Thursday, 14 December 2017

Phreatic eruptions on Mount Kanlaon, Negros Island.

The Philippine Institute of Volcanology and Seismology reported a series of phreatic eruptions (explosions caused by magma or other hot volcanic material coming into contact with water) on Mount Kanlaon, a 2465 m stratovolcano (cone shaped volcano made up of layers of ash and lava) on northern Negros Island in the central Philippines, between about 9.45 and 10.00 am local time on Saturday 9 December 2017. These eruptions were heard as far away as La Castellana, roughly 25 km to the southwest, and produced a column of ash and steam that rose 3-4 km above the summit of the volcano, with ashfalls recorded in the communities of Guintubdan, Ara-al, Sag-ang, and Ilihan.

Column of ash and steam over Mount Kanlaon, Negros Island, on 9 December 2017. GMA News.

The volcano has remained active since this event, with 578 seismic tremors recorded beneath it between 8.00 am on Tuesday 12 and Wednesday 13 December. Seismic activity beneath volcanoes can be significant, as they are often caused by the arrival of fresh magma, which may indicate that a volcano is about to undergo an eruptive episode.

The approximate location of Mount Kanloan. Google Maps.

The geology of the Philippines is complex, with the majority of the islands located on the east of the Sunda Plate. To the east of this lies the Philippine Sea plate, which is being subducted beneath the Sunda Plate (a breakaway part of the Eurasian Plate); further east, in the Mariana Islands, the Pacific Plate is being subducted beneath the Philippine Sea Plate. This is not a smooth process, and the rocks of the tectonic plates frequently stick together before eventually being broken apart by the rising pressure, leading to Earthquakes in the process. Material from the subducting Philippine Plate is heated by the temperature of the Earth's interior, causing lighter minerals to melt and the resultant magma to rise through the overlying Sunda Plate, fuelling the volcanoes of the Philippines.

 Subduction beneath the Philippines. Yves Descatoire/Singapore Earth Observatory.
 
See also...

http://sciencythoughts.blogspot.co.uk/2017/11/landslides-kills-two-on-luzon-island.htmlhttp://sciencythoughts.blogspot.co.uk/2017/11/landslide-kills-man-in-camarines-sur.html
http://sciencythoughts.blogspot.co.uk/2017/10/magnitude-54-earthquake-in-batangas.htmlhttp://sciencythoughts.blogspot.co.uk/2017/10/landslide-kills-man-in-cebu-city.html
http://sciencythoughts.blogspot.co.uk/2017/09/one-killed-in-landslide-and-three-in.htmlhttp://sciencythoughts.blogspot.co.uk/2017/09/landslide-kills-two-in-cebu-city.html
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Wednesday, 13 December 2017

The fate of Fish-hosting Anemones during the 2016 Great Barrier Reef bleaching event.

In February-April 2016 elevated surface temperates above the Great Barrier Reef caused one of the most severe Coral bleaching events ever recorded, with over 60% of the Corals losing their symbiotic Algae. This has been the subject of numerous studies, though the vast majority of these have concentrated on the Corals themselves rather than other inhabitants of the reef system.

In a paper published in the journal Coral Reefs on 4 April 2017, Anna Scott of the National Marine Science Centre at Southern Cross University and Andrew Hoey of the ARC Centre of Excellence for Coral Reef Studies at James Cook University, describe the effect of the bleaching event on the Fish-hosting Anemones and their attendant Anemonefish in the lagoon of Lizard Island on following the 2016 Great Barrier Reef bleaching event.

Scott and Hoey visited the lagoon in 10-15 April 2017, and recorded the Fish-hosting Anemones present, then retured on 17-22 October to re-examine the Anemones again.

