Sunday 30 June 2013

A new species of deepwater Goatfish from Vanuatu.

Goatfish are largish, often brightly coloured Fish in the Mullet Family, Mullidae (making them Perciformes). They are bottom feeding Fish that have deep, elongated bodies and whiskers which they use for probing sediments for invertebrate prey. Goatfish are highly prized as food Fish in many cultures.

In a paper published in the journal Zootaxa on 31 May 2013, Franz Uiblein of the Institute of Marine Research in Bergen and the South African Institute of Aquatic Biodiversity and Romain Causse of the Borea Research Unit at the Muséum national d'Histoire naturelle, discuss the discovery of a new species of deepwater-dwelling Goatfish from Vunuatu in the South Pacific.

The new species is placed in the genus Upeneus, and given the specific name vanuatu, in reference to where it was discovered - making it the Vanuatu Goatfish. Upeneus vanuatu was discovered living in the waters off Espiritu Santo and Malo Islands, at depths of 191-321 m. This is only the fourth species in the genus to have been found living at depths in excess of 100 m, though since two of the other three species have been discovered since 2000, Ublein and Causse suggest that there may be more, undiscovered, deepwater species in this genus around the world. 

Upeneus vanuatu has an adult size of 80-100 mm, it is a rose-pink Fish with patterns of bars on its fins, these patterns being variable and possibly specific to the individual Fish. 

Upeneus vanuatu, 8.3 cm specimen caught of the island of Malo in Vanuatu. Uiblien & Causse (2013).


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Two women killed in landslide in Darchula District, Nepal.

Two women have been killed, and a further two injured, in a landslide at Chhapari Village in the Nepalese part of Darchula District (part of the district lies in the Indian province of Uttarakhand), following heavy rains. The women, who were collecting fodder at the time of the incident, have been named as Manamati Devi Bam, who died instantly, Dhana Devi Bam, who died of her injuries while undergoing treatment, and Madhavi Devi Bam and Sarawoti Bam, who are undergoing treatment in a hospital on the Indian side of the border.

The location of the Chhapari landslide. Google Maps.

Nepal and Uttarakhand have suffered extensive flooding following the onset of the Monsoon Season earlier this month. This has lead to a number of landslide events, as well as rivers bursting their banks and the partial collapse of the Chorabari Glacier in Uttarakhand. 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, but the situation in Uttarkhand is thought to have been made much worse by extensive deforestation, sand extraction and quarrying (much of it illegal) and unregulated building construction across the affected area.


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A fossil Snake from the Cretaceous of Brazil.

Snakes are generally accepted to have appeared and diversified during the Mesozoic, though their fossil record is not extensive. This is due to their lightly mineralized, easily disarticulated skeletons, which tends to result in Snake fossils, where they are found at all, tend to be poorly preserved and fragmentary. Nevertheless, by the late Cretaceous, a reasonable diversity of Snakes is known from sites across the world. How these early forms are related to modern Snakes is unclear, some retained limbs, and clearly could not be placed in any modern group, others are placed in extinct family Madtsoiidae, which died out in the Pleistocene, but most are too fragmentary for any taxonomic assignment. Fossils which can be placed with reasonable confidence in modern groups appear in the Palaeocene-Eocene.

In a preliminary paper published in the journal Acta Palaeontologica Polonica on 21 January 2013, Anne Hsiou of the Departamento de Biologia at the Universidade de São Paulo, Adriana Albino of the Departamento de Biología at the Universidad Nacional de Mar del Plata and Manuel Medeiros and  Ronny Santos of the Departamento de Biologia at the  Centro de Ciências Biológicas e da Saúde at the Universidade Federal do Maranhão describe a new Snake fossil from the Cenomanian (early Late Cretaceous, 99.6 to 93.5 million years ago) of northeastern Brazil.

The new Snake is named Seismophis septentrionalis, where 'Seismophis' means 'Earthquake-snake' and  'septentrionalis' means 'from the north'. The fossil was discovered at a site called Falésia do Sismito (Cliff of the Earthquake) on Cajual Island in the north of Maranhão State, which itself is in the north of Brazil.

