Thought to be the source of inspiration for unicorn paintings on prehistoric cave walls, the extinct genus of the Elasmotherium rhinoceros has always puzzled scientists, mostly because of a gap in the fossil record.
According to a new report from paleontologists at the Chinese Academy of Sciences in Beijing, a recently discovered skull of a Sinotherium lagrelii, a so-called tandem-horned rhino, has filled that gap.
“Morphological and phylogenetic analyses confirm that Sinotherium is a transitional (population) between Elasmotherium and other elasmotheres,” the Chinese researchers wrote in a report that appeared in the journal Chinese Science Bulletin.
Unlike other elasmotheres which had a weak or strong nasal horn, Elasmotherium had a massive, six-foot unicorn-like horn on its forehead. Found in the Late Miocene red clays of the Linxia Basin in northwestern China, the new skull was determined to be around 7 million years old and an intermediate stage between the two horn types.
Because previous fossils of S. lagrelii were only teeth or cranial and mandibular fragments, its horn morphology was completely unknown. Although the fossil has provided more information about where the species fits in taxonomically, researchers were not able to determine many details about its frontal horn, muddying the evolutionary picture somewhat. They said the species’ position in the evolutionary tree as one of transition is consistent with other related elasmotheres in this region of China.
According to the researchers, S. lagrelli’s elongated skull shape, facial structures, and wrinkled enamel allowed it to resist the abrasion of a high-fiber grass diet.
Paleontologists describe Sinotherium as a massive rhinoceros weighing up to 7.7 tons, making it heavier than the largest modern African white rhinos, which weigh in at about 3.5 to 4.0 tons. If the extinct rhino lived by the river, its size would mean regularly getting stuck in wet mud. This potential problem causes scientists to theorize that S. lagrelii lived in an open, semi-arid environment in northern China.
Stories of these unicorn-like rhinos are prominent throughout Chinese mythology. Known as k’i-lin, stories of the animal were supposedly adopted by Turkish and Mongolian cultures. Other unicorn-type creatures – some mythic, some possibly historical – are also found throughout ancient Chinese culture.
The elasmothere’s modern-day relatives continue to struggle in the face of threats from poaching and destruction of their habitat. According to South African officials, the number of rhinos killed since the start of 2013 has risen to 428. During the same time span, officials have arrested 122 individuals for rhino poaching. Officials said 57 were caught in the country’s Kruger National Park. Five people in possession of rhino horns were also arrested.
“On Sunday, Kruger National Park rangers made contact with a group of three poachers near Letaba,” a government spokesperson said. “One poacher was wounded during the shoot-out and later died of his wounds. The other poachers managed to escape.”
Kruger alone has lost 267 rhinos to poachers this year. One of the largest game reserves in Africa, the park’s anti-poaching unit consists of 650 rangers who employ automated movement sensors along the Mozambique border, drone helicopters, and a special dog unit to fend off poachers.
Note : The above story is reprinted from materials provided by Brett Smith for redOrbit
Book Name : 3-D Structural Geology
A Practical Guide to Quantitative Surface
and Subsurface Map Interpretation
Second Edition By : Richard H. Groshong, Jr. Author
Richard H. Groshong, Jr.
University of Alabama
and
3-D Structure Research
10641 Dee Hamner Rd.
Northport, AL 35475
USA
E-mail: [email protected]
Library of Congress Control Number: 2005937627
ISBN-10 3-540-31054-1 Springer Berlin Heidelberg New York
ISBN-13 978-3-540-31054-9 Springer Berlin Heidelberg New York
ISBN 3-540-65422-4 (first edition) Springer Berlin Heidelberg New York
Gold, 6.8 cm high, Homestake Mine, Salmon River District, Siskiyou County. California State Mining and Mineral Museum.
Northwestern University scientists have struck gold in the laboratory. They have discovered an inexpensive and environmentally benign method that uses simple cornstarch — instead of cyanide — to isolate gold from raw materials in a selective manner.
This green method extracts gold from crude sources and leaves behind other metals that are often found mixed together with the crude gold. The new process also can be used to extract gold from consumer electronic waste.
Current methods for gold recovery involve the use of highly poisonous cyanides, often leading to contamination of the environment. Nearly all gold-mining companies use this toxic gold leaching process to sequester the precious metal.
“The elimination of cyanide from the gold industry is of the utmost importance environmentally,” said Sir Fraser Stoddart, the Board of Trustees Professor of Chemistry in the Weinberg College of Arts and Sciences. “We have replaced nasty reagents with a cheap, biologically friendly material derived from starch.”
Sir Fraser’s team discovered the process by accident, using simple test tube chemistry. A series of rigorous follow-up investigations provided evidence for the competitive strength of the new procedure.
The findings will be published May 14 in the online journal Nature Communications.
Zhichang Liu, a postdoctoral fellow in Stoddart’s lab and first author of the paper, took two test tubes containing aqueous solutions — one of the starch-derived alpha-cyclodextrin, the other of a dissolved gold (Au) salt (called aurate) — and mixed them together in a beaker at room temperature.
Liu was trying to make an extended, three-dimensional cubic structure, which could be used to store gases and small molecules. Unexpectedly, he obtained needles, which formed rapidly upon mixing the two solutions.
“Initially, I was disappointed when my experiment didn’t produce cubes, but when I saw the needles, I got excited,” Liu said. “I wanted to learn more about the composition of these needles.”
“Nature decided otherwise,” said Stoddart, a senior author of the paper. “The needles, composed of straw-like bundles of supramolecular wires, emerged from the mixed solutions in less than a minute.”
After discovering the needles, Liu screened six different complexes — cyclodextrins composed of rings of six (alpha), seven (beta) and eight (gamma) glucose units, each combined with aqueous solutions of potassium tetrabromoaurate (KAuBr4) or potassium tetrachloroaurate (KAuCl4).
He found that it was alpha-cyclodextrin, a cyclic starch fragment composed of six glucose units, that isolates gold best of all.
“Alpha-cyclodextrin is the gold medal winner,” Stoddart said. “Zhichang stumbled on a piece of magic for isolating gold from anything in a green way.”
Alkali metal salt waste from this new method is relatively environmentally benign, Stoddart said, while waste from conventional methods includes toxic cyanide salts and gases. The Northwestern procedure is also more efficient than current commercial processes.
The supramolecular nanowires, each 1.3 nanometers in diameter, assemble spontaneously in a straw-like manner. In each wire, the gold ion is held together in the middle of four bromine atoms, while the potassium ion is surrounded by six water molecules; these ions are sandwiched in an alternating fashion by alpha-cyclodextrin rings. Around 4,000 wires are bundled parallel to each other and form individual needles that are visible under an electron microscope.
“There is a lot of chemistry packed into these nanowires,” Stoddart said. “The elegance of the composition of single nanowires was revealed by atomic force microscopy, which throws light on the stacking of the individual donut-shaped alpha-cyclodextrin rings.”
The atomic detail of the single supramolecular wires and their relative disposition within the needles was uncovered by single crystal X-ray crystallography.
The research — a prime example of serendipity at work, brought to fruition by contemporary fundamental science — is poised to find technological application. This basic science has been forged by the team into a practical labscale process for the isolation of gold from scrap alloys.
Note : The above story is reprinted from materials provided by Northwestern University, via EurekAlert!, a service of AAAS.
DURHAM, NC — Homeowners living within one kilometer of shale gas wells appear to be at higher risk of having their drinking water contaminated by stray gases, according to a new Duke University-led study.
Duke scientists analyzed 141 drinking water samples from private water wells across northeastern Pennsylvania’s gas-rich Marcellus shale basin. Their study documented not only higher methane concentrations in drinking water within a kilometer of shale gas drilling — which past studies have shown — but higher ethane and propane concentrations as well.
Methane concentrations were six times higher and ethane concentrations were 23 times higher at homes within a kilometer of a shale gas well. Propane was detected in 10 samples, all of them from homes within a kilometer of drilling.