The most abundant  Fish-hosting Anemones in the lagoon belonged to the Bubble-tip Anemone, Entacmaea quadricolor, with ten colonial clumps and two individuals. Also present were single individuals of the Leather Anemone, Heteractis cripsa, and the Magnificent Sea Anemone, Heteractis magnifica. All of these Anemones were bleached. Living within these Anemones were nineteen Fire Clownfish, Amphiprion melanopus, three Orange Clownfish, Amphiprion  percula, and two Spine-Cheeked Anemonefish, Premnas biaculeatus. Also present were three Mertens' Carpet Sea Anemones, Stichodactyla mertensii, which was not bleached and which were host to nine Clark's Anemonefish, Amphiprion clarkii.

A bleached Magnificent Sea Anemone, Heteractis magnifica., with attendant Orange Clownfish, Amphiprion  percula, in April 2017. Scott & Hoey (2017).

By October the the Magnificent Sea Anemone, had completely recovered, but the Leather Anemone, had vanished, as had one of the solitary Bubble-tip Anemones and six of the colonies; the remaining colonies showed signs of having began to recover, but the remaining solitary Bubble-tip Anemone remained bleached. Most of the Fish remained, but the number of Fire Clownfish had fallen by nine (almost half), presumably in reaction to the loss of habitat.

 A recovering Magnificent Sea Anemone, Heteractis magnifica., with attendant Orange Clownfish, Amphiprion  percula, in October 2017. Scott & Hoey (2017).

See also...

http://sciencythoughts.blogspot.co.uk/2017/06/sinularia-mesophotica-new-species-of.htmlhttp://sciencythoughts.blogspot.co.uk/2017/04/flagelligorgia-gracilis-new-species-of.html
http://sciencythoughts.blogspot.co.uk/2017/02/muricea-subtilis-new-species-of.htmlhttp://sciencythoughts.blogspot.co.uk/2016/07/jellyfish-damage-to-farmed-salmon-on.html
http://sciencythoughts.blogspot.co.uk/2016/06/sclerangia-floridana-new-species-of.htmlhttp://sciencythoughts.blogspot.co.uk/2015/11/discovering-origins-of-myxozoan.html
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Using molecular genomics to understand the social behaviour of Woolly Mammoths.

The Woolly Mammoth, Mammuthus primigenius, is thought to have diverged from the earlier Steppe Mammoth Mammuthus trogontherii in northeast Asia around 700 000 years ago and by 200 000 years ago spread across Asia and into Europe and across the Bering Strait into North America. As a widespread and apparently numerous species living in the recent past they have left an extensive fossil record, primarily of isolated teeth and bones, but also including a number of mummified and frozen specimens, trapped within the Arctic permafrost. This has allowed a number of detailed anatomical and molecular studies of the Woolly Mammoth, using specimens that were excavated in the nineteenth and early twentieth centuries. Despite this wealth of data there is relatively little direct information on the behaviour of these animals available, with most of our ideas about the social structure of Mammoths based upon extrapolation from living Elephant species rather than direct evidence.

In a paper published in the journal Current Biology on 2 November 2017, Patrícia Pe cnerova of the Department of Bioinformatics and Genetics at the Swedish Museum of Natural History, and the Department of Zoology at Stockholm University, David Díez-del-Molino and Nicolas Dussex, also of the Department of Bioinformatics and Genetics at the Swedish Museum of Natural History, Tatiana Feuerborn, again of the Department of Bioinformatics and Genetics at the Swedish Museum of Natural History, amd of the Centre for GeoGenetics at the Natural History Museum of Denmark, Johanna von Seth, again of the Department of Bioinformatics and Genetics at the Swedish Museum of Natural History, and the Department of Zoology at Stockholm University, Johannes van der Plicht of the Centre for Isotope Research at Groningen University, and the Faculty of Archaeology at Leiden University, Pavel Nikolskiy of the Geological Institute of the Russian Academy of Sciences, Alexei Tikhonov of the Zoological Institute of Russian Academy of Sciences and the Institute of the Applied Ecology of the North at the North-Eastern Federal University, Sergey Vartanyan of the North-East Interdisciplinary Scientific Research Institute N.A.N.A. Shilo of the Far East Branch of the Russian Academy of Sciences, and Love Dal én, once again of the of Bioinformatics and Genetics at the Swedish Museum of Natural History, present the results of a study in which they determined the sexes of 98 Woolly Mammoth specimens from different locations in Siberia and on Wrangel Island.