The species is described from a pair of disarticulated mid-trunk vertebrae, not assumed to come from the same animal, though they are distinctive enough to say that they are Snake bones, and probably come from the same species. This is not unusual with Snakes fossils; the animals gain their extreme flexibility from having bones only lightly mineralized and loosely held together with tendons and muscles.

Seismophis septentrionalis, first specimen. Photographs (A1–E1) and schematic drawings (A2–E2), in anterior (A), posterior (B), lateral (C), dorsal (D), and ventral (E) views. Scale bar is 10 mm. Hsiou et al. (2013).


Seismophis septentrionalis, second specimen. Photographs (A1–E1) and schematic drawings (A2–E2), in anterior (A), posterior (B), lateral (C), dorsal (D), and ventral (E) views. Scale bar is 10 mm. Hsiou et al. (2013).


Due to the fragmentary nature of this material, it is not possible to say how this species is related to other Cretaceous or modern Snakes, but it is considered to be the oldest known Snake yet discovered in Brazil.

Map showing the locality where the specimen was found. Hsiou et al. (2013).


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Saturday 29 June 2013

Two people killed in Hunan landslide.

Two people were killed when a house collapsed in a landslide in Shuangqiao Village in Hunan Province, central China, following days of rainstorms that have led to flooding across much of the province, and a number of landslides and building collapses. A third person in the building survived the collapse, which occurred at around 1.00 pm local time (around 5.00 am, GMT) on Friday 28 June 2013.

The approximate location of the 28 June 2013 Hunan landslide. Google Maps.

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.


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Choking on Fish is a significant cause of death for Dolphins in Indian River Lagoon, Florida.


Bottlenose Dolphins (Tursiops truncatus) are predatory Ceteceans, which primarily hunt small Fish. They are intelligent, social animals, which hunt in packs and are capable of developing new hunting methods to deal with novel prey items.

In a study published in a paper in the journal PLoS One on 19 June 2013, a group of scientists led by Megan Stolen of the Hubbs-SeaWorld Research Institute looked at causes of death among stranded Dolphins in the Indian River Lagoon and adjacent areas of the Atlantic Ocean over a 14 year period from 1997 to 2011. During this period they found that 14 of 350 Dolphin deaths in the lagoon were a direct result of choking on fish (4% of the total), while none of the 186 dead Dolphins recovered from the open ocean had died in this way. Dolphins that have died in this way have been found before, but this is extremely rare; of 19 recorded cases of Dolphins choking on Fish known globally, 14 are from this location and discussed in this study. 

The body of a Bottlenose Dolphin with a Fish lodged in its esophagus. In this case the Fish is a Sheepshead (Archosargus probatocephalus). Stolen et al. (2013).

In all cases the Fish were lodged in the esophagus of the Dolphins, compressing or displacing the larynx, and preventing the Dolphins from breathing. In five cases the Fish were found with their tales still protruding from the Dolphin's mouth. In seven cases the Fish were held in place close to the larynx by strong dorsal spines. Eight of the Dolphins were male, two Female and one to badly decomposed to be identified. Twelve of the Dolphins were adults, two juveniles.

In five of the cases the Fish were associated with fishing tackle; two of the Fish had lures attached, and one Fish had a line attached with hooks that had become embedded in the Dolphin's esophagus. In the remaining two cases lines and lures were present, but not attached to the fish, making it hard to say with confidence that they had come from this Fish which had killed the Dolphin.

All the fish were between 19 and 40 cm in length; well within the normal range of Fish consumed by Bottlenose Dolphins. Eight of the fish could be identified to specific level; six Sheepshead (Archosargus probatocephalus), one Black Chin Tilapia (Sarotherodon melanotheron) and one striped mojarra (Diapterus plumieri). Two other fish were tentatively identified as Tilapia (Cichlidae) and one as a Jack (Carangidae).