“The methane, ethane and propane data, and new evidence from hydrocarbon and helium isotopes, all suggest that drilling has affected some homeowners’ water,” said Robert B. Jackson, a professor of environmental sciences at Duke’s Nicholas School of the Environment. “In a minority of cases, the gas even looks Marcellus-like, probably caused by faulty well construction.”
The ethane and propane contamination data are “new and hard to refute,” Jackson stressed. “There is no biological source of ethane and propane in the region and Marcellus gas is high in both, and higher in concentration than the Upper Devonian gas found in-between.”
The team examined which factors might explain their results, including topography, distance to gas wells and distance to geologic features. “Distance to gas wells was, by far, the most significant factor influencing gases in the drinking water we sampled,” said Jackson.
The peer-reviewed findings will appear this week in the online Early Edition of the Proceedings of the National Academy of Sciences.
Hydraulic fracturing, also called hydrofracking or fracking, involves pumping water, sand and chemicals deep underground into horizontal gas wells at high pressure to crack open hydrocarbon-rich shale and extract natural gas. Accelerated shale gas drilling and hydrofracking in recent years has fueled concerns about contamination in nearby drinking water supplies.
Two previous peer-reviewed studies by Duke scientists found direct evidence of methane contamination in water wells near shale-gas drilling sites in northeastern Pennsylvania, as well as possible connectivity between deep brines and shallow aquifers. A third study conducted with U.S. Geological Survey scientists found no evidence of drinking water contamination from shale gas production in Arkansas. None of the studies have found evidence of contamination by fracking fluids.
“Our studies demonstrate that distances from drilling sites, as well as variations in local and regional geology, play major roles in determining the possible risk of groundwater impacts from shale gas development,” said Avner Vengosh, professor of geochemistry and water quality at Duke’s Nicholas School. “As such, they must be taken into consideration before drilling begins.”
“The helium data in this study are the first from a new tool kit we’ve devised for identifying contamination using noble gas isotopes,” said Duke research scientist Thomas H. Darrah. “These tools allow us to identify and trace contaminants with a high degree of certainty.”
Note : The above story is reprinted from materials provided by Duke University
Secret Chamber inside of Clearwater Connection cave in Gunung Mulu National Park. (Credit: Syria Lejau)
A new set of long-term climate records based on cave stalagmites collected from tropical Borneo shows that the western tropical Pacific responded very differently than other regions of the globe to abrupt climate change events. The 100,000-year climate record adds to data on past climate events, and may help scientists assess models designed to predict how Earth’s climate will respond in the future
The new record resulted from oxygen isotope analysis of more than 1,700 calcium carbonate samples taken from four stalagmites found in three different northern Borneo caves. The results suggest that climate feedbacks within the tropical regions may amplify and prolong abrupt climate change events that were first discovered in the North Atlantic.
The results were scheduled to be published June 6 in Science Express, the electronic advance online publication of the journal Science, and will appear later in an issue of printed publication. The research was supported by the National Science Foundation.
Today, relatively subtle changes in the tropical Pacific’s ocean and atmosphere have profound effects on global climate. However, there are few records of past climate changes in this key region that have the length, resolution and age controls needed to reveal the area’s response to abrupt climate change events.
“This is a new record from a very important area of the world,” said Kim Cobb, an associate professor in the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology. “This record will provide a new piece of the puzzle from the tropical Pacific showing us how that climate system has responded to forcing events over the past 100,000 years.”
Among the findings were some surprises that show just how complicated Earth’s climate system can be. While the stalagmite record reflected responses to abrupt changes known as Heinrich events, another major type of event — known as Dansgaard-Oeschger excursions — left no evidence in the Borneo stalagmites. Both types of abrupt climate change events are prominently featured in a previously-published stalagmite climate record from China — which is only slightly north of Borneo.
“To my knowledge, this is the first record that so clearly shows sensitivity to one set of major abrupt climate change events and not another,” said Cobb. “These two types of abrupt change events appear to have different degrees of tropical Pacific involvement, and because the tropical Pacific speaks with such a loud voice when it does speak, we think this is extremely important for understanding the mechanisms underlying these events.”
The researchers were also surprised to discover a very large and abrupt signal in their stalagmite climate records precisely when super-volcano Toba erupted nearby, roughly 74,000 years ago.
The team recovered the stalagmites from caves in Gunung Mulu and Gunung Buda National Parks, in northern Borneo, which is located a few degrees north of the Equator in the western Pacific. Back at their Georgia Tech lab, they analyzed the stalagmites for the ratio of oxygen isotopes contained in samples of calcium carbonate, the material from which the stalagmites were formed. That ratio is set by the oxygen isotopes in rainfall at the site, as the water that seeped into the ground dissolved limestone rock and dripped into the caves to form the stalagmites. The stalagmites accumulate at a rate of roughly one centimeter every thousand years.
“Stalagmites are time capsules of climate signals from thousands of years in the past,” said Stacy Carolin, a Georgia Tech Ph.D. candidate who gathered and analyzed the stalagmites. “We have instrumental records of climate only for the past 100 years or so, and if we want to look deeper into the past, we have to find records like these that locked in climate signals we can extract today.”
In the laboratory, Carolin sawed each stalagmite in half, opening it like a hot dog bun. She then used a tiny drill bit to take samples of the calcium carbonate down the center at one-millimeter steps. Because the stalagmites grew at varying rates, each sample represented as little as 60 years of time, or as much as 200 years. The precise ages of the samples were determined by measuring uranium and thorium isotope ratios, an analysis done with the help of Jess F. Adkins, a professor at the California Institute of Technology and a co-author of the study.
Rainfall oxygen isotopic ratios are good indicators of the amount of rainfall occurring throughout the region, as determined by a modern-day calibration study recently published by another graduate student in Cobb’s lab.
Merging data from the four different stalagmites provided a record of precipitation trends in the western Pacific over the past 100,000 years. That information can be compared to stalagmite and ice core climate records obtained elsewhere in the world.
“This record, which spans the entire last glacial period, adds significantly to the understanding of how various climate forcings are felt by the western tropical Pacific,” Carolin added.
Climate scientists are interested in learning more about abrupt climate changes because they indicate that the climate system may have “tipping points.” So far, the climate system has responded to rising carbon dioxide levels at a fairly steady rate, but many scientists worry about possible nonlinear effects.
“As a society, we haven’t really thought enough about the fact that we are moving Earth’s climate system toward a new state very quickly,” said Cobb. “It’s important to remember that the climate system has important nonlinearities that are most evident in these abrupt climate events. Ultimately, we’d like to be able to reproduce the global signatures of these abrupt climate events with numerical models of the climate system, and investigate the physics that drive such events.”
For Carolin, studying the half-meter-long stalagmites brought an awareness that Earth has not always been as we know it today.
“You have to be impressed with the scope of what you are studying, and recognize that the state our climate is in today is incredibly different from Earth’s climate during the last Ice Age,” she said. “As we consider how humans may be affecting climate, dissecting what was going on tens of thousands of years ago in all regions of the globe can help scientists better predict how the Earth will respond to modern climate forcings.”
In addition to those already mentioned, the research team included Brian Clark, manager of the Gunung Mulu National Park where the samples were gathered; Syria Lejau and Jenny Malang, Gunung Mulu cave guides who aided in sample collection; Jessica Conroy, a Georgia Tech postdoctoral fellow; and Andrew Tuen, a professor at the Universiti Malaysia Sarawak.
This research was funded by the National Science Foundation through PECASE Award ATM-0645291. The findings and conclusions are those of the authors and do not necessarily represent the official views of the NSF.
Note : The above story is reprinted from materials provided by Georgia Institute of Technology. The original article was written by John Toon.
Artist impression of Broomistega seeking shelter in Thrinaxodon’s burrow. (Credit: Image courtesy of University of the Witwatersrand)
Scientists from South Africa, Australia and France have discovered a world first association while scanning a 250 million year old fossilised burrow from the Karoo Basin of South Africa.
The burrow revealed two unrelated vertebrate animals nestled together and fossilised after being trapped by a flash flood event. Facing harsh climatic conditions subsequent to the Permo-Triassic (P-T) mass extinction, the amphibian Broomistega and the mammal forerunner Thrinaxodon cohabited in a burrow.
