Analysis of coprolites from the extinct mountain goat Myotragus balearicus
Welker et al
Humans colonized the Balearic Islands 5–4 ka ago. They arrived in a uniquely adapted ecosystem with the Balearic mountain goat Myotragus balearicus (Bovidae, Antilopinae, Caprini) as the only large mammal. This mammal went extinct rapidly after human arrival. Several hypotheses have been proposed to explain the extinction of M. balearicus. For the present study ancient DNA analysis (Sanger sequencing, Roche-454, Ion Torrent), and pollen and macrofossil analyses were performed on preserved coprolites from M. balearicus, providing information on its diet and paleo-environment. The information retrieved shows that M. balearicus was heavily dependent on the Balearic box species Buxus balearica during at least part of the year, and that it was most probably a browser. Hindcast ecological niche modelling of B. balearica shows that local distribution of this plant species was affected by climate changes. This suggests that the extinction of M. balearicus can be related to the decline and regional extinction of a plant species that formed a major component of its diet. The vegetation change is thought to be caused by increased aridity occurring throughout the Mediterranean. Previous hypotheses relating the extinction of M. balearicus directly to the arrival of humans on the islands must therefore be adjusted.
Saturday, November 30, 2013
An analysis of the late glacial lake levels within the western Lake Superior basin based on digital elevation models
This study establishes a detailed lake-level history for the Lake Superior basin by mapping strandlines from 10-m and 3-m digital elevation models. There are 24 levels above the mid-Holocene Nipissing level, and elevations increase along a direction of 23.1° due to post-glacial rebound. The highest level, the Epi-Duluth, is steeper than subsequent levels and may pre-date the Lake View ice advance into the western Lake Superior basin at the end of the Younger Dryas stade. The most prominent level is the Duluth, ca. 10,800 cal yr BP. Ice retreat exposed successively lower outlets, routing overflow to the Lake Michigan and Huron basins. By 10,600 cal yr BP, lake levels in the western Superior basin had dropped almost 200 m. This transformative period is complicated by multiple basin-wide events: the influx of glacial Lake Agassiz overflow, the creation of three sub-aqueous moraines, and a red to gray color transition in basin sediments. A later drawdown event has been hypothesized to have initiated the 9300 cal yr BP cooling event, but this flood was much smaller than estimated previously. If freshwater triggered the 9300 cal yr BP event, the source of the water must have been Lake Agassiz, not Lake Superior.
What caused the low-water phase of glacial Lake Agassiz?
Lowell et al
First-order modeling suggests that a low-water phase in late-glacial Lake Agassiz can be explained through changes in the balance between evaporation, precipitation, and runoff, rather than drainage. The low-water Moorhead Phase is often attributed to drainage through outlets opened by isostatic depression and retreat of the Laurentide ice margin. However, new data indicate that the proposed outlets were ice-covered during the Moorhead Phase. Instead, the lake water levels dropped to the Moorhead Phase before the start of the Younger Dryas chronozone and remained there until 11.3 ka. Thus, drainage seems to be an implausible explanation for Younger Dryas-aged low water levels in Lake Agassiz. An alternative explanation is that evaporation equaled or exceeded water inputs from the adjacent ice margin and the deglaciated parts of the drainage basin. To evaluate whether this hypothesis is plausible, we constructed a simple model that considers the paleo-basin geometry, hydrology, and meltwater production from the adjacent ice margin. Modest hydrologic changes (within the range of present-day variability), coupled with low meltwater production, produce a closed basin. Shifts in the location of the polar jet, driven by increased Arctic albedo, may explain our inferred hydrologic changes.
Forests of the tropical eastern Andean flank during the middle Pleistocene
Cárdenas et al
Inter-bedded volcanic and organic sediments from Erazo (Ecuador) indicate the presence of four different forest assemblages on the eastern Andean flank during the middle Pleistocene. Radiometric dates (40Ar–39Ar) obtained from the volcanic ash indicate that deposition occurred between 620,000 and 192,000 years ago. Examination of the organic sediment composition and the fossil pollen, wood and charcoal it contains provides insight into depositional environment, vegetation assemblage and fire history. The high organic content and abundance of macro fossils found throughout the sediment suggest that during the period of deposition the local environment was either a swamp or a shallow water body. The correlation of fire activity (peaks in charcoal abundance) with volcanic ash deposits through most of the record suggests that volcanoes were the main source of ignition. The low abundance of grass (typically less than 10%) throughout the sedimentary sequence along with the low abundance of other taxa indicative of open vegetation suggests the persistence of forest at Erazo. Four types of forest assemblage were identified (with the first taxa as the most dominant): i) Alnus-Arecaceae, ii) Miconia-Melastomataceae/Combretaceae-Moraceae/Urticaceae, iii) Arecaceae-Alnus, and iv) Podocarpus with Oreopanax sp. and Melastomataceae/Combretaceae. Changes in the forest floristic composition indicate high vegetation turnover and reassortment of taxa between upper and lower montane forests during the middle Pleistocene as well as the persistence of forest cover.
Evidence of Abrupt Climate and Precinpitation Change Pleistocene Glaciations From Stalagmites in China
A stalagmite record of abrupt climate change and possible Westerlies-derived atmospheric precipitation during the Penultimate Glacial Maximum in northern China
Railsback et al
The geochemistry and petrography of a stalagmite from Wanxiang Cave in central China provide a paleoclimate record of the Penultimate Glacial Maximum (PGM) suggesting unexpectedly abundant non-monsoonal atmospheric precipitation at the nadir of the PGM. Eleven U–Th (230Th) ages from 149 to 140ka BP place the stalagmite in Marine Isotope Stage 6b, coincident with the greatest benthic marine δ18Ocalcite values of MIS 6. Carbon and oxygen stable isotope data, measurements of layer-specific width, positions of surfaces of non-deposition or dissolution, changes in the character and thickness of seemingly annual layers, changes in concentration of organic acids within the stalagmite's calcite, and patterns in the Mg concentration of that calcite all combine to give a coherent paleoclimate record. These data suggest that the stalagmite represents a wetter period than before or after its growth, with the wettest and coldest phase at 145 to 144ka BP. This extreme in climate yields a striking correlation with the LR04 stack of oxygen isotope records from marine benthic forams, if the latter is subjected to a 4500-year chronological adjustment previously suggested by U–Th data from corals. The timing of the Wudu stalagmite's deposition combines with findings elsewhere to suggest that the PGM was the most extreme of later Pleistocene glacial maxima.Petrography and U–Th age determinations suggest dramatic changes in climate during the PGM. At the beginning (149–146ka BP) and end (143–140ka BP) of the stalagmite's growth, abrupt (century-scale) drying caused lengthy hiatuses as dripwater to the stalagmite diminished. On the other hand, delivery of water to the stalagmite during the wettest phase (145–144ka BP) caused dissolution of previous layers of the stalagmite.Enhanced atmospheric precipitation during the cold of a glacial maximum is unexpected because, within the spectrum of Holocene climate, cooler conditions lessen the impact of the East Asian monsoon. Changes in the character of stalagmite layers indeed suggest weakened to negligible influence of the East Asian monsoon during the nadir of the PGM. However, data from the stalagmite are compatible with atmospheric precipitation from westerly winds that today reach only northwestern China but that may have been deflected southward in the PGM by southward migration of the Siberian High. This unexpected significance of the Westerlies during the PGM may be a result of the hypothesized extreme nature of the PGM relative to other glacial maxima of the later Pleistocene.