Sheepshead are a common Fish on the southern Atlantic and Gulf coasts of the US, but are not normally considered an important prey item for Dolphins. They are spiny members of the Perch order (Perciformes) and have a deeper body profile than the Fish usually favored by Dolphins, suggesting that they are a rather risky prey item, which Dolphins would normally avoid. Why the Dolphins of Indian River Lagoon are targeting this Fish is unclear.

The Sheepshead (Archosargus probatocephalus), a deep-bodied, spiny, Perciform Fish. Wikimedia Commons/Bulletin of the United States Fish Commission.

Tilapia (which are also Perciformes) are not native to Florida, but have been introduced via Fish farms and are becoming increasingly common in the lagoons. They are similar in shape to familiar prey Fish, but again have prominent spines which may facilitate them becoming lodged in the throats of Dolphins.

The Black Chin Tilapia (Sarotherodon melanotheron), a spiny non-native Fish. Jacques Panfili/Fishbase.

The precise reason for the high number of choking mortalities among Dolphins in Indian River Lagoon cannot be stated with confidence. One case could clearly be attributed to fishing tackle associated with the Fish, and in four other cases tackle was present but could not be established as the cause of death. Three Dolphins died as a result of consuming an unfamiliar, introduced fish, but far more died after consuming native Fish that Dolphins usually avoid; the reason for this change in feeding behavior is not clear.


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Friday 28 June 2013

Two new species of Potter Wasps from Yunnan Province, China.

Potter Wasps are a group of solitary Wasps that get their name from their construction of mud or clay 'pots', which often resemble Greek urns, in which they place their eggs, along with paralyzed prey animals, usually Caterpillars or Spiders, for their young to consume as they grow. Potter Wasps are often large Insects, closely related to Social Wasps, and can be fairly formidable looking, though in fact they are fairly harmless to humans and will usually only sting if severely provoked. In many ecosystems they are considered to be an important control on the populations of plant pests, particularly Caterpillars.

In a paper published in the journal ZooKeys on 21 May 2013, Ju You, Bin Chen and Ting-jing Li of the Institute of Entomology & Molecular Biology at the College of Life Sciences at Chongqing Normal University, describe two new species of Potter Wasps from Diqing Prefecture in Yunnan Province in southwest China.

Both new species are placed in the genus Ancistrocerus; the so-called 'hook-horned' Potter Wasps, due to the hooks on the ends of their antennae.  The first new species is named Ancistrocerus transpunctatus, in reference to a row of pits on one of the segments of its abdomen. The species is described from four specimens from two different locations in Weixi County, all male. It is a 7.5-8.0 mm black Wasp with yellow and red markings on parts of its body. 

Ancistrocerus transpunctatus, male specimen. You et al. (2013).

The second species is named Ancistrocerus deqinensis, where deqinensis derives from Dequin County, where the species was discovered. The species is described on the basis of five male specimens from a single location. It is a 7.0-7.8 mm black Wasp, with yellow markings and yellow stripes on its abdomen.

Ancistrocerus deqinensis, male specimen. You et al. (2013).


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Two new species of Earthworm from Korea.

Earthworms play a major role in the formation of soils in many parts of the world (though soils can and do form in there absence), ingesting and breaking larger portions of organic material and producing a nitrogen rich humus. This role in soil formation makes them very important members of many ecosystems, yet they are often not well understood, with the biology of only a few European species studied extensively.

In a paper published in the journal ZooKeys on 6 June 2013, Robert Blakemore, Seunghan Lee and Wonchoel Lee of the Biodiversity Laboratory at the College of Natural Science at Hanyang University, and Hong-Yul Seo of the National Institute of Biological Resources, describe two new species of Earthworm from Jeollabuck and Gangwon Provinces in South Korea.

The first new species is placed in the genus Amynthas and given the specific name daeari, after the location where it was discovered, Daea-ri village in Jeollabuck Province. Amynthas daeari is a 150 mm Earthworm found living in leaf-litter in woodland. It has a single female pore on segment 14 and paired male pores on segment 18.

Amynthas daeari. Blackmore et al. (2013).