Scanning shows that the amphibian, which was suffering from broken ribs, crawled into a sleeping mammal’s shelter for protection. This research suggests that short periods of dormancy, called aestivation, in addition to burrowing behaviour, may have been a crucial adaptation that allowed mammal ancestors to survive the P-T extinction.
The international team of scientists was led by Dr Vincent Fernandez from Wits University, South Africa and the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. The other authors from Wits University include Prof. Bruce Rubidge (Director of the newly formed Palaeosciences Centre of Excellence at Wits), Dr Fernando Abdala and Dr Kristian Carlson. Other authors include Dr Della Collins Cook (Indiana University); Dr Adam Yates (Museum of Central Australia) and Dr. Paul Tafforeau (ESRF).
After many impressive results obtained on fossils, synchrotron imaging has led to revived interest in the studies of the numerous fossilised burrows discovered in the Karoo Basin of South Africa and dated to 250 million years ago. The first attempt to investigate one of these burrow-casts surprisingly revealed a world-first association of two unrelated animals.
The fossil was recovered from sedimentary rock strata in the Karoo Basin. It dates from 250 million years ago, at the beginning of the Triassic Period. At that time, the ecosystem was recovering from the Permo-Triassic mass extinction that wiped out most of life on Earth. In the Pangea Supercontinent context, what is now South Africa was an enclave in the southern half called Gondwana. It was the scene of pronounced climatic warming and increased seasonality marked by monsoonal rainfall. To survive this harsh environment, many animals, including mammal-like reptiles (mammal forerunners), developed a digging behaviour, attested by the numerous fossilised burrow casts discovered in the Karoo Basin. These casts have long been thought to enclose fossilised remains, triggering interest from palaeontologists. Early this year, an international group of scientists started to research the contents of these burrows using X-ray synchrotron computed microtomography.
Two burrow casts were selected from the collection at Wits to be scanned using the state-of-the-art facility at the European Synchrotron Radiation Facility (ESRF). Using the unique properties of the X-ray beam which enables non-destructive probing, the scan of the first burrow started to reveal the skull of a mammal-like reptile called Thrinaxodon, an animal previously reported in another burrow.
As the scan progressed, the three-dimensional reconstruction displayed results beyond expectations: the mammal-like reptile was accompanied by an amphibian Broomistega, belonging to the extinct group of Temnospondyl.
“While discovering the results we were amazed by the quality of the images,” says lead author Fernandez, “but the real excitement came when we discovered a second set of teeth completely different from that of the mammal-like reptile. It was really something else.”
Besides the pristine preservation of the two skeletons, the team focused on the reasons explaining such an unusual co-habitation. Fernandez explains: “Burrow-sharing by different species exists in the modern world, but it corresponds to a specific pattern. For example, a small visitor is not going to disturb the host. A large visitor can be accepted by the host if it provides some help, like predator vigilance. But neither of these patterns corresponds to what we have discovered in this fossilised burrow.”
The scientists gathered all the information to try to reconstitute the events that led to this incredible fossil aggregation, testing scenarios one after another. “It’s a fascinating scientific question: what caused the association of these two organisms in the burrow? One of the more obvious possibilities is a predator-prey interaction, but we inspected both skeletons looking for tooth marks or other evidence implying predation, ultimately finding no support for one having attempted to feed on the other,” says Carlson.
His colleague, Cook, adds that the consecutive broken ribs resulted from a single, massive trauma. The amphibian clearly survived the injury for some time because the fractures were healing, but it was surely quite handicapped. According to Fernandez this Broomistega is the first complete skeleton of this rare species that has been discovered. “It tells us that this individual was a juvenile and mostly aquatic at that time of its life,” he says.
The scientists eventually concluded that the amphibian crawled into the burrow in response to its poor physical condition but was not evicted by the mammal-like reptile.
Numerous Thrinaxodon specimens have been found in South Africa, many of them fossilised in a curled-up position. Abdala says: “I have always been fascinated by the preservation of Thrinaxodon fossils in a curled-up position that show even tiny bones of the skeleton preserved. It’s as if they were peacefully resting in shelters at the time of death.”
The shelters prevented disturbance of the skeletal remains from scavengers and weathering. “We also think it might reflect a state of torpor called aestivation in response to aridity and absence of food resources,” Abdala says.
Piecing all the clues together, the team finally elucidated the enigmatic association, concluding that “the mammal-like reptile, Thrinaxodon, was most probably aestivating in its burrow, a key adaptation response together with a burrowing behaviour which enabled our distant ancestors to survive the most dramatic mass extinction event. This state of torpor explains why the amphibian was not chased out of the burrow,” says Rubidge.
Both animals were finally entrapped in the burrow by a sudden flood and preserved together in the sediments for 250 million years.
Tafforeau says: “Thanks to the unique possibilities for high quality imaging of fossils developed during the last decade at the ESRF, these unique specimens remain untouched, protected by their mineral matrix. Who knows what kind of information we’ll be able to obtain from them in the future and which would have been completely lost if the specimen had been prepared out of its burrow cast?”
Note : The above story is reprinted from materials provided by University of the Witwatersrand.
The Yangtze River, or Chang Jiang is the longest river in Asia, and the third longest in the world. It flows for 6,418 kilometres (3,988 mi) from the glaciers on the Qinghai-Tibet Plateau in Qinghai eastward across southwest, central and eastern China before emptying into the East China Sea at Shanghai. It is also one of the biggest rivers by discharge volume in the world. The Yangtze drains one-fifth of the land area of the People’s Republic of China (PRC) and its river basin is home to one-third of the PRC’s population.
Along with the Yellow River, the Yangtze is the most important river in the history, culture and economy of China. The prosperous Yangtze River Delta generates as much as 20% of the PRC’s GDP. The Yangtze River flows through a wide array of ecosystems and is itself habitat to several endemic and endangered species including the Chinese alligator and the Yangtze sturgeon. For thousands of years, people have used the river for water, irrigation, sanitation, transportation, industry, boundary-marking and war. The Three Gorges Dam on the Yangtze River is the largest hydro-electric power station in the world.
In recent years, the river has suffered from industrial pollution, agricultural run-off, siltation, and loss of wetland and lakes, which exacerbates seasonal flooding. Some sections of the river are now protected as nature reserves. A stretch of the Yangtze flowing through deep gorges in western Yunnan is part of the Three Parallel Rivers of Yunnan Protected Areas, a UNESCO World Heritage Site.
Geography
The river originates from several tributaries, two of which have claims to be the source. The Chinese
Yangtze watershed
government has recognized the source of the Tuotuo tributary at the base of a glacier lying on the west of Geladandong Mountain in the Dangla Mountain Range on the eastern part of the Qinghai-Tibet Plateau. However, the geographical source (i.e., longest river distance from the sea) lies in wetlands at 32°36′14″N 94°30′44″E and 5,170 m (16,960 ft) above sea level at the head of the Dan Qu tributary. These tributaries join and the river then runs eastward through Qinghai, turning southward down a deep valley at the border of Sichuan and Tibet to reach Yunnan. In the course of this valley, the river’s elevation drops from above 5,000 m (16,000 ft) to less than 1,000 m (3,300 ft). The headwaters of the Yangtze are situated at an elevation of about 4,900 m (16,100 ft). In its descent to sea level, the river falls to an altitude of 305 m (1,001 ft) at Yibin, Sichuan, the head of navigation for riverboats, and to 192 m (630 ft) at Chongqing. Between Chongqing and Yichang (I-ch’ang), at an altitude of 40 m (130 ft) and a distance of about 320 km (200 mi), it passes through the spectacular Yangtze Gorges, which are noted for their natural beauty but are dangerous to shipping.
It enters the basin of Sichuan at Yibin. While in the Sichuan basin, it receives several mighty tributaries, increasing its water volume significantly. It then cuts through Mount Wushan bordering Chongqing and Hubei to create the famous Three Gorges. Eastward of the Three Gorges, Yichang is the first city on the Yangtze Plain.
