Friday, 6 March 2015

Asteroid (90416) 2003 YK118 passes the Earth.

Asteroid (90416) 2003 YK118 passed by the Earth at a distance of 11 700 000 km (30.4 times the average distance between the Earth and the Moon, or 7.82 % of the average distance between the Earth and the Sun), slightly after 7.30 pm GMT on Friday 27 February 2015. There was no danger of the asteroid hitting us, though had it done so it would have presented a considerable threat. (90416) 2003 YK118 has an estimated equivalent diameter of 380-1200 m (i.e. it is estimated that a spherical object with the same volume would be 380-1200 m in diameter), and an object of this size would pass through the atmosphere and directly impact the ground with a force of about 2900-160 000 megatons (about 170 000-9 400 000 times the explosive energy of the Hiroshima bomb), causing devastation over a wide area and creating a crater 5-15 kilometers across, and resulting in global climatic problems that could last for decades or even centuries.

Image of (90416) 2003 YK118 taken from Balen in Belgium on 12 February 2015. Elongate objects are stars, the shape caused by their movement over a nine minute exposure. Dot at center of image is asteroid. Alfons Diepvens.

(90416) 2003 YK118 was discovered on 28 December 2003 by the Massachusetts Institute of Technology's Lincoln Near Earth Asteroid Research Laboratory in Socorro, New Mexico. The designation 2002 YK118 implies that it was the 2960th asteroid (asteroid K118) discovered in the second half of December 2003 (period 2003 Y). The longer designation, (90416), indicates that the asteroid was the 90 416th asteroid ever discovered. Asteroids are not given this longer designation immediately, to avoid duplicate or false sightings.

The calculated orbit of (90416) 2003 YK118. JPL Small Body Database.

(90416) 2003 YK118 has a 806 day orbital period and an eccentric orbit tilted at an angle of 7.84° to the plane of the Solar System, which takes it from 0.86 AU from the Sun (i.e. 86% of the average distance at which the Earth orbits the Sun) to 2.53 AU from the Sun (i.e. 253% of the average distance at which the Earth orbits the Sun, considerably outside the orbit of 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 close encounters between the asteroid and Earth are extremely common, with the last having occurred in February 2004 this year and the next predicted in April 2026. As an asteroid probably larger than 150 m in diameter that occasionally comes within 0.05 AU of the Earth, (90416) 2003 YK118 is also classified as a Potentially Hazardous Asteroid.

See also...

At three minute past eleven pm on 7 May 1991 the brightest fireball (large meteor) ever recorded was observed over the Czech Republic. This was recorded by four all-sky and two spectral cameras at...

Asteroid 2015 CO13 passed by the Earth at a distance of 5 145 000 km (13.4 times the average distance between the Earth and the Moon, or 3.44% of the average distance between the Earth and the Sun), at about 7.30 pm GMT on Tuesday 24 February...

People across the state of Kerala in southwest India reported seeing a bright fireball in the sky between 10.00 and 10.30 pm local time on Friday 27 February 2015. A fireball is defined as a meteor (shooting...

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Thursday, 5 March 2015

A new species of Limonid Crane Fly from Eocene Baltic Amber.

The Limoniidae are a large group of small-to-medium sized Crane Flies, Tipuloidea, with coloured or patterned wings, which are sometimes shortened or otherwise reduced. There are over 11 000 extant species within the family Limoniidae, divided into four subfamilies, the Chioneinae, Dactylolabinae, Limnophilinae and Limoniinae, with phylogenetic analyses suggesting that the Dactylolabinae are likely to be the oldest group. All members of the subfamily Dactylolabinae are currently placed within a single genus, Dactylolabis, with living members divided into four subgenera, Bothrophorus, Coenolabis, Dactylolabis and Eudactylolabis. Of these subgenera only Dactylolabis has a fossil record, being known from Eocene Baltic Amber, with four extinct subgenera, Aurolabis, Eobothrophorus, Eolabis and Idiolabis also used to describe Baltic Amber species.

In a paper published in the journal Palaeontologica Electronica in January 2015, Iwona Kania of the Department of Environmental Biology at Rzeszów University and Wiesław Krzemiński of the Institute of Systematic and Evolution of Animals at the Polish Academy of Sciences describe a new species of Dactylolabis from Eocene Baltic Amber.