The second new species is also placed in the genus Amynthas, and given the specific name jinburi, after the location where it was found, Jinbu-ri in Gangwon Province. Amynthas jinburi is a 210 mm Earthworm, living in deep burrows in remote mountain areas, where it is thought to be geophagus (i.e. consume significant amounts of rock-derived minerals. It also has a single female pore on segment 14 and paired male pores on segment 18.

Amynthas jinburiBlackmore et al. (2013).


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Exploration company claims to have struck oil off Lagos State, Nigeria.

Nigeria is the world's fifth largest oil producer, earning over 98% of its export earnings from the sale of hydrocarbons. However the presence of oil has widely been seen as a curse as much as a blessing, with the oil producing areas of the Niger Delta having suffered numerous pollution events in the industry's fifty-year history, and little of the wealth generated filtering down to ordinary Nigerians, 70% of whom still live on less than US$1 a day. The population of the oil producing southeast has long harbored a suspicion that they are being cheated of their share of the oil income by foreign companies and national politicians, particularly those from other parts of the country, while people in other parts of the country have accused the southeast of wanting too much of a national asset. In the late 1960s the southeast tried to succeed in a three year civil war, and violent incidents occur in the area till this day.

On 26 June 2013 two exploration companies mounting a joint drilling operation, Lekoil and Afren Plc., released a statement to the effect that they had discovered significant reserves of oil off the coast of Lagos State, in the southwest of the nation. The find came at a depth of 3600 m in Late Cretaceous to Early Palaeocene sandstones, in an exploration block named OPL 310, to which the companies have obtained rights. The explorers found 66 m of oil bearing sediment beds over a 160 m section of deposits. This is only an initial report, and the lateral extent of the oil bearing deposits is not yet clear, since these findings are from a single well, though this does have the potential to be a very lucrative find. 

Drill head on an offshore rig off the coast of Nigeria. Afren Plc.

Natural gasses are formed from the 'cooking' of biological material (principally plant matter) in deeply buried sediments. When  biological material is sufficiently heated and pressurized, then volatile compounds are forced off as gas. In porous sediments this will typically escape from its point of origin, rising up until it becomes trapped at a high point in the porous rock, with impermeable sediments, such as clays, above.

The geology off the coast of West Africa, as determined by seismic survey, showing the location of the OPL 310 concession. Afren Plc.

The position of the OPL 310 concession relative to Lagos. energy-pedia.


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Further eruptions on Mount Pavlof.

Mount Pavlof, an active volcano on the Alaska Peninsula, which has been erupting intermittently since mid-May 2013, underwent a sharp increase in seismic activity on 24 June, accompanied by an increase in explosive eruptions, ash and lava production, according to the Alaska Volcano Observatory. On 25 June it produced an ash column 8.5 km high, which drifted to the southwest, causing an ashfall in King Cove, 48 km away. Since then there has been only minor ash and lava production on the volcano, but infra-red satellite images are still showing a strong thermal signal, suggesting the presence of a large magma body with the potential to trigger further eruptions.

Eruption on Mount Pavlof. MSN.


Pavlof is a 2500 m high, 7 km wide stratovolcano (cone-shaped volcano) between Cold Bay and Pavlof Bay near the tip of the Alaskan Peninsula. It has several active vents on its north and east flanks, it's remoteness and inaccessibility meaning that it is usually hard to tell from exactly which of these an individual eruption is occurring. Pavlof is considered to be one of America's most active volcanoes, and though it is located in a remote spot with no settlement close by, it still presents a serious threat to air-traffic.

The volcanoes of the Alaskan Peninsula and Aleutian Islands are fed by magma rising from the Pacific Plate, which is being subducted beneath the North American Plate to the south. As the subducting plate sinks into the Earth it is subjected to enormous heat and pressure, causing more volatile minerals to melt. These then rise through the overlying North American plate as magma, fueling the Alaskan volcanoes.


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Magnitude 3.9 Earthquake in north California.

