that evolved into birds shrank in body size continuously for 50 million years, as seen in this handout illustration provided by Eurekalert.org July 31, 2014. Credit: Reuters/Eureka.org/David Bonnadonna/Handout via Reuters
(Reuters) – Large flesh-eating dinosaurs evolved into small flying birds, but it did not happen overnight.
An international team of scientists on Thursday described an extraordinary evolutionary process that unfolded over a period of 50 million years in which a lineage of carnivorous dinosaurs shrank steadily and acquired numerous traits that led to the first appearance of birds.
The researchers, using techniques developed by molecular biologists to reconstruct virus evolution, examined 1,500 anatomical traits in 120 different dinosaurs from the theropod group. These bipedal meat-eaters included giants like Tyrannosaurus rex and Giganotosaurus as well as the lineage that produced birds.
“Our study measured the rate of evolution of different groups of theropod dinosaurs,” said lead researcher Michael Lee, a paleontologist at the University of Adelaide and the South Australian Museum.
“The fastest-evolving group also happened to be ancestral to birds. So, ultimately, the most adaptable dinosaurs proved to be the best long-term survivors, and surround us today in their feathered splendor,” Lee explained.
The earliest known bird was the crow-sized Archaeopteryx, which lived in Germany 150 million years ago. It was characterized by primitive traits like teeth, a long bony tail and the absence of a bony, keeled sternum where flight muscles attach, as well as some attributes shared with modern birds.
“What was impressive was the consistency of the size change along the dinosaur-to-bird transition – every descendent was smaller than its ancestor. The lineage was continually pushing the envelope of life at a smaller body size, little by little, over 50 million years,” Lee said.
The researchers completed a family tree of this dinosaur lineage and their bird descendants. These dinosaurs decreased in size from about 440 pounds (200 kg) to 1.7 pounds (0.8 kg) in 12 discernible steps.
Aside from sustained miniaturization, this lineage also benefited from new traits such as feathers, wishbones, wings, shorter snouts and smaller teeth. The study found that this lineage acquired evolutionary adaptations at a rate four times faster than other dinosaurs.
“The dinosaurs most closely related to birds are all small, and many of them – like the aptly named Microraptor – had some ability to climb and glide,” said study participant Gareth Dyke, a paleontologist at Britain’s University of Southampton.
The decrease in body size may have helped dinosaurs in the lineage that evolved into birds to take advantage of certain ecological niches that would have been off-limits to their larger relatives and to experiment with unique body shapes.
“It would have permitted them to chase insects, climb trees, leap and glide, and eventually develop powered flight,” Lee said.
The changes may have helped these creatures to survive the cataclysm that doomed the other dinosaurs – an asteroid that struck Earth 65 million years ago, Lee said. Flight, for example, would have allowed them to cover vast territory in search of suitable habitat, and warm-bloodedness would have buffered them against climate changes, he said.
The study was published in the journal Science.
Note : The above story is based on materials Reporting by Will Dunham; Editing by Gunna Dickson “Reuters”
NASA’s Hubble Space Telescope snapped this portrait of Mars within minutes of the planet’s closest approach to Earth in nearly 60,000 years in this picture taken by NASA on August 27, 2003. Credit: Reuters/NASA/Handout via Reuters
(Reuters) – For the past four months, a team of researchers have been living in a mockup Mars habitat on a Hawaiian volcano practicing isolated living on the Red Planet.
For the most part, expedition leader Casey Stedman and his five crewmates have stayed inside their 1,000-square foot (93-square meter) solar-powered dome, venturing out only for simulated spacewalks and doing so only when fully attired in mock spacesuits.
“I haven’t seen a tree, smelled the rain, heard a bird, or felt wind on my skin in four months,” Stedman wrote in a blog on Instagram. Stedman is a U.S. Air Force Reserve officer, graduate student at Embry-Riddle Aeronautical University Worldwide.
“We are simulating a long-duration mission on Mars, with a focus on crew psychology in isolation,” the crew said during an online interview with Reddit on Sunday.
