Observations of the 1006 Supernova by Ibn Sina (Avicenna)

An Arabic report about supernova SN 1006 by Ibn Sina (Avicenna)

Authors:

Neuhaeuser et al

Abstract:

We present here an Arabic report about supernova 1006 (SN 1006) written by the famous Arabic scholar Ibn Sina (Lat. Avicenna, AD 980-1037), which was not discussed in astronomical literature before. The short observational report about a new star is part of Ibn Sina's book called al-Shifa', a work about philosophy including physics, astronomy, and meteorology. We present the Arabic text and our English translation. After a detailed discussion of the dating of the observation, we show that the text specifies that the transient celestial object was stationary and/or tail-less ("a star among the stars"), that it "remained for close to three months getting fainter and fainter until it disappeared", that it "threw out sparks", i.e. it was scintillating and very bright, and that the color changed with time. The information content is consistent with the other Arabic and non-Arabic reports about SN 1006. Hence, it is quite clear that Ibn Sina refers to SN 1006 in his report, given as an example for transient celestial objects in a discussion of Aristotle's "Meteorology". Given the wording and the description, e.g. for the color evolution, this report is independent from other reports known so far.

"Late Antique Little Ice Age" Contributed to Decline of Eastern Roman Empire, Bolstered Arab Conquests?

Researchers from the international Past Global Changes (PAGES) project write in the journal Nature Geoscience that they have identified an unprecedented, long-lasting cooling in the northern hemisphere 1500 years ago. The drop in temperature immediately followed three large volcanic eruptions in quick succession in the years 536, 540 and 547 AD (also known as the Common Era CE). Volcanoes can cause climate cooling by ejecting large volumes of small particles - sulfate aerosols - that enter the atmosphere blocking sunlight.

Within five years of the onset of the "Late Antique Little Ice Age", as the researchers have dubbed it, the Justinian plague pandemic swept through the Mediterranean between 541 and 543 AD, striking Constantinople and killing millions of people in the following centuries. The authors suggest these events may have contributed to the decline of the eastern Roman Empire.

Lead author, dendroclimatologist Ulf Büntgen from the Swiss Federal Research Institute said, "This was the most dramatic cooling in the Northern Hemisphere in the past 2000 years."

A later "Little Ice Age" between 14th and 19th centuries has been well documented and linked to political upheavals and plague pandemics in Europe, but the new study is the first to provide a comprehensive climate analysis across both Central Asia and Europe during this earlier period.

"With so many variables, we must remain cautious about environmental cause and political effect, but it is striking how closely this climate change aligns with major upheavals across several regions," added Büntgen.

The multidisciplinary research team made up of climatologists, naturalists, historians and linguists mapped the new climate information against a particularly turbulent period in history in Europe and central Asia. The volcanic eruptions probably affected food supplies - a major famine struck the region at precisely this time followed immediately by the pandemic.

Further south, the Arabian Peninsula received more rain allowing more vegetation to grow. The researchers speculate this may have driven expansion of the Arab Empire in the Middle East because the vegetation would have sustained larger herds of camels used by the Arab armies for their campaigns.

In cooler areas, several tribes migrated east towards China, possibly driven away by a lack of pastureland in central Asia. This led to hostilities between nomadic groups and the local ruling powers in the steppe regions of northern China. An alliance between these steppe populations and the Eastern Romans brought down the Sasanian Empire in Persia, the final empire in the region before the rise of the Arab Empire.

The researchers write, "The Late Antique Little Ice Age fits in well with the main transformative events that occurred in Eurasia during that time."

link.

Did Homo sapiens Come out of Africa Once or Multiple Times as Climate & Precipitation Allowed?

Considerable debate surrounds the migration of human populations out of Africa. Two predominant hypotheses concerning the timing contrast in their emphasis on the role of the Arabian interior and its changing climate. In one scenario, human populations expanded rapidly from Africa to southern Asia via the coastlines of Arabia approx. 50,000 to 60,000 years ago. Another model suggests that dispersal into the Arabian interior began much earlier (approx. 75,000 to 130,000 years ago) during multiple phases, when increased rainfall provided sufficient freshwater to support expanding populations.

Ash Parton and colleagues fall into the second camp, writing, "The dispersal of early human populations out of Africa is dynamically linked with the changing climate and environmental conditions of Arabia. Although now arid, at times the vast Arabian deserts were transformed into landscapes littered with freshwater lakes and active river systems. Such episodes of dramatically increased rainfall were the result of the intensification and northward displacement of the Indian Ocean Monsoon, which caused rainfall to reach across much of the Arabian Peninsula."