The new species is placed in the subgenus Idiolabis and given the specific name ryszardi, in honour of Ryszard Szadziewski, an expert on fossil and living flies. Dactylolabis (Idiolabis) ryszardi i described from a single male specimen 7.3 mm in length, with 9.76 mm wings.

Dactylolabis (Idiolabis) ryszardi, male specimen in lateral view. Kania & Krzemiński (2015).

The long-lived status of the subgenus Dactylolabis (Dactylolabis), with all other described subgenera being either modern or Eocene, has recently been questioned. A phylogenetic analysis carried out by Kania and Krzemiński suggests that all the described subgenera are indeed discreet evolutionary lineages (although some of the Eocene subgenera contain only a single species), though the Eocene and modern members of Dactylolabis (Dactylolabis) are not particularly closely related.

Kania and Krzemiński observe that while the Eocene forests of Fennoscandia, which produced the Baltic Amber, were a warm-forest environment with little seasonal variation, similar to forests found closer to the equator today, these forests covered a vast geographical range, extending a long way north-to-south and also containing a wide range of altitudinal variation. This suggests that these forests would have had a high number of different environments within them, as is the case with modern tropical forests, but that this ecological variation is hidden somewhat by the nature of the Baltic Amber deposits, which contain river-transported material carried from many different areas by the action of vast ancient waterways.

Modern members of the subgenus Dactylolabis (Dactylolabis) are widely distributed, and have are tolerant of a broad range of environments, while the other modern subgenera of Dactylolabis are much more limited, with more specialized environmental requirements. Kania and Krzemiński suggest that the same may have been the case in the Eocene, with subsequent environmental change wiping out the more specialized groups while the more tolerant Dactylolabis (Dactylolabis) survived. This scenario makes it highly likely that Dactylolabis (Dactylolabis) is in fact polyphyletic as well as morphologically conservative, with more specialized forms repeatedly arising from within this subgenus

See also…

Winter Crane Flies from the Middle Jurassic Jiulongshan Formation of Inner Mongolia.
Winter Crane Flies (Trichoceridae) are large True Flies (Diptera) with a (slightly erroneous) reputation for being tolerant of cold conditions. In fact a few species are capable of remaining active in winter, with some even mating and laying eggs beneath snow cover, but...

A Non-biting Midge from Late Eocene Ukrainian amber.
Non-biting Midges (Chironomidae) are small Flies closely related to the Biting Midges, Solitary Midges and Blackflies. They closely resemble Mosquitoes, but despite their appearance and relationships, they...

A new species of Axymyid Fly from the northwest United States.
Axymyids are medium sized, stout bodied, True Flies (Diptera) related to the Gnats, Midges, Mosquitoes and Crane Flies. They have a fossil record going beck to the Jurassic, but are rare today, with only six described species.

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At least 33 dead following Donetsk mine explosion.

Thirty three miners are known to have died and it is feared than many more deaths will still be discovered following an explosion at the Zasyadko Coal Mine in the Donetsk Province of Ukraine on Wednesday 5 March 2015. Sixteen workers are receiving hospital treatment following the incident, which has been described as a methane explosion, and as many as fifty may remain bellow ground. Coal mines in Ukraine have a poor reputation for safety, and workers who are caught below ground in this sort of incident and not evacuated quickly are seldom found alive.

A miner being treated for injuries at the Republican Center for Traumatology hospital in Donetsk following the 4 March explosion at the Zasyadko Mine. Kyiv Post.

Coal is formed when buried organic material, principally wood, in heated and pressurized, forcing off hydrogen and oxygen (i.e. water) and leaving more-or-less pure carbon. Methane is formed by the decay of organic material within the coal. There is typically little pore-space within coal, but the methane can be trapped in a liquid form under pressure. Some countries have started to extract this gas as a fuel in its own right. When this pressure is released suddenly, as by mining activity, then the methane turns back to a gas, expanding rapidly causing, an outburst or explosion. This is a bit like the pressure being released on a carbonated drink; the term 'explosion' does not necessarily imply fire in this context, although as methane is flammable this is quite likely.

