Monday, 30 April 2012

Earthquake in Snowdonia National Park, Friday 27 April 2012.

On Friday 27 April 2012 slightly after 5.35 am British Summer Time (slightly after 4.35 am GMT) an Earthquake occurred in the north of the Snowdonia National Park, about 2.5 km east of the village of Bethesda in Gwynedd, at a depth of about 3 km. This was recorded by the British Geological Survey as measuring 1.4 on the Richter Scale.

The location of the 27 April Quake. BGS.

A quake as small as this is unlikely to have been felt unless anyone was very close to it, and there is no realistic danger of any damage or casualties. This area of Wales, while a long way from any active plate margin, is not completely strange to seismic activity, and will suffer several quakes of this magnitude in a year, and a larger quake roughly once every three years. Occasionally these quakes cause minor damage and injuries, and the only Earthquake related casualty ever recorded in Wales happened in Gwynedd, in 1940, when an elderly woman fell down a flight of stairs during a quake measuring 4.7 on the Richter Scale.

The source of individual quakes is hard to determine, as the rocks of Wales are subject to tectonic stresses from a variety of forces. The whole of Eurasia is being pushed eastwards by the expansion of the Atlantic Ocean. At the same time western Eurasia is being pushed northward by the impact of Africa. There is also expansion going on to a lesser extent under the North Sea, the Bay of Biscay and the Rhine Valley, all of which exert pressure on British rocks. In addition Britain is still subject to glacial rebound; the north of the country was covered by hundreds of meters of ice as recently as 10 000 years ago, pushing the lithosphere down into the underlying mantle. Since the ice melted the whole island has been slowly rebounding, exerting more stress on the rocks at the surface.

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An Assassin Bug from the Palaeocene of Spitsbergen Island.

The fossil Hymenopterites deperditus was first described from the Middle Palaeocene Firkanten Formation at Kapp Starostin on Spitsbergen Island in 1870. At the time it was believed to be the forewing of a wasp. In 1977 a review of H. deperditus suggested it might in fact be the wing of a seed, similar to that of a Sycamore.

In a forthcoming paper in the journal Acta Palaeonontoligica Polonica, a team of scientists lead by Torsten Wappler of the Steinmann-Institut für Geologie, Mineralogie und Paläontologie at Universität Bonn, re-examine H. deperditus and come to the conclusion it is in fact an Assassin Bug.

The Assassin Bugs, Reduviidae, are carnivorous True Bugs, often noted for their ability as mimics. Wappler et al. were not confident enough about the classification of H. deperditus to place it within a specific subfamily, but are confident enough to assign it to the Emesine-Saicine group, probably most closely related to the modern Saicinae.

(A-D) Modern Saicinid Assassin Bugs. (A) Tagalis.
inornata. (B) Polytoxus wahlbergi. (C) Saica tibialis. (D) Wings of Tagalis sp. (E-H) Hymenopterites deperditus. (E) Whole specimen with original labeling. (F) Close up of wing under normal light conditions. (G) Close up under alcohol. (H) Line drawing of wing. Abbreviations. –– Veins: Cu, cubitus; M, Media; Pcu, Postcubitus; R, Radius; Rs, radial sector; Cells: (M) cell between Cu and M; (t) triangular cell between Pcu and Cu. Scale Bars equal 1 mm.

The Saicinae are often wasp-mimics, which helps toe explain the original diagnosis of the wing as that of a wasp. The modern Saicinae are almost entirely tropical in distribution, with no known species surviving anything cooler than a Mediterranean climate. If the same is true for H. deperditus then subarctic Spitsbergen must have been considerably warmer in the Palaeocene; this is not a total surprise, other fossils from the Palaeocene of Spitsbergen have also suggested a warmer climate.

A fossil Assassin Bug has previously been described from the Cretaceous of China, but this is now thought to have been inaccurate. Assassin Bugs have also been reported from the Cretaceous of Mongolia, but not yet formally described. This makes the Palaeocene H. deperditus the oldest yet described Assassin Bug, the next members of the group appearing in the Eocene Messel Shale. The Saicinae are thought to be highly derived members of the group, suggesting that Assassin Bugs must have been around for quite a while before H. deperditus. This fits well with the known biogeography of the Assassin Bugs; they are found throughout the tropics, suggesting that the group must have come into existence before the breakup of Gondwanaland, about 100 million years ago.

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Friday, 27 April 2012

What a 4.6 million-year-old Three Toed Horse can tell us about the climate of Mid Pliocene Tibet.

The Indian Plate has been pushing into the Eurasian Plate from the south for about 55 million years, creating uplift in the Tibetan Plateau and Himalayas in the process. This has had a profound effect on the global climate and the development of monsoon rain patterns in Asia, and is therefore of great interest to scientists. The majority of this uplift is thought to have happened within the last 5.5 million years (the Himalayas are very young mountains) but the rate at which this happened is far from clear.