Global constraints on net primary production and inorganic carbon supply during glacial and interglacial cycles
Pelegri et al
Relaxation-type models have good skill at reproducing glacial-interglacial transitions in climatic variables. Here we propose a simple two-box and two-state relaxation-type model for the upper ocean (surface and permanent thermocline layers) where dissolved inorganic carbon/nutrients are supplied by the deep-ocean and through remineralization within the upper ocean. The model is tuned using genetic algorithms to simulate the atmospheric CO2 time series for the last four glacial-interglacial cycles. The fit to the data is very good, with correlations above 0.8, as the upper ocean responds to shifts in (1) the intensity of the Meridional Overturning Circulation (MOC), from off to on during the glacial-interglacial transition, and (2) the size and sign of net primary production, with respiration greatly exceeding primary production during interglacial periods and production larger than respiration during the glacial phase. The glacial-interglacial transitions are interpreted as shifts between two distinct metabolic states of the Earth system, with high/low supply of dissolved inorganic carbon and nutrients to the productive upper ocean during interglacial/glacial periods.
Russian universities need change of tack
Of the factors contributing to Russia's poor scientific performance (see, for example, A. Gorobets Nature 503, 39; 2013), the plight of the country's university professors stands out.
These professors are poorly paid; most are forced to supplement their earnings with other employment. Their typical annual teaching load of up to 1,000 hours is three to five times higher than that in universities elsewhere, leaving them little time for research or writing up their work. On top of this, professors are now under pressure from Russia's Ministry of Education and Science to publish two or three papers a year in international journals to help their universities to reach the top 200 in global rankings.
Research: Discard Soviet doctorate systems
The research performance of most former Soviet states is still low compared with that of many Western countries. In my view, progress will be stifled as long as the archaic academic systems passed down from the former Soviet Union persist.
I have analysed the research performance of several of these nations on the basis of their per capita gross expenditure on research and development from 1998 to 2010 and their number of research publications from 1998 to 2012.
Friday, November 29, 2013
The developers of bitcoin are trying to show that money can be successfully privatized. They will fail, because money that is not issued by governments is always doomed to failure. Money is inevitably a tool of the state.
10,000 [...] Chinese babies were born in America last year, according to an estimate by an online platform dedicated to monitoring and rating confinement centers for Chinese women giving birth in the States.
Lockheed Martin has labeled the hypersonic technology to be used in the proposed SR-72 Mach 6 aircraft as the “new stealth.” It is really the old stealth, and it points to a classic example of how almost every military and political leader in Western defense fell in line behind a technical miscalculation.
He's wrong on a few points. I ought to be well enough either on Sunday or Monday, a response will be posted.
The US Army has released a final request for proposals (RfP) for an Armoured Multi-Purpose Vehicle (AMPV), meant to replace the ageing M113-series armoured personnel carriers, as the programme appears to be inching forwards despite a looming budget crunch that is threatening major procurement efforts.
A contract is expected to be awarded late next year for a USD436 million engineering and manufacturing development (EMD) phase that would run from fiscal year 2015-2019 (FY2015-2019), according to the RfP, which was released on 26 November.
The final RfP keeps a similar EMD schedule for budgets for about USD22 million less than the most recent draft RfP that was released early in October.
The winning contractor would deliver 29 prototype vehicles for testing, and the RfP noted that the army "intends to have discussions with the winning offer or, after contract award, regarding opportunities to expedite EMD prototype deliveries, in an effort to accelerate the programme milestones".
Army officials are to hold a competition for the EMD phase 'cost plus incentive fee' contract, which is to include three options years of low-rate initial production (LRIP) worth USD1.2 billion - consistent with the draft request that was published in October. The RfP said that the LRIP contracts would have cost and performance incentives.
BAE Systems has said it expects to compete with a platform based on the Bradley infantry fighting vehicle, and General Dynamics has said it may submit a variant - possibly tracked - of the Stryker wheeled combat vehicle.
Lots of interesting methane papers this week. In Nature Geoscience, Shakhova et al (2013) have published a substantial new study of the methane cycle on the Siberian continental margin of the Arctic Ocean. This paper will get a lot of attention, because it follows by a few months a paper from last summer, Whiteman et al (2013), which claimed a strong (and expensive) potential impact from Arctic methane on near-term climate evolution. That economic modeling study was based on an Arctic methane release scenario proposed in an earlier paper by Shakhova (2010). In PNAS, Miller et al (2013) find that the United States may be emitting 50-70% more methane than we thought. So where does this leave us?
“Terror Birds” (Phorusrhacidae) from the Eocene of Europe Imply Trans-Tethys Dispersal
Angst et al.
Phorusrhacidae was a clade including middle-sized to giant terrestrial carnivorous birds, known mainly from the Cenozoic of South America, but also occurring in the Plio-Pleistocene of North America and the Eocene of Africa. Previous reports of small phorusrhacids in the Paleogene of Europe have been dismissed as based on non-phorusrhacid material.
we have re-examined specimens of large terrestrial birds from the Eocene (late Lutetian) of France and Switzerland previously referred to gastornithids and ratites and have identified them as belonging to a phorusrhacid for which the name Eleutherornis cotei should be used.
The occurrence of a phorusrhacid in the late Lutetian of Europe indicates that these flightless birds had a wider geographical distribution than previously recognized. The likeliest interpretation is that they dispersed from Africa, where the group is known in the Eocene, which implies crossing the Tethys Sea. The Early Tertiary distribution of phorusrhacids can be best explained by transoceanic dispersal, across both the South Atlantic and the Tethys.
A New Oviraptorosaur (Dinosauria: Oviraptorosauria) from the Late Cretaceous of Southern China and Its Paleoecological Implications
Lu et al
A new oviraptorosaur Nankangia jiangxiensis gen. et sp. nov. is described on the basis of a partial postcranial skeleton with a partial lower jaw collected from the Upper Cretaceous Nanxiong Formation of Ganzhou, in Jiangxi Province of southern China. The new taxon is diagnosed by: (1) a mandibular symphysis that is not turned down; (2) neural spines of the cranial caudal vertebrae that are wider transversely than anteroposteriorly, forming a large posterior fossa with rugose central areas; (3) a femoral neck extending at an angle of about 90 to the shaft; and (4) a ratio of femur to tibia length of 0.95. Phylogenetic analysis recovers Nankangia as basal to the oviraptorid Yulong, but more derived than Caenagnathus, which also has a mandibular symphysis that is not turned down. The coexistence of Nankangia jiangxiensis, Ganzhousaurus nankangensis, Jiangxisaurus ganzhouensis, an unnamed oviraptorid from Nanxiong Basin and Banji long suggests that they occupied distinct ecological niches. Nankangia may have been more herbivorous than carnivorous.
The Nanxiong Formation seems to have been an interesting locale during the Maastrichtian (?). The reason I saw that is that there are two carnivorous oviraptorosarus and three herbivorous ones from the same place. What an interesting and odd fauna...
A WORCESTER schoolboy has discovered a rare fossil from the time of dinosaurs.
The plant fossil, which was found on a rock, is part of a Lycopod plant, common during the Triassic period, and is estimated to be about 250 million years old.
The find is particularly rare as the fossil has come from the overlap of two time periods, the Permian and Triassic. Plant fossils are not usually found in Triassic rock – and even less usually in Worcester.