A Magnitude 3.9 Earthquake at a depth of 6.9 km occurred roughly 150 km southeast of San Francisco slightly after 8.50 pm on Thursday 27 June 2013, local time (slightly after 3.50 am on Friday 28 June, GMT), according to the United States Geological Survey. The quake is not reported to have caused any damage or injuries, but was felt across much of Silicon Valley and as far north as San Francisco. The quake was followed by a Magnitude 2.8 aftershock which came about 40 minutes after the initial quake.

The location of the 27 June 2013 California Earthquake. Google Maps.

California is extremely prone to Earthquakes due to the presence of the San Andreas Fault, a tectonic plate margin that effectively bisects the state. The west of California, including Santa Barbara and Los Angeles, is located on the Pacific Plate, and is moving to the northwest. The east of California, including Fresno and Bakersfield is on the North American Plate, and is moving to the southeast. The plates do not move smoothly past one-another, but constantly stick together then break apart as the pressure builds up. This has led to a network of smaller faults that criss-cross the state, so that Earthquakes can effectively occur anywhere.

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


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Earthquake near Doncaster.

A Magnitude 1.9 Earthquake occurred at a depth of about 1 km roughly 10 km to the east of Doncaster in South Yorkshire, slightly after 4.50 am British Summertime (slightly after 3.50 am GMT) on Wednesday 26 June 2013, according to the British Geological Survey. This is not large enough to have caused any damage or injuries, but should have been large enough to have been felt; though no one has reported this, possibly due to the early hour at which it happened.

The location of the 26 June Earthquake. Google Maps.

As a rule of thumb 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. 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. 

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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Two killed in Nepal Landslide.

Two people, described as migrant workers returning home after surviving the floods in Uttarakhand Province, India, were killed in a landslide in Serighat in Kalikot District, Nepal, early in the morning of Thursday 27 June 2013. The two, named as Jakte Biswokarma, 45, and Daljit Biswokarma, 40, of Rachuli Village, were sleeping on the roof of a house that was struck by the event, following heavy rains associated with the onset of the Asian Monsoon. A third person, Buche Biswokarma, also from Rachuli, was injured and taken to hospital in Surkhet. The trio had reportedly travelled to India to find work along with four other friends, all of whom are missing following the flooding in Uttarakhand.

The approximate location of the 27 June 2013 Kalikot landslide. Google Maps.

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.


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Thursday 27 June 2013

The British Geological Survey reports on Shale Gasses in the Bowland-Hodder Unit.

Shale gasses have become an economically important source of hydrocarbons in the early twenty-first century, as other reserves have run low and exploration companies have begun to look for new supplies of energy. In conventional oil and gas reserves the hydrocarbons are usually trapped within pore spaces in discrete pocket, usually of sandstone or porous limestones, which can be drilled into to release the hydrocarbons. In shales the gasses are found throughout larger, essentially impermeable, units, and need to be released proactively. This can be done through a process known as Hydraulic Fracturing, or Fracking, in which water, sand and chemicals are blasted into the rock at high pressure, causing it to shatter and release the gas. This has proved to be highly lucrative in some parts of the world, notably the US where it has fueled a small hydrocarbons boom, but has also caused great alarm among environmentalists, who linked the process to small Earthquakes and pollution of important aquifers, as well as raising concerns that making large amounts of new hydrocarbons available will lead to further rises in atmospheric CO₂, with consequences for the global climate.

As in other countries, there is growing interest in developing shale gasses as a source of fuel in the UK, though the extent of potentially exploitable reserves is largely a matter of speculation. One of the geological units that has been of particular interest is the Bowland-Hodder Carboniferous Shales, which underlie much of northern England.  With this in mind the Department of Enregy and Climate Change and British Geological Survey have produced a report into possible gas reserves within the Bowland Shales, published on 27 June 2013. This report does not make any judgement on the ethics of shale gas exploitation, or wether it would be possible to extract these gasses at all, but simply to assess the extent of the reserves in order to facilitate further discussion. In the absence of such published information governments have sometimes naively (or possibly dishonestly) underestimated the value of mineral reserves within their territories and granted concessions to companies at far less than their actual worth.

Location of the DECC/BGS study area in central Britain, together with prospective areas for shale gas, currently licensed acreage and selected urban areas. Other shale gas and shale oil plays may exist. DECC/BGS (2013).