In a paper published in the Proceedings of the National Academy of Sciences on 23 April 2012, a team of scientists led by Tao Deng of the Key Laboratory of Evolutionary Systematics of Vertebrates at the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences and the Department of Geology at Northwest University discuss the functional morphology of the Mid Pliocene Three Toed Horse, Hipparion zandaense from the Zanda Basin of the southwest Tibetan Plateau, and the implications that can be made about the local climate, and therefore elevation, from this.

Maps showing the location where Hipparion zandaense was found. Deng et al. (2012), supplemental material.

Hipparion zandaense has enlarged trochlear ridge on its femur, an adaptation which enables modern Horses to lock their knee joints, enabling them to stay erect for long periods of time, but which is absent in other Three Toed Horses. It also has reduced side-toes and an elongated central tie compared to other Three Toed Horses; these animals are believed to have run using only their central toe, but to have stood on all three toes when stationary or walking. H. zandaense (like modern Horses), stood permanently on a single toe, so that it was always in running mode.

The skeletal anatomy of Hipparion zandaense, preserved bones in grey, white bones are inferred. (a1) The foot of Hipparion zandaense, showing the shortened side toes. (a2) The foot of the closely related H. primigenium with longer side toes. (b1) Central hind toe of Hipparion xizangense. (b2) Central hind toe of H. zandaense. (b3) Central hind toe of the modern Wild Horse Equus caballus. (c1) Femur tip of Hipparion primigenium, lacking an enlarged trochlear ridge. (c2) Femur tip of H. zandaense with an enlarged trochlear ridge. (c3) Femur tip of the modern Wild Horse Equus caballus, with an enlarged trochlear ridge. Deng et al. (2012).

Hipparion zandaense also has high tooth crowns compared to other Three Toed Horses, which suggests a diet of grasses rather than leaves, and isotopic studies of these teeth further suggests that they were feeding on cold adapted C₃ grasses rather than warm adapted C₄ grasses.

Grasses are less nutritious than leaves, requiring grass feeders to remain on their feet grazing for more hours per day. Such animals also need to be alert for predators, which is best done from an upright position; modern Horses sleep on their feet, and Hipparion zandaense appears to have been well adapted to doing the same. The best strategy for a grasslands grazer faced with a predator is to try to outrun it, whereas woodland grazing animals will often try to hide.

Taken together these adaptations strongly suggest that Hipparion zandaense was a grassland animal, almost certainly living in a cool climate.

The most likely explanation for this is that the portion of the Tibetan Plateau on which Hipparion zandaense was living had already been elevated above the permanent tree line by 4.6 million years ago, when it was alive. The Mid Pliocene climate was on average 2.5°C warmer than today, which would have made the tree line about 400 m higher than it is now. This suggests that the Mid Pliocene Zanda Basin was at least as high as it is today.

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Thursday, 26 April 2012

Fragments of 22 April meteor found in California.

On Sunday 22 April a fireball was seen passing over Nevada and California generating a sonic boom as it went, before finally exploding over central California. Scientists estimate this explosion released energy the equivalent to that from 4-5 kilotons of TNT a height of about 10 km (the Hiroshima bomb was equivalent to 15 kilotons of TNT, but was closer to the ground). This occurred during the Lyrid Meteor Shower, but is thought to have been caused by a large solitary asteroid weighing about 70 tonnes impacting the atmosphere, separate from the Lyrids, which are small fragments from the tail of comet C/1861 G1 (Thatcher).

Since this time meteorite hunters (a meteor is an object observed in the sky, a meteorite a peice of rock on the ground) have been flocking to the area to look for pieces of the object, ahead of heavy rains expected later this week.

The first piece was found by Arizona-based meteorite hunter Robert Ward on Tuesday 24 April, by the side of a road in the town of Lotus, California. It is a piece of carbonaceous chondrite weighing about 10 grams. Carbonaceous chondrites are carbon rich meteorites, thought to have originated early in the formation of the solar system. They often contain amino acids and other organic compounds, and some scientists believe they may have played a role in the origin of life on Earth.

Robert Ward with his fragment of chondrite. AP.

Shortly after this a second chunk of similar size was found in a nearby parking lot by meteorite hunter Peter Jenniskens. Since this there have been several reports of other finds. Experts think that given the size of the explosion, material could be scattered over several kilometers, probably strung out in a rough line extending eastwards from Coloma California.

Map of California showing the area where the meteorites were found. ESRI/AP.

Objects of this size probably hit the Earth several times a year, but most are likely to fall over open oceans or other uninhabited areas. Scientists that study meteorites particularly value fresh specimens, as they have had less time to be altered by the Earth's atmosphere.

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A fossil termite from the Late Oligocene of northern Ethiopia.

Termites are an ancient group of social insects related to Cockroaches; in fact many entomologists (scientists that study insects) now regard them as a specialized group of social Cockroaches rather than a separate group. Though the group is thought to be very old, it does not have a very good fossil record, with the oldest unambiguous fossils coming from the Cretaceous, though structures thought to be termite nests have been found from the Triassic of Australia, and isolated wings that may have come from early Termites from the Permian of Kansas.

