Thursday, 19 April 2018

Colombian gold miners trapped by collapse at Marmato mine.

Sixteen gold miners were trapped by a roof collapse at the entrance to the San Pedro Mine in the 100 Peso Sector of Marmato in Caldas Department on Wednesday 18 April 2018. The miners were trapped between 15 and 20 m below the ground, but were not thought to have been in any immediate danger as ventilation to the mine was maintained (other the immediate danger of being crushed by falling rocks, the biggest risk to miners trapped in collapsed mines is running out of oxygen). Fourteen of the miners have now been released, with rescue teams in contact with the remaining two, who are said to be unhurt.

Rescued miners emerging from the San Pedro Mine in Marmato following the 18 April 2018 collapse. La Patria.

The town of Marmato has a long tradition of gold mining, and many small independently run gold mines, which have historically attracted miners from as far away as Cornwall in the UK. Since 2007 the town has been in dispute with the central government of Colombia, which has backed a plan to give the entire area to Gran Colombia Gold, which planned to strip mine the whole area, removing the town in the process. This plan was dropped in 2017, with Gran Colombia still retaining control of the area, but now planning to concentrate on deep-pit mining.

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Eruption on Io Yama volcano, Japan.

Iō Yama, a 1562 m stratovolcano (cone shaped volcano made up of layers of ash and lava) at the northwestern end of the Kirishima Volcanic Complex on southern Kyūshū Island, erupted suddenly slightly before 3.40 pm Japan Standard Time on Thursday 19 April 2018. The Japan Meteorological Agency has issued a warning to avoid going within 3 km of the volcano, due to the dangers of flying rock fragments or pyroclastic flows.

Eruption on Io Yama on 19 April 2018. Japan Meteorological Agency.

Japan has a complex tectonic situation, with parts of the country on four different tectonic plates. Kyūshū 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 Kyūshū.

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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Wednesday, 18 April 2018

Chelonus spinigaster: A new species of Braconid Wasp from Uttar Pradesh.

Moths of the Family Gracillariidae are found throughout the world except on Antarctica and some remote islands. Their larvae are leaf-miners, worm-like caterpillars that live in tunnels inside leaves. This makes these Moths significant agricultural pests, and considerable amounts of research have been dedicated to finding ways to control them. One of the most successful methods of reducing Mining Moth populations is the deliberate introduction of parasitoid predators, Insects (usually Wasps) which lay their eggs on or in the leaf-mining caterpillar, which the parasitoid larvae then consume. Since most parasitoids target only a single prey species, which is an advantage when introducing a biological control, as it makes them highly unlikely to target unintended species. However, before this can be done, suitable parasitoids need to be identified, something which has not been done in every part of the world.

In a paper published in the journal ZooKeys on 12 February 2018, Zubair Ahmad of the Department of Biology at King Khalid University, and Hamed Ghramh, also of the Department of Biology, and of the Research Centre for Advance materials Science, at King Khalid University, describe a new species of Braconid Wasp targetting Acrocercops lysibathra, a Mining Moth which feeds on a number of fruiting trees in India, a country where parasitoid-prey relationships have been little studied.

Braconid Wasps are small parasitoid wasps (Wasps whose larvae grow inside the bodies of a living animal host) targeting a variety of Insect and Spider species. They are unusual in that they will lay multiple eggs within the same host (most parasitoid Wasps lay a single egg on each host), thereby allowing multiple larvae to mature within a large host, which is not necessarily killed in the process. Braconid Wasps are often fearsome in appearance, but are harmless, other than to targeted host species, as they lack stings.

The new species is placed in the genus Chelonus and given the specific name spinigaster, meaning 'spiney tail'. The species is described from eight female and fourteen females collected from Acrocercops lysibathra caterpillars living on Cordia latifolia (Sebesten Fruit) trees at Aligarh in Uttar Pradesh. These are small Wasps, reaching about 2.4 mm, black in colour with yellow and brown markings, with a rugose (corrugated) epidermis.

Chelonus spinigaster, female specimen. Ahmed & Ghramh (2018).

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The Lyrid Meteor Shower.

The Lyrid Meteors are typically visible between 16 and 25 April each year, and will be at peak visibility on the morning of Sunday 22 April in 2017. This coincides with the First Quarter Moon, also on Sunday 22 April, so viewing this year should be good. At its peak the Lyrid Meteor shower typically produces about 20 meteors per hour, though higher rates have been recorded.

Sky map showing the radiant point for the Lyrid Meteors (i.e. the point from which the meteors appear to radiate). Earth Sky.

The Lyrid Meteors are comprised of debris from the comet C/1861 G1 Thatcher (named after the astronomer A. E. Thatcher, not the politician). This is a long-period comet that spends most of its time in the Oort Cloud, only visiting the inner Solar System once every 415 years, the last occasion being in 1861. When the comet visits the inner Solar System it is heated by the Sun, melting the ices that make up its surface and releasing a trail of dust, which continues to follow the path of the comet. The Earth passes through this trail in April each year, creating a light show as the dust particles burn in the upper atmosphere which appears to radiate from the star Vega in the constellation of Lyra. 

