Wednesday 30 April 2014

Major fire after oil train derailed in Lynchburg, Virginia.

Firefighters are battling a major blaze after a train carrying crude oil was derailed by the James River in Lynchburg, Virginia, at about 2 pm local time on Wednesday 30 April 2014. The train was traveling from Chicago to Virginia when the incident occurred, with 12-14 oil cars from the 15 car train leaving the track and about four being breached. The oil was ignited shortly after, prompting local authorities to evacuate the immediate vicinity. There are no reports of any casualties, although oil has been seen in the river, from which the town draws its water supply, and it is unclear how extensive the clean-up operation will need to be.

Oil burning on the James River in Lynchburg, Virginia, after the 30 April 2014 train derailment. ABC.

Trains carrying crude oil have become an increasingly important part of the distribution system in North America as both production of and demand for oil has exceeded the capacity of the pipeline network. There have been a number of incidents involving derailments and oil spills, and concerns about the safety of the trains following an incident in Lac-Megantic, Quebec, when a 72 car oil train derailed and exploded, killing 47 people.

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Eruptions on Mount Slamet.

Indonesian authorities have raised the alert level on Mount Slamet, an active volcano in Central Java, to three (out of a possible four), after a series of eruptions this week. The volcano began a new eruptive cycle in March, but has become notably more active over the past few days, with lava bombs being thrown 500-700 m into the air and landing up to 1500 m from the crater. On Tuesday 29 April 2014 the volcano produced an ash column that rose 700 m above the crater, and a series of lound booms were heard issuing from the summit. Almost a hundred Earthquakes were recorded beneath the volcano between midnight and 6.00 am on the same day.

Incandescent material over Mount Slamet  on Saturday 26 April 2014. Berita Daerah.

The Indo-Australian Plate, which underlies the Indian Ocean to the south of Java, is being subducted beneath the Sunda Plate, a breakaway part of the Eurasian Plate which underlies Java and neighbouring Sumatra, along the Sunda Trench, passing under Java, where friction between the two plates can cause Earthquakes. As the Indo-Australian Plate sinks further into the Earth it is partially melted and some of the melted material rises through the overlying Sunda Plate as magma, fuelling the volcanoes of Java and Sumatra.

The approximate location of Mount Slamet. Google Maps.

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One confirmed fatality after Omsk hit by 'hurricane'.

One person has been confirmed dead after storms and high winds hit the Omsk region in southern Russia on Saturday 26 April 2014. The 23-year-old woman, who has yet to be named, was hit by a bus-shelter that had been uprooted by high winds in the village of Troitskoye. Another five people were reported to need hospital treatment for a variety of injuries, around 550 buildings were damaged or destroyed and 26 districts left without power affecting about 50 000 people. Winds of 25-30 meters per second were recorded across the Omsk region, combined with two months worth of rainfall within 24 hours. High winds and wet snow were also recorded in the Tomsk, Kemerovo and Novosibirsk regions, while the Altai region suffered heavy dust storms.

Damage to the roof of an apartment building in the village of Trinity in the Omsk region of Russia. The Day X.

April is usually considered to be the windiest month in the Omsk region, often followed by dust storms in May and June, but this year's weather is exceptional, and has been described in the Russian press as a 'hurricane'. The storms have apparently been caused by a slowing down of climate cells, that caused a cyclone system to remain over the region for longer than would normally happen.

The location of the Omsk Region. Google Maps.

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A new species of Stem-mining Moth from Eastern Europe.

Stem-mining Moths of the family Nepticulidae are found across the world, but are at their most numerous and diverse in Southern Europe. The larvae feed on shrubs and herbs, making leaf or stem mines which enable them to tunnel through the soft tissues of the host plant as they feed, rather than living on the surface where they would be exposed to predators, although they typically emerge from the stems before pupating, forming a cocoon attached to the stem or leaf.

