Wednesday 31 January 2018

Homes evacuated after landslide in British Colombia.

Several homes have been evacuated after a landslide in the city of White Rock in British Columbia, Canada, at about 4.30 pm local time on Monday 29 January 2018. An area of land about 50 m by 60 m has shifted downslope, pushing into the side of an apartment block, covering at least one patio and potentially disturbing the foundations of the structure. Four apartments were initially evacuated, but residents of two of these have now been allowed to return. 

The scene of the 29 January 2018 White Rock landslide. White Rock Sun.

The incident occurred after several days of heavy rain that have caused a number of flooding and landslip events in the Metro Vancouver area. Landslides are a common problem after severe weather events, as excess pore water pressure can overcome cohesion in soil and sediments, allowing them to flow like liquids. Approximately 90% of all landslides are caused by heavy rainfall. n another incident in the same area a landslide has blocked part of the train line connecting Vancouver to Bellingham in Washington State, USA, with the result that train services will be replaced with a bus service till at least Wednesday 31 January.

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Asteroid 2018 BN6 passes the Earth.

Asteroid 2018 BN6 passed by the Earth at a distance of about 362 500 km (0.94 times the average distance between the Earth and the Moon, or 0.24% of the distance between the Earth and the Sun), at about 9.30 am GMT on Wednesday 24 January 2018. There was no danger of the asteroid hitting us, though were it to do so it would not have presented a significant threat. 2018 BN6 has an estimated equivalent diameter of 8-28 m (i.e. it is estimated that a spherical object with the same volume would be 8-28 m in diameter), and an object of this size would be expected to explode in an airburst (an explosion caused by superheating from friction with the Earth's atmosphere, which is greater than that caused by simply falling, due to the orbital momentum of the asteroid) in the atmosphere between 35 and 18 km above the ground, with only fragmentary material reaching the Earth's surface.

The calculated orbit of 2018 BN6. Minor Planet Center.

2018 BN6 was discovered on 27 January 2018 (three days after its closest approach to the Earth) by the University of Arizona's Mt. Lemmon Survey at the Steward Observatory on Mount Lemmon in the Catalina Mountains north of Tucson. The designation 2018 BN6 implies that the asteroid was the 173rd object (object N6) discovered in the second half of January 2018 (period 2018 B).  

2018 BN6 has a 429 day orbital period and an eccentric orbit tilted at an angle of 2.50° to the plane of the Solar System, which takes it from 0.73 AU from the Sun (i.e. 73% of he average distance at which the Earth orbits the Sun, slightly outside the orbit of Venus) to 1.49 AU from the Sun (i.e. 149% of the average distance at which the Earth orbits the Sun, and slightly inside the orbit of the planet Mars). It is therefore classed as an Apollo Group Asteroid (an asteroid that is on average further from the Sun than the Earth, but which does get closer). This means that the asteroid has occasional close encounters with the Earth, with the last thought to have occurred in April 2017 and the next predicted in February 2025. The asteroid also has occasional close encounters with the planet Venus, with the next predicted for 25 October 2023.

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Warning issued after seismic activity beneath Mount Zaō, Japan.

The Japan Meteorological Agency has issued a warning for people to keep away from the  Mount Zaō volcanic complex, which straddles the border between Yamagata and Miyagi prefectures on Honshū Island, Japan, after a series of small seismic tremors were detected beneath the area on Tuesday 30 January 2018, as well as a slight swelling of the ground. The tremors are thought to have been caused by the movement of hot water and volcanic gas, which could indicate that the volcano is about to erupt.

The  Mount Zaō volcanic complex on Honshū Island, Japan. Kyodo News Agency.

Japan has a complex tectonic situation, with parts of the country on four different tectonic plates. Kyushu Island lies at the northeast end of the Ryukyu Island Arc, which sits on top of the boundary between the Eurasian and Philippine Plates. The Philippine Plate is being subducted beneath the Eurasian Plate, in the Ryukyo Trench, to the Southeast of the Islands. As it is drawn into the interior of the Earth, the tectonic plate is partially melted by the heat of the Earth's interior, and liquid magma rises up through the overlying Eurasian Plate to form the volcanoes of the Ryukyu Islands and Kyushu.