The Zasyadko Mine is in a part of Donetsk Province held by Russian-backed separatist rebels, who have reportedly not allowed Ukrainian rescue workers to enter the region. What provision the rebels have for rescuing mineworkers is unclear, and press reports are describing searches for bodies being carried out by local miners without outside support. 

The political situation in Donetsk and neighbouring Lunhansk provinces (which together make up the Donbass mining region, where the bulk of Ukraine's mines are situated), is currently extremely unstable, with pro-Russian separatists seeking independence for the region. This has led to a series of armed encounters between separatists and Ukrainian authorities, and an incursion into the region by Russian troops. A referendum on independence was organized by the separatists in May 2014, but the (pro-independence) results of this have not been recognized by the Ukrainian government, the EU or the US. This is likely to lead to ongoing political instability in the region, and therefore improvements in the mining industry's safety standards are unlikely to come soon.

See also...

Seven miners are known to have died and two more are still missing following an accident at an underground coal mine at Kirovsk in Luhansk Province in eastern...

Seven workers have been killed and an eighth is being treated in hospital after an explosion at the Skochinsky Coal Mine at Donetsk in eastern Ukraine. The explosion occurred when the miners hit a pocket of methane gas early in the morning, resulting in an...

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Magnitude 2.1 Earthquake off the east coast of Scotland.

The British Geological Survey recorded a Magnitude 2.1 Earthquake at a depth of about 3 km beneath the Moray Firth off the east coast of Scotland, slightly before 6.20 am GMT on Thursday 5 March 2015. Earthquakes of this size are not threatening to human life or property, although they are often felt.

The approximate location of the 5 March 2015 Moray Firth 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.

See also...

The British Geological Survey recorded a Magnitude 2.1 Earthquake at a depth of about 7 km to the north of Loch Carron...

The British Geological Survey recorded a series of Earthquakes to the southeast of Durness in Sutherland, Scottish Highlands, overnight on Thursday 8-Friday 9 January 2015. The first occured slightly after 8.25 pm GMT, and had a Magnitude of 1.5, occuring at a depth...

The British Geological Survey recorded a Magnitude 1.2 Earthquake at a depth of 8 km close to the town of Alness in...

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Tuesday, 3 March 2015

Hunting for fragments of the Benešov Superbolide.

At three minute past eleven pm on 7 May 1991 the brightest fireball (large meteor) ever recorded was observed over the Czech Republic. This was recorded by four all-sky and two spectral cameras at three observatories belonging to the European Fireball Network, enabling detailed recording of its trajectory, spectrographic analysis of its chemistry and reconstruction of its orbit, and enabling a very detailed estimate of the area where any surviving fragments might have fallen. As this was only the third instrumentally recorded meteor fall (after Příbram in 1961, Lost City in 1971 and Innisfree in 1978) and was clearly a particularly large object, there were great hopes for material from the Benešov Superbolide being recovered. However several extensive searches failed to recover any such material.

In a paper published in the journal Astronomy & Astrophysics on 13 October 2014, Pavel Spurný of the Astronomical Institute of the Academy of Sciences of the Czech Republic, Jakub Haloda of the Czech Geological Survey and of Oxford Instruments NanoAnalysis, Jiří Borovička and Lukáš Shrbený, also of the Astronomical Institute of the Academy of Sciences of the Czech Republic and Patricie Halodová, also of the Czech Geological Survey re-examine the data obtained on the Benešov Superbolide with modern methods, in order to gain a better insight to the area where any fragments might have fallen, with the aim of recovering such fragments and studying the nature of the object which produced them.

Detail of the Benešov Superbolide recorded by the fixed all-sky camera at Telč station showing the main terminal flare at a height of 24 km from where a cloud of small fragments originated. Spurný et al. (2014).

Since the Benešov a number of such bolides have been observed and tracked in order to locate debris which have reached the Earth’s surface (notably Morávka in 2000, Neuschwanstein in 2002, Villalbeto de la Peña in 2004, Bunburra Rockhole in 2007, Jesenice in 2009, Košice in 2010 and Mason Gully in 2010), enabling scientists to considerably improve the methods involved.