In a forthcoming paper in the journal Acta Palaeontologica Polonica, Michael Engel of the Division of Entomology (Paleoentomology) at the Natural History Museum, and the Department of Ecology & Evolutionary Biology at the University of KansasAaron Pan of the Don Harrington Discovery Center and the Botanical Research Institute of Texas and Bonnie Jacobs of the Roy M. Huffington Department of Earth Sciences at Southern Methodist University announce the discovery of a fossil termite from the Late Oligocene of Ethiopia, incidentally the first fossil termite ever found in Africa.

The new species is described from a pair of shed wings (breeding termites undertake a single flight after which they shed their wings, and settle down to found a new colony; non-reproductive castes never have wings), and named Chilgatermes diamatensis; Chilgatermes meaning termite from Chilga (the region in which it was found) and diamatensis deriving from Diamat, an ancient kingdom that included this part of Ethiopia, as well as part of neighboring Eritrea.

The shed wings from which Chilgatermes diamatensis is described. The wing is 17.4 mm × 5.9 mm.  Engel et al. (2012).

Chilgatermes diamatensis is thought to be a member of the Stolotermitidae, a group of termites that nest in rotting wood. It is part of the Guang River assemblage, which is almost entirely made up of plant fossils, leading Engel et al. to suggest there is a good chance of discovering traces of its nesting behavior. 

Stolotermes, a modern Stolotermitid Termite found in South Africa, Australia and New Zealand. Barbara Thorne/United Nations Environment Program

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Wednesday, 25 April 2012

Earthquake in northern Algeria.

On Wednesday 25 April 2012, slightly before 4.20 am local time (slightly before 3.20 am GMT), an Earthquake occurred on the Algerian north coast, about 3 km south of the village of Bani h'awa and 21 km east of the town of Tanas, recorded by the United States Geological Survey as measuring 4.7 on the Richter Scale and occurring at a depth of 9.6 km. There are no reports of any damage or casualties, but it was felt as far away as Algiers, and apparently caused considerable alarm.

Map showing the location of the 25 April quake. USGS.

Africa is pushing into Europe from the south, which causes Earthquakes around the Mediterranean Basin. These are most common in southeast Europe, but those in northwest Africa, while less frequent, are often larger and more deadly. In February 2004 a magnitude 6.4 quake on the north Moroccan coast destroyed over 2500 homes, killing at least 628 people and making over 15 000 homeless. In 2003 a magnitude 6.8 quake hit the town of Thénia in northern Algeria, destroying over 1200 buildings, killing 2266 people and making 150 000 homeless. In 1980 a magnitude 7.3 quake hit the city of El Asnam in Algeria (now known as Chlef, 46 km south of the 25 April 2012 quake) killed 3500 and made another 300 000 homeless. In 1960 a magnitude 5.7 quake hit the city of Agadir in southern Morocco, killing about a third of the city's population (about 35 000 people).

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New species of moth from Yunnan Province.

In May 1992 entomologist Xue Dayong collected a single moth of an unknown species outside Heinitang village in western Yunnan Province, China, near the border with Myanmar. In the intervening 20 years no further specimens of this moth have been found, while the area has suffered steady deforestation due to slash-and-burn agriculture, leading to a distinct possibility that there are no more of these moths to be found.

The effects of slash-and-burn agriculture near Heinitang village. Li et al. (2012).

In the absence of any further material the species has been described from the single specimen in a paper published in the journal Zootaxa on 25 April 2012 by Jing Li, Nan Jiang and Hongxiang Han of the Key Laboratory of Zoological Systematics and Evolution at the Institute of Zoology at the Chinese Academy of Sciences.

The new moth is (tentatively) placed in the genus Heterophleps, though Li et al. are cautious of making a full taxonomic analysis based upon a single specimen. It is given the specific name inusitata, meaning rare. Heterophleps inusitata is a brown larentiine moth with a yellow underside, with a 17 mm forewing (the only measurement given).

Heterophleps inusitata. Li et al. (2012).

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Monday, 23 April 2012

Fireball over Nevada and California.

On Sunday 22 April 2012, at about 8.00 am, local time (3.00 pm GMT) witnesses saw a fireball streak across the sky over Nevada and California in broad daylight, from as far east as Elko and Las Vegas to San Francisco in the west. This was accompanied by a sonic boom that rattled houses and knocked some people of their feet.

The fireball passing over Nevada. News Lincoln County.

The fireball occurred at during the Lyrid Meteor Shower, but was not necessarily connected to this; the Lyrids are not generally associated with such large objects. Meteor showers are caused by when the Earth passes through the orbital path of comets, encountering large amounts of small debris from the tail of the comet, larger objects are not generally found in such showers, tending to be individual asteroids.

For an object to have created an audible boom and been visible in daylight it must have been particularly large, and have penetrated deep into the atmosphere. Estimates of the size vary: Bill Cook of NASA's Meteoroid Environments Office at the Marshall Space Flight Center suggested that it might be caused by a 3-4 m object weighing about 70 tonnes, and causing an explosion equivalent to 3.8 kilotons of TNT, Dan Ruby of the Fleischmann Planetarium at the University of Nevada suggests the object was 'a little bigger than a washing machine' and Donald Yeomans of NASA's Near-Earth Object Program Office said 'The meteor was probably about the size of an SUV'.