After entering Hubei, the Yangtze receives more water from thousands of lakes. The largest of these lakes is Dongting Lake, which is located on the border of Hunan and Hubei provinces, and is the outlet for most of the rivers in Hunan. At Wuhan, it receives its biggest tributary, the Han River, bringing water from its northern basin as far as Shaanxi.
At the northern tip of Jiangxi, Lake Poyang, the biggest freshwater lake in China, merges into the river. The river then runs through Anhui and Jiangsu provinces, receiving more water from innumerable smaller lakes and rivers, and finally reaches the East China Sea at Shanghai.
Four of China’s five main freshwater lakes contribute their waters to the Yangtze River. Traditionally, the upstream part of the Yangtze River refers to the section from Yibin to Yichang; the middle part refers to the section from Yichang to Hukou County, where Lake Poyang meets the river; the downstream part is from Hukou to Shanghai. It is home to many thousands of people.
The origin of the Yangtze River is dated to about 45 million years ago in the Eocene, but many people do not accept this point.
Photo :
The first turn of the Yangtze (Changjiang) at Shigu (石鼓), Yunnan Province, where the river turns 180 degree from south- to north-boundThe Yangtze river as seen from the Beijing-Lhasa train, on the so-called “First Bridge”
.
The Yangtze is open to navigation all the year around. The picture to the left features one of the so-called “Three Gorges,” dangerous to navigate because of its currents and shallows, but of incredible beauty. China Pictorial, ed., Across China (Beijing: China Pictorial Publishing Company, 1985),The picture to the right shows the Yangtze River flowing into the sea near the biggest city in China, Shanghai. Lu Yinghui, Xinbian Shanghai daguan (Shanghai: Shanghai shehui kexueyuan chuban she, 1993)
Note : The above story is reprinted from materials provided by Wikipedia
Earthquake researchers have now identified a 30 kilometers long and ten kilometers deep area along the North Anatolian fault zone just south of Istanbul that could be the starting point for a strong earthquake. The group of seismologists including Professor Marco Bohnhoff of the GFZ German Research Centre for Geosciences reported in the current online issue of the scientific journal Nature Communications that this potential earthquake source is only 15 to 20 kilometers from the historic city center of Istanbul.
The Istanbul-Marmara region of northwestern Turkey with a population of more than 15 million faces a high probability of being exposed to an earthquake of magnitude 7 or more. To better understand the processes taking place before a strong earthquake at a critically pressurized fault zone, a seismic monitoring network was built on the Princes Islands in the Sea of Marmara off Istanbul under the auspices of the Potsdam Helmholtz Centre GFZ together with the Kandilli Earthquake Observatory in Istanbul. The Princes Islands offer the only opportunity to monitor the seismic zone running below the seafloor from a distance of few kilometers.
The now available data allow the scientists around GFZ researcher Marco Bohnhoff to come to the conclusion that the area is locked in depth in front of the historic city of Istanbul: “The block we identified reaches ten kilometers deep along the fault zone and has displayed no seismic activity since measurements began over four years ago. This could be an indication that the expected Marmara earthquake could originate there,” says Bohnhoff.
This is also supported by the fact that the fracture zone of the last strong earthquake in the region, in 1999, ended precisely in this area — probably at the same structure, which has been impeding the progressive shift of the Anatolian plate in the south against the Eurasian plate in the north since 1766 and building up pressure. The results are also being compared with findings from other fault zones, such as the San Andreas Fault in California, to better understand the physical processes before an earthquake.
Currently, the GFZ is intensifying its activity to monitor the earthquake zone in front of Istanbul. Together with the Disaster and Emergency Management Presidency of Turkey AFAD, several 300 meter deep holes are currently being drilled around the eastern Marmara Sea, into which highly sensitive borehole seismometers will be placed. With this Geophysical borehole Observatory at the North Anatolian Fault GONAF, measurement accuracy and detection threshold for microearthquakes are improved many times over. In addition, the new data also provide insights on the expected ground motion in the event of an earthquake in the region. Bohnhoff: “Earthquake prediction is scientifically impossible. But studies such as this provide a way to better characterize earthquakes in advance in terms of location, magnitude and rupture progression, and therefore allow a better assessment of damage risk.”
Note : The above story is reprinted from materials provided by Helmholtz Centre Potsdam – GFZ German Research Centre for Geosciences.
NOAA/NGDC image of the Atlantic crustal age of the ocean floor. Geologists have detected the first evidence that a passive margin in the Atlantic ocean is becoming active. The team mapped the ocean floor and found it was beginning to fracture, indicating tectonic activity around the apparently passive South West Iberia plate margin. (Credit: Mr. Elliot Lim and Mr. Jesse Varner, CIRES & NOAA/NGDC)
A new subduction zone forming off the coast of Portugal heralds the beginning of a cycle that will see the Atlantic Ocean close as continental Europe moves closer to America.
Published in Geology, new research led by Monash University geologists has detected the first evidence that a passive margin in the Atlantic ocean is becoming active. Subduction zones, such as the one beginning near Iberia, are areas where one of the tectonic plates that cover Earth’s surface dives beneath another plate into the mantle — the layer just below the crust.
Lead author Dr João Duarte, from the School of Geosciences said the team mapped the ocean floor and found it was beginning to fracture, indicating tectonic activity around the apparently passive South West Iberia plate margin.
“What we have detected is the very beginnings of an active margin — it’s like an embryonic subduction zone,” Dr Duarte said.
“Significant earthquake activity, including the 1755 quake which devastated Lisbon, indicated that there might be convergent tectonic movement in the area. For the first time, we have been able to provide not only evidences that this is indeed the case, but also a consistent driving mechanism.”
The incipient subduction in the Iberian zone could signal the start of a new phase of the Wilson Cycle — where plate movements break up supercontinents, like Pangaea, and open oceans, stabilise and then form new subduction zones which close the oceans and bring the scattered continents back together.
This break-up and reformation of supercontinents has happened at least three times, over more than four billion years, on Earth. The Iberian subduction will gradually pull Iberia towards the United States over approximately 220 million years.
The findings provide a unique opportunity to observe a passive margin becoming active — a process that will take around 20 million years. Even at this early phase the site will yield data that is crucial to refining the geodynamic models.
“Understanding these processes will certainly provide new insights on how subduction zones may have initiated in the past and how oceans start to close,” Dr Duarte said.
Note : The above story is reprinted from materials provided by Monash University.
A “cold snap” 116 million years ago triggered a similar marine ecosystem crisis to the ones witnessed in the past as a result of global warming, according to new research. (Credit: Copyright Michele Hogan)
A “cold snap” 116 million years ago triggered a similar marine ecosystem crisis to the ones witnessed in the past as a result of global warming, according to research published in Nature Geoscience.
The international study involving experts from the universities of Newcastle, UK, Cologne, Frankfurt and GEOMAR-Kiel, confirms the link between global cooling and a crash in the marine ecosystem during the mid-Cretaceous greenhouse period.
It also quantifies for the first time the amplitude and duration of the temperature change. Analysing the geochemistry and micropaleontology of a marine sediment core taken from the North Atlantic Ocean, the team show that a global temperature drop of up to 5oC resulted in a major shift in the global carbon cycle over a period of 2.5 million years.
Occurring during a time of high tectonic activity that drove the breaking up of the super-continent Pangaea, the research explains how the opening and widening of new ocean basins around Africa, South America and Europe created additional space where large amounts of atmospheric CO2 was fixed by photosynthetic organisms like marine algae. The dead organisms were then buried in the sediments on the sea bed, producing organic, carbon rich shale in these new basins, locking away the carbon that was previously in the atmosphere.
The result of this massive carbon fixing mechanism was a drop in the levels of atmospheric CO2, reducing the greenhouse effect and lowering global temperature.
This period of global cooling came to an end after about 2 million years following the onset of a period of intense local volcanic activity in the Indian Ocean. Producing huge volumes of volcanic gas, carbon that had been removed from the atmosphere when it was locked away in the shale was replaced with CO2 from Earth’s interior, re-instating a greenhouse effect which led to warmer climate and an end to the “cold snap.”