Parton and colleagues present a unique alluvial fan aggradation record from southeast Arabia spanning the past approx. 160,000 years. Situated along the proposed southern dispersal route, the Al Sibetah alluvial fan sequence provides a unique and sensitive record of landscape change in southeast Arabia. This record is to date the most comprehensive terrestrial archive from the Arabian Peninsula, and provides evidence for multiple humid episodes during both glacial and interglacial periods.

Evidence from the Al Sibetah alluvial fan sequence indicates that during insolation maxima, increased monsoon rainfall led to the widespread activation of drainage systems and grassland development throughout regions that were important for the dispersal of early human populations.

link.

Salt Domes in Arabia Dating From Ediacaran & Cryogenian NeoProterozoic

Salt domes of the UAE and Oman: probing eastern Arabia

Authors:

Thomas et al

Abstract:

The emergent salt domes of the United Arab Emirates (UAE) have been investigated in detail and examples from central Oman have been studied for comparison. The salt domes contain exotic clasts of igneous, sedimentary and low-grade metamorphic rocks of the Arabian basement that have been brought to the surface from depths of over 8 km. The clasts thus provide an opportunity to examine the lithology, geochemical composition and age of the “basement” underlying this part of eastern Arabia, where no other outcrops are available for direct study. Five volcanic rocks give consistent latest Ediacaran U-Pb zircon crystallisation dates of ca. 560 to 545 Ma, with Neoproterozoic, Palaeoproterozoic and Neoarchaean ages of inherited zircons. These rocks, although strongly altered, preserve geochemical characteristics compatible with formation in a within-plate, extensional setting along the northern edge of Gondwana, adjacent to Prototethys. U-Pb analyses of detrital zircons in sedimentary and low-grade metamorphic rocks indicate deposition younger than ca. 597 Ma in UAE and less than 734 Ma in Oman. The two UAE sedimentary rocks may correlate with the Shuram and Khufai Formations of the Nafun Group (Huqf Supergroup) in Oman. Like the volcanic rocks, the two sedimentary samples from the UAE show derivation from the erosion of Neo-, Palaeoproterozoic and Neoarchaean sources. These sources could be from the Arabian basement itself or from other basement blocks such as those embedded in present-day Iran and Afghanistan, the precise whereabouts of which in Neoproterozoic times remains somewhat uncertain. The zircon age spectra of samples from the UAE show Neoproterozoic age peak characteristics of sources from both the western and eastern Arabian basement blocks, indicating that the two segments were juxtaposed by about 597 Ma, the maximum age of their deposition.

A Freshwater Oasis Existed in the Nefud Desert at the Pleistocene/Holocene Boundary

Epipalaeolithic occupation and palaeoenvironments of the southern Nefud desert, Saudi Arabia, during the Terminal Pleistocene and Early Holocene

Authors:

Hilbert et al

Abstract:

The transition from the Terminal Pleistocene to the Early Holocene is poorly represented in the geological and archaeological records of northern Arabia, and the climatic conditions that prevailed in the region during that period are unclear. Here, we present a new record from the site of Al-Rabyah, in the Jubbah basin (southern Nefud desert, Saudi Arabia), where a sequence of fossiliferous lacustrine and palustrine deposits containing an archaeological assemblage is preserved. Sedimentological and palaeoenvironmental investigations, both at Al-Rabyah and elsewhere in the Jubbah area, indicate phases of humid conditions, during which shallow lakes developed in the basin, separated by drier periods. At Al-Rabyah, the end of a Terminal Pleistocene phase of lake expansion has been dated to ∼12.2 ka using optically stimulated luminescence (OSL), with a mid-Holocene humid phase dated to after ∼6.6 ka. Palaeoecological reconstructions based primarily on non-marine molluscs and ostracods from the younger lacustrine deposits indicate a relatively shallow body of freshwater surrounded by moist, well-vegetated environments. A lithic assemblage characterized by bladelets and geometric microliths was excavated from sediments attributed to a drier climatic phase dated to ∼10.1 ka. The lithic artefact types exhibit similarities to Epipalaeolithic industries of the Levant, and their occurrence well beyond the ‘core region’ of such assemblages (and at a significantly later date) has important implications for understanding interactions between Levantine and Arabian populations during the Terminal Pleistocene–Early Holocene. We suggest that the presence of foraging populations in the southern Nefud during periods of drier climate is due to the prolonged presence of a freshwater oasis in the Jubbah Basin during the Terminal Pleistocene–Early Holocene, which enabled them to subsist in the region when neighbouring areas of northern Arabia and the Levant were increasingly hostile.