Late Triassic compositional changes of aeolian dusts in the pelagic Panthalassa: Response to the continental climatic change
Nakada et al
The Carnian pluvial event (CPE) is considered as the drastic environmental change that occurred in the western Tethys during the Carnian (Late Triassic). Although some studies have suggested that the CPE was a global event, no studies have referred to pelagic environment related to the CPE. To reveal the pelagic environment during the Carnian, X-ray absorption fine structure (XAFS) analysis was used to determine the iron (Fe) species in chert samples collected from the Ladinian–Carnian strata in the Tamba–Mino–Ashio Belt, Japan. The X-ray absorption near-edge structure (XANES) analysis shows that all the red cherts contain hematite with a combination of clay minerals, such as illite, chlorite, and smectite. The existence of these minerals is identified using extended XAFS (EXAFS). The XANES analysis of the green and the white cherts does not show any hematite signatures, while the EXAFS analysis indicated increasing amounts of chlorite.
The stratigraphic change in the Fe-bearing compositions observed in this study can be divided into three stages: (i) a stage where a relatively stable mineral composition (chlorite + illite + hematite) is observed in cherts deposited during the early Carnian (Julian), (ii) the abrupt change in mineral composition (lack of chlorite and appearance of smectite) observed in the middle area in the studied section and corresponding to the middle part of Carnian (late Julian–early Tuvalian), and (iii) the recovery of the previous stable mineral composition during the late Carnian (Tuvalian). These variations in the mineralogical composition of pelagic cherts can be interpreted to mean that the continental climate conditions changed during the Carnian, and different clay fractions were delivered to the pelagic region. These data, combined with the results of previous studies performed around the continental realm, can be interpreted as follows: (i) there was a relatively stable dry climate before the CPE, (ii) there were increasing amounts of precipitation owing to the CPE, and (iii) the climate returned to dry conditions similar to those prior to the CPE.
Cadomian (Ediacaran-Cambrian) arc magmatism in the ChahJam-Biarjmand metamorphic complex (Iran): Magmatism along the northern active margin of Gondwana
Moghadam et al
The ChahJam-Biarjmand complex (CJBC), flanked by the Alborz Mountains in the north and the Lut-Tabas block to the south, is part of Central Iranian block, where the oldest continental crust of Iran is found. This complex contains granitic to tonalitic orthogneissic rocks (old plutons) and associated metasediments, amphibolites and paragneisses. Metamorphosed granitic and granodioritic dikes intrude orthogneisses as well as metasediments and are abundant close to the plutons (orthogneissic rocks). Based on the results of bulk rock trace and rare earth elements, the orthogneissic rocks are inferred to have crystallized from subduction-related melts. Amphibolites also have subduction-related signatures and are inferred to have formed both as metamorphosed volcanoclastic sediments and as attenuated basic dikes. The presence of para-amphibolites associated with paragneisses and metasediments (mica schists) could represent a sedimentary basin filled with magmatic arc erosional products. U-Pb zircon dating of the ChahJam-Biarjmand rocks yielded 238U/206Pb crystallization ages of ca. 550 to 530 Ma (Ediacaran-early Cambrian). Sr-Nd isotope systematics on whole rocks (εNd(t) = -2.2 to -5.5) and zircon Hf isotope results indicate that CJBC Cadomian granitic rocks contain older, possible Mesoproterozoic, continental crust in their source. The ChahJam-Biarjmand granitic-tonalitic gneissic rocks are coeval with other similar-aged metagranites and gneisses within Iranian basement exposed in Central Iran, the Sanandaj-Sirjan Zone and the Alborz Mountains, as well as in the Tauride-Anatolide platform in western Anatolia and in NW Turkey. All these dispersed Cadomian basement rocks are interpreted to show fragments of Neoproterozoic-early Cambrian continental arcs bordering the northern active margin of Gondwana.
Two new Project 955 Borey submarines - Vladimir Monomakh and Aleksandr Nevskiy - are expected to join the Pacific Fleet in 2014.
but they don't have ballistic missiles what with the problems with the Bulava SLBM.
ACUTELY conscious that the emergence of new powers on the world stage has more often than not led to war, China’s leaders make much of their plans for a “peaceful rise”. But they often have an odd way of showing it. Take China’s declaration on November 23rd of an Air Defence Identification Zone (ADIZ) above a stretch of the East China Sea that includes the Senkaku or Diaoyu islands, which it disputes with Japan. This was bound to create alarm in China’s own neighbourhood and tension in its relations with the incumbent superpower. So it calls into question the priority China really places on maintaining peace; or, perhaps, its skill in managing its rise without sparking conflict.
It makes you wonder if China's perception is they no longer need to be patient, because they are already the superpower because of their view of American internal problems...
Thursday, November 28, 2013
China sent fighter jets into its newly claimed -- and hotly disputed -- air defense zone above the East China Sea on Thursday, the same day that Japan's military firmly insisted its own patrols over the area wouldn't stop because of Beijing's declaration.
The People's Liberation Army Air Force flew warplanes, including Su-30 and J-11 aircraft, into the "air defense identification zone" that Beijing announced last week, air force spokesman Col. Shen Jinke said. A KJ-2000 -- an airborne radar early warning system -- also took flight.
The Russian-developed Su-30 is a two-seat aircraft described by its manufacturer as "a highly maneuverable fighter" capable of hitting ground and sea-surface targets. The Chinese-made J-11 is a single-seat fighter also capable of ground attacks.
The fighter jets conducted "routine air patrols ... aiming to strengthen monitoring on air targets in the zone and fulfill the air force's historic mission," Shen said in a statement posted on the Chinese defense ministry's website.
Jinke portrayed the mission as a "defensive measure ... in line with international practices." China's military has been on "high alert," he added, and is prepared to act "based on different air threats to firmly ensure air-defense safety."
As storm clouds loom over the Army’s controversial Ground Combat Vehicle, both contractors competing for GCV say they’re focused on completing the program of record still on the books. But if the Army slows the program down – a near-certainty at this point – both BAE Systems and General Dynamics told me they are ready to adapt. In fact, they’ll make the best of any extra time to refine their designs and develop new technologies.
The biggest single criticism of the GCV has been how heavy it is. The Congressional Budget Office estimated up to 84 tons, although the fine print noted that figure was for a hypothetical future version that had grown to the maximum the vehicle could bear. News stories often describe it as weighing over 70 tons. But both contractors insist their designs are already below that figure and that they can keep whittling the weight down over time.
Depending on how much modular armor you bolt on to BAE’s current design, “it’d be in the 60- to 70-ton range depending on the configuration,” said BAE program director Deepak Bazaz.
Not coincidentally, 70 tons plus 20 percent more weight for future upgrades — a margin for growth the Army requires the GCV designs to have — is how CBO came up with its 84-ton figure.
General Dynamics was more specific, perhaps because their choice of a traditional diesel engine leaves them with less uncertainty than BAE’s hybrid drive. Even allowing for 20 percent growth, said GD’s GCV director, Robert Sorge, a future upgrade of their design would still max out at 76 tons. In the most heavily armored configuration currently planned, it’s about 62 tons, he told me. If commanders decide to sacrifice some protection for easier deployment by aircraft, they could get it down to 56.
"We direct the NRC Staff to complete and issue the Safety Evaluation Report (SER) associated with the construction authorization application.” So states the Memorandum and Order issued by the commissioners of the Nuclear Regulatory Commission (NRC) in compliance with an August decision of the U.S. Court of Appeals to restart the review of the Yucca Mountain high-level radioactive waste repository.
Javelins From 80,000 Years Before Oldest Homo sapiens Fossil: Modern Humans Older or Not First Spear Chuckers?
The oldest known stone-tipped projectiles have been discovered in Ethiopia. The javelins are roughly 280,000 years old and predate the earliest known fossils of our species, Homo sapiens, by about 80,000 years.
These javelins are some 200,000 years older than previous examples of similar weapons, suggesting that modern humans and their extinct relatives had the know-how to create these sorts of complex thrown projectiles much earlier than often thought.