To have created an audible boom the object probably reached within 10 km of the ground, most visible meteors burn up ten times as high. It is still unlikely any material from the object reached the ground, though the area will probably be visited by a lot of meteorite hunters in the next few months (a meteorite is an object that has fallen from the sky and can physically be touched, a meteor is a shooting star, an object witnessed burning as it enters the atmosphere, and an asteroid is an object orbiting the Sun too small to be called a planet).

Objects the size of this hit the Earth several times a year, but are seldom observed, most falling over the ocean or other uninhabited areas.

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Eruption on Rincón de la Vieja, Costa Rica.

Rincón de la Vieja is a complex volcano in northwest Costa Rica. It takes the form of a ridge with a number of craters along a northwest-southeast axis, within an ancient volcanic caldera. Volcanic activity has been recorded on Rincón de la Vieja since 1765, during which time all significant eruptions have occurred from a lake filled crater known as 'The Active Crater' on the side of one of the higher summits, Von Seebach Peak.

Rincón de la Vieja. Blue River Resort & Hot Springs.

On 14 April 2012 villagers living to the north of the volcano reported seeing a phreatic eruption from the Active Crater (a phreatic eruption is an eruption in which lava emerges underwater, prompting an explosion of steam and rock fragments), according to the Observatorio Vulcanológico y Sismológico de Costa Rica. After this eruption volcanic material was found on the outer northern flank of the summit, and a plume of steam was seen over the crater for some time.

There were four similar eruptions in February this year, two on the 24th and one each on the 19th and 20th. A larger eruption occurred on 16 September 2012 this caused fish kills in streams and rivers up to 18 km away and ashfall deposits up to 15 cm thick within 2 km of the crater. Prior to this there had been intermittent Earthquake and fumarole (gas vent) activity around the crater since September 2006, but no actual eruptions.

Previous eruptive cycles have tended to follow a pattern of a long period of fumaroles and Earthquakes, followed by short bursts of phreatic eruptions, followed by more fumaroles and quakes, followed by a quiet period which may last several years, then the start of a new eruptive period. In the past some phreatic eruptions have been large enough to be heard over 25 km away, and have triggered lahars (floods of water and ash) that have swept down rivers and streams causing considerable damage.

The volcanoes of Costa Rica, and neighboring parts of Central America, are caused by the subduction of the Cocos Plate (which underlies the area of the Pacific immediately to the south of Central America) beneath the Caribbean Plate (upon which Central America sits). As the Cocos Plate passes under Central America it is partially melted by the heat of the Earth's interior and friction with the overlying plate. Some of the melted material then rises through the overlying Caribbean Plate as magma, fueling the volcanoes.

Diagrammatic representation of the Cocos Plate passing beneath the Central American Plate, showing how it fuels the volcanoes of Central America. VCS Mining.

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Earthquake beneath Barmouth, Gwynedd, northwest Wales.

Slightly before 3.30 British Summer Time (2.30 GMT) on Saturday 21 April 2012, the British Geological Survey recorded an Earthquake 12 km beneath the Welsh seaside resort of Barmouth, on the north side of the Mawddach Estuary. An Earthquake this small and this deep is unlikely to have been noticed by residents of the town, and there is no danger of any damage or casualties.

The location of the 21 April Earthquake. British Geological Survey.

Despite being a long way from any plate margins Wales is still moderately Earthquake prone, suffering a magnitude three quake roughly once every three years, and a magnitude four quake roughly every thirty years. Larger quakes are rarer, but do occur; most recently in 1984 when a quake on the Llŷn Peninsula, Gwynedd, recorded as measuring 5.4 on the Richter Scale, was felt across much of the UK and Ireland, causing damage and minor injuries as far away as Liverpool. The most recent Earthquake related fatality was in Porthmadog in 1940, when an elderly lady fell down a flight of stairs during a quake measuring 4.7 on the Richter Scale. In 1906 Swansea in South Wales was hit by a magnitude 5.2 quake that caused considerable damage. Caernarfon, in Gwynedd, suffered a magnitude 4.9 quake in 1903 and a magnitude 5.0 quake in 1893.

These quakes are the result of a variety of influences; Eurasia is being pushed eastwards by the expansion of the Atlantic Ocean, at the same time Africa is pushing into the continent from the south, which causes a considerable number of quakes in southern and southeastern Europe, and a smaller number in northern Europe. Britain is also subject to stresses caused by expansion of the crust beneath the North Sea, in the Rhine Valley and in the Bay of Biscay, though to a lesser extent. Finally the UK is still undergoing glacial rebound; much of the country was covered by a thick layer of ice until about 10 000 years ago. This pushed down on the rocks beneath it, which are now slowly springing back up again.

The British Geological Survey are interested in hearing from anyone in the area who felt (or didn't feel, which is also data) the quake. This can be reported here.