The Benešov was recorded from three observation stations, Ondřejov, Telč, and Přimda, equipped with fixed high resolution fish-eye cameras which recorded all-sky hemisphere images. These cameras had rotating shutters which caused 12.5 interruptions per second. The Ondřejov station also had a guided camera used to determine the time of the fireball, though images from both Ondřejov stations were badly overexposed. The event was also observed with two spectrographic cameras, producing the most detailed spectrographic recordings of a fireball event ever recorded.

Modern GPS technology has enabled more precise positioning of the three observatories than was possible in 1991. At the time the positions of the observatories were calculated using 1:25 000 scale topographic maps; the units have now been placed with GPS units with a precision of 10 cm, leading to the precise longitude and latitude of each station being adjusted by as much as 20 m. Improvements in computer technology have enabled considerably improved calculations of bolide trajectories to be made from recorded images, and (importantly) an error made in the recording of the time on the Telč images (which at the time was done by hand) was detected by analysis of the position of the stars using modern software and corrected.

This led to a revision of the calculated location of the meteorite fall by about 385 m to the southwest, placing any such material in a ploughed field rather than coppiced woodland, and explaining the inability of searchers in the 1990s to find any meteorite material.

Detail of the terminal part of the Benešov bolide, where the projection of the original trajectory solution (dashed line) is plotted along with the new solution from 2011(filled line). Spurný et al. (2014).

This data also enabled Spurný et al. to recalculate the orbital properties of the Benešov Superbolide, which they calculate had a 1429 day orbital period and a highly eccentric orbit tilted at an angle of 24˚ to the plane of the Solar System, which took it from 0.92 AU from the Sun (i.e. 0.92 times the average distance at which the Earth orbit the Sun) to 4.04 AU from the Sun (4.04 times the average distance at which the Earth orbits the Sun, and considerably more than twice the distance at which the planet Mars orbit the Sun). This would make the Benešov Superbolide an Apollo Group Asteroid, i.e. an asteroid which spends most of it time outside the orbit of Earth, but which does occasionally pass closer to the Sun than us.

Heliocentric orbit of the Benešov meteoroid projected onto the plane of the ecliptic along with the orbits of all inner planets and Jupiter and the direction to the vernal equinoctial point. Spurný et al. (2014).

The Benešov Superbolide is calculated to have been between one and two meters in diameter, with a mass of about 4100 kg (4.1 tons). It is known to have undergone a final bright flare at an altitude of 24.4 km, interpreted as an airburst in which the bolide reached a sufficiently high temperature to explode. In 1991 it was believed that such an explosion would leave only a few large fragments intact, which would continue along the original path of the bolide until impacting the ground. Since then it has been realized that a much larger proportion of such objects will survive as smaller fragmentary material, with the Benešov Superbolide likely to produce around 250 000 fragments in the 1-10 g range including around 40 000 fragments larger than 5 g, for a total mass of 800-1000 kg, most of which would reach the ground.

Such small fragments would be heavily influenced by wind-speeds (also not fully appreciated in 1991). On 7 May 1991 the highest winds in the area were found at altitudes of between 5 and 12 km, and were blowing from the west and southwest, shifting the likely impact area for any small fragments roughly 2.5 km to the east-north-east.

New trajectory of the fireball with marked position of the main flare and the corresponding impact area for small pieces that originated in this flare. Spurný et al. (2014).

The area where any meteorite remains is calculated to have fallen lies in a field which has been ploughed at least 20 times since the Benešov event, and which is subject to winter frosts reaching a depth of 30 cm. This is not conducive to the preservation of meteorite remains at the surface, making it likely that any meteorite remains will have been buried at depth of 30-40 cm, and that they will have undergone considerable surface alteration, making them hard to distinguish from other rocks found locally.

Such conditions are far from ideal for searching for meteorite remains, however spectrographic analysis of the Benešov fireball suggested that the meteorite was chondritic in nature, and likely to have a very high iron content. This suggested that it might be possible to search for meteorites with metal detectors. Spurný et al. therefore assembled a team of about 20 searchers, and having gained permission from the landowner (searching the land without such permission would be illegal in the Czech Republic) made a series of transverse scans of the field a few hundred meters long and about fifteen meters wide, centred on the calculated line of highest probability for meteorite finds.

Details on meteorite finds and their positions with respect to the predicted impact line and impact area. Spurný et al. (2014).