Drought is heating up around the warming world. Particularly hot drought has cost more than US$40 billion and claimed 218 human lives since 2010 in the United States alone. These hot and dry conditions have also contributed to unusually widespread and devastating wildfires, fuelled by wide expanses of weakened and dead trees that were unable to deal with heat stress and subsequent insect attack. Yet, to get a real sense of how this recent change in drought severity might shape the future, one has to look to the past. An analysis of regional and pan-continental North American drought over the past 1,000 years, reported by Cook et al.3 in the Journal of Climate, makes it clear that recent droughts, as costly as they have been, are only a taste of what might lie ahead, independently of any big climate change.
Is Torosaurus Triceratops? Geometric Morphometric Evidence of Late Maastrichtian Ceratopsid Dinosaurs
Authors:Maiorino et alAbstract:BackgroundRecent assessments of morphological changes in the frill during ontogeny hypothesized that the late Maastrichtian horned dinosaur Torosaurus represents the “old adult” of Triceratops, although acceptance of this finding has been disputed on several lines of evidence.Methodology/Principal FindingsExamining the cranial morphology of 28 skulls in lateral view and 36 squamosals of Nedoceratops hatcheri, Triceratops spp. and Torosaurus spp. by means of landmark-based geometric morphometrics, we compared ontogenetic trajectories among these taxa. Principal Component Analysis and cluster analysis confirmed different cranial morphologies. Torosaurus shape space is well separated from Triceratops, whereas Triceratops horridus and Triceratops prorsus partially overlap within Triceratops shape space. Linear regressions between shape and size suggest different ontogenetic trajectories among these taxa. Results support the “traditional” taxonomic status of Torosaurus. We hypothesize that ontogeny drives cranial morphology with different patterns between Torosaurus and Triceratops.Conclusions/SignificanceTorosaurus is a distinct and valid taxon. Whether looking at entire skulls, skulls without the frill, frills alone, or squamosals, Torosaurus has different morphologies and distinct allometric trajectories compared to Triceratops. This new approach confirms the taxonomic status of Torosaurus as well as the comparatively low diversity of ceratopsids at the end of the Maastrichtian in North America.
The Rugosa-Scleractinia gap re-examined through microstructural and biochemical evidence: a tribute to H.C. Wang
More than sixty years ago, H.C. Wang carried out an extensive study of skeletal microstructures of the Paleozoic corals and concluded that a “direct descent” may have existed between the two coral suborders: the Paleozoic Rugosa and the younger Scleractinia that had been established as distinct phyla by Haeckel (1896). Skeletal microstructures and three-dimensional reconstructions of walls and septa have revealed remarkable similarities between some Permian and Triassic corals, but it is only during the recent years that significant relationships were established between the structural properties of coral skeletons and their control by the biological process. Supported by recent genetic studies of calcareous biomineralization among various invertebrate phyla, the Wang's opinion now appears a reasonable working hypothesis.
Evidence of the Collison of the Precambrian Kokchetav Microcontinent With Future Asia During Paleozoic
Formation of the Kokchetav subduction-collision zone (northern Kazakhstan): Insights from zircon U-Pb and Lu-Hf isotope systematics
Glorie et al
The Kokchetav subduction-collision zone is located in the western part of the ancestral Central Asian Orogenic Belt. This zone is built up by the Precambrian Kokchetav microcontinent which includes a HP-UHP metamorphic belt, and the North Kokchetav tectonic zone (NKTZ) which represents an accretionary complex between the Kokchetav microcontinent and the adjacent Stepnyak island-arc. The entire region is widely intruded by Palaeozoic granitoids which were emplaced after the collision of the Stepnyak island-arc with the Kokchetav microcontinent. We present zircon U-Pb ages and Lu-Hf systematics in zircon to better characterize the tectonic evolution of the Kokchetav subduction-collision zone.
The Lu-Hf results indicate that the Kokchetav basement rocks are derived from late Neoarchaean – early Palaeoproterozoic (~ 2.5 Ga) crust. For the granite-gneiss basement of the Kokchetav microcontinent, early Mesoproterozoic (Grenville-age, ~ 1.17-1.14 Ga) zircon U-Pb crystallization ages were obtained. For the NKTZ, two main age-components were recognized: (1) an oldest Mesoproterozoic age-component (~ 1.20-1.05 Ga) similar as for the Kokchetav microcontinental zircons, and (2) a younger Early Cambrian (540-520 Ma) or Late Cambrian - Early Ordovician (~ 490-480 Ma) age-component. Th/U ratios (< 0.1) are indicative of a metamorphic origin for both Early Cambrian and Late Cambrian - Early Ordovician zircon populations. The oscillatory zoned Mesoproterozoic zircons have higher Th/U ratios (> 0.1) and are typical of a magmatic protolith. The distinction between both zircon types is supported by characteristic cathodoluminescence images. These results confirm previous observations, indicating early Palaeozoic high-grade metamorphism (~ 540-520 Ma) and collisional deformation (~ 490-480 Ma) of the Mesoproterozoic Kokchetav zone as a result of subduction-accretion and collision of the Stepnyak island-arc to the Kokchetav microcontinent. For two additional samples of the Balkashin granitic complex Early Devonian (~ 415-395 Ma) zircon crystallization ages (magmatic Th/U ratios) were obtained. The occurrence of a Mesozoic xenocryst within these leucogranites may indicate that they were emplaced in a continental-arc setting.
The Russian navy has taken delivery of its first four series-produced MiG-29K/KUB carrier based fighter jets, the Defense Ministry said Monday.
“The MiG aircraft-manufacturing corporation has handed over two MiG-29K single-seat and two MiG-29KUB twin-seat carrier-based fighter aircraft,” a spokesman said.
The Russian Defense Ministry signed a contract with MiG in February 2012 for delivery of 20 MiG-29K and four MiG-29KUB fighters by 2015.
The aircraft will be deployed on Russia’s sole serving carrier, the Admiral Kuznetsov, based in Murmansk with the Northern Fleet. The Admiral Kuznetsov currently operates Sukhoi Su-33 naval fighter aircraft.
The MiG-29K is a naval variant of the MiG-29 Fulcrum fighter jet, and has folding wings, an arrester tail-hook, strengthened airframe and multirole capability thanks to its Zhuk-ME slotted array radar, MiG says.
Unlike the Su-33, which is capable of air defense missions only, the MiG-29K can be armed with a wide variety of air-to-surface as well as air-to-air weaponry and laser-designation systems.
The aircraft is also capable of “buddy” refueling other MiG-29Ks using the PAZ-1MK refueling pod.
The future basing of the UK's nuclear weapons capability continues to face uncertainty, with the Scottish government setting an aspirational date of 2021 to remove nuclear weapons from Scotland in the case of independence.
Currently all the UK's nuclear weapons are based and stored in Scotland, with the Scottish Nationalist Party (SNP) government pledging to remove them as "a priority" if independence occurs. Although Scottish independence appears likely to be rejected by voters in September 2014, the implication of a 'Yes' vote would be substantial on the nuclear deterrent of one of the world's only eight declared nuclear powers.
Scottish independence would see nuclear weapons removed from Scottish territory within the first term of an independent Scottish Parliament, it was claimed in the Scottish government's long-awaited White Paper on Scottish independence, 'Scotland's Future: Your guide to an independent Scotland', published on 26 November.
With the first independent Scottish government outlined to take power in 2016, this sets a 2021 timeline for the removal of the UK's Trident submarine-launched ballistic missile (SLBM) capability from Scotland. The entire UK submarine force is currently based at HMNB Clyde, with RNAD Coulport responsible for storage and loading of the Royal Navy's Trident SLBMs.