Natural gasses are formed from the 'cooking' of biological material (principally plant matter) in deeply buried sediments. When  biological material is sufficiently heated and pressurized, then volatile compounds are forced off as gas. In porous sediments this will typically escape from its point of origin, rising up until it becomes trapped at a high point in the porous rock, with impermeable sediments, such as clays, above. However when such material is trapped within clays or shales (finely laminated clays) it is unable to escape, and remains in situ. In order for gasses to develop in such sediments they need to be deeply buried, but they may subsequently be uplifted and found closer to the surface.

The Bowland Shales and underlying Hodder Mudstones were laid down in shallow marine basins in the early Carboniferous (347-318 million years ago), a time when Britain was close to the equator and sea-levels were rising and falling with the spread and shrinkage of ice caps. These deposits are not shale and/or mudstone throughout, rather there are layers of limestone within, formed as reefs which formed close to the shore spread back and forth with the rising and lowering level of the sea. These deposits have been deeply buried since the Carboniferous (which ended around 299 million years ago), and for the most part are still at some depth, though in places they have been uplifted and outcrop at the surface.

Shales from the Hodder Mudstone Formation outcropping on the flank of Ashnott High, Bowland Basin, Lancashire. Nicholas Riley in DECC/BGS (2013).

In order to assess the amount of gas trapped in these deposits, it was necessary to asses the amount of organic material within the sediment (estimated as typically 1-3%, but rising to 8% in places), as well as the thickness of the deposits. As these deposits are for the most part very deeply buried (the top of the unit is 4753 m bellow sea level at its deepest), they were only directly accessed by boreholes in a limited number of places, with much of the study being based upon geophysical data, principally from seismic studies and gravitational data. 

The depth of the top of the Bowland-Hodder Unit below sea-level. Note that in places this is a negative figure; the deposits are above sea-level but still underground. DECC/BGS (2013).

Previous estimates of the thickness of the Bowland-Hodder Unit have ranged from 2500 m to 4000 m. The DECC/BGS study estimates it to be around 3575 m at its thickness, thinning down to zero in places.  

The thickness of the Bowland Hodder Unit; it was not possible to measure map the unit in Derbyshire. DECC/BGS (2013).

However the volume of the unit cannot be correlated absolutely to the amount of gas it will contain. In order for organic material to have been converted to gas it will have to have been buried deeply enough for the process to have occurred, considered to be sediments that have been buried to a depth of 2900 m for the purposes of this study (even if they have subsequently been uplifted or exposed). This is referred to as the 'gas window', and can be mapped as a discrete horizon in itself.

The depth bellow modern ground level of the 'gas window' in the Bowland-Hodder Unit. Below this level the unit can be expected to contain shale gas, above it this is not likely to be the case. DECC/BGS (2013).

Thus the maps of the depth and thickness of the Bowland-Hodder unit do not give a reasonable estimate of the distribution of gas-bearing sediments in the study area. Furthermore sediments at depths of less than 5000 ft (1500 m) are not considered to be workable by hydraulic fractionation; the pressures in the rock are too low for the method to work.

Thickness and distribution of shales of the lower Bowland-Hodder unit that are within the gas window and at a depth greater than 5000 ft (1500 m). DECC/BGS (2013).

Thickness and distribution of shales of the upper Bowland-Hodder unit that are within the gas window and at a depth greater than 5000 ft (1500 m). DECC/BGS (2013).

The study produced three estimates of the total volume of gas in the rock (not the same as the total recoverable gas), referred to as the low, central and high estimates. The low estimate predicts a total volume of 4.6 trillion m³ of gas in the lower unit and 18.6 trillion m³ of gas in the upper unit, for a total of 23.3 trillion m³ of gas. The central estimate predicts a total volume of 7.5 trillion m³ of gas in the lower unit and 30.2 trillion m³ of gas in the upper unit, for a total of 37.6 trillion m³ of gas. The high estimate predicts a total volume of 12.7 trillion m³ of gas in the lower unit and 51.9 trillion m³ of gas in the upper unit, for a total of 64.6 trillion m³ of gas. 