In a paper published in the journal Zootaxa on 3 December 2012, Povilas Ivinskis of the Nature Research Centre in Vilnius, Lithuania, Erik van Nieukerken of the Naturalis Biodiversity Center in Leiden, the Netherlands and Jolanta Rimsaite, also of the Nature Research Centre in Vilnius, describe a new species of Leaf-mining Moth from Eastern Europe.

The new species is placed in the genus Trifurcula, and given the specific name lituanica, meaning ‘from Lithuania’, although the species was in fact found in seven countries, Lithuania, the Czech Republic, Austria, Slovenia, Romania, Bulgaria and Greece, and is likely to be more widely distributed, as its larvae grow inside the stems of Salvia pratensis (Meadow Sage) which is found from the Netherlands to Russia. The adults are 2.2-2.4 mm brown Moths, the males slightly larger than the females, but with similar markings.

Trifurcula lituanica, adult specimens in dorsal view. (1) Male from Lithunia; (2) female from Austria. Scale bars are 1 mm. Ivinskis et al. (2012).

The eggs are laid on the lower part of the stem of the host-plant, with the larvae constructing a mine up to 23 cm in length before emerging in August to form a cocoon within the epidermis of the stem, but elevated compared to the rest of the stem and clearly visible. The larvae is apparently confined to one internode (i.e. it does not seem able to cross points at which the stem branches). The mine grows in width as the larvae progresses, eventually forming up to two thirds of the stem width. The frass (excreta) of the larvae remain within the mine, helping with its concealment. Up to four such mines were found in a single stem.

(23) Leaf mine of Trifurcula lituanica larvae within a stem of Salvia pratensis. (24) Exit wound caused by larvae of Trifurcula lituanica emerging to form a pupae. (25) Stem of Salvia pratensis cut to reveal larvae of Trifurcula lituanica. (26-28) Cocoons of Trifurcula lituanica. Ivinskis et al. (2012).

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Tuesday 29 April 2014

Magnitude 4.7 Earthquake in South Australia.

Geoscience Australia recorded a Magnitude 4.7 Earthquake close to the ground surface about 258 km northeast of Adelaide in South Australia, slightly before 7.55 pm local time (slightly before 9.55 am GMT) on Tuesday 29 April 2014. This is the largest Earthquake recorded in South Australia for 20 years, and was felt across much of the Mid North and Flinders Ranges, however it's epicenter was in a remote location, and there are no reports of any damage or casualties.

The approximate location of the 29 April 2014 South Australia Earthquake. Google Maps.

The precise causes of Earthquakes in South Australia are often unclear (at least in part because these events are somewhat rare, limiting the amount of data available to seismologists). The Flinders Ranges are ancient fold mountains, formed during the Delamerian Orogeny in the Late Cambrian and Early Ordovician (between about 514 and 500 million years ago), an episode of mountain building driven by a collision between Australia and southern Africa during the formation of the supercontinent of Pangea. These mountains contain many deep faults, and Earthquake activity in the area is likely to be connected to movement on these faults. However the area also contains large areas of poorly consolidated sediments, which can result in movement in an Earthquake being more intense at locations far from the moving fault than occurs on the fault itself, making the identification of moving faults very difficult.

Witness statements can help geologists to understand Earthquakes and the geological processes that cause them; if you felt this quake (or if you were in the area but did not, which is also useful information) you can report it to Geoscience Australia here.

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Asteroid 2014 HS46 passes the Earth.

Asteroid 2014 HS46 passed by the Earth at a distance of 12 890 000 km (over 33 times the average distance between the Earth and the Moon), slightly after 11.05 am GMT on Wednesday 23 April 2014. There was no danger of the asteroid hitting us, though had it done so it would have presented a moderate threat. 2014 HS46 is calculated to have an equivalent diameter of 47-150 m (that is to say a spherical body with an equal volume would have a diameter of 47-150 m), and an object towards the upper end of this scale would be capable of passing through the Earth's atmosphere intact and impacting the planet's surface, resulting in an explosion roughly 9350 times as large as the one caused by the Hiroshima bomb, and the formation of a crater around 2.4 km across. Such an event would result in devastation across a wide area, and climatic effects that would last for several years.