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An early Ray-Finned fish from the Middle Triassic Luoping Biota of Yunnan Province, China.

Neopterygian (Ray-Finned) Fish first appeared in the Late Permian, and became the most abundant group of fish during the Mesozoic; they remain such today. Neopterygians cane be divided into three groups, the Teleosts, fish with expandable mouthparts, which are the most abundant fish today, and two other groups, the Semiontids (which include the modern Gars) and Halecomorphs (which include the modern Bowfin), which were abundant during the Mesozoic but are now represented by only a few species. The relationships of the early Neoptergyians are unclear, but the Semiontids and Halecomorphs are generally thought to be more closely related to each other than either is to the Teleosts; together they are collectively referred to as Holosteians.

A fisherman with an Alligator Gar, Atractosteus spatula, one of North America's largest fish and a surviving Semiontid Fish. The Megafishes Project.

In a paper in the April edition of the journal Acta Palaeonotologica Polonica a team of palaeontologists led by Wen Wen of the Chengdu Institute of Geology and Mineral Resources announce the discovery of an early Neopterygian Fish that does not fit clearly into any of these groups, and the implications of this.

The new species is named as Luoxiongichthys hyperdorsalis, meaning 'The humpbacked fish from Luoxing'. It has a distinctive forward curving hump on its back that Wen Wen et al. compare to a 'reverse shark’s dorsal fin'. This is unlikely to have been advantageous to the fish when swimming, and was probably used for display.

Luoxiongichthys hyperdorsalis. Top, photograph of original specimen. Middle, interpretive drawing based upon photograph. Bottom, reconstruction of living fish. From Wen Wen et al. (2012).

Luoxiongichthys hyperdorsalis was described from a single specimen found in the Daaozi Section of the Guanling Formation, at Daaozi Village in Luoping County, about 25 km northeast of the town of Luoxiong. This is a muddy limestone that has produced a large number of excellently preserved vertebrates, invertebrates and plants from the Middle Triassic, collectively refered to as the Luoping Biota.

The location of the section that produces the Luoping Biota. From Wen Wen et al. (2012).

Luoxiongichthys hyperdorsalis does not fit easily into any group of Neopterygian Fish, but appears to be more closely related to the Semiontids and Halecomorphs than to the Teleosts, supporting the theory that these groups are related, and probably more closely related to the the Semiontids than to the Halecomorphs. Several early Semiontids have also been shown to have humped backs, supporting this relationship.

Diagram showing the probable relationships of Luoxiongichthys hyperdorsalis to other groups of fish. From Wen Wen et al. (2012).

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Friday, 20 April 2012

Mapping Africa's groundwater resources.

Many parts of Africa have long struggled to find sufficient clean water to provide for the needs of their populations or for agriculture or industry. The continent also has a growing population, and is likely to suffer severe changes in rainfall patterns due to climate change in the next few decades. The continent is known to have large groundwater resources in places, but the records of these are scattered, making continent-wide studies of water resources difficult.

In a paper published in the journal Environmental Research Letters on 19 April 2012 a team of scientists lead by Alan MacDonald of the British Geological Survey produce a series of maps detailing groundwater resources across the continent, collated from a wide range of sources.

Map showing the depth of water in aquifers across Africa. Contour lines show rates of recharge. MacDonald et al. (2012).

MacDonald et al. collated data from a variety of sources including previous regional studies, governmental reports, and data from oil exploration companies. The quality of the data varies from region to region. Water resources for much of Southern Africa are very well documented, and North Africa is nearly as well studied. West and Central Africa are generally poorly known, except in Ghana and Nigeria, where there have been a number of good studies.

Maps showing the depth of the water-table bellow the surface (top), and the likely productivity of aquifers, based upon how difficult the water is likely to be to extract. MacDonald et al. (2012).

The most significant resources are found beneath the Sahara, where they could potentially be of great use. However these are ancient resources that have not been significantly replenished in the last 5000 years; if they are used then they will not be replenished, permanent plans for their use could not be made. The study does not take into account the possibility of aquifers containing contaminated water, though this is likely to be the case in places, either from natural contaminants derived from rocks, such as arsenic of fluorides, or from man-made sources such as contamination from sewers in major cities.

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The Lyrid Meteors.

Tomorrow, Saturday 21 April 2012, the Earth will cross the orbit of the comet C/1861 G1 (Thatcher), and be showed in material shed from the comet's tail and still following (roughly) the same path. We will not pass particularly close to the comet, which is currently sixty times as far from the Sun as the Earth - outside the main Kuiper Belt.

The orbit of C/1861 (Thatcher). Wolfram Alpha.

C/1861 G1 (Thatcher) is named after its discoverer, A. E. Thatcher (nothing to do with the politician) who discovered it in 1861. It takes 415 years to orbit the Sun, coming at its closest slightly within the orbit of the Earth (0.921 AU compared to Earth's 1.00 AU) and at its furthest reaches 110 times the distance at which the Earth orbits the sun. It last came closest to the Sun in 1861, and will do this again in 2276.