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Magnitude 4.3 Earthquake in central Washington State.

A Magnitude 4.3 Earthquake occurred in central Washington State at around 7.45 pm on Wednesday 26 June 2013 local time (2.45 am on Thursday 27 June, GMT), according to the United States Geological Survey. The quake happened roughly 120 km east of Seattle at a depth of 9.1 km, and was felt across much of the State, though there have not been any reports of any serious damage or injuries. 

The location of the 26 June 2013 Washington Earthquake. Google Maps.

Washington State is located on the western margin of the North American Plate, to the west the Juan de Fuca Plate is being subducted along the Cascadia Subduction Zone, passing under Washington State as it sinks into the Earth. This is not a smooth process, and the two plates frequently stick together then break apart again as the pressure builds up, causing Earthquakes in the process. 

The heat and pressure within the Earth also slowly melts the subducting plate, liquifying more volatile minerals which then rise through the overlying North American Plate as magma, fueling the volcanoes of America's Pacific Northwest.

The subduction of the Juan de Fuca Plate beneath Washington State. University of Florida.

Witness accounts of quakes can help geologists to understand these events and the rock structures that cause them. If you felt this quake you can report it to the USGS here.


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New eruption on Mount Shiveluch.

Mount Shiveluch, a volcano on the Kamchatka Peninsula in the Russian Far East, underwent a major eruption on Thursday 27 June 2013, according to the Kamchatka Volcanic Eruption Response Team. The eruption started at about 7.10 am local time (7.10 pm on Wednesday 26 June, GMT), and produced an ash column reaching 10 km into the air, accompanied by about 40 minutes of tectonic activity (Earthquakes). There have been ashfalls in the villages of Klyuchi and Lazo, 50 km and 156 km away from the volcano respectively, and while local authorities are not anticipating any hazard to life, they have distributed gas-masks and are asking people to remain indoors as a precaution.

Ash from the Shiveluch eruption. Damir Shakurov/NovostiTV.

The volcano has been producing lava flows throughout May and June, and has produced ash column twice in June 2013 - something it typically does several times a year. Ash from Shiveluch last reached the closest settlement, Ust-Kamchatsk, 85 km to the southeast, in October 2010, when an explosive eruption also destroyed much of a lava dome that had formed on the volcano, forming a new crater at the summit.

Shiveluch is the northernmost of 30 active volcanoes on the Kamchatka peninsula, fueled by the subduction of the Pacific Plate beneath the Okhotsk Plate, upon which the Kamchatka Peninsula is located. As the Pacific Plate sinks into the Earth it is partially melted by the heat and pressure of the planet's interior. Some of the melted material then rises through the overlying Okhotsk Plate, fueling the volcanoes of the Kamchatka Peninsula.


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Series of Earthquakes off the Lleyn Peninsula, northwest Wales.

A series of three minor Earthquakes happened roughly 2 km off the northeast coast of the Lleyn Peninsula in northwest Wales on the evening of Wednesday 26 June 2013, according to the British Geological Survey. The quakes took place over a period of about two and a half minutes at about 11.30 British Summertime (10.30 GMT) . The quakes ranged in Magnitude from 1.2 to 2.8, and occurred at depths of between 2 and 8 km. There are no reports of any damage or casualties. but the quakes were apparently felt across much of the peninsula as well as on Anglesey and as far away as Barmouth and Rhyl.

Map showing the locations of the 26 April Earthquakes, and areas where people have reported feeling them. British Geological Survey.

As a rule of thumb 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. 

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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Wednesday 26 June 2013

Three new species of Ant-mimicking Mirid Bugs from central Thailand.

Mirid Bugs of the genus Pilophorus are found on every continent except Australia and South America. They are Mimics of Ants, and are commonly found living with Ants, suggesting the mimicry fools the Ants themselves, not just Ant-avoiding predators. Furthermore, unlike most Mirid Bugs, Pilophorus spp. are carnivorous, typically eating insects such as Aphids that ants often protect. They are used as biological controls of such pests in some parts of the world.