The movement of the Pacific and Philippine Plates beneath eastern Honshu. Laurent Jolivet/Institut des Sciences de la Terre d'Orléans/Sciences de la Terre et de l'Environnement.

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Cis mooihoekite: A new species of Minute Tree-Fungus Beetle from Mpumalanga Province, South Africa.

Minute Tree-Fungus Beetles, Ciidae, are a large group of very small Beetles fond inhabiting Bracket Fungi. They seldom reach longer than 5 mm in length, and can live their entire life-cycle within their host Fungi, with many species able to reproduce parthenogenitically (without sex), with a life time of about two months, and a sexual generation produced annually that leaves the host Fungus and looks for new sites to settle. Minute Tree-Fungus Beetles are known from across the globe, though they are more numerous in warmer regions. To date 72 species have been described from Sub-Saharan Africa, of which 49 are placed within the genus Cis, with 16 of these known from Southern Africa.

In a paper published in the journal African Invertebrates on 26 January 2018, Igor Souza-Gonçalves of the Programa de Pós-Graduação em Ecologia and Laboratório de Sistemática e Biologia de Coleoptera at the Universidade Federal de Viçosa, and Cristiano Lopes-Andrade, also of the Laboratório de Sistemática e Biologia de Coleoptera at the Universidade Federal de Viçosa, describe a new species of Cis from  Mpumalanga Province in South Africa.

The new species is named Cis mooihoekite, in reference to the copper iron sulphide mineral mooihoekite, which is similar in colour and sheen to these Beetles. Measured males of this species ranged from 1.20 to 1.25 mm in length, with females measuring from 1.13 to 1.25 mm, both sexes were brown in colour with numerous yellow bristles.

Cis mooihoekite. Male specimen in (1) Dorsal view, note acute corners of male anterocephalic edge (arrows), and (2) Lateral view. Scale Bar is 0.5 mm. Souza-Gonçalves & Lopes-Andrade (2018).

The species was found at two locations, in grassland at Mooihoek Farm in southern Mpumalanga and Savanah in the Transvaal region of northern Mpumalanga. It was found on two species of Fungus, Trametes versicolor and an unidentified species of Thelephora.

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Tuesday 30 January 2018

Total Lunar Eclipse on 31 January 2018.

A total Lunar Eclipse will occur on 31 January 2018, starting slightly before 10.50 am GMT. It will be visible across much of East Asia and Australasia, as well as northwest North America, and the islands of the Pacific. Part of the eclipse will be visible from remaining areas of Asia and North America as well as east Africa, Eastern Europe, the islands of the Indian Ocean and Caribbean and northwest South America, although in these areas the Moon will either rise part way through the eclipse, or set before it is complete.

Areas from which the 31 January 2018 Lunar Eclipse will be visible. In the white area the full extent of the eclipse will be visible, in the shaded areas it will either begin before the Moon rises or end after the Moon has set, while in the darkest area it will not be visible at all. HM Nautical Almanac Office.

The Moon produces no light of its own, but 'shines' with reflected light from the Sun. Thus at Full Moon the Moon is on the opposite side of the Earth to the Sun, and its illuminated side is turned towards us, but at New Moon the Moon is between the Earth and the Sun, so that its illuminated side is turned away from us.

Lunar eclipses occur when the Moon passes through the Earth's shadow. This can only happen at Full Moon (unlike Solar Eclipses, which happen only when the Moon passes between the Earth and the Sum, and therefore only occur at New Moon), but does not happen every Lunar Month as the Sun, Moon and Earth are not in a perfect, unwavering line, but rather both the Earth and the Moon wobble slightly as they orbit their parent bodies, rising above and sinking bellow the plane of the ecliptic (the plane upon which they would all be in line every month).

 Phases of the Lunar Eclipse that will be seen on 31 January 2018. The times are given in GMT, to the nearest 10th of a minute, thus 10.49.7 represents 36 seconds after 10.49 am GMT. HM Nautical Almanac Office.

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Monday 29 January 2018

Phosphotriton sigei: A 'mummified' Salamander from the Eocene of southern France.