The initial search took place on 9 April 2011, when several tens of samples were located, had their positions recorded with portable GPS units, were collected, weighed and labelled. These samples were then returned to the lab where they were cleaned, weighed, photographed and more carefully inspected, resulting in all but eight being rejected as possible meteorites. These remaining samples were further cleaned by ultrasound, then had part of their surfaces brushed and examined by microscope, eventually determining that two samples were genuine meteorites (a better result than was expected). Further visits to the site on 21 April 2011 and 25 April 2012 (when a method involving sieving topsoil from close to the line was employed) yielded two more such meteorites.

First three Benešov meteorites found by metal detectors in April 2011. From left to right: 1.56 g H5 chondrite (M1), 7.72 g LL3.5 chondrite with achondrite clast (M2), and 1.99 g LL3.5 chondrite (M3). Spurný et al. (2014).

There is a faint possibility that these meteorite could have come from some event other than the Benešov Superbolide. However the meteorites do not appear to be more than a few decades old and the area in question has been scanned for meteors photographically on every clear night since 1951, and photoelectrically on every night, clear or otherwise, since 1999. The area also has a reasonably high population density, with a high level of public interest in such events, making it unlikely that any such events would fail to be recorded. As the meteorites found were of a size which implies a parent body in excess of a meter in diameter, and only about 40 such objects strike the entire surface of the Earth each year, seldom going un-noticed in populated areas, the chances of tow such events happening in the same area within a few decades and one of them not being recorded are considered negligible.

The first meteorite discovered (M1) is an H chondrite (High Iron Chondrite) which weighed 2.91 g when found and 1.54 g after cleaning. It lacks a fusion crust (the outer layer of a meteorite formed by melting of its surface by the friction with the atmosphere) and it outer surface was heavily weathered. A section of the meteorite examined under the petrographic microscope revealed that it had a fairly homologous composition, with some chondrules (large distinct clasts of different material within the matrix) which appear to have been recrystallized as a result of thermal metamorphism. The rock contains olivine, low- and high-calcium pyroxene and plagioclase silicate minerals, with extensive shock-fracture features within the olivine. Heavy weathering of the sample has led to oxidation of about 80% of the iron and nickel minerals.

Backscattered electron images documenting the texture of H5 lithology of meteorite M1 – designated as Benešov (b). All Fe-Ni phases and troilite are strongly oxidized from weathering processes, and weathering products also fill visible microfractures. Spurný et al. (2014).

The second meteorite examined (M2) is an LL chondrite (Low Iron Low Total Metal Chondrite) which weighed 12.93 g when discovered and 7.72 g after weighing. This meteorite was also heavily weathered, and lacked a fusion crust. Microscopic examination of a thick section revealed a fine-grained matrix with well-defined chondrules. The silicate minerals were dominated by olivine, low-calcium pyroxene and plagioclase, as well as weathered alcalic glass. Iron and nickel minerals were again predominantly oxidised. The chodrules are 0.2-1.9 mm across and chemically distinct from the matrix, being dominated by olivins and low calcium pyroxene, with alkaline glasses with a variety of chemical compositions also present. Shock features are present in the olivine, pyroxene and plagioclase minerals, suggesting shock pressures in the range of 15-20 giga-Pascals.

Backscattered electron images documenting the texture of the LL3.5 lithology of meteorite M2 – designated as Benešov (a). Well-defined chondrules and fine-grained matrix are disrupted by a network of microfractures filled by weathering products. Spurný et al. (2014).

The meteorite also contained a large clast of achondritic material measuring approximately 4.8 by 2.6 mm. thi achondritic clast is cemented to the chondritic material by an irregular vein of impact melt, and has a composition dominated by olivine and low-calcium pyroxene, with anorthitic plagioclase and high calcium pyroxene also present.

Contact between LL3.5 lithology and achondritic clast of meteorite M2 – Benešov (a). The achondritic clast is cemented to LL3.5 lithology by an irregular vein of impact melt. Spurný et al. (2014).

The third meteorite collected (M3) weighed 2.29 g when found and 1.99 g after cleaning. This also lacked a fusion crust and was heavily weathered, and petrographically resembled the LL3.5 chondrite material from the second meteorite.

Backscattered electron images documenting the texture of the LL3.5 lithology of meteorite M3 – designated as Benešov (a). Well-defined chondrules and fine-grained matrix are disrupted by a network of microfractures filled by weathering products. Spurný et al. (2014).