When C/1861 G1 (Thatcher) reaches the inner part of its orbit it is heated by the Sun's radiation, causing the ices in its makeup (water, carbon dioxide and carbon monoxide) to evaporate away. This causes chunks of the surface to break away, as the rocky parts are no longer glued together by the ice. This forms a stream of small rocky particles that continues to follow the orbit of the comet. Each April the Earth passes through this stream, creating a display of meteors, as the rocky particles burn up in our atmosphere. Because these are all following more-or-less the same path, they all appear to originate at the same point in the sky, in the constellation of Lyra, close to the star Vega.

The radial point from which the Lyrid Meteors all appear to originate. NASA/Windows to the Universe/National Earth Science Teachers Association.

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Canberra shaken by mild Earthquake.

On Friday 20 April at 5.09 am, local time (7.09 pm on Thursday 19 April GMT), the Australian capitol city, Canberra, was shaken by an Earthquake recorded by Geoscience Australia as measuring 3.7 on the Richter Scale and occurring 40 km west of the city at a depth of 4 km. There are no reports of any damage or casualties, but the quake was apparently felt across much of the city, as well as in the communities of Tumut, Murrumbateman, Batlow, Carwoola and Tuggeranong.

Map showing the location of the quake, and the area across which it was felt. Geoscience Australia.

While Canberra is a long way from any active tectonic plate margins, it is moderately Earthquake-prone. This is due to ancient folding of the rocks of the region, which has left many areas where the layers of strata are arranged vertically rather than horizontally, which is a less stable configuration. Typically strata lie flat, like a stack of books or magazines laid flat on a table. When geological movements turn these on their sides the resemble books or magazines lined up on a shelf, but without the shelf to provide a steady base. Such rocks are often prone to mild quakes.

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Wednesday, 18 April 2012

Looking for HD 97658b.

HD 97658b is a planet with a mass 8.2 times that of the Earth, orbiting a K-type star (HD 97658b) 69 light years from Earth. It was discovered in 2010 by the High Resolution Echelle Spectrometer at the Keck Observatory; its discovery was reported in 2011 by a team of scientists lead by Andrew Howard of the Department of Astronomy and Space Sciences Laboratory at the University of California, Berkeley, and reported in a paper in The Astrophysics Journal. The planet was discovered using the radial-velocity technique: it orbits a star with a mass 85% of that of the Sun every 9.5 days, this causes the star to wobble on its access, enabling astronomers to detect the planet and calculate its mass.

Diagram showing the orbits of HD 97658b (white) and Earth (green) about their respective stars. Planet and star not to scale.

Later in 2011, in a paper on the online arXiv database at Cornell University Library, which was also submitted to The Astrophysics Journal, a team lead by Gregory Henry of Center of Excellence in Information Systems at Tennessee State University described observations of HD97685b transiting its star (passing in front of the star when seen from Earth) by the Automated Photometric Telescopes at Fairborn Observatory, from which they calculated that it has a radius of 2.93 times that of the Earth, which translates to a volume of 105 times the Earth's.

In a new paper published on arXiv on 14 April 2012 and submitted for publication in Astrophysical Journal Letters, a team of astronomers lead by Diana Dragomir of the Department of Physics and Astronomy at the University of British Columbia publish the results of a new study of HD 97658b, using the MOST Space Telescope.

An artist's impression of the MOST Space Telescope. University of British Columbia.

The new study was unable to detect HD 97658b transiting the star, despite using a more sensitive instrument. They calculate that the MOST Space Telescope would have been able to detect such transits if the planet had a radius 1.87 times that of the Earth or greater. They therefore conclude that the Fairborn Observatory study was erroneous; either HD 97658b does not transit its star, or it is too small to have been detected by the instruments at Fairborn.

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New species of Owlfly from Morocco.

Owlflys, or Ascalaphidaens, are members of the Lacewing order Neuroptera, closely related to the Antlions, (Myrmeleontidae). They are flying predatory insects that superficially resemble Dragonflys, though they are not closely related. About 500 species of Owlflys have been described worldwide.

In a paper published in the journal Zootaxa on 17 April 2012, Davide Badano of the Istituto per lo Studio degli Ecosistemi at the Consiglio Nazionale delle Ricerche and Roberto Pantaleoni of the Dipartimento di Protezione delle Piante at the Università degli Studi di Sassari describe a new species of Owlfly from the Anti–Atlas Mountains of Morocco.

The new species is named as Agadirius trojani, Trojan's Agadirfly, in honor of Ilja Trojan, a Czech entomologist who collected the specimen from which the species is described, and Agadir, the capital of the Souss–Massa–Draâ Region, where the fly was discovered. It is an 18 mm hairy black fly, with forewings larger than the hindwings and black fore-parts to the hindwings.

Agadirius trojani, the new species of Owlfly. Badano & Pantaleoni (2012).

The species was described from a single specimen found in a valley near the village of Aït Mansour, where a mountain stream flows through a rocky valley with a stand of Date Palms.

The valley at Aït Mansour where Agadirius trojani was found. Badano & Pantaleoni (2012).

