Wednesday 30 January 2019

Seven injured and one missing following Magnitude 4.1 Earthquake in Lower Silesia, Poland.

The United States Geological Survey recorded a Magnitude 4.1 Earthquake at a depth of 10.0 km, approximately 3 km to the southwest of the town of Grębocice in Lower Silesia Province, Poland, slightly before 1.55 pm local time (slightly before 12.55 pm GMT) on Tuesday 29 January 2019. The event was felt across much of southeast Poland, and caused a roof collapse at a copper mine at Rudna, trapping eight miners. Seven of these miners have now been rescued and are being treated at a local hospital for non-life-threatening injuries, while one remains missing.

The approximate location of the 29 January 2019 Lower Silesia Earthquake. USGS

Poland is in northern Europe, an area not noted for its Earthquakes, but not completely immune either. Like other areas where Earthquakes are uncommon, it is seldom possible to give a precise cause for Polish Earthquakes, with both probably being the result of more than one source of tectonic pressure. The strongest source of tectonic stress in southern Poland is the impact of Africa with Europe, far to the south. This is causing uplift and folding in the Alpine region of Central Europe, and exert pressure on the rocks further to the north. There are also areas of minor tectonic spreading beneath the Rhine Valley and North Sea, both of which cause stress over a wide area. Finally there is glacial rebound; until about 10 000 years ago much of northern and upland Europe was covered by a thick layer of glacial ice, pushing the rocks of the lithosphere down into the underlying mantle. This ice is now gone, and the rocks are slowly springing back into place, causing occasional Earthquakes in the process.

Witness accounts of Earthquakes can help geologists to understand these events, and the structures that cause them. The international non-profit organisation Earthquake Report is interested in hearing from people who may have felt this event; if you felt this quake then you can report it to Earthquake Report here.

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Sunday 27 January 2019

Priapulid-like Scalidophoran Worms preserved within burrows from the Early Cambrian of southern Sweden.

The first Worm-burrows appear in the Late Ediacaran Period, about 560 million years ago. These burrows are two-dimensional in form, apparently made by creatures that burrowed a few millimetres beneath the surface but did not venture deeper into the sediment. The onset of the Cambrian is marked by a dramatic increase in burrowing activity, with burrows dug three-dimensionally into the substrate, and the bioturbated sediments, previously unknown, becoming widespread in the rock record. However, while these burrows have been widely used as a way of dating the beginning of the Cambrian, the identity of the burrow makers has remained unclear, though many palaeontologists have speculated that it might be a Priapulid-like Scalidophoran Worm. The Scalidophora is the wider group comprised of Priapulids, Kinorinches and Loriciferans, phyla united by a chitinous cuticle which is periodically moulted and denticle-covered pharynxes which can be everted to form proboscises; the Scalidophorans along with the Panrthropods (Arthropods, Tardigrades and Velvet Worms), the Nematodes and the Nematomorphs (Horsehair Worms) make up the Ecdysozoa. Numerous Scalidophoran Worms are known from the Burgess Shale and other similar Cambrian Lagerstätten, but these deposits do not record the Earliest Cambrian, where their presence has been inferred from sclerites (fragments of exoskeleton) which appear to be of Scalidophoran origin.

In a paper published in the journal Proceedings of the Royal Society Series B: Biological Sciences on 16 January 2019, Giannis Kesidis and Ben Slater of the Department of Earth Sciences (Palaeobiology) at Uppsala University, Sören Jensen of the Área de Paleontologıá at the Universidad de Extremadura, and Graham Budd, also of the Department of Earth Sciences (Palaeobiology) at Uppsala University, describe a series of exceptionally preserved trace and body fossils from sandstones of the Early Cambrian File Haidar Formation of southern Sweden that can unequivocally be assigned to a Scalidophoran producer.