The fourth meteorite weighed 0.50 g when collected and 0.38 grams after cleaning. This meteorite was not examined petrographically.

Spurný et al. believe that the meteorites all share a common parent body, which they propose had a brecciated composition (i.e. was made up of large pieces of material with different mineral compositions), which would account for the different mineralogy of meteorite M1 compared to M2 and M3, and for the large clast of mineralogically distinct material within M2. As such they wished to name all the meteorite as ‘Benešov Meteorites’. However the Nomenclature Committee of the Meteoritical Society did not accept this, due to the distinctive mineralogy of M1 (this is not entirely unreasonable, as such formal name and descriptions are used to compare meteorites to other meteorites, and a formal designation which includes meteorites with different compositions could be problematic). Spurný et al. therefore classed M2 and M3 together as ‘Benešov (a) Meteorites’, while M1 is classed as a ‘Benešov (b) Meteorite’.

Brecciated compositions in meteorites and asteroids are a relatively new idea, and a few years ago would have proved highly controversial. However the Almahata Sitta meteorite fall of 2009(?) has also been shown to contain brecciated material, as has asteroid (21) Lutetia, confirming that such lithologies are possible and do occur in asteroids.

See also…

The nature of the Nathdwara Meteorite.
On 25 December 2012 at about 6.20 pm local time a single meteorite fell in a field near the town of Nathdwara in southern Rajastan. The meteorite was an oblong shape, 12 cm along its longest axis, and weighed about 1.5 kg. It was covered by a dark fusion crust, formed by melting of its outer surfaces by friction as it...

The Chelyabinsk Meteorite and its implications for the origin of the Baptistina Asteroid Family.
The Chelyabinsk Meteorite detonated in the atmosphere over the southern Russia on 15 February 2013 with an equivalent energy to 500 kilotons of TNT. From the size of the explosion it is estimated to have been an...

The nature of the Košice Meteorites.
On 28 February 2010 a meteor shower fell over Slovakia, accompanied by a bright fireball and a series of sonic booms. Subsequently a number of meteorites were recovered from the area to the northwest of the city of Košice, in the east of the country, most within four weeks of the observed shower (meteors are ‘shooting stars’ observed in the sky, a meteorite is...

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A new species of Tick-borne Virus from Bourbon County, Kansas.

In late spring 2014 a previously healthy man in his 50s was admitted to a hospital in Bourbon County, Kansas, suffering from Tick bites and a fever. Despite intensive care and treatment with broad-spectrum anti-microbial drugs he died of cardiopulmonary arrest brought on by multiple organ failure eleven days after the onset of the illness. Tests for a wide variety of wide variety of pathogens during treatment failed to identify the cause of the fever, but a previously unknown species of Thogotovirus was later isolated from his blood serum.

In a forthcoming paper in the journal Emerging Infectious Disease, Olga Kosoy and Amy Lambert of the Centers for Disease Control and Prevention at Fort Collins, Colorado, Dana Hawkinson of the University of Kansas Medical Center, Daniel Pastula of the Centers for Disease Control and Prevention at Fort Collins, Colorado, Cynthia Goldsmith of the Centers for Disease Control and Prevention at Atlanta, Georgia, Charles Hunt of the Kansas Department of Health and Environment and Erin Staples, also of the Centers for Disease Control and Prevention at Fort Collins, Colorado, formerly describe the new Thogotovirus as Bourbon County Virus.

The genus Thogotovirus is a member of the family Orthomyxoviridae, which also includes Influenza Viruses. At least seven species of Thogotovirus have previously been described; Araguari Virus, Aransas Bay Virus, Batken Virus, Dhori Virus, Jos Virus, Thogoto Virus, and Upolu Virus, all of which appear to be carried by Ticks. Of these only one has previously been isolated in North America, Aransas Bay Virus, which was isolated from Soft Ticks (Ornithodoros spp.) from seabird nests off the Texas coast. Two members of the genus have previously been shown capable of infecting and producing illnesses in humans. 