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Tuesday, 17 April 2018

German tourist attacked by Leopard in Namibia.

A German tourist has been badly mauled by a Leopard in Kuiseb Canyon in western Namibia on Thursday 12 April 2018. Hardy Specker, 61, was sleeping in a camper van with a window open when he heard the animal scratching at the vehicle. He attempted to close the window but was seized by the Leopard, which attempted to drag him out of the vehicle, while his partner attempted to pull him back in. Eventually the Cat released him, leaving him with severe lacerations, but stayed close by, preventing either passenger from leaving the camper. Eventually they were able to alert a passing motorist to their plight and Mr Specker was taken to a hospital in Walvis Bat for treatment.

Bloodstains on the side of a vehicle that a Leopard attempted to drag a tourist from. The Namibian.

Leopards, unlike most animals., are natural predators of Humans and will often attack us if the opportunity arises. They are also extremely flexible in their habitat requirements, and can adapt to live in Human-modified environments quite readily. Humans will generally do their best to avoid this, and in areas where Leopards are found tend to take precautions, such as building secure barriers around villages or killing the Leopards. Leopards are considered to be Vulnerable under the terms of the International Union for the Conservation of Nature's Red List of Threatened Species, due to habitat loss, licenced hunting, poaching for the illegal wildlife trade and loss of prey species, though Southern African populations have been less depleted than populations in other parts of Africa and Asia.

A Leopard killed by a hunter in Namibia. Wikimedia Commons.

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Magnitude 2.2 Earthquake in the Highlands of Scotland.

The British Geological Survey recorded a Magnitude 2.2 Earthquake at a depth of about 9 km roughly 15 km to the north  of the village of Kinlochewe in the Highlands of Scotland, slightly before 7.00 pm British Summertime (slightly before 6.00 pm GMT) on Friday 13 April 2018. This was not a major event, and presented no threat to human life or property, but may have been felt locally.
The approximate location of the 13 April 2018 Kinlochwe Earthquake. Google Maps.
Earthquakes become more common as you travel north and west in Great Britain, with the west coast of Scotland being the most quake-prone part of the island and the northwest of Wales being more prone  to quakes than the rest of Wales or most of England.
The precise cause of Earthquakes in the UK can be hard to determine; the country is not close to any obvious single cause of such activity such as a plate margin, but is subject to tectonic pressures from several different sources, with most quakes probably being the result of the interplay between these forces.
Britain is being pushed to the east by the expansion of the Atlantic Ocean and to the north by the impact of Africa into Europe from the south. It is also affected by lesser areas of tectonic spreading beneath the North Sea, Rhine Valley and Bay of Biscay. Finally the country is subject to glacial rebound; until about 10 000 years ago much of the north of the country was covered by a thick layer of glacial ice (this is believed to have been thickest on the west coast of Scotland), pushing the rocks of the British lithosphere down into the underlying mantle. This ice is now gone, and the rocks are springing (slowly) back into their original position, causing the occasional Earthquake in the process. 
 (Top) Simplified diagram showing principle of glacial rebound. Wikipedia. (Bottom) Map showing the rate of glacial rebound in various parts of the UK. Note that some parts of England and Wales show negative values, these areas are being pushed down slightly by uplift in Scotland, as the entire landmass is quite rigid and acts a bit like a see-saw. Climate North East.

Witness accounts of Earthquakes can help geologists to understand these events, and the structures that cause them. If you felt this quake, or were in the area but did not (which is also useful information) then you can report it to the British Geological Survey here.
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Monday, 16 April 2018

Smilax sailenii: A new species of Greenbrier from Assam State, India.

Greenbriers, Smilax spp., are thorny vines closely related to Lilies. There are between 300 and 350 species around the world, found predominantly in the tropics. There are currently 33 described species in India, the majority from the Himalayan region.

In a paper published in the journal Taiwania on 23 February 2018, Sanjib Baruah of the Department of Botany at Bodoland University, Jatindra Sarma of the Hamren Territorial Division of the Department of Environment & Forest, and Sachin Kumar Borthakur of the Department of Botany at Gauhati University describe a new species of Greenbrier from Assam State in India.

The new species is named Smilax sailenii in homour of Sailendra Prasad Borah, formerly of the Department of Botany at Gauhati University, who passed away in 2012. The species is a woody vine with a prickly stem, producing greenish female flowers in clusters of 18-22 in September to October, that develop into green fruit up to 3 cm in diameter that become red when white.

Smilax sailenii, fruiting branch. Baruah et al. (2018).

The species was found growing in a subtropical forest at altitude of between 300 and 400 m above sealevel, in an area currently subject to rapid deforestation. For this reason Baruah et al. recommend that the species be treated as Critically Endangered under the terms of the International Union for the Conservation of Nature’s Red List of Threatened Species.

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