Owlflys are an ancient group, dating back to at least the Jurassic. The larger group to which they belong, the Neuropterans (Lacewings), date back to the Permian, reaching their maximum diversity in the Jurassic, when they appear to have been the most abundant group of flying insects.

Fossil Owlfly larva in amber from the La Toca Amber Mine in the Dominican Republic. 33-40 million years old; Eocene or Oligocene. TerraTreasures and Adventures101.

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Tuesday, 17 April 2012

Report recommends Fracking should be allowed to continue in the UK.

Fracking, or Hydraulic Fracturing, is a process by which water, sand and chemicals are forced into buried sediments in order to shock them into releasing trapped hydrocarbons, which can then be extracted for commercial use. This has proved highly controversial with environmentalists, who accuse the process of causing Earthquakes, polluting groundwater, and using large amounts of fresh water.

To date the UK has been host to only a single, experimental, fracking project, at Preese Hall near Blackpool in Lancashire. Operations were stopped at Preese Hall in 2011, after two small Earthquakes in April and May were connected to activities there.

The Preese Hall well site in Lancashire. The Australian.

This week a report commissioned by the Department of Energy and Climate Change was published, entitled 'Preese Hall Shale Gas Fracturing: Review and Recommendations for Induced Seismic Mitigation'. This was written by Peter Styles of the Department of Geography, Geology and the Environment at Keele University, Brian Baptie of the British Geological Survey and Christopher Green, director of GFrac Technologies, and concludes that fracking should be allowed to continue in the UK, as long as certain conditions are met.

The team recognize that the Preese Hall operations were the most likely cause of the Lancashire Earthquakes, and that there was a high likelyhood of continued operations in the same area causing further quakes. In addition the report found that the quakes caused deformation in the structure of the well - deformation that could lead to chemicals used in the process leaking into other strata than the ones intended.

An earlier report in the US found that chemicals from a fracking operation there had entered aquifers, but was unable to say whether this was due to the process itself, or due to spillages at ground level. This was widely cited as vindication of the process, which is odd since clearing the fracking element of the operation could only be achieved by claiming blundering incompetence in another part of the process, but spin often seems to overtake logic in debates over fracking (and the energy industry in general).

Fracking undoubtably does cause Earthquakes. An Earthquake is shaking in the ground, a large truck driving past your house doesn't just feel like an Earthquake, it is an Earthquake. Blasting pressurized water and sand into buried rocks in the hope of causing them to fracture will definitely cause Earthquakes (if it didn't there wouldn't be any fracturing, and the process would not work). Unfortunately extraction companies involved in hydraulic fracturing employ lobbyists and press spokesmen who do not always appreciate this, and who may not be concerned too much if the truth gets slightly obscured in getting their side of the story across, leading to some confusion on this point.

What should be being discussed is the scale of Earthquakes that can be caused by fracking. Engineers in the industry have repeatedly estimated that the process should not be causing quakes greater than magmitude 1.0 on the Richter Scale, but several areas in the US where fracking operations are underway have suffered increases in seismic activity with quakes in excess of 3.0 being reported. The Richter Scale is logarithmic, so a magnitude 3.0 quake is 100 times as powerful as a 1.0 quake. Nobody has been able to explain how fracking could be causing quakes this much larger than predicted, leading the industry to claim that the increases are co-incidental, and that without a proposed mechanism they cannot be held responsible. In this light the UK report, which directly links fracking to two Earthquakes measuring 1.5 and 2.3 on the Richter Scale is a blow to the industry.

The report recommends that all hyrdraulic fractioning operations in the UK should be carefully monitored for seismic activity, at the operators expense, and any operation shown to have caused a quake in excess of 0.5 on the Richter Scale should be halted immediately. They furthermore note that it is highly unlikely that a fracking operation in the UK could ever cause a quake in excess of 3.0 on the Richter Scale, and that a quake on that scale could not cause any serious damage.

While this has widely been reported as a green-light for the fracking industry in the UK, it potentially places a considerable additional burden upon them, since the expense of installing seismic monitors would add significantly to the cost of the operation, and the possibility of being forced to close down at any point would make investing in any such operation highly risky (an industry that cannot explain how it causes larger quakes would probably be unable to prevent or predict this).

Environmental groups in the UK have expressed a great deal of concern at the report, even though it recommends tight regulation of the industry. This is not surprising, as the current UK government has a track record of friendliness towards the hydrocarbons industry (Business Secretary Vince Cable is a former oil-man), and of opposing environmental regulation of any sort. In addition Chancellor of the Exchequer George Osborne recently announced plans to encourage the building of gas-fired power stations in the UK, which suggests that fracking operations targeting natural gas are likely to be welcomed. In the light of this there is clearly a concern that the report could be used to justify resumption and expansion of fracking operations in the UK, without putting into place the recommended regulatory measures.