The SNP's priority is stated as the "speediest and safest possible transition" of nuclear weapons from Scotland, although it notes that the "detailed process and timetable for removal would be a priority for negotiation between the Scottish government and the Westminster government".
The paper also outlines the SNP's vision for a future Scottish Defence Force. The land force element would comprise a headquarters and single combined-arms brigade, initially armed with equipment currently in UK service. This would include six helicopters and two light armoured reconnaissance units, two light artillery units, although no mention is made of any heavy armour capability.
Scotland would hope to inherit on independence 2 of the Royal Navy's Type 23 frigates, a 'command platform', plus 10 smaller patrol and mine vessels. They would be supported by the procurement of about four maritime patrol aircraft, which are planned to enter service by 2021.
The combat edge of a Scottish Air Force would be provided by 12 Eurofighter Typhoons, potentially later 16 Typhoons, with transport provided by 6 Lockheed Martin C-130J Hercules aircraft and a helicopter squadron, all from current Royal Air Force stocks - the SNP hopes.
Meanwhile, the White Paper outlines a force strength of 7,500 regular personnel and 2,000 reservists in 2016, rising to 10,000/3,500 in 2021 and 15,000/5,000 in 2026.
Manning is likely to be a key issue at first for any future Scottish Defence Force, with the White Paper containing no plans to transfer 'Scottish' units on mass into Scottish hands. Instead it will be down to individual soldiers, the SNP states, to choose their allegiance (although Westminster may take a different view).
Wednesday, November 27, 2013
Anthropogenic emissions of methane in the United States
Miller et al
This study quantitatively estimates the spatial distribution of anthropogenic methane sources in the United States by combining comprehensive atmospheric methane observations, extensive spatial datasets, and a high-resolution atmospheric transport model. Results show that current inventories from the US Environmental Protection Agency (EPA) and the Emissions Database for Global Atmospheric Research underestimate methane emissions nationally by a factor of ∼1.5 and ∼1.7, respectively. Our study indicates that emissions due to ruminants and manure are up to twice the magnitude of existing inventories. In addition, the discrepancy in methane source estimates is particularly pronounced in the south-central United States, where we find total emissions are ∼2.7 times greater than in most inventories and account for 24 ± 3% of national emissions. The spatial patterns of our emission fluxes and observed methane–propane correlations indicate that fossil fuel extraction and refining are major contributors (45 ± 13%) in the south-central United States. This result suggests that regional methane emissions due to fossil fuel extraction and processing could be 4.9 ± 2.6 times larger than in EDGAR, the most comprehensive global methane inventory. These results cast doubt on the US EPA’s recent decision to downscale its estimate of national natural gas emissions by 25–30%. Overall, we conclude that methane emissions associated with both the animal husbandry and fossil fuel industries have larger greenhouse gas impacts than indicated by existing inventories.
Silence on Shangri-La: Attenuation of Huygens Acoustic Signals Suggests Surface Volatiles
Lorenz et al
Characterize and understand acoustic instrument performance on the surface of Titan
The Huygens probe measured the speed of sound in Titan’s atmosphere with a 1 MHz pulse time-of-flight transducer pair near the bottom of the vehicle. We examine the fraction of pulses correctly received as a function of time.
This system returned good data from about 11 km altitude, where the atmosphere became thick enough to effectively transmit the sound, down to the surface just before landing: these data have been analyzed previously. After an initial transient at landing, the instrument operated nominally for about 10 minutes, recording pulses much as during descent. The fraction of pulses detected then declined and the transmitted sound ceased to be detected altogether, despite no indication of instrument or probe configuration changes.
The most likely explanation appears to be absorption of the signal by polyatomic gases with relaxation losses at the instrument frequency, such as ethane, acetylene and carbon dioxide. These vapors, detected independently by the GCMS instrument, were evolved from the surface material by the warmth leaking from the probe, and confirm the nature of the surface materials as ‘damp’ with a cocktail of volatile compounds. Some suggestions for future missions are considered.
Plant remains from Early Cretaceous deposits on the Goban Spur, Bay of Biscay, North Atlantic Ocean, and their palaeoenvironmental significance
Batten et al
Site 549 of the Deep Sea Drilling Project was drilled on the Goban Spur in the Bay of Biscay in 1981. The core recovered from this North Atlantic location included 290 m of Barremian and possibly partly Hauterivian “syn-rift” deposits overlain unconformably by rocks of early Albian age. The number and variety of spores and pollen grains in the palynomorph assemblages and associated palynofacies through these units together with the presence of some pieces of wood, fragments of foliage, and a few megaspores in the lowest part of the Cretaceous succession suggest that the source area vegetation was, at least initially, relatively close to the site of deposition. Ginkgoalean, bennettitalean, and other gymnosperm groups are represented in the plant mesofossil assemblage but most of the fragments of foliage show cheirolepidiaceous characteristics. Five species belonging to this family have been identified and described. Two of these, Frenelopsis atlantica Zhou and Batten and Frenelopsis? alvinii Zhou and Batten, are new and one is unnamed. The composition of the three informally identified suites of spore and pollen assemblages recovered from 49 samples through the Early Cretaceous succession is consistent with age determinations of parts of it determined previously on the basis of dinoflagellate cysts, foraminifera, nannoplankton, and other fossils.
Climate and humans set the place and time of Proboscidean extinction in late Quaternary of South America
Lima-Ribeiro et al
The late Quaternary extinctions have been widely debated for a long time, but the varying magnitude of human vs. climate change impacts across time and space is still an unresolved question. Here we assess the geographic range shifts in response to climate change based on Ecological Niche Models (ENMs) and modeled the timing for extinction under human hunting scenario, and both variables were used to explain the extinction dynamics of Proboscideans during a full interglacial/glacial cycle (from 126 ka to 6 ka) in South America. We found a large contraction in the geographic range size of two Proboscidean species studied (Cuvieronius hyodon and Notiomastodon platensis) across time. The largest contractions of their geographical ranges occurred in the northern part of South America, where we previously reported no evidence of coexistence among earliest humans and non-sloth megafauna, including Proboscideans. Our results herein support a strong effect of climatic changes on geographical range dynamics of Proboscideans throughout late Quaternary, although this does not fully support climate change as the single cause of their extinctions. We show that both Proboscideans were narrowly distributed on scattered patches of suitable habitats (i.e., refugia) around 11 ka, period in which the earliest humans potentially arrived in South America, increasing the population density thereafter. Under this overall unsuitable climatic condition at 11 ka, both Proboscideans would be extinct after around 550 years of human hunting, but if climatic conditions were suitable like in Last Glacial Maximum (LGM), the time-for-extinction would be at least 3 times longer under the same human hunting pressures. Thus, our findings support the “Broken Zig-Zag” model and show that South American Proboscideans might have been completely extinct due to human impacts during periods of climate crisis. We conclude, in agreement with an increasing body of evidence in the recent literature, that the late Quaternary megafaunal extinction event was the result of additive effects from different stressors, and that the relative magnitude of these impacts vary across space and time. Indeed, climate changes set the place where the Proboscideans were extinct in South America, whereas the humans set the time of these extinctions.