The calculated orbit of 2014 HS46. JPL Small Body Database Browser.

2014 HS46 was discovered on 24 April 2014 (the day after 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 2014 HS46 implies that it was the 1168th asteroid (asteroid S46) discovered in the second half of April 2014 (period 2014 H).

While 2014 HS14 occasionally comes near to the Earth, it does not actually cross our orbital path. It has an elliptical 616 day orbit, tilted to the plane of the Solar System, that takes it from 1.06 AU from the Sun (1.06 times the distance at which the Earth orbits the Sun), slightly outside our orbit, to 1.77 AU from the Sun, (1.77 times the distance at which the Earth orbits the Sun, somewhat more than the distance at which the planet Mars orbits the Sun). As a Near Earth Object that remains strictly outside the orbit of the Earth it is classed as an Amor Family Asteroid.

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An enigmatic Walrus from the Miocene of California.

Walruses (Odobenidae) are large Seals (Pinnipedia) related to Sea Lions and Fur Seals (Otariidae). The group first appears in the fossil record about 16 million years ago towards the end of the Early Miocene. The modern Walrus (Odobenus rosmarus) is one of the largest living Seals, and is a specialized shellfish eater, with well-developed tusks used to root out Clams, a thick moustache used to probe muddy sediments and a highly developed feeding system capable of sucking large Clams from their shells. Fossil Walruses, of which numerous species have been documented from the North Pacific region, apparently pursued a more diverse range of diets, with suction-feeding, specialist Fish eaters and generalist species all recorded.

Pelagiarctos thomasi is a large fossil Walrus described from partial remains from the Middle Miocene Sharktooth Hill Bonebed of Kern County, California in 1988. This has been identified as a large predatory Walrus, possibly a top-predator specializing in hunting other Marine Mammals, though it was initially described only from a partial lower jaw with most of the teeth missing.

In a paper published in the journal PLoS One on 16 January 2013, Robert Boessenecker of the Department of Geology at the University of Otago and the University of California Museum of Paleontology and Morgan Churchill of the Department of Geology and Geophysics and the Program in Ecology at the University of Wyoming, describe a second specimen of Pelagiarctos from the Middle Miocene ‘Topanga’ Formation of Orange County, California. The new specimen differs enough from the original that it is not placed within the species Pelagiarctos thomasi, but since modern Walruses are known to be somewhat morphologically variable, Boessenecker & Churchill refine from erecting a new species to describe it, instead referring to it as Pelagiarctos sp.

Mandibles of Pelagiarctos. Comparison of (A) Pelagiarctos sp. in dorsal aspect, and Pelagiarctos thomasi in (B) dorsal and (C) lateral aspect. Boessenecker & Churchill (2013).

The new specimen comprises the partial lower jaw of an animal similar to the first specimen, but this time with most of the teeth intact. Based upon comparison of these teeth to those of other large marine and predatory Mammals, Boessenecker & Churchill reject the idea that Pelagiarctos was a specialized predator hunting other large Marine Mammals. It was certainly a large animal, probably comparable to a Sea Lion in size, but its teeth were not exceptionally large and do not appear specialized for a subduing large prey, as its jaw structure, with robust strongly fused mandibles, while clearly strong, does not appear well suited to subduing large struggling prey or cracking the bones such animals, tasks which require a degree of flexibility apparently absent in the jaw of Pelagiarctos. Instead Boessenecker & Churchill suggest that Pelagiarctos was probably a more generalist feeder, which would have consumed the meat of large prey should this be available, but which principally ate fish or even foraged for shellfish.

