Wednesday, 21 March 2018

German skier killed and Canadian injured by avalanche in French Alps.

A German skier has died after being caught in an avalanche while skiing near Grenoble in the French department of Isèreon Sunday 18 March 2018. The unnamed 25-year-old man was one of a party of five who were caught in the event when the snow gave way downslope of them. A second skier, Katie Combaluzier, 24, from Toronto, who was studying medicine in Dublin, suffered a fractured spine and other injuries in the same incident.

Katie Combaluzier, 24, from Toronto, injured by an avalache in the French Alps on 18 March 2018. CBC News.

Avalanches are caused by the mechanical failure of snowpacks; essentially when the weight of the snow above a certain point exceeds the carrying capacity of the snow at that point to support its weight. This can happen for two reasons, because more snow falls upslope, causing the weight to rise, or because snow begins to melt downslope, causing the carrying capacity to fall. Avalanches may also be triggered by other events, such as Earthquakes or rockfalls. Contrary to what is often seen in films and on television, avalanches are not usually triggered by loud noises. Because snow forms layers, with each layer typically occurring due to a different snowfall, and having different physical properties, multiple avalanches can occur at the same spot, with the failure of a weaker layer losing to the loss of the snow above it, but other layers below left in place - to potentially fail later.
Diagrammatic representation of an avalanche, showing how layering of snow contributes to these events. Expedition Earth.

The Alps have seen a number of avalanche related incidents this winter, largely due to high levels of snowfall. This is, in turn caused by warmer conditions over the Atlantic, which leads to higher rates of evaporation over the ocean, and therefore higher rates of precipitation over Europe, which falls as snow in cooler regions such as the Alps, where the moist air meets cold air fromt the east.

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Asteroid 2018 EB4 passes the Earth.

Asteroid 2018 EB4 passed by the Earth at a distance of about 559 000 km (1.45 times the average distance between the Earth and the Moon, or 0.37% of the distance between the Earth and the Sun), at about 6.00 am GMT on Friday 16 February 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 EB4 has an estimated equivalent diameter of 16-49 m (i.e. it is estimated that a spherical object with the same volume would be 16-49 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 26 and 9 km above the ground, with only fragmentary material reaching the Earth's surface.

The calculated orbit of 2018 EB4. Minor Planet Center.

2018 EB4 was discovered on 12 March 2018 (four days before its closest approach to the Earth) by the University of Arizona's Catalina Sky Survey, which is located in the Catalina Mountains north of Tucson. The designation 2018 EB4 implies that it was the 104th asteroid (asteroid B4) discovered in the first half of March 2018 (period 2018 E).
2018 EB4 has a 1292 day orbital period and an eccentric orbit tilted at an angle of 1.46° to the plane of the Solar System, which takes it from 0.96 AU from the Sun (i.e. 88% of he average distance at which the Earth orbits the Sun) to 3.76 AU from the Sun (i.e. 376% of the average distance at which the Earth orbits the Sun, more than twice as far from the Sun as 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 2018 EB4 has occasional close encounters with the planet Jupiter, with the last thought to have occurred in March 1941 next predicted for August 2022.

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Tuesday, 20 March 2018

Ceratotherium simum cottoni: Last surviving male Northern White Rhinoceros had died.

The last surviving male Northern White Rhinoceros, a 45-year-old called Sudan, has died. The Rhinoceros, who had been suffering from a degenerative illness, was put down by a vet on Monday 19 March 2018, at the Ol Pejeta Conservancy in Kenya, to prevent any further suffering. He is survived by only two females of the species, his daughter and granddaughter, making prospects for the survival of the species now very poor, though sperm was collected from Sudan before he died, with a view to the artificial insemination of the females.

Sudan, the last surviving White Male Rhinoceros. Ol Pejeta Conservancy.