 The Siegsdorfer Mammut, in the Südostbayerisches Naturkunde und Mammut-Museum, the largest complete Mammoth specimen in Europe, thought to be a male. Lou Gruber/Wikimedia Commons.

Pecnerova et al. were able to identify the sex of 95 Mammoths, of which 66 were male and 29 were female, a noteworthy and clearly significant difference. Modern Elephants, like almost all Mammals, produce male and female offspring in equal proportions, and there is no reason to suspect that Mammoths were any different in this regard, suggesting that male Mammoths were more likely to enter the fossil record than female Mammoths.

Elephants show distinct sexual dimorphism, with males significantly larger than females. As a rule of thumb, the hard tissues of larger animals are more likely to survive intact until they are buried than those of smaller animals, simply because they are harder for other animals to break down. However Pecnerova et al.do not believe that this is likely to have been a significant factor in the case of Mammoths, as all Mammoths were sufficiently large to be difficult for any other animal found in their environment to break down. Furthermore most Mammoth specimens for which data on their origins are available seem to have come from natural traps, such as sinkholes, mudflows or pools, where their remains were buried rapidly, whereas remains left on open tundra will tend to remain exposed for years or even centuries, where the action of the weather can break down even the largest bones.

Instead, Pecnerova et al. suggest that the behaviour of the Mammoths when they were alive may have played a role in how likely they were to enter the fossil record.Modern Elephants have a complex social structure, with female Elephants living in family groups with their young and each such group having a set territory which they know very well. Males leave these groups when they approach sexual maturity, and live in male groups which are much wider ranging, and less defined in structure, with the youngest males not being automatically accepted into such a group, and often having to range over very large areas before they find a male pack that will accept them - if they do so at all. The largest, sexually mature, males leave these packs, becoming intolerant of other males, particularly when they are in musth (a heightened state of sexual agitation, and range over very wide areas looking for available females.

This more adventurous lifestyle means that male Elephants, unlike females, spend much of their lives in unfamiliar territory. If the same held true for Woolly Mammoths then males of this species would have been more likely to encounter unfamiliar hazards, such as sinkholes or swamps, which females would be taught to avoid by older members of the herd if they lie within their territory. This matches closely with what is observed in the fossil record, with predominantly male specimens preserved in geographical traps, which Pecnerova et al. believe is evidence of a similar social structure in Mammoths to that in Elephants.

See also...

http://sciencythoughts.blogspot.co.uk/2017/11/image-of-elephant-human-conflict-wins.htmlhttp://sciencythoughts.blogspot.co.uk/2017/10/elephants-kill-four-rohingya-refugees.html
http://sciencythoughts.blogspot.co.uk/2017/02/elephas-cf-e-planifrons-new-elephant.htmlhttp://sciencythoughts.blogspot.co.uk/2017/02/loxodonta-cyclotis-african-forest.html
http://sciencythoughts.blogspot.co.uk/2016/08/understanding-demise-of-last-mammoths.htmlhttp://sciencythoughts.blogspot.co.uk/2016/03/partial-gomphothere-tooth-from-miocene.html
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Explosion kills one at Austrian gas distribution centre.

One person has died and at least 21 more have been injured following an explosion at a gas-processing plant at Baumgarten in Austria on Tuesday 12 December 2017. The incident happened at about 8.45 am local time, and triggered a fire which swept through the plant, which is operated by Austrian gas company Gas Connect, and caries natural gas supplied by Russia's Gazprom to Austria and countries to the south. The cause of the blast has not yet been established.

Column of fire over the Baumgarten Gas-hub following an explosion on 12 December 2017. Tomáš Hulik/Reuters.

The explosion has caused immediate concerns about gas supplies to southern Europe, with Italy declaring a state of emergency after retail gas prices rose 97% in twenty four hours, and supplies to Croatia, Hungary, Slovakia and Slovenia are also threatened. The incident has effected even parts of Europe not directly supplied through the Baumgarten plant, with gas prices up 35% in the UK, Europe's largest consumer of natural gas, though this partly due to technical problems interrupting supplies from both the British and Norwegian North Sea Oilfields.