The research team highlight in this study how global climate is intrinsically linked to processes taking place in Earth’s interior at million year time scales. These processes can modify ecospace for marine life, driving evolution.
Current research efforts tend to concentrate on global warming and the impact that a rise of a few degrees might have on past and present day ecosystems. This study shows that if global temperatures swing the other way by a similar amount, the result can be just as severe, at least for marine life.
However, the research team emphasise that the observed changes of the Earth system in the Cretaceous happened over millions of years, rather than decades or centennial, which cannot easily be related to our rapidly changing modern climate conditions.
“As always it’s a question of fine balance and scale,” explains Thomas Wagner, Professor of Earth Systems Science at Newcastle University, and one of the leaders of this study.
“All earth system processes are operating all the time and at different temporal and spatial scales; but when something upsets the balance — be it a large scale but long term natural phenomenon or a short and massive change to global greenhouse gases due to anthropogenic activity — there are multiple, potential knock-on effects on the whole system.
“The trick is to identify and quantify the initial drivers and consequences, which remains an ongoing challenge in climate research.”
Note : The above story is reprinted from materials provided by Newcastle University.
This is an alternative version with a pircture depicting the location in the fossil fish — virtual thin section made in a nodule showing preserved bundles of muscles attached to the skull plate of a placoderm (fossil armored fish). (Credit: ESRF/Sophie Sanchez)
Swedish, Australian and French researchers present for the first time miraculously preserved musculature of 380 million year old armoured fish discovered in north-west Australia. This research will help scientists to better understand how neck and abdominal muscles evolved during the transition from jawless to jawed vertebrates.
The scientific paper describing the discovery is published today in the journal Science.
The team of scientists who studied the fossilised fish was jointly directed by Prof. Kate Trinajstic, Curtin University, Perth, Australia and Prof. Per Erik Ahlberg of Uppsala University Sweden. The team also included scientists from the European Synchrotron Radiation Facility (ESRF), Grenoble, France; the Western Australian Museum, Perth; Flinders University, Adelaide; the Research School of Earth Sciences at the Australian National University, Canberra; the Research School of Physics and Engineering at the Australian National University; and the Australian Regenerative Medicine Institute, Monash University, Australia.
The word “fossil” naturally conjures up a vision of rattling skeletons. Bones and teeth fossilise far more easily than soft tissues and are usually the only traces of the animal that remain. This makes the rare fossils of soft tissues all the more valuable as windows to the biology of extinct organisms. Such tissues almost never fossilise and scientists usually have to extrapolate skin coverings and musculature from knowledge of modern organisms and from the fossilised skeletons.
The Gogo Formation, a sedimentary rock formation in north-western Australia, has long been famous for yielding exquisitely preserved fossil fish. Among other things it contains placoderms, an extinct group that includes some of the earliest jawed fish.
A few years ago, an Australian research team work led by Prof. Trinajstic made the remarkable discovery that these fossils also contained soft tissues including nerve and muscle cells. Now they have collaborated with the research group of Professor Per Ahlberg, Uppsala University, and with the European Synchrotron (ESRF) in Grenoble, France, to document and reconstruct the musculature of the placoderms. “High contrast X-ray images were produced thanks to a powerful beam and a protocol developed for fossil imaging at the ESRF. This is unique in the world and has enabled us to “reconstruct” some fossilised muscles and document the muscles of neck and abdomen in these early jawed fish, without damaging or affecting the fossilised remains,” says Sophie Sanchez, one of the authors, from the ESRF and Uppsala University.
These early vertebrates prove to have a well-developed neck musculature as well as powerful abdominal muscles — not unlike some human equivalents displayed on the beaches of the world every summer. Living fish, by contrast, usually have a rather simple body musculature without such specialisations.
“This shows that vertebrates developed a sophisticated musculature much earlier than we had thought” says Per Ahlberg, co-author of the project. “It also cautions against thinking that we can interpret fossil organisms simply by metaphorically draping their skeletons in the soft tissues of living relatives.”
Note : The above story is reprinted from materials provided by European Synchrotron Radiation Facility, via EurekAlert!, a service of AAAS.
The holotypes of the species recognized as valid by the researchers, put to the same scale, illustrate how diverse this pterosaur fauna was. (Credit: Dr. Taissa Rodrigues & NHMUK PV 39412, NHMUK PV R 1822, NHMUK PV 39409 and NHMUK PV 43074 – Natural History Museum)
Brazilian paleontologists Taissa Rodrigues, of the Federal University of Espirito Santo, and Alexander W. A. Kellner, of the National Museum of the Federal University of Rio de Janeiro, have just presented the most extensive review yet available of toothed pterosaurs from the Cretaceous of England. The study features detailed taxonomic information, diagnoses and photographs of 30 species and was published in the open access journal ZooKeys.
Pterosaurs from the Cretaceous of England were first described by British naturalists Richard Owen and Harry Seeley in the 19th century, when little was known about the diversity of the group, resulting in the description of dozens of species, all based on very fragmentary remains, represented mostly by the tips of the snouts of these animals. However, more recent findings of pterosaur fossils have challenged views on their diversity.
Results show that these pterosaurs had a remarkable diversity in their appearances. Some species had head crests of different sizes and shapes, while others had none. Most had large teeth at the tip of their snouts and were fish eaters, but others had smaller teeth, suggesting different feeding preferences. The paleontologists were able to identify fourteen different species, belonging to at least five different genera, showing a greater diversity than previously thought.
Most of these fossils were found in a deposit known as the Cambridge Greensand, located in the eastern part of the country. This unit, one of the most important for the study of flying reptiles, records a past marine environment where the bones that were already fossilized and buried, were eroded, exposed to weathering, and then buried again. Cycles of erosion and burial must have taken place during several years. Due to this peculiarity, the pterosaur assemblage from this deposit probably presents temporal mixing of faunas, thus explaining the high diversity found.
Another find was that these English flying reptiles turned out to be closely related to species unearthed in northeastern Brazil and eastern China. According to Dr. Rodrigues, ‘This is very interesting, especially because the continents had already drifted apart. If these animals were migratory, we would expect to find the same species in all these deposits.’ Instead, the scientists have discovered that England, Brazil and China all had their own species and genera.
Analysis of fossils from other continents showed that this group of pterosaurs was already widespread in the whole planet 110 million years ago, and must have been important faunistic elements at this time of the Cretaceous period, being early bird competitors, before they went extinct a few million years later.
Note : The above story is reprinted from materials provided by Pensoft Publishers. The original story is licensed under a Creative Commons License.
Checking core samples in the lab. (Credit: Dan Anthon, Royal Roads University)
Understanding the size and frequency of large earthquakes along the Pacific coast of North America is of great importance, not just to scientists, but also to government planners and the general public. The only way to predict the frequency and intensity of the ground motion expected from large and giant “megathrust ” earthquakes along Canada’s west coast is to analyze the geologic record.
A new study published today in the Canadian Journal of Earth Sciences presents an exceptionally well-dated first record of earthquake history along the south coast of BC. Using a new high-resolution age model, a team of scientists meticulously identified and dated the disturbed sedimentary layers in a 40-metre marine sediment core raised from Effingham Inlet. The disturbances appear to have been caused by large and megathrust earthquakes that have occurred over the past 11,000 years.
One of the co-authors of the study, Dr. Audrey Dallimore, Associate Professor at Royal Roads University explains: “Some BC coastal fjords preserve annually layered organic sediments going back all the way to deglacial times. In Effingham Inlet, on the west coast of Vancouver Island, these sediments reveal disturbances we interpret were caused by earthquakes. With our very detailed age model that includes 68 radiocarbon dates and the Mazama Ash deposit (a volcanic eruption that took place 6800 yrs ago); we have identified 22 earthquake shaking events over the last 11,000 years, giving an estimate of a recurrence interval for large and megathrust earthquakes of about 500 years. However, it appears that the time between major shaking events can stretch up to about a 1,000 years.