Northern White Rhinos formerly ranged across much of East and Central Africa, but were wiped out by poaching by 2008, when the last four surviving wild members of the species were officially declared to be dead when the could not be located despite extensive searches in the Garamba National Park and surrounding areas in northeastern Democratic Republic of Congo, where they were last seen alive in 2006. The animals at the Ol Pejeta Conservancy are captive bred Rhinos that were transferred from the Dvur Kralove Zoo in the Czech Republic, in the hope of re-introducing the species to the wild, though this now seems unlikely.

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Monday, 19 March 2018

Nyctibatrachus mewasinghi: A new species of Night Frog from the Western Ghats of India.

Night Frogs, Nyctibatrachus spp., are a groups of robust-bodied Frogs found only in the Western Ghats mountain range of southwest India. They get their name from their dark colouration and nocturnal habits. They were formerly placed in the True Frog family, Ranidae, but are now recognised as belonging to a distinct family of their own, the Nyctibatrachidae, which includes only one other Frog, the Sri Lankan Wart Frog, Lankanectes corrugatus.

In a paper published in the Journal of Threatened Taxa on 26 December 2017, Keerthi Krutha of the Wildlife Information Liaison Development Society, Neelesh Dahanukar of the Indian Institute of Science Education and Research, and the Systematics, Ecology and Conservation Laboratory at the Zoo Outreach Organization, and Sanjay Molur, also of the Systematics, Ecology and Conservation Laboratory at the Zoo Outreach Organization,describe a new species of Night Frog from the Malabar Wildlife Sanctuary, in Kerela State, India.

The new species is named Nyctibatrachus mewasinghi, in honour of Mewa Singh of the University of Mysore, the Institution of Excellence, and the Jawaharlal Nehru Centre for Advanced Scientific Research. The species is small for a Night Frog, reaching 21-23 mm in length as adults, and grayish brown in colour with a lighter underside. The Frogs were found at a single location, a drainage stream near the Peruvannamuzhi Dam.

Nyctibatrachus mewasinghi, female speciemen. Krutha et al. (2018).

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Sunday, 18 March 2018

Homoneura yanqingensis: A new species of Lauxaniid Fly from northern China.

Lauxaniid Flies are small True Flies, Diptera, that tend to have plain coloured bodies, patterned wings and large, often brightly coloured eyes. The larvae of these flies are saprotrophs (detritovores) that often play a role in soil formation, helping to break down fallen leaves and other material. Lauxaniids are commonest in the Asian and American tropics, being rarer in temperate regions, and uncommon in Africa.

In a paper published in the journal ZooKeys on 29 December 2017, Li Shi and Xuefeng Gao, of the College of Agronomy at the Inner Mongolia Agricultural University, and Wenliang Li of the College of Forestry at the Henan University of Science and Technology, describe a new species of Lauxaniid from northern China.

The new species is placed in the genus Homoneura and given the specific name yanqingensis, meaning 'from Yanqing' in reference to Yanqing County in the Beijing Municipal Area, where the species was first discovered. This species ranges from 3.8 to 4.3 mm in length and is yellow in colour with brown spots on the wings. The species was found in the Beijing Municipal Area and Shaanxi Province.

Homoneura yanqingensis, male specimen from Shaanxi Province. Shi et al. (2017).

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Magnitude Earthquake in Zambezia Province, Mozambique.

The United States Geological Survey recorded a Magnitude 4.9 Earthquake at a depth of 10.0 km in western Zambezia Province, Mozambique, about 22 km to the northeast of the town of Nsanje in Malawi which was hit by an Earthquake on 6 March, slightly after 5.10 pm local time (slightly after 3.10 pm GMT) on Saturday 17 March 2018. This is unlikely to have caused any damage or casualties, though it is large enough that it was probably felt locally, although there have been no reports of anybody having done so at this time.

 The approximate location of the 17 March 2018 Zambezia Earthquake. USGS.

Western Zambezia lies within the the of the Great Rift Valley, which is slowly splitting the African Plate in two along a line from the Red Sea through Ethiopia, and which includes the great lakes and volcanoes of east-central Africa. This has the potential to open into a new ocean over the next few tens of millions of years, splitting Africa into two new, smaller, continents; Nubia to the west and Somalia to the east.