Evidence of at Least Three Proterozoic Islands Arcs in the Northern Arabian–Nubian Shield

Three successive Proterozoic island arcs in the Northern Arabian–Nubian Shield: Evidence from SIMS U–Pb dating of zircon

Authors:

Eyal et al.

Abstract:

Four isolated metamorphic complexes located within post-collisional granitoids occupying up to 70% of the total area, were distinguished in Sinai (Egypt) and Elat area (southern Israel), the northernmost part of the Arabian–Nubian Shield. The metamorphic rocks include metasediments, felsic and mafic metavolcanic rocks intruded by granitic, dioritic, and gabbroic plutons, all subjected to penetrative deformation.

We present new SIMS U–Pb dating of zircons from 13 rock units comprising metasediments, volcanic rocks, gneisses and plutons from three metamorphic complexes (Sa'al, Feiran–Solaf, and Kid). In addition we present a SIMS U–Pb titanite age of a granitic gneiss previously dated using zircon. On the basis of the new and published U–Pb data, three successive Meso- to Neoproterozoic island arcs formed during a period of ca. 500 My are recognized. The Sa'al arc (represented by the oldest arc rocks in the ANS) evolved from 1.03 to 0.93 Ga (100 My); the Feiran–Elat arc developed from ca. 870 to 740 Ma (130 My), and the Kid arc formed from ca. 640 to 620 Ma (20 My). Evidence for an older, ca. 1.1 Ga, pre-Sa'al island arc was established from the zircon xenocryst population, though no exposures of rocks of this age were found. In the Sa'al and Kid arcs both volcanic and sedimentary rocks are preserved, whereas in the Elat–Feiran arc volcanic rocks are missing. We suggest that at ~ 700 Ma the Elat−Feiran arc was subjected to rifting that resulted in separating of the Qenaia block and its movement to the SE.

MERS May be Transmitted by Camel

Ever since people in the Middle East started dying of a mysterious new infection last year, scientists have been trying to pinpoint the source of the outbreak. Now they may finally have found a clue in an unlikely population: retired racing camels.

The Middle East respiratory syndrome (MERS) virus has sickened 94 people so far and killed 46 of them. While some patients have clearly been infected by others, there are also cases who have been nowhere near a known patient. So scientists suspect that one or more animal species harbor the virus and are transmitting it to people.

Like severe acute respiratory syndrome (SARS), MERS belongs to the coronaviruses, a group of viruses thought to originate in bats. Indeed, researchers investigating the new pathogen have found a closely related virus in bats in South Africa, and they have been able to grow the MERS virus in various bat cell lines. But direct infection by bats is unlikely because humans have very little interaction with them. Instead, researchers suspect that there is an intermediate host.

Now, an international team of scientists has tested the blood of various livestock species, including cattle, sheep, goats, and camels from the Netherlands, Spain, Chile, and Oman. They also tried to get samples from countries that have had human MERS cases, such as Saudi Arabia and Qatar, says Marion Koopmans, an infectious disease researcher at the National Institute of Public Health and the Environment in the Netherlands and one of the authors of the paper. But none of those countries cooperated.

To find out if the animals had been exposed to the MERS virus, the team screened the blood for antibodies against part of an important protein called spike on the viral surface. In order to ensure that the antibodies were specific to MERS, the scientists also tested the spike proteins of SARS and OC43, a human coronavirus closely resembling one circulating in cows, sheep, goats, and camels.

As expected, several animals had antibodies against OC43 in their blood, and none carried antibodies against SARS. But 50 dromedary camels from Oman that were tested all had antibodies against the MERS virus, the scientists report today in The Lancet Infectious Diseases. (This link will be live after 6:30 pm U.S. Eastern time.) "There is something circulating in dromedary camels that looks very much like MERS coronavirus," Koopmans says. The camels are all female retired racing camels used for breeding, but they belong to different owners in separate locations.

"That's a really important paper," says coronavirus researcher Matthew Frieman of the University of Maryland School of Medicine in Baltimore. "The fact that 100% of the Omanian camels are positive means that the result is highly significant and likely very real." Ian Lipkin, a virologist at Columbia University who's also searching for MERS in animal samples, says that the paper provides "compelling evidence that camelids [a group that includes camels, llamas, and alpacas] may be implicated." But the search for other hosts needs to continue, he adds.