“The last megathrust earthquake originating from the Cascadia subduction zone occurred in 1700 AD. Therefore, we are now in the risk zone of another earthquake. Even though it could be tomorrow or perhaps even centuries before it occurs, paleoseismic studies such as this one can help us understand the nature and frequency of rupture along the Cascadia Subduction Zone, and help Canadian coastal communities to improve their hazard assessments and emergency preparedness plans.”
“This exceptionally well-dated paleoseismic study by Enkin et al., involved a multi-disciplinary team of Canadian university and federal government scientists, and a core from the 2002 international drill program Marges Ouest Nord Américaines (MONA) campaign,” says Dr. Olav Lian, an associate editor of the Canadian Journal of Earth Sciences, professor at the University of the Fraser Valley and Director of the university’s Luminescence Dating Laboratory. “It gives us our first glimpse back in geologic time, of the recurrence interval of large and megathrust earthquakes impacting the vulnerable BC outer coastline. It also supports paleoseismic data found in offshore marine sediment cores along the US portion of the Cascadia Subduction Zone, recently released in an important United States Geological Survey (USGS) paleoseismic study by a team of researchers led by Dr. Chris Goldfinger of Oregon State University.
In addition to analyzing the Effingham Inlet record for earthquake events, this study site has also revealed much information about climate and ocean changes throughout the Holocene to the present. These findings also clearly illustrate the importance of analyzing the geologic record to help today’s planners and policy makers, and ultimately to increase the resiliency of Canadian communities. ”
Note : The above story is reprinted from materials provided by Canadian Science Publishing (NRC Research Press).
Electron microscope image showing the 700-million-year-old Martian clay veins containing boron (100 µm = one tenth of a millimeter). (Credit: Image courtesy of Institute for Astronomy at the University of Hawaii at Manoa)
Researchers from the University of Hawaii at Manoa NASA Astrobiology Institute (UHNAI) have discovered high concentrations of boron in a Martian meteorite. When present in its oxidized form (borate), boron may have played a key role in the formation of RNA, one of the building blocks for life.
The work was published on June 6 in PLOS ONE.
The Antarctic Search for Meteorites team found the Martian meteorite used in this study in Antarctica during its 2009-2010 field season. The minerals it contains, as well as its chemical composition, clearly show that it is of Martian origin.
Using the ion microprobe in the W. M. Keck Cosmochemistry Laboratory at UH, the team was able to analyze veins of Martian clay in the meteorite. After ruling out contamination from Earth, they determined boron abundances in these clays are over ten times higher than in any previously measured meteorite.
“Borates may have been important for the origin of life on Earth because they can stabilize ribose, a crucial component of RNA. In early life RNA is thought to have been the informational precursor to DNA,” said James Stephenson, a UHNAI postdoctoral fellow.
RNA may have been the first molecule to store information and pass it on to the next generation, a mechanism crucial for evolution. Although life has now evolved a sophisticated mechanism to synthesize RNA, the first RNA molecules must have been made without such help. One of the most difficult steps in making RNA nonbiologically is the formation of the RNA sugar component, ribose. Previous laboratory tests have shown that without borate the chemicals available on the early Earth fail to build ribose. However, in the presence of borate, ribose is spontaneously produced and stabilized.
This work was born from the uniquely interdisciplinary environment of UHNAI. The lead authors on the paper, Stephenson, an evolutionary biologist, and Lydia Hallis, a cosmochemist who is also a UHNAI
On our planet, borate-enriched salt, sediment and clay deposits are relatively common, but such deposits
Thin section of the Martian meteorite MIL 090030 analyzed by the UHNAI researchers.
The significance goes beyond an interest in the red planet, as Hallis explains: “Earth and Mars used to have
The presence of ancient borate-enriched clays on Mars implies that these clays may also have been present on the early Earth. Borate-enriched clays such as the ones studied here may have represented chemical havens in which one of life’s key molecular building blocks could form.
UHNAI is a research center that links the biological, chemical, geological, and astronomical sciences to better understand the origin, history, distribution, and role of water as it relates to life in the universe.
had never previously been found on an extraterrestrial body. This new research suggests that when life was getting started on Earth, borate could also have been concentrated in deposits on Mars.
much more in common than they do today. Over time, Mars has lost a lot of its atmosphere and surface water, but ancient meteorites preserve delicate clays from wetter periods in Mars’ history. The Martian clay we studied is thought to be up to 700 million years old. The recycling of the Earth’s crust via plate tectonics has left no evidence of clays this old on our planet; hence Martian clays could provide essential information regarding environmental conditions on the early Earth.”
postdoctoral fellow, first came up with the idea over an after-work beer. “Given that boron has been implicated in the emergence of life, I had assumed that it was well characterized in meteorites,” said Stephenson. “Discussing this with Dr. Hallis, I found out that it was barely studied. I was shocked and excited. She then informed me that both the samples and the specialized machinery needed to analyze them were available at UH.”
Note : The above story is reprinted from materials provided by Institute for Astronomy at the University of Hawaii at Manoa.
Phase portrait of a two environmental variable system where is in the very large limit, essential range = 100, niche function width = 5. Stable points, are indicated by circles. The basins of attraction which lead to these points are indicated by the different coloured enclosing regions, while initial conditions which would leave the essential range of are coloured white. Environmental variables do not necessarily move immediately towards stable points. doi:10.1371/journal.pcbi.1003050.g007 (Credit: James G. Dyke, Iain S. Weaver. The Emergence of Environmental Homeostasis in Complex Ecosystems. PLoS Computational Biology, 2013; 9 (5): e1003050 DOI: 10.1371/journal.pcbi.1003050)
Researchers at the University of Southampton have proposed an answer to the long-running debate as to how stable the Earth system is.
Earth, with its core-driven magnetic field, oceans of liquid water, dynamic climate and abundant life is arguably the most complex system in the known Universe. Life arose on Earth over three and a half billion years ago and it would appear that despite planetary scale calamities such as the impacts of massive meteorites, runaway climate change and increases in brightness of the Sun, it has continued to grow, reproduce and evolve ever since.
Has life on Earth simply been lucky in withstanding these events or are there any self-stabilising processes operating in the Earth system that would reduce the severity of such perturbations? If such planetary processes exist, to what extent are they the result of the actions of life?
Forty years ago James Lovelock formulated his Gaia Hypothesis in which life controls aspects of the planet and in doing so maintains conditions that are suitable for widespread life despite shocks and perturbations. This hypothesis was and remains controversial in part because there is no understood mechanism by which such a planetary self-stabilising system could emerge.
In research published in PLOS Computational Biology, University of Southampton lecturer Dr James Dyke and PhD student Iain Weaver detail a mechanism that shows how when life is both affected by and alters environmental conditions, then what emerges is a control system that stabilises environmental conditions. This control system was first described around the middle of the 20th Century during the development of the cybernetics movement and has until now been largely neglected. Their findings are in principle applicable to a wide range of real world systems — from microbial mats to aquatic ecosystems up to and including the entire biosphere.
Dr Dyke says: “As well as being a fascinating issue in its own right, we quite desperately need to understand what is currently happening to Earth and in particular the impacts of our own behaviour.
“Pretty much whatever we do, life on Earth will carry on, just as it did for the previous 3.5 billion years or so. It is only by discovering the mechanisms by which our living planet has evolved in the past can we hope to continue to be part of its future.”
Note : The above story is reprinted from materials provided by University of Southampton, via AlphaGalileo.
The large lesion is located above the tubercular facet and extends laterally. The trabeculae have been destroyed and the cortex appears expansive. The thin cortical bone forming the superior surface of the cavern was broken away postmortem. (b) Krapina 120.6 shows the normal pattern of bony trabeculae in the medullary space. The surface irregularities are post-mortem. (Credit: Janet Monge et al. Fibrous Dysplasia in a 120,000 Year Old Neandertal from Krapina, Croatia. PLoS ONE, 2013; 8 (6): e64539 DOI: 10.1371/journal.pone.0064539)
The first-known definitive case of a benign bone tumor has been discovered in the rib of a young Neandertal who lived about 120,000 years ago in what is now present-day Croatia. The bone fragment, which comes from the famous archaeological cave site of Krapina, contains by far the earliest bone tumor ever identified in the archaeological record.