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Observing Asteroid 99942 (2004 MN4) Apophis with the Herschel Space Observatory.

99942 (2004 MN4) Apophis was discovered on 19 June 2004 by the Spacewatch Project at  University of Arizona's Lunar and Planetary Laboratory operating out of the Kitt Peak Observatory. The designation 2004 MN4 indicates that it was the 113th asteroid (asteroid N13) discovered in the second half of June 2004 (period 2004 M) while the number 99942 indicates that it was the 99 942nd asteroid discovered (asteroids are not given such a name immediately, to avoid numbering false or duplicate observations) and named Apophis refers to an Egyptian god of darkness and destruction. 

It has an eccentric orbit which takes it from 0.746 AU from the Sun (74.6% of the average distance between the Earth and the Sun, ad slightly outside the orbit of the planet Venus) to 1.0985 AU from the Sun (109.85% of the average distance between the Earth and the Sun), making it an Aten type Near Earth Asteroid (an asteroid that crosses the Earth’s orbit but is closer to the Sun than we are most of the time); although it is predicted that a close encounter with the Earth in April 2029 will result in the asteroids orbit being altered in such a way that it becomes an Apollo type asteroid (one that crosses the Earth's orbit but is on average further away from the Sun than the Earth). 

It was initially estimated to have an equivalent diameter of between 320 m and 970 m (i.e. a spherical object with the same volume would have a diameter of between 320 m and 970 m), and was calculated to have a 2.7% chance of impacting the Earth in April 2029. An object of this size would be capable of passing straight through the Earth’s atmosphere resulting in an explosion up to 250 000 times as large as the one caused by the Hiroshima bomb, the formation of a crater between 5 and 12 km in diameter, and climatic effects that would last decades if not centuries. As such 99942 (2004 MN4) Apophis was also classified as a Potentially Hazardous Asteroid.

The current orbit of (99942) 2004 MN4 Apophis. JPL Small Body Database Browser.

Subsequent observations have ruled out the possibility of 99942 (2004 MN4) Apophis impacting the Earth in 2029, though it is still thought that it will pass extremely close, reaching about 38 310 km from the Earth at its closest, roughly 10% of the average distance between the Earth and the Moon, and within orbits of some satellites, however the possibility of such a collision occurring at some point in the future cannot be ruled out.

The size of the asteroid has also been recalculated, and reduced to about 270 m, still very bad news should it hit us, but a considerable improvement on the original size estimation. Observations made in the near infrared part of the spectrum suggested that 99942 (2004 MN4) Apophis is a Sq-class asteroid (a stoney asteroid with a high olivine and pyroxine content) with a composition similar to an LL ordinary chondrite type meteorite (Low iron, Low metal ordinary chondrite). This is similar to the asteroid 25143 (1998 SF36) Itokawa, which was visited by the Japan Aerospace Exploration Agency's Hayabusa Probe in 2005. 25143 (1998 SF36) Itokawa has an estimated porosity of 40%, and if the same is true for 99942 (2004 MN4) Apophis then it is likely to have a mass of about 20 000 000 tons. Such an object impacting the Earth would be predicted to result in a 375 Megatonne explosion, over 22 000 times as large as that caused by the Hiroshima bomb, resulting in the formation of a crater 3 km in diameter.

In a paper published in the journal Astronomy & Astrophysics on 24 April 2014, and on the arXiv database at Cornell University Library on 23 April 2014, a team of scientists led by Thomas Müller of the Max-Planck-Institut für extraterrestrische Physik, describe the results of a series of observations of 99942 (2004 MN4) Apophis in the far infrared part of the spectrum using the Herschel Space Observatory’s Photodetector Array Camera and Spectrometer instrument on 6 January and 14 March 2013. 

Each observation consisted of a series of scans at different wavelengths, used to create a mini scan-map of the Asteroid. These scan-maps were then compared to a physical shape model of 99942 (2004 MN4) Apophis created by a team of scientists led by Petr Pravec of the Astronomical Institute of the Academy of Sciences of the Czech Republic to create a three dimensional thermal map of the asteroid. 