Thogoto Virus was found in two patients in Nigeria in 1966, an adult male with a febrile illness who later developed neuromyelitis optica (expand) and a fourteen-year-old boy who developed meningitis and died of complications of Sickle Cell Anemia. Antibodies to this Virus have been isolated from humans from other parts of Africa, Asia and Europe, suggesting that it may be more widespread. Dhori Virus has infected five workers at a Russian lab after accidental exposure in 1987, two of these patients went on to develop encephalitis. Antibodies to this Virus have also been found in human populations in Europe, Asia and Africa, suggesting that it too may be a more widespread cause of infections than is currently appreciated.

The viral particles isolated from the Bourbon County patient clearly belonged to a Thogotovirus, and appeared to be closely related to Batken Virus and Dhori Virus, neither of which has ever been isolated in the Western Hemisphere. The precise method of transmission for this Virus is unknown; all previously described species of Thogotovirus have been transmitted by Ticks and the patient was suffering from Tick bites when admitted to hospital making this the most likely cause of infection, but Batken Virus is known to also be carried by Mosquitoes, so a non-Tick vector cannot be ruled out for Bourbon County Virus.

Electron microscopic images of novel Thogotovirus isolate. Filamentous (A) and spherical (B) virus particles with distinct surface projection are visible in culture supernatant that was fixed in 2.5% paraformaldehyde. Kosoy et al. (2015).

See also…

Ixodid Ticks of the genus Amblyomma are parasites of Mammals found on all continents except Europe and Antarctica, but at their most diverse in South America, with 31 species described from Brazil alone (46% of all known Tick species from Brazil). These Ticks are...

In December 2013 cases of the haemorrhagic Virus Ebola began to be reported from the village of...

At least 467 people have died in an outbreak of  Ebola Hemorrhagic Fever in West Africa that began in February this year. The disease initially appeared in the remote border area between Guinea, Sierra Leone...

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Evacuations begin after major eruption on Villarrica.

Authorities in Chile have began to evacuate people from the vicinity of Volcán Villarrica, following a major eruption overnight between Sunday 1 and Monday 2 March 2015. Villarrica is active at some level more-or-less all of the time, but in mid February the level of activity began to rise sharply, leading to the Chilean National Service of Geology and Mining raising of the alert level around the volcano on Sunday. This was followed by a sharp rise in activity overnight, with material being thrown up to 600 m from the crater of the volcano and a sharp rise in Earthquake activity.

Volcanic activity on Volcán Villarrica. 24 Horas.

The volcanoes of Chile and the Andean region of South America in general are fed by the subduction of the Nazca Plate beneath the South American Plate along the Peru-Chile Trench, which lies offshore parallel to the west coast of South America. As the Nazca Plate sinks it is melted by the heat of the Earth's interior, and the lighter portions of it rise up through the overlying South American Plate to form volcanoes at the surface. These are dotted throughout the Andes Mountains; a range of mountains that is formed by a mixture of volcanism and crumpling of the South American Plate where is is forced against the Nazca Plate.

The subduction of the Nazca Plate beneath the South American Plate. Marot et al. (2012).

Volcán Villarrica is the westernmost of three volcanoes lying on the Gastre Fault Zone (the other two being Quetrupillán and Lanín, which are far less active) which runs toughly northwest-southeast, cutting across the Liquiñe-Ofqui Fault, which runs north-south along the Chilean Andes, and upon which the majority of the country's volcanoes sit. The Gastre Fault Zone is thought to be part of the ancient Lanalhue Fault Zone, which formed along an ancient subduction zone during the Permian (about 300-250 million years ago), during the assembly of the ancient supercontinent of Pangea.

The locations of the Gastre Fault volcanoes, Villarrica (green), Lanín (orange) and Quetrupillán (red). Google Maps.

See also...

The Projecto Observación Visual Volcán Villarrica recorded incandescence (glowing) around the crater of Volcán Villarrica, an active volcano in southern Chile, overnight between 4 and 5 February 2015. On 6 February tephra (hot fragmentary material) was observed being ejected from the crater, reaching...

The United States Geological Survey recorded a Magnitude 4.9 Earthquake at a depth of 51 km roughly 35 km to the west of Ovalle in the Coquimbo Region...

The United States Geological Survey recorded a Magnitude 5.1 Earthquake at a depth of 22.6 km, roughly 10 km offshore of the Chilean City of Quintero...

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