See also...

http://sciencythoughts.blogspot.co.uk/2017/11/seven-dead-as-north-sea-storm-herwart.htmlhttp://sciencythoughts.blogspot.co.uk/2017/09/understanding-deposition-of-suevites-in.html
http://sciencythoughts.blogspot.co.uk/2017/09/gaseous-emissions-kill-three-family.htmlhttp://sciencythoughts.blogspot.co.uk/2017/08/earthquake-kills-two-in-italian-island.html
http://sciencythoughts.blogspot.co.uk/2017/08/eight-missing-after-landslide-in.htmlhttp://sciencythoughts.blogspot.co.uk/2017/03/eight-injured-following-phraetic.html
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Tuesday, 12 December 2017

Magnitude 5.9 Earthquake in Kerman Province, Iran.

The United States Geological Survey recorded a Magnitude 5.9 Earthquake at a depth of 10.0 km about 56 to the northeast of the city of Kerman, the Iranian province of the same name, slightly before 12.15 pm local time (slightly before 8.45 am GMT) on Tuesday 12 December 2017. The was felt across much of Iran, and is reported to have destroyed more than 50 houses, as well as injuring at least 43 people, though none of those injured is described as being in a life-threatening condition.

The approximate location of the 12 December 2017 Kerman Earthquake. USGS.

Iran is situated on the southern margin of the Eurasian Plate. Immediately to the south lies the Arabian Plate, which is being pushed northward by the impact of Africa from the south. This has created a zone of faulting and fold mountains along the southwest coast of the country, known as the Zagros Thrust Belt, while to the northeast of this the geology is dominated by three large tectonic blocks, the Central Iran, Lut and Helmand, which move separately in response to pressure from the south, stretching and compressing the rock layers close to the surface and creating frequent Earthquakes, some of which can be very large.

The movement of the Arabian Plate and extent of the Zagros Thrust Belt. Rasoul Sorkhabi/Geo ExPro.

To the northeast of this the geology is dominated by three large tectonic blocks, the Central Iran, Lut and Helmand, which move separately in response to pressure from the south, stretching and compressing the rock layers close to the surface and again creating frequent Earthquakes.

The population of Iran is particularly at risk from Earthquakes as, unlike most other Earthquake-prone nations, very few buildings in the country are quake-resistant. The majority of residential buildings in Iran are made of mud-brick, a building material particularly vulnerable to Earthquakes as the bricks often liquefy, trapping people inside and quickly asphyxiating them with dust. This is particularly dangerous at night when the majority of people are inside sleeping.

 Section through the Zagros Fold Belt. Sarkarinejad & Azizi (2007).

Witness accounts of Earthquakes can help geologists to understand these events, and the structures that cause them. The international non-profit organisation Earthquake Report is interested in hearing from people who may have felt this event; if you felt this quake then you can report it to Earthquake Report here.
 
See also...
 
http://sciencythoughts.blogspot.co.uk/2017/08/magnitude-52-earthquake-in-hormozgan.html
http://sciencythoughts.blogspot.co.uk/2017/11/magnitude-73-earthquake-in-kermanshah.html
 
http://sciencythoughts.blogspot.co.uk/2017/05/twenty-one-confirmed-fatalities.html
http://sciencythoughts.blogspot.co.uk/2017/05/twenty-one-confirmed-fatalities.html
http://sciencythoughts.blogspot.co.uk/2014/04/magnitude-44-earthquake-in-khuzestan.html
http://sciencythoughts.blogspot.co.uk/2014/04/magnitude-50-earthquake-on-coast-of.html

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Parapercis altipinnis: A new species of Sandperch from Cebu Island, the Philippines

Sandperch, Pinguipedidae, are usually small, elongate, spiny fish in the Perch order. They are often brightly coloured and live close to the seafloor, where they feed on Crustaceans and other invertebrates. Male Sandperch are often territorial, defending a harem of females. Some forms excavate burrows.