Viewing geometry during the two Herschel observing epochs at phase angles of roughly 60˚ angle before (left) and after opposition (right). Top: calculated observing geometry on basis of the nominal solution in Pravec et al. (2014). L is fixed vector of angular momentum, the Aries sign is the X axis of the ecliptical frame, S is a direction to the Sun, and x, y, z are the axes of the asteroid co-rotating coordinate frame (corresponding to the smallest, intermediate and the largest moment of inertia of the body, respectively). Middle: The solar insolation in [W/m²]. Bottom: TPM temperature calculations assuming a Itokawa-like thermal inertia of 600 Jm¯²s¯⁰˙⁵K¯¹. Müller et al (2014).

Using this thermal profile it was possible to form a revised model of the size of 99942 (2004 MN4) Apophis, using the apparent distances between the two ends of the asteroid on the two observation dates. This suggests an asteroid with an equivalent diameter of 371-385 m, considerably larger than the previous model. 

The temperature differentiation between the two ends of the object suggest that it has a thermal inertia of between 250 and 800 Jm¯²s¯⁰˙⁵K¯¹ (this is the capacity of the object to redistribute its heat internally by conduction as one side is heated by the Sun and the other is in darkness), probably about 600 Jm¯²s¯⁰˙⁵K¯¹. This suggests that 99942 (2004 MN4) Apophis is probably comprised of a small amount of fine regolith (which has a low conductivity) and a larger volume of denser rocks and boulders (with higher conductivities). This suggests that Apophis is slightly larger and more dense than 25143 (1998 SF36) Itokawa, and with a mass of about 53 000 000 tonnes.

Such an object would clearly be more dangerous than previously thought, and if it were to collide with the Earth it would result in an explosion around 16 000-16 500 times as large as the Hiroshima bomb, and the formation of a crater up to 6 km across. However in addition to raising the danger level associated with 99942 (2004 MN4) Apophis, the new more refined model of the asteroids mass and density should allow a more detailed modelling of its orbital properties, enabling us to make better predictions of the threat it presents.

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Magnitude 1.7 Earthquake in Rutland, Central England.

The British Geological Survey recorded a Magnitude 1.7 Earthquake at a depth of about 2 km, roughly 5 km to the north of Oakham in Rutland, at about 11.05 pm British Summertime (10.05 pm GMT) on Monday 28 April 2014. This is quite a small quake, and there are no reports of any damage or casualties, but people did report feeling it throughout much of Rutland County.

The location of the 28 April 2014 Rutland Earthquake, and locations where people reported feeling it. British Geological Survey.

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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At least 32 dead as tornados hit Arkansas, Alabama, Iowa, Kansas, Mississippi and Oklahoma.

Thirty two people are known to have died in the southern and midwestern United States after a series of tornadoes struck on the evening of Sunday 27 April and morning of Monday 28 April 2014. Most of the fatalities occurred around Little Rock, where a single storm system carved a 130 km trail of destruction to the north and west of the city.  The Little Rock storm is thought likely to have reached at least a three on the on the Enhanced Fujita scale (or an EF-3 tornado). Such a tornado is associated with winds of 218-266 km per hour (61-73 meters per second), and is capable of damaging most ordinary homes.

In Mayflower, to the west of Little Rock, Rob Tittle and his daughters Tori (20) and Rebekah (14) were killed when the tornado destroyed their home, leaving only foundations, one of about 45 homes destroyed in the town. Six other family members are said to have required hospital treatment. 

In the suburb of Vilonia to the north of the city Daniel Wassom (31) was killed by a piece of lumber that struck his home, and Cameron and Tyler Smith (9 and 7 respectively) were killed when their home was destroyed by the tornado. A total of six people are said to have died in the town, with many more injured or made homeless.