Biopores and root features as new tools for improving paleoecological understanding of terrestrial sediment-paleosol sequences
Gocke et al
The important role of roots and rhizosphere processes is accepted nowadays for the top soil, but is still under debate for the deep subsoil including soil parent material. Especially for terrestrial sediments like loess and dune sands, roots and root traces are mostly recognized in profile description, but not interpreted in the paleoenvironmental context. Further, synchrony of sediment deposition and root trace formation is commonly assumed within a respective stratigraphic unit (sediment or paleosol). This is challenged by partially large maximum rooting depth of plants, exceeding the soil depth, and by frequent occurrence of secondary carbonates and biopores of potential root origin below recent soil and paleosols. To improve understanding of paleoenvironmental records in terrestrial sediment-paleosol sequences, recent roots and root traces, including calcified roots and root-derived biopores, were investigated in six soil, loess and dune sand profiles across Middle and Southeastern Europe. Visualization of small carbonate accumulations (diameter ≤ 1 mm), frequently called ‘pseudomycelia‘, by X-ray microtomographic scanning, and morphologic comparison with rhizoliths (calcified roots; diameter mostly 3–20 mm, up to 100 mm possible) indicate root origin of the former, therefore requiring renaming to so-called microrhizoliths. Quantification of roots, biopores, rhizoliths and microrhizoliths on horizontal levels yielded maximum frequencies of 2,100 m- 2, 4,100 m- 2, 196 m- 2 and 12,800 m- 2, respectively. Considering the pore volume remaining from former root growththis indicates their significant contribution to structural properties of the sediments and paleosols. Depth distribution of roots and root traces was frequently related to soil and paleosols, respectively, and mostly showed maximum frequencies within or immediately below these units. Root traces are therefore not necessarily directly associated to the surrounding sediment, but are typically of younger age. The time lag between root traces and the surrounding stratigraphic unit can vary between small time periods (likely decades to centuries) in case of microrhizoliths and several millenia in case of larger rhizoliths penetrating several stratigraphic units. With assumed radii of former rhizosphere extention of 5 mm for microrhizoliths, a frequency of 12,500 m- 2 corresponded to 100% rhizosphere area in the respective depth interval. These findings emphasize the meaning of root traces in sediment-paleosol sequences. Potential temporal and spatial inhomogeneity of root growth on the one hand, especially for shrub and tree vegetation, and occurrence of root remains of different age and origin in identical depth intervals on the other hand, hamper the assessment of the chronologic context of these with the surrounding sediment or paleosol. Nevertheless, root traces in terrestrial archives provide valuable information with respect to paleovegetation and paleoenvironmental conditions, if their chronological context is known.
As the first round of nuclear talks got under way on Nov. 7 in Geneva, select leaks to the Western media suggested that Saudi Arabia was planning to buy nuclear weapons from Pakistan. A month before, former Israeli military intelligence chief Amos Yadlin told a conference in Sweden that if Iran got a bomb, “the Saudis will not wait one month. They already paid for the bomb, they will go to Pakistan and bring what they need to bring.”
There may be truth to Yadlin’s comments. Saudi Arabia has backed and at times helped fund Pakistan’s nuclear program, according to proliferation experts. (The program became public in 1998.) That doesn’t mean that acquiring a nuclear bomb is as easy as shipping it across the Arabian Sea. Saudi, as a signatory to the Nuclear Non-Proliferation Treaty, would risk global reproach, possible sanctions and the launch of a regional arms race if it had its own bomb. A more likely scenario, says Gary Samore, Obama’s former arms control advisor and Director for Research at the Belfer Center for Science and International Affairs at Harvard University, would be some sort of pact that could see Pakistani nuclear weapons moved to Saudi Arabia. “Even if U.S. diplomacy fails and Iran gets nuclear weapons, Pakistan isn’t just going to hand over nuclear weapons; it’s more likely that Pakistan would station forces in Saudi, and those forces will have the ability to deploy nuclear weapons from Saudi soil,”— much like American troops are able to do in Europe, with out contravening those country’s non-proliferation treaties.
Still, such a pact would have significant drawbacks, points out Gause. Pakistan may not be willing to attack its neighbor Iran for fear of repercussions, and it would be a death-knell for the U.S.-Saudi friendship. “In terms of putting at risk relations with the United States, a Pakistani nuclear pact would be the most provocative Saudi foreign policy decision since the 1973 oil embargo,” says Gause. That might serve Saudi pique at being sidelined by its old ally America as that ally pursues a lasting deal with Iran, but it would be ultimately self-defeating. Better for Saudi in the long run would be a deal that brings Iran closer to the U.S., and further from a bomb.
Watch and see. We might be witnessing a beginning of a new shift in power. Pakistan as a guaranteer of Saudi Arabia is a pretty profound change... and if Pakistani nukes were there, India's position would shift, too. And the US as well.
Ukrainian President Viktor Yanukovich said on Tuesday that the terms of a financial aid offer from the EU had been humiliating and he would consider signing a landmark free trade pact with the bloc only when it suited Ukraine's interests.
He said the EU had offered aid worth 610 million euros and had linked this to Ukraine agreeing on a new program with the International Monetary Fund which itself had laid down unacceptable conditions.
"We don't have to be humiliated like this. We are a serious country. A European one," he said in a television declaration.
And pride maketh you a Russian now, President Yanukovich.
Two B-52 bombers flew unarmed and unescorted through a no-fly zone declared by China over disputed islands in the East China Sea Monday in a direct challenge by the U.S. to Beijing’s attempts to intimidate its neighbors, defense officials said Tuesday.
The overflight came less than 48 hours after Defense Secretary Chuck Hagel said that the U.S. would not recognize China’s “Air Defense Identification Zone” over the uninhabited Senkaku Islands, claimed by Japan, China and Taiwan.
A Pentagon spokesman, who spoke on condition of anonymity, confirmed that U.S. aircraft flying out of Guam had carried out the overflight on a previously scheduled training mission and returned to Andersen Air Base on Guam “without incident.”
The spokesman would not identify the type of aircraft but other officials said they were B-52H Stratofortresses. In August, B-52s from the 20th Bomber Squadron at Barksdale Air Force Base, La., deployed to Guam as part of the U.S. effort to re-balance forces to the Pacific.
Tuesday, November 26, 2013
me at the hospital yesterday
I have a lung infection of some kind which will not let go. I've had it for a week now and the dox are concerned. They are concerned enough they asked me to wear a mask in public. Work exiled me. So I am home. Sleeping mostly. Replying to rocket business stuff, too. Also leaving my lungs on the floor as sacrifices to the dark gods of pain, maliciousness and pettiness.
Many scientists believe that global warming will come to an end if, some day, human succeeds in stopping the release of greenhouse gas emissions into the atmosphere. It would, indeed, be hotter on Earth than before industrialisation, but nonetheless it would not get even hotter. Climate physicist Thomas Frölicher questions this notion by using model calculations and creates a more pessimistic picture in a study published in the scientific journal Nature Climate Change. According to his model calculations, it is very possible that the Earth's atmosphere could continue to warm for hundreds of years even after a complete stop of CO2 emissions, and that temperature levels stabilise at an even higher level at a later stage. "In the long term, the temperature increase could be 25 per cent greater than assumed today," says the scientist, who carries out research as an Ambizione Fellow of the Swiss National Science Foundation in ETH professor Nicolas Gruber's group.
If life does exist anywhere else in the universe, it may only be fleeting. Now scientists are researching how signs of life might look on dying planets.
Astronomers have discovered hundreds of distant alien planets in the past two decades. Future missions could detect potential signs of life called biosignatures on those worlds, such as oxygen or methane in their atmospheres.
Astrobiologist Jack O'Malley-James at the University of St. Andrews in Fife, Scotland and his colleagues noted that biosignatures of life on Earth have not remained the same over time, but have altered considerably over its history. This led the researchers to speculate about how Earth and other planets might look in the future.