New Record of the Carbon Cycle From Early Triassic Arabia

A new high-resolution δ13C record for the Early Triassic: Insights from the Arabian Platform

Authors:

1. M.O. Clarkson (a)
2. S. Richoz (b)
3. R.A. Wood (a)
4. F. Maurer (c)
5. L. Krystyn (d)
6. D.J. McGurty (a)
7. D. Astratti (e)

Affiliations:

a. The Grant Institute, School of Geosciences, University of Edinburgh, West Mains Road, Edinburgh, EH9 3JW, UK

b. Commission for the Palaeontological and Stratigraphical Research of Austria, Austrian Academy of Sciences c/o Institute of Earth Sciences, University of Graz, Heinrichstraße 26, 8010 Graz, Austria

c. Maersk Oil, Esplanaden 50, 1263 Copenhagen K, Denmark

d. Institute for Paleontology, Vienna University, Althanstrasse 14, 1090 Vienna, Austria

e. Schlumberger Stavanger Research Center, Risabergveien 3, P.O. Box 8013, N-4068 Stavanger, Norway

Abstract:

A new carbon isotope record with conodont biostratigraphy is presented for the entire Early Triassic from the Musandam Peninsula, United Arab Emirates (UAE). This is a near-continuous and exclusively shallow marine carbonate succession that allows analysis of a high-resolution primary carbon cycling signature in the absence of significant depth-dependent or lithologic controls. The Musandam carbon isotope record can be broadly correlated with global isotopic events but also resolves additional features, including the presence of significant negative events during the previously identified positive excursions at both the Dienerian/Smithian and Smithian/Spathian boundaries. A further positive event is revealed during the development of the mid-Spathian negative excursion, a feature not previously reported in any other section. These new short-lived events are probably related to the occurrence of the more widely recognized Early Triassic excursions, and may represent fluctuations in the driving mechanisms superimposed on the continued instability of the global carbon cycle in the aftermath of the end-Permian extinction. Together, these features highlight additional complexities to the Early Triassic carbon cycle perturbations than previously documented.

Significant Climate Change From Bajocian to Bathonian Jurassic in Negev

Jurassic flora of the Negev Desert: Plant taphonomy, palaeoecology and palaeogeographic inference

Authors:

1. Valentin Krassilov (a)
2. Alex Berner (b)
3. Sophia Barinova (a)

Affiliations:

a. Institute of Evolution, University of Haifa, Mount Carmel, Haifa 31905, Israel

b. Israel Institute of Technology, Haifa, 32000, Israel

Abstract:

Jurassic fossil plants of Makhtesh Ramon, the northern Negev, are collected from the Early Bajocian paralic Inmar Formation conformably overlain with the marine Mahmal Formation, which contains ammonite markers of the Middle–Upper Bajocian age. Plant remains occur in the thin ferruginous layers traceable all over the questa exposures, composed of re-deposited sand at the base and the fine-grained ferro-alumosilicate lamella on top. Plants are preserved as ferruginous molds of leafy shoots and reproductive material, buried by turbid run-over sand flows and embedded in the back-wash clayey deposits as calcified plant debris. On account of their peculiar taphonomy and elementary composition, the fossiliferous horizons are interpreted as tsunamites. The coastal plant assemblages are endemic at the syntaxonomic level, with Gondwana affinities extended to insular landmasses north of the Tethys. The abundance of bennettitalean plants and the inferred proximity of Araucaria-like brachyphylls gives the Bajocian Inmar flora a thermophilic paratropical aspect, while the Bathonian flora of Sinai is of a more temperate aspect, suggesting a major mid-Jurassic climate change.

More DIno Tracks Found in Yemen

Jurassic theropods and maybe sauropods are present.

Chemical Traces Hint Sponges Predate Snowball Earth

Chemical traces left in 635 million-year-old rocks in Oman provide the earliest evidence so far of animal life, researchers said Wednesday.

[...]

"There is a great wealth of evidence these sponges were the first multi-cellular organisms to exist."

Using a chemical analysis of molecules in rocks dated to 635 million years ago, the researchers discovered a modified form of cholesterol only produced by the sponges.

This suggests the creatures existed before a monstrous ice age that occurred around 630 million years ago, an interesting finding because many scientists believe the frozen periods spurred the development of complex forms of life, Summons said.

These simple forms of animal life came about 200 million years before land plants appeared on Earth, Summons added. The first single cell bacteria and other similar forms of life appeared around two-and-a-half billion years ago.

The oldest visible fossils of animals found in rocks are 580 million years old but the findings from this paper published in the journal Nature show that looking at molecular evidence is also key to better understanding evolution, he said.

hmmm. This one needs to have the paper before I'll say more than hmm. (wish eureka alert ad had this one up first)