Crewmembers, who include a NASA chemical engineer and a neuropsychologist at the Fort Wayne Neurological Center in Indiana, have been isolated from direct human contact and have been eating dehydrated and shelf-stabilized foods.
“We’ve basically been subsisting on mush. Flavorful mush, but mush nonetheless,” crewmember Ross Lockwood wrote on Instagram. Lockwood is finishing a doctorate in physics at the University of Alberta.
The habitat, which is outfitted with waterless composting toilets, is basically self-sustaining except for a water resupply and wastewater recovery every two- to three weeks.
Communications with the outside world have been time-delayed to match the 20-minute travel time of radio waves passing between Earth and Mars. In addition to a battery of daily psychological surveys, the researchers tend to science projects and other studies, including expeditions outside the habitat to scout Mars-like features on Hawaii’s Mauna Loa volcano. The landscape is similar to a region on Mars known as Tharsis. For fun, there are movies, board games and exercise, Lockwood told Reddit.
“We don’t have a lot of spare time, but I count work as part of the fun as well. Planning EVAs (spacewalks), preparing food, even chores – these are all enjoyable activities,” he said.
The operational part of the Hawaii Space Exploration Analog and Simulation mission, known as Hi-SEAS 2, wraps up on Friday, but it will take months to synthesize all the findings.
The point of the project is to create guidelines for future missions to Mars, the long-term goal of the U.S. human space program.
“Hopefully, when we send humans to Mars, we will have done enough missions like HI-SEAS that we’ll remember to bring the really important stuff, like extra toilet paper,” mission support team member Gary Strawn said on Reddit.
The simulation, which is funded by NASA and overseen by the University of Hawaii, began on March 28.
Note : The above story is based on materials provided by Irene Klotz “Reuters”
The Blue Lake occupies one of the craters of Mount Gambier and famously changes colour each year, going from a dull grey to a vibrant blue. Credit: Keith McGann
Volcanos in south-eastern Australia are still considered active, and a PhD candidate is hoping to determine whether we might expect more eruptions any time soon.
The Newer Volcanics Province includes more than 400 volcanoes, stretching from the Central Highlands north of Melbourne to South Australia’s Mount Gambier district.
Curtin University Geologist and PhD candidate Korien Oostingh says it is a very young geological province.
“It started erupting 4.6 million years ago and the last eruption [at Mount Gambier] is actually thought to have been witnessed by Aboriginal people around 5,000 years ago,” she says.
She is using the province as a case study as she develops a new technique that makes use of cosmogenic radiation for dating purposes.
Ms Oostingh has travelled to many locations throughout the Newer Volcanics Province, collecting samples that she is subjecting to tests at Curtin University’s Argon Laboratory.
“I’m looking at olivine in basalts,” she says.
“Part of the calcium in olivine will be converted into an isotope of Argon, [Argon 38] that we can measure here for the first time quite reliably in Curtin University.
“I will also combine that with chemistry data on the rocks from the new volcanic province so that I can look at some trends in the area and hopefully answer two big questions.
“One of them is if we can expect new eruptions in an area in the near future.
“Also, where the basalts were actually coming from at some point, so what is the source in the deep sub-surface?”
The province is more than 2000km from the edge of the Australian tectonic plate.
She says there are two current hypotheses proposed to explain this “intra-plate” volcanism.
“One possibility is that it is caused by the principle of a mantle plume,” she says.
“A mantle plume is rising magma from very deep in the earth—a little bit like if you are making a soup, the very hot material in the middle starts to rise.
“Very hot magma rises in pockets and it all starts to rise to the surface and creates a volcanic province or volcano.
“Some other people propose some local inhomogeneities in the underlying mantle.”
Ms Oostingh says she is not yet inclined to support either hypothesis.
“I am hoping to gain completely new data and to put forward my own model, I will do some advanced modelling here,” she says.
Note : The above story is based on materials provided by Science Network WA