"Astrobiology as a field seems to put a lot more focus on the origins of life and how to find life beyond Earth, but less emphasis is put on the end of life, which is what got me interested in finding out more about how biospheres on other planets might meet their ends, and by extension, how long we could expect to detect life on a habitable planet over the course of its habitable lifetime," said O'Malley-James, the lead author of the study.
The scientists were testing a computer model of the climates and biospheres — the overall life — of possible exoplanets.
"That was when the idea came about to run this model forward in time to see when all water and all life would disappear from the planet," O'Malley-James said.
The Sun is a middle-aged star, currently about 4.6 billion years old. In the later stages of its evolution, about 2 billion to 3 billion years from now, the Sun will grow much hotter, leading to much higher surface temperatures on the future Earth and thus far harsher environments for any last life to grow and survive on the planet.
The research team modeled the biosignature gases Earth's biosphere would generate up to 2.8 billion years from the present.
Scientists should take the conservative approach when searching for habitable zones where life-sustaining planets might exist, according to James Kasting, Evan Pugh Professor of Geosciences at Penn State, including when building Terrestrial Planet Finders.
That conservative approach means looking for planets that have liquid water and solid or liquid surfaces, as opposed to gas giants like Jupiter or Saturn. The habitable zone in a solar system is the area where liquid water, and by extension life, could exist. Defining the habitable zone is key to the search for life sustaining planets in part because the idea of a habitable zone is used in designing the space-based telescopes that scientists would use to find planets where metabolism -- and potentially life -- life might exist.
"It's one of the biggest and oldest questions that science has tried to investigate: is there life off the earth?" Kasting said. "NASA is pursuing the search for life elsewhere in the Solar System, but some of us think that looking for life on planets around other stars may actually be the best way to answer this question."
Recent research by Ravi Kopparapu, a post-doctoral researcher working with Kasting, suggests that the frequency of Earth-like planets in the habitable zones of stars known as M-dwarfs is 0.4 to 0.5. To find four potential Earth-like candidates, scientists would need to survey the habitable zones of about 10 cool stars. This data came from NASA's Kepler Space Telescope, which collected information on transiting exoplanets for almost four years before being partially disabled. Previous estimates put this frequency at 0.1, which would have forced scientists using planet finders to survey more stars, searching farther away from our Solar System.
An even more recent estimate of the frequency of Earth-like planets was announced by Eric Petigura and colleagues at the Kepler Science Conference in early November. They calculated the figure at 0.22 around stars more similar to the Sun. But Kopparapu and Kasting think Petigura and colleagues' estimate could be too high by a factor of two because they used an overly optimistic estimate for the width of the habitable zone. If so, then the old value of 0.1 may be closer to the truth.
The ability of a planet to sustain liquid water is traditionally part of the criteria when searching for life-sustaining planets. While some have argued that subsurface water would be enough to sustain life, testing that hypothesis remotely would be virtually impossible, so the focus for astronomers should remain on surface water, Kopparapu and Kasting note in a special issue of the Proceedings of the National Academy of Sciences.
The ‘Unicorn’ Dinosaur That Wasn’t: A New Reconstruction of the Crest of Tsintaosaurus and the Early Evolution of the Lambeosaurine Crest and Rostrum
Albert Prieto-Márquez and Jonathan R. Wagner
The lambeosaurine Tsintaosaurus spinorhinus has traditionally been reconstructed with an elevated, hollow, spike-like crest composed entirely of the nasal bones, although this has been disputed. Here, we provide a new reconstruction of the skull of this species based on reexamination and reinterpretation of the morphology and articular relationships of the type and Paratype skulls and a fragmentary crest. We confirm the presence of a supracranial crest composed of the elevated nasal bones, but also including the premaxillae. We hypothesize that the crest is a tall, lobate, hollow structure that projects dorsally and slightly caudally a distance greater than the height of the skull along the quadrate. In our reconstruction, the nasal passage passes through the crest, but enters the skull rostral to the tubular process of the nasals, not through it. Tsintaosaurus spinorhinus is rediagnosed on the basis of a suite of cranial autapomorphies including a circumnarial fossa subdivided into three accessory fossae, prefrontal with ascending rostral process and lateral flange, nasals fused sagittally to form elongate tubular process that rises dorsally from skull roof, each nasal being expanded rostrocaudally into a rhomboid distal process, and medial processes of premaxillae at the summit of the cranial crest inserted between rhomboid processes of nasals. Tsintaosaurus spinorhinus lacks characters that are present in more derived lambeosaurines (parasaurolophins and lambeosaurins), such as rotation of the caudal margin of the crest to an acute angle with the skull roof, lateral processes of the nasals that enclose part of the intracranial cavity and participate in the formation of the walls of the common median chamber, and a smooth narial fossa lacking ridges and accessory fossae. We hypothesize that ancestrally the rostrum of lambeosaurines may have been more similar to that in Saurolophinae, and became subsequently reduced in complexity during evolution of the group.
Awesomely Intact Ceratopsid Chasmosaurus belli Juvenile Fossil Found From Campanian Cretaceous Canada
The tiny, intact skeleton of a baby rhinoceroslike dinosaur has been unearthed in Canada.
The toddler was just 3 years old and 5 feet (1.5 meters) long when it wandered into a river near Alberta, Canada, and drowned about 70 million years ago. The beast was so well-preserved that some of its skin left impressions in the nearby rock.
The fossil is the smallest intact skeleton ever found from a group of horned, plant-eating dinosaurs known as ceratopsids, a group that includes the iconic Triceratops.
Acid rain and ozone depletion from pulsed Siberian Traps magmatism
Black et al.
The Siberian Traps flood basalts have been invoked as a trigger for the catastrophic end-Permian mass extinction. Widespread aberrant plant remains across the Permian-Triassic boundary provide evidence that atmospheric stress contributed to the collapse in terrestrial diversity. We used detailed estimates of magmatic degassing from the Siberian Traps to complete the first three-dimensional global climate modeling of atmospheric chemistry during eruption of a large igneous province. Our results show that both strongly acidic rain and global ozone collapse are possible transient consequences of episodic pyroclastic volcanism and heating of volatile-rich Siberian country rocks. We suggest that in conjunction with abrupt warming from greenhouse gas emissions, these repeated, rapidly applied atmospheric stresses directly linked Siberian magmatism to end-Permian ecological failure on land. Our comprehensive modeling supplies the first picture of the global distribution and severity of acid rain and ozone depletion, providing testable predictions for the geography of end-Permian environmental proxies.
A funny little map I found. I have nontrivial doubts about it, to say the least, but Catalonia is watching Scotland closely. However, if you Balkanized the big countries enough, Brussels becomes even more important, so long as the new countries are welcomed into the EU immediately.
Monday, November 25, 2013
The Scottish government will focus on the potential economic gains from independence on Tuesday when it unveils its vision for the future if Scots choose to end a 306-year union with England.
Alex Salmond, head of a devolved government in Scotland - which for now is still part of the United Kingdom - has promised to spell out exactly what would happen if Scots vote on September 18 next year to leave the UK.
With separatists lagging in opinion polls, his Scottish National Party is hoping the 670-page blueprint will win over the many skeptics, answering questions the SNP has been accused of dodging, such as the currency of an independent Scotland, its membership of the European Union and border arrangements.
"We are setting out a positive plan for job opportunities and economic growth based on Scotland's vast natural resources, key growth sectors and human talent," said Salmond, whose party has a majority in Scotland's parliament.
Nicola Sturgeon, the deputy first minister, has described the document as "the most comprehensive and detailed blueprint ever drawn up for a prospective independent country".