In a paper published in the journal Zootaxa on 2 November 2017, Hsuan-Ching Mo of the  National Museum of Marine Biology & Aquarium in Pingtung, Taiwan, and the Institute of Marine Biology at the National Dong Hwa University, and Miranda Van Heden of Heusden in Belgium, describe a new species of Sandperch from Cebu Island in the Philippines.

The new species is placed in the genus Parapercis, and given the specific name altipinnis, meaning 'long-fin', in reference to the unusually high dorsal fin of this species. The species is described from a single specimen obtained by Miranda Van Heden from De Jong Marinelife, and initially confirmed as species by Hsuan-Ching Mo from a photograph sent to him. The specimen is 50.3 mm in length, reddish in colour above and black below, with a pattern of irregular deep coloured saddles, bars, dots and white patches. It was reportedly obtained at a depth of between 55 and 65 m. 

Living or fresh coloration of Parapercis altipinnis. Miranda Van Heden in Ho & Van Heden (2017).

Sandperch of the genus Parapercis are protogynous, which is to say individuals start out as female and become male as they mature. The single known specimen of Parapercis altipinnis is a female, but has no eggs in its ovaries, which Ho and Van Heden suggest is probably associated with either a juvenile yet to produce any eggs or a mature female which has just spawned.

See also...

http://sciencythoughts.blogspot.co.uk/2017/11/navigobius-kaguya-new-species-of.htmlhttp://sciencythoughts.blogspot.co.uk/2016/11/opistognathus-ensiferus-new-species-of.html
http://sciencythoughts.blogspot.co.uk/2016/10/grammatonotus-brianne-new-species-of.htmlhttp://sciencythoughts.blogspot.co.uk/2016/05/callionymus-alisae-new-species-of.html
http://sciencythoughts.blogspot.co.uk/2015/10/symphysanodon-andersoni-second-specimen.htmlhttp://sciencythoughts.blogspot.co.uk/2015/04/philometrid-nematodes-from-perciform.html
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Ankalodous sericus: A new species of Mult-jawed Chaetognath from the Early Cambrian Chengjiang Lagerstätte of Yunnan Province.

The Chaetognaths, or Arrow Worms, are an enigmatic group of marine invertebrates, with a bodyplan which is not close to that of any other group. They are pelagic ambush predators, with torpedo-like bodies and large external jaw-structures comprising two prominent bundles of anterior grasping spines and associated teeth. Attempts to determine how Chaetognaths are related to other animals using molecular methods have met with limited success; Chaetognaths have consistently been recovered as members of the Protostomes (the group that includes Arthropods, Molluscs, Annelids and the Lophophorate groups), with some studies suggesting that they occupy a basal position within the Protostomes (i.e. they branched off from the rest of the Protostomes before all other groups diverged from one-another, closer to the base of the family tree), or that they occupy a basal position within the lophotrochozoans (Molluscs, Annelids and Lophophorate phyla). To make matters worse, the Chaetognaths have almost no fossil record, with only one fossil species described, Protosagitta spinose, from the Early Cambrian Chengjiang Lagerstätte of Yunnan Province, which appears to be essentially similar to living Chaetognaths.

In a paper published in the journal Palaeontology on 1 September 2017, Degan Shu of the Early Life Institute, Department of Geology, and State Key Laboratory of Continental Dynamics at Northwest University, Simon Conway Morris of the Department of Earth Sciences at the University of Cambridge, Jian Han, also of the Early Life Institute, Department of Geology, and State Key Laboratory of Continental Dynamics at Northwest University, Jennifer Hoyal Cuthill, also of the Department of Earth Sciences at the University of Cambridge, and of the Earth-Life Science Institute at the Tokyo Institute of Technology, Zhifei Zhang and Meirong Cheng, again of the Early Life Institute, Department of Geology, and State Key Laboratory of Continental Dynamics at Northwest University, and Hai Huang of the College of Petroleum Engineering at Xi’an Shiyou University, describe a second species of Chaetognath from the Chengjiang Lagerstätte, which may shed more light on the origin of the group.