The operators of the Preese Hall site, Cuadrilla Resources, are certainly keen to resume operations. They estimate that the Lancashire field contains about 11.3 trillion m³ of natural gas; enough to power the UK for over 50 years. However the British Geological Survey estimate the field contains much less gas, 0.13 trillion m³, and that only 5-10% of this will be recoverable - enough to power the UK for 21 days. This big a disparity in estimates shows a surprising degree of optimism on the part of Cuadrilla Resourses, which if extended to other areas of the business would in themselves raise concerns about the companies safety and environmental policies.

In addition to the Lancashire field the company has obtained licenses for sites in Sussex, Kent and Surrey. There are thought to be reserves of shale gas suitable for extracting by fracking in Wales, Northern Ireland and Scotland as well as in England.

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Monday, 16 April 2012

A Heterodontosaurid Dinosaur from the Late Jurassic of Colorado.

Heterodontosaurid Dinosaurs were an early group of Ornithischians that appeared in the Late Triassic in Gondwanaland and spread across the globe during the Early Jurassic, surviving into the Early Cretaceous. They were probably the smallest of the Ornithischians, typically under a meter in length, and gain their name from their dentition; they had different shaped teeth in different parts of the jaw, as with modern mammals, which is unusual in dinosaurs, though it has been observed in other Ornithischians.

Fruitadens haagarorum is a Late Jurassic Heterodontosaurid Dinosaur known from a number of fragmentary skeletons from the Upper Jurassic Morrison Formation of the Fruita Paleontological Area, northwest of Grand Junction, Colorado, USA. It is generally considered to be the smallest known Ornithischian Dinosaur, at only 65-75 cm in length and weighing 500-750 grams.

Reconstruction of Fruitadens haagarorum, and the location of the site where it was found. Butler et al. (2010).

In a paper published in the journal PLoS One on 11 April 2012, a team of scientists lead by Richard Butler of the Bayerische Staatssammlung für Paläontologie und Geologie and the GeoBio-Center at Ludwig-Maximilians-Universität München discuss a new reconstruction of the head of Fruitadens haagarorum, and the implications of this for our understanding of the evolution and ecology of Heterodontosaurid Dinosaurs.

Reconstruction of the head of Fruitadens haagarorum. Butler et al. (2012).

Butler et al. conclude that compared that compared to reconstructions of earlier Heterodontosaurid Dinosaurs, Fruitadens haagarorum appears to have been less well suited to tearing at tough vegetation, but much better adapted to making sudden, and repeated, snapping motions with widely opened jaws. From this they conclude that while all Heterodontosaurids were probably omnivorous, the earlier forms probably ate more vegetation, whereas Fruitadens haagarorum, probably ate mostly insects or other invertebrates, with a smaller amount of plant material being consumed, probably on a selective basis.

They furthermore note that Heterodontosaurid Dinosaurs tended to become smaller throughout their evolutionary history. In modern lizards, which also tend to be omnivorous, larger species tend to consume more plant material, whereas smaller species tend to consume more insects. Combining this observation with the new reconstruction of Fruitadens haagarorum, Butler et al. suggest that the Heterodontosaurids probably originated as general omnivores consuming a lot of tough plant material, but over time came to incorporate a lot more non-plant material into their diet, and became more selective about what plant material they would take.

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Earthquake in Cumbria.

On Sunday 15 April at 16.01 British Summertime (15.01 GMT) the British Geological Survey recorded an Earthquake measuring 0.7 on the Richter Scale occurring at a depth of 7 km beneath the Cumbrian village of Ambleside, at the north end of Lake Windermere. It is highly unlikely that such a small event have been felt by anyone, and it is doubtful that they would have recognized it as a quake if they did. This was followed 101 seconds later by a second quake in more-or-less the same location and depth that measured 2.0 on the Richter Scale. This second quake is far more likely to have been felt, though it was still small enough that any damage or injuries would be highly unlikely.

The location of the 15 April quakes.

Cumbria is probably England's most Earthquake-prone county, although this is hardly a major achievement in a country where major quakes are extremely rare (twelve years into the twenty-first century Earthquakes have caused a single injury in the UK, in Lincolnshire in 2008). Most quakes in northern England (and slightly more quake prone Scotland) are attributed to glacial rebound; during the most recent glaciation (the Devensian) Cumbria was buried beneath up to 900 m of ice, which did not clear till about 14 000 years ago. This much ice weighed down heavily on the rocks of Cumbria (as well as scouring the landscape and carving out the lakes of the Lake District), and they are still rebounding from the load.

The UK is also effected by movements on tectonic plate margins, even though it is a long way from any of these. The Atlantic Ocean is spreading at a rate of 20-40 mm per year, pushing Eurasia eastwards and North America to the west. Africa is pushing into Eurasia from the south at slightly over 20 mm a year; this causes regular quakes in southern and southeastern Europe, but the northwest of the continent is not immune. In addition there is some spreading occurring in the North Sea, the Rhine Valley, and the Bay of Biscay, of of which place pressure on rock formations in Britain, which can contribute to quakes (realistically most quakes are causes by a combination of all these stresses).

If you felt the quake you can report it to the British Geological Survey here. The BGS is also interested in hearing from people in the area who didn't feel the quake, which is also useful data.

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