In a paper published in the American Museum Novitates on 15 February 2013, Tomohide Yasunaga and Randall Schuh of the Division of Invertebrate Zoology at American Museum of Natural History describe three new species of Pilophorus from Nakhon Nayok and Nakhon Ratchasima Provinces in central Thailand, discovered during a review of the genus in the country.

The first new species is named Pilophorus barbiger, where barbiger means bearded, referring to the dense setae (hairs) on the underside of the head. Pilophorus barbiger is a 3.1-3.6 mm, elongate, velvety, dark brown bug found living with an unidentified species of Ant on a variety of broadleaved trees.

Pilophorus barbiger (top) male and (bottom) female. Yasunaga & Schuh (2013).

The second new species is named Pilophorus giraffoides, due to its elongated and constricted protonum (front part of the thorax), which resembles the neck of a giraffe. This is a brownish bug 3-3.24 mm long. It's ecology is unknown, the specimens found were captured in light traps. 

Pilophorus giraffoides, female specimen. Yasunaga & Schuh (2013).

The final new species is named Pilophorus portentosus, where 'portentosus' means 'extraordinary' or 'monsterous', in reference to its unusually long antennae and legs. This is a 3.79 coffee-brown Bug, described from a single male specimen caught in a light trap.

 Pilophorus portentosus, male specimen. Yasunaga & Schuh (2013).


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Thirty seven dead after collapse at gold mine in the Central African Republic.

Thirty seven people are known to have died and dozens more to have been injured in a collapse at the Ndassima Gold Mine on Sunday 23 June 2013, following heavy rains. It is feared that many more bodies may be burried at the site. The mine was formerly operated by the Canadian company Axmin Mining, but operations were suspended in 2009  over safety concerns, following an incident that killed 16 miners. 

Bodies recovered from the Ndassima Gold Mine. National Turk.

Plans to re-open the mine officially were suspended in March this year following the overthrow of the French-backed government of François Bozizé, and the instillation of a new regime under Michel Djotodia, a former rebel leader. The site had been occupied by artisanal miners, technically illegally, though the government has been clear that it understands these activities to be driven by poverty, and declared a three day period of national mourning for the deceased miners. Axmin has expressed sadness at the deaths of the miners, but has underlined that it feels the deathes were the result of illegal and unregulated mining, and indicated a willingness to work with the new government to resume control of the site.

The Ndassima mine is an open pit mine, and the collapse is effectively a landslide brought on by rainfall. 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.

The Central African Republic has significant reserves of percious minerals, including gold, diamonds, oil and uranium, but long term political instability and poor infrastructure has ensured that these bring little benefit to the nation, which is one of the poorest in Africa with a pre capita income of less than US$300 per year.


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Man killed in Kerala Landslide.

A man was killed when a landslide struck a the Rocha Hotel in the resort town of Munnar in the Idukki District of Kerala State, India at around 3.30 am on Tuesday 25 June local time (10.00 pm on Monday 24 June, GMT). He has been named as Zakariahkutty, a chef in his 40s from Kottayam. Munar has been badly affected by severe rainfall associated with the onset of the Indian Monsoon, with flooding closing several streets, several properties being evacuated due to rising water levels and a bridge in the old part of the town being washed away.

Damage to the Rocha Hotel in Munnar, Kerala State. The Hindu.

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.

Munnar is located at the confluence of the Madhurapuzha, Nallathanni and Kundaly rivers, in the Western Ghats, at an altitude of 1700 m. It receives high levels of rainfall during the rainy season, feeding the local tea-growing industry, while the high altitude keeps the area cool during the warmest part of the year, making it a popular tourist spot. However the combination of mountainous terrain and high rainfall is extremely conducive to landslides, and casualties happen there almost every year. In 2008 the  Amrita Centre for Wireless Networks and Applications installed a system of geophysical sensors around the town, which aim to give up to 24 hours notice of landslide events, since when the number of fatalities has fallen, though not been halted altogether.


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