The new species is named Ankalodous sericus, where ‘Ankalodous’ means ‘bundles of teeth’ and ‘sericus’ means ‘silk’, a reference to the medieval Silk Road, connecting China to the Mediterranean region, which started at Xi’an in Shaanxi Province, the location of both Northwest and Xi’an Shiyou universities. The species is described from a number of specimens collected from outcrops of the Qiongzhusi Formation in Jingning and Haikou counties of Yunnan Province. Only the jaws of these specimens are preserved, nothing of the rest of the animals, but the preserved parts conform to the Chaetognath pattern, of opposed pairs of bundles of bristles. However, unlike modern Chaetognaths, Ankalodous sericus appears to have not just one pair of opposable jaw bundles but a whole series. 

Multi-jawed Chaetognath Ankalodous sericus. (A)-(B) Specimen and interpretative drawing; bilaterally symmetrical assemblage of grasping spines, five bundles (A-E) on either side (L, left; R, right) of midline; up to six spines per bundle; some spines (Lc6, Rc2, 3) show basal apertures. (C)–(D) Part and interpretative drawing; assemblage of grasping spines; three bundles (A–C) from left (L) and right (R) sides, latter rotated; details from counterpart incorporated by reversal; cross-hatched areas oxides (originally pyrite), mostly as infills of internal cavities of spines. (E)–(F) Assemblage of grasping spines and interpretative drawing; assemblage of grasping spines is bilateral but right-hand array (RA–RC) somewhat displaced relative to left-hand array (LA–LC). (G)–(H) Part and interpretative drawing; left (L) and right (R) assemblages of grasping spines, separated by thick layer of sediment; left assemblage comprises five (A–E) bundles of spines, with up to six spines per bundle; right assemblage somewhat less clear, but at least four bundles discernible; drawing is combination of part and by reversal counter-part. In all drawings stippled areas represent sediment, hachured lines breaks in slope with hachures down-slope. All scale bars represent 1 mm. Shu et al. (2017).

Shu et al. suggest that the arrangement seen in Ankalodous sericus, with several pairs of opposed bristle-bundles, may have been used as part of an ambush strategy by a buried benthic animal rather than a free swimming one, with an attack something like that of an Ant-lion.

Reconstruction of Ankalodous sericus. Animal depicted here with feeding apparatus open prior to prey capture. Position of the plate-like structure suggests that it was located on a mouth-cone or similar protrusion. Details of region posterior to feeding apparatus are hypothetical. Shu et al. (2017). 

Shu et al. observe that the arrangement of bristles in Ankalodous sericus resembles that seen in an enigmatic group of early Cambrian fossils called Protoconodonts, suggesting that these may have been related to Chaetognaths. They suggest that the group could have evolved from a primitive Lophotrochozoan ancestor with a complex jaw arrangement that has become simplified as an adaptation to a pelagic lifestyle, and thatbthis might imply a close relationship with the Gnathifera, a subdivision of the Lophotrochozoans which includes the Gnathostomulids, Micrognathozoans, Rotifers and Acanthocephalans, which are united by their complex jaw apparatuses.

See also...

http://sciencythoughts.blogspot.co.uk/2017/11/siphusauctum-lloydguntheri-enigmatic.htmlhttp://sciencythoughts.blogspot.co.uk/2017/02/ovatiovermis-cribratus-luolishanid.html
http://sciencythoughts.blogspot.co.uk/2016/10/utahcaris-orion-and-origin-of.htmlhttp://sciencythoughts.blogspot.co.uk/2016/08/oesia-disjuncta-enigmatic-cambrian.html
http://sciencythoughts.blogspot.co.uk/2016/01/scathascolex-minor-palaeoscolecid-worm.htmlhttp://sciencythoughts.blogspot.co.uk/2015/12/eokinorhynchus-rarus-kinorhynch-from.html
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