Damage caused by a tornado in the town of Mayflower, Arkansas on Sunday 27 April 2014. Danny Johnson/AP.

In Alabama at six people died when a tornado hit the Billy Bob Trailer Park west of Athens in Limestone County on Monday 28 April, and another 17 required hospital treatment. The tornado also hit an electricity substation, and leaving about 14 600 people without power.

In southwest Iowa a woman was killed when a building collapsed in high winds near Kinross. A number of other people were also injured and other buildings damaged.

In Kansas at least one person was killed and 34 injured when an EF2 tornado hit the town of Baxter Springs in the southeast of the state on Sunday evening. About 100 homes and 12 businesses were damaged or destroyed by the storm, which has left 40% of the town without electricity and 93% without gas supplies.

Tornado near Baxter Springs, Kansas, on Sunday 27 April 2014. KMBC.

In Mississippi seven people are thought to have died and 45 required hospital treatment after a string of tornados across the state, and around 19 000 people have been left without electricity.

In Oklahoma two people were killed and six injured after a tornado struck the town of Quapaw in Ottowa County (about 10 km south of Baxter Springs, Kansas). One of the deceased has been named as John Brown (68), who was crushed when a wall collapsed onto his car.

Tornados were also reported in a number of other US states. One person was injured and several homes damaged in northwest Louisiana, while tornados were observed but no damage reported in Missouri, Georgia and Tennessee. 

Tornadoes are formed by winds within large thunder storms called super cells. Supercells are large masses of warm water-laden air formed by hot weather over the sea, when they encounter winds at high altitudes the air within them begins to rotate. The air pressure will drop within these zones of rotation, causing the air within them so rise, sucking the air beneath them up into the storm, this creates a zone of rotating rising air that appears to extend downwards as it grows; when it hits the ground it is called a tornado. 

Tornadoes can occur anywhere in the world, but are most common, and most severe, in the area of the American mid-west known as 'Tornado Ally', running from Texas to Minnisota, which is fueled by moist air currents from over the warm enclosed waters of the Gulf of Mexico interacting with cool fast moving jet stream winds from the Rocky Mountains. Many climatologists are concerned that rising temperatures over the Gulf of Mexico will lead to more frequent and more severe tornado events.

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Monday 28 April 2014

A new species of Ground Beetle from Papua New Guinea.

Ground Beetles (Carabidae) are large carnivorous Beetles with destictive black or metalic elytra (wing-cases) that are sometimes fused, preventing flying. They have paired glands on their lower abdomens which produce noxious chemicals, used to defend the Beetles against predators (in one group of Carabids, the Bombadier Beetles,these secretions have evolved to react violently, even explosively, to one-another). The group has a fossil record dating back to the Triassic.

In a paper published in the journal ZooKeys on 29 November 2012, Kipling Will of the Essig Museum of Entomology at the University of California, Berkeley and David Kavanaugh of the Department of Entomology at the California Academy of Sciences describe a new species of Carabid Beetle from the Finisterre Mountain Range on the northeastern coast of Papua New Guinea.

The new species is placed in the genus Lesticus and given the specific name finisterrae, meaning ‘from Finisterre’. The species is described from a single male specimen collected near Teptep on the borders between Madang and Morobe Provinces in a pitfall trap in montane moss forest at an altitude of 3050 m. The area was at the upper limit of the forest’s distribution, being replaced by open grassland slightly higher. The single specimen is a dark brown Beetle, 20 mm in length, with sharply hooked mandibles.

Male specimen of Lesticus finiterrae, in dorsal view. Will & Kavanaugh (2012).

View within upper montane moss forest habitat at 3050m elevation, Finisterre Range, Papua New Guinea. The pitfall trap in which the unique specimen of Lesticus finisterrae was collected was located in the shaded area just below the middle of the figure. Will & Kavanaugh (2012).

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