 Movement on the African Rift Valley, with associated volcanoes. Rob Gamesby/Cool Geography.

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.
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Microbial biodiversity around the Garga Hot Spring in southern Siberia.

Microbial mats are thought to be the oldest biological communities on Earth, with a fossil record that dates back at least 3.5 billion years. Today these communities rend to be found in extreme environments where other organisms cannot thrive, such as hot springs or hypersaline lakes. The Baikal Rift Zone in southern Siberia is home to a number of hot spring systems with unusually alkaline waters, which are likely to be host to unique communities of mat-forming microbes, but which are relatively understudied.

In a paper published in the journal BMC Evolutionary Biology on 28 December 2017, Alexey Sergeevich Rozanov and Alla Victorovna Bryanskaya of the Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences, Timofey Vladimirovich Ivanisenko, also of the Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences, and of the Novosibirsk State University, and Tatyana Konstantinovna Malup and Sergey Evgenievich Peltek, again of the Institute of Cytology and Genetics of the Siberian Branch of the Russian Academy of Sciences, present the results of a study of the biodiversity of microbial mats around the Garga Hot Spring in the Barguzin Valley of the Republic of Buryatia in southern Siberia, which has the most alkaline known waters of any hot spring in the Baikal Rift Zone, with pH values of between 8.0 and 9.0.

 (a) Eastern Siberia; (b, Eastern Baikal, Barguzin Valley, satellite photo. Red cross marks the location of the Garga hot spring (54°19′3.72″N, 110°59′38.4″E). Rozanov et al. (2017).

Rozanov et al sampled waters originating from the spring at four points. The first of there was close to the spring itself, with waters at temperatures in excess of 74°C, where there was a simple biofilm of white material was present. The second was located in a stream running from the spring towards the Barguzin River, where the waters were about 70°C, and a thicker biofilm with three distinct layers had developed. The upper two layers were yellowish, with the upper being dense and about 2 mm thick and the lower being thinner and about 2 cm. The bottom layer was about 1 cm thick, white, gelatinous and adhered to the substrate. The third point was further downstream, where the temperature had fallen to 55°C. Here the mat still had three layers, with the top layer being yellowish green and about 2 mm thick, the middle layer being membranous, gelatinous and whitish-green and about 2 cm thick, while the bottom layer was again 1 cm thick, gelatinous and white. The final point was further downstream, where the temperature had fallen to 45°C. Here there were again three layers, with the upper two layers being apparently identical to those at the third site, while the bottom layer as thinner, about 3-5 mm, and 'skin coloured'.

Microbial mats of the Garga hot spring. (a) Microbial mat of the upper reaches of the spring; red circle, second sampling point. (b) Microbial mat of the middle reaches; red circle, third sampling point. (c) Layers of the third sample. (d) Sampling scheme. Rozanov et al. (2017).

The sample taken from the first location contained a significant proportion of Archaeans (Prokaryotic micro-organisms resembling Bacteria, but only distantly related to them, and more closely related to Eukaryotes, about 20% of the sample, the highest proportion found at any site in the Baikal Rift Zone to date. Many of these belonged to the Crenarchaeota, a group widely associated with hot springs, with about 7.9% of the sample closely related to Thermopro teusuzonensis, a species isolated from acid hot springs on the Kamchatka Peninsula, and Vulcanis aetasouniana, a species from acidic springs in Japan. However, the sample also contained other, non-Crenarchaeote, Archaeans, with no apparent close relationships to any other described species.

The remaining three sites had essentially similar structures, with an upper layer dominated by Cyanobacteria (filament-forming photosynthetic Bacteria) of the genera Leptolyngbya, Synechococcus and Nostoc, all associated with hot springs in a variety of other locations around the world. The second layer contained lower numbers of Cyanobacteria, though they were still present, along with heterotrophic Bacteria (Bacteria that gain nutrition by consuming other Bacteria), principally Proteobacteria and Actinobacteria. The lowermost layer was anearobic and dominated by saprotrphic Bacteria such as Clostridia, obtain nutrition by breaking down organic material externally.

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