Details of the tumor confirmation, announced by an international research team led by Penn Museum Associate Curator and Paleoanthropologist Janet Monge, is available in a research paper, “Fibrous dysplasia in a 120,000+ year old Neandertal from Krapina, Croatia,” in the online scientific journal PLOS ONE.
Joining Dr. Monge on the research team were Morrie Kricun, Department of Radiology, University of Pennsylvania; Jakov Radovcic and Davorka Radovcic, Croatian Natural History Museum; Alan Mann, Department of Anthropology, Princeton University; and David Frayer, Department of Anthropology, University of Kansas.
Bone tumors are exceptionally rare finds in the evolutionary fossil and archaeological records of human prehistory, with the earliest known instances, before now, dating to 1,000 to 4,000 years ago. Primary bone tumors are rare in modern populations, thus, finding a tumor in a fossil so old is a unique discovery.
From a u-CT scan and an X-ray, researchers identified a fibrous dysplastic neoplasm — today, the most common form of benign bone tumor in humans — located on a Neandertal left rib fragment that measured 30 mm (4 ½ inches) long. Judging by the size of the rib fragment, at the end of the rib that joins to the vertebrae, the rib belonged to a young male Neandertal, probably in his teens. Though he died young, and fibrous displasia is a developmental disorder of bone, there are no other known fossils that can be attributed to this individual, and there is not enough evidence to determine if this was or contributed to the cause of his death, according to Dr. Monge.
The confirmation of this tumor, Dr. Monge believes, may have implications for scholars studying the relationship between Neandertals and modern humans. “This tumor may provide another link between Neandertals and modern peoples, links currently being reinforced with genetic and archaeological evidence. Part of our ancestry is indeed with Neandertals — we grow the same way in our bones and teeth and share the same diseases.”
About the Kaprina Archaeological Record and Past Research
Paleoanthropologists continue to debate the exact relationship between homo sapiens, or humans today, and Neandertals — an extinct species who lived throughout Eurasia from as early as 600,000 years to as late as 30,000 years ago. One of the most important early Neandertal sites was discovered in modern-day Croatia in 1899, when Dragutin Gorjanovic-Kramberger, Director of the Geology and Paleontology Department of the National Museum and Professor of Paleontology and Geology at Zagreb University, alerted by a local schoolteacher, first visited the Krapina cave and noted cave deposits, including a chipped stone tool, bits of animal bones, and a single human molar. Beginning that year, and continuing through six years, Gorjanovic-Kramberger and his associates completely, and for that era, carefully, excavated the cave. By 1905, Krapina had yielded more hominid remains than any other site known at the time.
In the 1990s, the Penn Museum was invited to study the radiographic images of the famous Krapina Neandertal fossil bone collection. The team identified 874 human remains, representing more than 75 individuals — the largest such collection of Neandertal remains from one locale. Looking for signs of pathology, disease, and weakness in a group of hominids long thought by many to have “died out” in classic Darwinian survival-of-the-fittest style, the team’s ultimate diagnosis was surprising: these Neandertals were in large part a robust, healthy people. The researchers, Janet Monge among them, shared the results of their studies in a 1999 book, The Krapina Hominids: A Radiographic Atlas of the Skeletal Collection, published by the Republic of Croatia.
Not among the skeletal fossils, however, was the rib now identified as having the bone tumor. At the time of the Krapina excavations, it was mistakenly identified and placed in a faunal collection. In 1986, it was discovered by TD White (University of California, Berkeley) and N Toth (Indiana University, Bloomington) and preliminarily identified as a pathological specimen by M Kricun and J Monge in 1999. It was not until scholars could employ u-CT scans and analysis that the exact nature of the pathology was identified.
Note : The above story is reprinted from materials provided by University of Pennsylvania.
These are spindle-like microstructures from the Farrel Quartzite , Western Australia.Credit: Christopher House, Penn State
Spindle-shaped inclusions in 3 billion-year-old rocks are microfossils of plankton that probably inhabited the oceans around the globe during that time, according to an international team of researchers.
“It is surprising to have large, potentially complex fossils that far back,” said Christopher H. House, professor of geosciences, Penn State, and lead author.
However, the researchers not only showed that these inclusions in the rocks were biological in origin, but also that they were likely planktonic autotrophs — free-floating, tiny ocean organisms that produce energy from their environment.
The researchers looked at marine sediment rocks from the Farrel Quartzite in Western Australia. Isotopic analysis using secondary ion mass spectrometry was carried out at UCLA. “Ken (Kenichiro Sugitani, professor, Graduate School of Environmental Studies, Nagoya University, Japan, and a co-author) discovered these unusually shaped microfossils embedded in really old rock,” said House.
To determine if these inclusions were actually biological in origin, the researchers looked at 15 different samples of Farrel Quartzite and determined their stable carbon isotope ratios. The percentage of carbon 13 in the microfossils was indicative of material produced by biological processes. They found that the carbon 13 percentage in the background organic matter in the surrounding rock was different from that of the microstructures.
“When considered along with published morphological and chemical studies, these results indicate that the Farrel Quartzite microstructures are bona fide microfossils, and support the interpretation that the spindles were planktonic,” the researchers report in the current issue of Geology. The morphological and chemical studies were done by Sugitani and Dorothy Oehler, who is also a co-author and research scientist, Astromaterials Research and Exploration Science Directorate, NASA — Johnson Space Center.
The spindle-shaped microfossils are from 20 to 60 microns in length, about the size of fine sand and within the size range of today’s microplankton.
Stable carbon isotope analysis can determine the biological origin of these microfossils because they used carbon dioxide to create energy and incorporated the carbon into themselves. During this process, the organisms selectively incorporate more carbon 12 than carbon 13 from the available carbon, producing a signature of biological origin.
Oehler notes that the spindles appear to be the same as those found in rocks from the Strelly Pool Formation in Western Australia and the Onverwacht Group in South Africa and Swaziland that are both 3.4 billion years old.
“The existence of these microfossils in diverse locations as far back as 3.4 billion years ago suggests that the oceans probably had life in them for a very extended period of time,” said Oehler. “Moreover, this has implications beyond what we have done here, suggesting the evolution of diverse life proceeded quickly.”
Also working on this project was Koichi Mimura, Graduate School of Environmental Studies, Nagoya University, Japan.
Note : The above story is reprinted from materials provided by Penn State
The asteroid Eros was studied by NASA’s NEAR mission in the early 2000s. Researchers want to find out whether asteroids such as this contain minerals and other resources that can be mined and used on Earth or for space-based industries. (Credit: NASA)
The prospects of a robotic manufacturing base operating off Earth is not as far-fetched as it used to be according to a study published by a team of NASA researchers led by a Kennedy Space Center physicist.
Because asteroids are loaded with minerals that are rare on Earth, near-Earth asteroids and the asteroid belt could become the mining centers for remotely operated excavators and processing machinery. In 20 years, an industry barely imagined now could be sending refined materials, rare metals and even free, clean energy to Earth from asteroids and other bodies.
In their paper called “Affordable, Rapid Bootstrapping of the Space Industry and Solar System Civilization,” published in the Journal of Aerospace Engineering, Phil Metzger, Anthony Muscatello, Robert Mueller and James Mantovani detail an intriguing path toward developing a self-sustaining, space-based industry that would use resources from asteroids and other heavenly bodies to meet the needs of humanity.
The result would provide the most profound societal changes since the Industrial Revolution introduced large-scale machinery and manufacturing techniques in the late 18th and early 19th centuries, said Metzger the Kennedy-based physicist who led the evaluation.
“We’re predicting that we are on the verge of the next revolution in human civilization,” Metzger said.
Two fundamental developments make this prospect possible: robotics and the discovery of fundamental elements to make plastic and rubber and metals existing throughout space.