If there was a tipping point, a moment that crystallized the anger building here toward the so-called technorati for driving up housing prices and threatening the city’s bohemian identity, it came in response to a diatribe posted online in August by a young Internet entrepreneur.
The author, a start-up founder named Peter Shih, listed 10 things he hated about San Francisco. Homeless people, for example. And the “constantly PMSing” weather. And “girls who are obviously 4s and behave like they’re 9s.”
The backlash was immediate. Fliers appeared on telephone poles calling Mr. Shih a “woman hatin’ nerd toucher.” CheapAir offered him a free ticket back to New York. Readers responded that what they hated about San Francisco were “entitled” technology workers like him.
Mr. Shih, who said he received death threats after the post, deleted it and apologized.
But a nerve had been struck. As the center of the technology industry has moved north from Silicon Valley to San Francisco and the largess from tech companies has flowed into the city — Twitter’s stock offering unleashed an estimated 1,600 new millionaires — income disparities have widened sharply, housing prices have soared and orange construction cranes dot the skyline. The tech workers have, rightly or wrongly, received the blame.
Russia's Sukhoi T-50 (PAK-FA) fighter will complete factory trials by the end of 2013 and then begin state testing, the commander of the Russian Air Force, Lieutenant General Viktor Bondarev, has said.
State tests of the T-50 will take three years, at which point the Ministry of Defence will decide whether to accept it into service, Gen Bondarev told Russian magazine Voenno-Promyshlenny Kuryer .
Gen Bondarev also provided details on procurement of an interceptor to replace the Mikoyan MiG-31 'Foxhound'. The Sukhoi Su-35 'Flanker E' will be outfitted with modern air-to-air missiles by 2015 and, together with the T-50, will fulfil the air superiority mission, according to the general.
General Atomics unveiled a land-based artillery version of its Blitzer electromagnetic railgun (EMRG) at the Association of the US Army (AUSA) conference in Washington, DC, with a company official telling IHS Jane's that with adequate funding the concept could be demosntrated in "two to three years".
In 2007, building upon knowledge gained under an Office of Naval Research (ONR) Innovative Naval Prototype contract, GA initiated development of the Blitzer system using internal funds.
Despite 2010 testing that included firing a projectile up to Mach 5 speeds the USN opted to develop a larger railgun. General Atomics is now marketing Blitzer as a near-term railgun solution and is pursuing possible land, ship, and submarine-based variants.
A non-monotonic eddy diffusivity profile of Titan's atmosphere revealed by cassini observations
Li et al
Recent measurements from the limb-view soundings of Cassini/CIRS and the stellar occultations from Cassini/UVIS revealed the complete vertical profiles of minor species (e.g., C2H2 and C2H4) from 100 to 1000km in the atmosphere of Titan. In this study, we developed an inversion technique to retrieve the eddy diffusion profile using C2H2 as a tracer species. The retrieved eddy profile features a low eddy diffusion zone near the altitude of the detached haze layer (∼550km), which could be a consequence of stabilization through aerosol heating. Photochemical modeling results using the retrieved eddy profile are in better agreement with the Cassini measurements than previous models. The underestimation of C2H4 in the stratosphere has been a long-standing problem in planetary photochemical modeling, and the new eddy diffusion profile does not solve this problem. In order to match the observations, we suggest a new expression for the rate coefficient of the key reaction, H+C2H4+M⟶C2H5+M. The new reaction rate coefficient is estimated to be ∼10 times lower than that used by Moses et al. (2005)'s model, and should be validated in the laboratory and tested against the hydrocarbon chemistry of giant planets.
A Florida State University scientist has uncovered what may be the first recognized example of ancient Martian crust.link.
The work of Munir Humayun — a professor in FSU's Department of Earth, Ocean and Atmospheric Science and a researcher at the National High Magnetic Field Laboratory (MagLab) — is based on an analysis of a 4.4 billion-year-old Martian meteorite that was unearthed by Bedouin tribesmen in the Sahara desert. The rock (NWA 7533) may be the first recognized sample of ancient Martian crust and holds a wealth of information about the origin and age of the Red Planet's crust.
Humayun's groundbreaking discoveries about the crust and what it reveals about the Red Planet's origins will be published in the journal Nature.
In order to detect minute amounts of chemicals in this meteorite, Humayun and his collaborators performed complex analysis on the meteorite using an array of highly sophisticated mass spectrometers in the MagLab's geochemistry department. High concentrations of trace metals such as iridium, an element that indicates meteoritic bombardment, showed that this meteorite came from the elusive cratered area of Mars' southern highlands.
"This cratered terrain has been long thought to hold the keys to Mars' birth and early childhood," Humayun said.
While craters cover more than half of Mars, this is the first meteoric sample to come from this area and the first time researchers are able to understand Mars' early crustal growth.
Using the chemical information found in pieces of soil contained in the meteorite, the researchers were able to calculate the thickness of Mars' crust. Their calculation aligned with estimates from independent spacecraft measurements and confirms that Mars did not experience a giant impact that melted the entire planet in its early history.
Using a powerful microprobe at Curtin University in Perth, Australia, the team dated special crystals within the meteorite — called zircons — at an astounding 4.4 billion years old.
"This date is about 100 million years after the first dust condensed in the solar system," Humayun said. "We now know that Mars had a crust within the first 100 million years of the start of planet building, and that Mars' crust formed concurrently with the oldest crusts on Earth and the Moon."
Much like the Grand Canyon, Nanedi Valles snakes across the Martian surface suggesting that liquid water once crossed the landscape, according to a team of researchers who believe that molecular hydrogen made it warm enough for water to flow.
The presence of molecular hydrogen, in addition to carbon dioxide and water, could have created a greenhouse effect on Mars 3.8 billion years ago that pushed temperatures high enough to allow for liquid water, the researchers state in the current issue of Nature Geoscience.
The team includes Ramses M. Ramirez, a doctoral student working with James Kasting, Evan Pugh Professor of Geosciences, Penn State.
Previous efforts to produce temperatures warm enough to allow for liquid water used climate models that include only carbon dioxide and water and were unsuccessful. The researchers used a model to show that an atmosphere with sufficient carbon dioxide, water and hydrogen could have made the surface temperatures of Mars warm to above freezing. Those above-freezing temperatures would allow liquid water to flow across the Martian surface over 3.8 billion years ago and form the ancient valley networks, such as Nanedi Valles, much the way sections of the Grand Canyon snake across the western United States today.
"This is exciting because explaining how early Mars could have been warm and wet enough to form the ancient valleys had scientists scratching their heads for the past 30 years," said Ramirez. "We think we may have a credible solution to this great mystery."
The researchers note that one alternative theory is that the Martian valleys formed after large meteorites bombarded the planet, generating steam atmospheres that then rained out. But this mechanism cannot produce the large volumes of water thought necessary to carve the valleys.
"We think that there is no way to form the ancient valleys with any of the alternate cold early Mars models," said Ramirez. "However, the problem with selling a warm early Mars is that nobody had been able to put forth a feasible mechanism in the past three decades. So, we hope that our results will get people to reconsider their positions."
Ramirez and post-doctoral researcher Ravi Kopparapu co-developed a one-dimensional climate model to demonstrate the possibility that the gas levels from volcanic activity could have created enough hydrogen and carbon dioxide to form a greenhouse and raise temperatures sufficiently to allow for liquid water. Once they developed the model, Ramirez ran the model using new hydrogen absorption data and used it to recreate the conditions on early Mars, a time when the sun was about 30 percent less bright than it is today.
"It's kind of surprising to think that Mars could have been warm and wet because at the time the sun was much dimmer," Ramirez said.