In 1873-7 the French naturalist Henri Filhol published a series of descriptions of 'mummified' animals from the Quercy region of southwest France, which were actually external moulds of the animals preserved in phosphatic clays within fissures on a limestone plateau. Unfortunately Filhol did not accurately record the locations from which these fossils originated, preventing accurate dating of individual specimens, though the collection as a whole are thought to range from Early Eocene to Early Miocene in age. In 2013 a a team of scientists led by Fabien Laloy of the Centre national de la recherche scientifique, the Muséum national d’histoire naturelle and the Université Pierre et Marie Curie published a paper  in the journal PLoS One, in which a Frog from the Phosphorites du Quercy was shown to have preservation of not just its external morphology, but also of some internal structures, principally the skeleton, which were revealed by computerised tomography, which enabled the formation of a three dimensional computer model of the specimen, showing its internal structure.

In a paper published in the journal PeerJ on 3 October 2017, Jérémy Tissier of the Cenozoic Research Group at the JURASSICA Museum, and the Department of Geosciences at the University of Fribourg, and Jean-Claude Rage and Michel Laurin of the Département Histoire de la Terre at the Museum national d'Histoire naturelle, describe the results of a similar study of a large Salamander from the Quercy deposits, Phosphotriton sigei.

The specimen was shown to preserve part of the skeleton, particularly the spine, plus some muscle structure, some of the nervous system, including the spinal column and lumbosacral plexus, part of the digestive tract and the urogental organ.

Exceptional preservation of nerves, digestive tract and stomachal content. (A) and (B) 3D reconstructions of the pelvic section of Phosphotriton sigei, in laterodorsal (A) and ventral (B) views. The lumbosacral plexus (in blue) is partly preserved. Nerves exit the last trunk, the sacral and the first caudosacral vertebrae through the spinal nerve foramina. (C) Preserved bones of an Anuran Frog (Ranoid?), in green, inside the digestive tract. (D) Anuran humerus found inside digestive tract of Phosphotriton sigei, in lateral and ventral views. (E) Anuran vertebrae found inside digestive tract of Phosphotriton sigei. The centrum is very thin; the holes may represent segmentation artifacts. (F) 3D reconstruction of Phosphotriton sigei in ventral view, showing the nearly complete digestive tract. The caudal end is very close to the cloaca, and is bordered near the pelvic girdle by presumed dorsal cloacal glands (see Fig. 4A). (G) Virtual section of the trunk, showing the digestive tract (in yellow) and its content (frog bones).

The digestive tract contains a bone, interpreted as the humerus of a Frog, implying that the living Phosphotriton sigei, was a carnivore capable of tackling comparatively large prey. This is unusual in Salamanders which are predominantly insectivores today.

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Comet C/2016 T3 (PANSTARRS) makes its closest approach to the Earth.

Comet C/2016 T3 (PANSTARRS) makes its closest approach to the Earth on Friday 29 January 2018 (today) reaching a distance of 2.19 AU from the Earth (2.19 times as far from us as the Sun, or 328 011 000 km). At this distance the comet will not be naked eye visible, having a magnitude of 17.38, which means it would require a good telescope to observe it, and then only in the Northern Hemisphere, as it is currently in the constellation of Hydra, which cannot be seen clearly from south of the Equator.

The orbit and current position of Comet C/2016 T3 (PANSTARRS) . The Sky Live 3D Solar System Simulator.

C/2016 T3 (PANSTARRS) was discovered on 10 October 2016 by the University of Hawaii's PANSTARRS telescope. The name C/2016 T3 (PANSTARRS) implies that it is a non-periodic comet (C/) (all comets are, strictly speaking, periodic since they all orbit the Sun, but those with periods longer than 200 years are considered to be non-periodic), that it was the first comet (comet 3) discovered in the first half of October 2016 (period 2016 T) and that it was discovered by the PANSTARRS telescope.

C/2016 T3 (PANSTARRS) has an estimated orbital period of 1708 years and a highly eccentric orbit tilted at an angle of 58.2° to the plain of the Solar System, that brings it to 2.65 AU from the Sun at perihelion (265% of the distance between the Earth and the Sun, considerably outside the orbit of Mars); to 283 AU from the Sun at aphelion (283 times as far from the Sun as the Earth or 9.4 times as far from the Sun as the planet Neptune, between the Kuiper Belt and  the Oort Cloud.

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