“Now that we know we can get carbon in space, the basic elements that we need for industry are all within reach,” Metzger said. “That was game-changing for us. The asteroid belt has a billion times more platinum than is found on Earth. There is literally a billion times the metal that is on the Earth, and all the water you could ever need.”
Another critical technology also is coming in at just the right time: additive manufacturing in the form of 3D printers that can turn out individual pieces that can be assembled into ever-more-complex machinery and increasingly capable robots.
“The idea is you start with resources out of Earth’s gravity well in the vicinity of the Earth,” Metzger said. “But what we argued is that you can establish industry in space for a surprisingly low cost, much less than anybody previously thought.”
The finished minerals could be returned to Earth or used in space to build new machinery or as supplies for astronauts as they explore the solar system.
So where to start?
The closer to Earth, the better — at least at first.
NASA is searching for an asteroid of about 500 tons that can be moved into a path within the moon’s orbit so astronauts can visit it as early as 2021 to take samples of the space rock.
“When we wrote this paper we were focused on the moon as a source of near-Earth resources, but near Earth asteroids work equally well and offer several additional advantages,” Metzger said. “It takes less fuel to bring resources away from the lower gravity of an asteroid, and since the ultimate goal is to move the industry to the asteroid main belt starting with asteroids first will help develop the correct technologies.”
But all asteroids are not created equal, and each one is likely to offer a unique fingerprint of substances created when the solar system formed billions of years ago.
“There are some types of asteroids that would be fantastic for space resources,” Metzger said. “It’s primordial solar system material. You can make plastics and you can make rubber by combining the carbon and the hydrogen.”
A near-Earth asteroid or other nearby body presumably will contain enough material to allow a robotic system to mine the materials and refine them into usable metal or other substances. Those materials would be formed into pieces and assembled into another robot system that would itself build similar models and advance the design.
“The first generation only makes the simplest materials, it can include metal and therefore you can make structure out of metal and then you can send robots that will attach electronics and wiring onto the metal,” Metzger said. “So by making the easiest thing, you’ve reduced the largest amount of mass that you have to launch.”
The first generation of machinery would be akin to the simple mechanical devices of the 1700s, with each new generation advancing quickly to the modern vanguard of abilities. They would start with gas production and the creation of solar cells, vital for providing a power source.
Each new robot could add improvements to each successive model and quickly advance the mining and manufacturing capabilities. It would not take long for the miners to produce more material than they need for themselves and they could start shipping precious metals back to Earth, riding on heat shields made of the leftover soil that doesn’t contain any precious material.
Kennedy researchers already have tested heat shield samples made from soil.
Bodies near Earth also were recently revealed to contain water ice, which gives planners the chemicals needed to produce fuel and air. With those resources available, the robotic miners would be able to propel themselves farther out into the solar system, mainly to the resource-rich asteroid belt between Mars and Jupiter. There they could set up more manufacturing and refining facilities.
Perhaps the most unusual aspect of the whole endeavor is that it would not take many launches from Earth to achieve. Launch costs, which now run at best $1,000 per pound, would be saved because robots building themselves in space from material gathered there wouldn’t need anything produced by people. Very quickly, only the computer chips, electronics boards and wiring would need to come from Earth.
“We took it through six generations of robotic development and you can achieve full closure and make everything in space,” Metzger said. “We showed you can get it down to launching 12 tons of hardware, which is incredibly small.”
For comparison, that would be less than half the weight of the Apollo command and service modules flown on a moon mission.
This enterprise would take years to establish, but not as long as one might think. And the payoff for Earth would be felt when the first shipments of materials began arriving from space. A sudden influx of rare metals, for instance, would drive down the price of those materials on Earth and allow a similar drastic reduction in manufacturing costs for products made with the materials.
There are numerous examples of such revolutions taking place over and over again on Earth, including the discovery after the Civil War of a process for refining bauxite into aluminum that made the metal go from being as valuable as gold to something soda cans are made of. Does that mean soda cans would be made from platinum? Maybe not, but the changes could be just as dramatic.
“You could grow an industry that is a million times bigger than the United States’ in the main asteroid belt,” Metzger said. “Then you really are capable of terraforming planets and doing all the other great things because it wouldn’t cost you anything” in terms of labor, resources or materials.
Reference:
Philip T. Metzger, Anthony Muscatello, Robert P. Mueller, James Mantovani. Affordable, Rapid Bootstrapping of the Space Industry and Solar System Civilization. Journal of Aerospace Engineering, 2013; 26 (1): 18 DOI: 10.1061/(ASCE)AS.1943-5525.0000236
Note : The above story is reprinted from materials provided by NASA.
Medieval chronicles have given an international group of researchers a glimpse into the past to assess how historical volcanic eruptions affected the weather in Ireland up to 1500 years ago.
By critically assessing over 40,000 written entries in the Irish Annals and comparing them with measurements taken from ice cores, the researchers successfully linked the climatic aftermath of volcanic eruptions to extreme cold weather events in Ireland over a 1200-year period from 431 to 1649.
Their study, which has been published today, 6 June, in IOP Publishing’s journal Environmental Research Letters, showed that over this timescale up to 48 explosive volcanic eruptions could be identified in the Greenland Ice Sheet Project (GISP2) ice-core, which records the deposition of volcanic sulfate in annual layers of ice.
Of these 48 volcanic events, 38 were associated, closely in time, with 37 extreme cold events, which were identified by systematically examining written entries in the Irish Annals and picking out directly observed meteorological phenomena and conditions, such as heavy snowfall and frost, prolonged ice covering lakes and rivers, and contemporary descriptions of abnormally cold weather.
Lead author of the study, Dr Francis Ludlow, from the Harvard University Center for the Environment and Department of History, said: “It’s clear that the scribes of the Irish Annals were diligent reporters of severe cold weather, most probably because of the negative impacts this had on society and the biosphere.
“Our major result is that explosive volcanic eruptions are strongly, and persistently, implicated in the occurrence of cold weather events over this long timescale in Ireland. In their severity, these events are quite rare for the country’s mild maritime climate.”
Through the injection of sulphur dioxide gas into the stratosphere, volcanic eruptions can play a significant role in the regulation of the Earth’s climate. Sulphur dioxide gas is converted into sulphate aerosol particles after eruptions which reflect incoming sunlight and result in an overall temporary cooling of the Earth’s surface.
Whilst the global effects of recent eruptions are quite well-known, such as the Mount Pinatubo eruption almost 22 years ago (15 June 1991), less is known about their effects on climate before the beginning of instrumental weather recording, or their effects on regional scales; the Irish Annals provided an opportunity to explore both of these issues.
The Irish Annals contain over one million written words and around 40,000 distinct written entries, detailing major historical events on an annual basis, and providing both systematic and sustained reporting of meteorological extremes.
The dating and reliability of the Annals can be gauged by comparing reported events to those which are independently known, such as solar and lunar eclipses.
“With a few honourable exceptions, the Irish record of extreme events has only been used anecdotally, rather than systematically surveyed and exploited for the study of the climate history of Ireland and the North Atlantic, and so the richness of the record has been largely unrecognized,” continued Dr Ludlow.
Although the effect of big eruptions on the climate in summer is largely to cause cooling, during the winter, low-latitude eruptions in the tropics have instead been known to warm large parts of the northern hemisphere as they cause a strengthening of the westerly winds that brings, for example, warmer oceanic air to Europe; however, this study identified several instances when low-latitude eruptions appeared to correspond to extreme cold winters in Ireland.
One example is the 1600 eruption in Peru of Huaynaputina, which the researchers found, against expectations, to be associated with extreme cold winter weather in Ireland in the following years.
“The possibility that tropical eruptions may result in severe winter cooling for Ireland highlights the considerable complexity of the volcano-climate system in terms of the regional expression of the response of climate to volcanic disturbances.
“It is on the regional scale that we need to refine our understanding of this relationship as ultimately, it is on this scale that individuals and societies plan for extreme weather,” continued Dr Ludlow.
Note : The above story is reprinted from materials provided by Institute of Physics (IOP), via AlphaGalileo.