Kesidis et al. report a series of fossils in positive semirelief on the base of a sandstone bed within the Mickwitzia Sandstone Member of the File Haidar Formation. These are associated with burrow systems, but show details of the structure of the surface of an animal of clear Scalidophoran affinities, which appear to be casts of the actual animals. These have bulbous protrusions with longitudinal striations, which appear remarkably similar to modern Priapulids.

(a) Close-up of specimen detailing lateral bulbous protrusions (aborted probes). (b), (c) Anterior details of bulb-like terminations in specimen, illustrating 20 radiating longitudinal striations. Note that striations bifurcate distally, indicating rotation of the worm’s prosoma during excavation. (d ) Schematic of morphology observed in (b), (c). Scale bars: 5 mm (a) 2 mm (b), (c). Kesidis et al. (2019).

In order to try to understand the formation of these fossils, Kesidis et al. tried experimentally placing specimens of the modern Priapulid Priapulus caudatus, which appears similar in size and morphology to the specimens, in tanks where mud has been allowed to settle and then topped off with a layer of fine sand (this is unlike the typical environment of Priapulus caudatus, a species which typically dwells in soupy mud where any tunnels will collapse behind it as it moves). The activities of the Worms drew the sand into the burrows, and prising the burrows apart showed striated marks left by the sclerites of the Worms, which appeared similar to the striations in the Mickwitzia Sandstone burrows. Subsequent filling of some burrows with Plaster of Paris produced structures almost identical to the Cambrian material.

(a) Specimen A, discrete cylindrical structure interpreted as a mouldic Priapulid body fossil. (b) Specimen B, elongated burrow, with bulb-shaped aborted probes emanating from the main burrow. (c), (d) Plaster of Paris casts of extant Priapulus caudatus burrows exhibiting strikingly similar wall ornamentation to that of Specimens A and B. Scale bars: 5 mm (a), (b), 10 mm (c), 8 mm (d ).  Kesidis et al. (2019).

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Asteroid 2019 BU1 passes the Earth.

Asteroid 2019 BU1 passed by the Earth at a distance of about 1 147 000 km (2.98 times the average distance between the Earth and the Moon, or 0.77% of the distance between the Earth and the Sun), at about 12.30 pm GMT on Tuesday 22 January 2019. There was no danger of the asteroid hitting us, though were it to do so it would not have presented a significant threat. 2019 BU1 has an estimated equivalent diameter of 11-34 m (i.e. it is estimated that a spherical object with the same volume would be 11-34 m in diameter), and an object of this size would be expected to explode in an airburst (an explosion caused by superheating from friction with the Earth's atmosphere, which is greater than that caused by simply falling, due to the orbital momentum of the asteroid) in the atmosphere between 30 and 12 km above the ground, with only fragmentary material reaching the Earth's surface.

The calculated orbit of 2019 BU1. JPL Small Body Database.

2019 BU1 was discovered on 7 April 20108 by the University of Arizona's Catalina Sky Survey, which is located in the Catalina Mountains north of Tucson. The designation 2019 BU1 implies that it was the 44th asteroid (asteroid U - in numbering asteroids the letters A-Y, excluding I, are assigned numbers from 1 to 24, with a number added to the end each time the alphabet is ended, so that A = 1, A1 = 25, A2 = 49, etc., which means that U1 = 20 + 24 = 44) discovered in the second half of January 2019 (period 2019 B).

2019 BU1 has an 914 day orbital period and an eccentric orbit tilted at an angle of 5.42° to the plane of the Solar System, which takes it from 0.78 AU from the Sun (i.e. 78% of the the average distance at which the Earth orbits the Sun) to 2.90 AU from the Sun (i.e. 290% of the average distance at which the Earth orbits the Sun, slightly less than twice the distance at which Mars orbits). 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 fairly common, with the last having occurred in February 1952 and the next predicted in January 2029.

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Saturday 26 January 2019

Alfaites romeo: A new species of Hyolith from the Middle Cambrian of the Czech Republic.

The Hyoliths are an enigmatic group of shelled invertebrates known from the Earliest Cambrian until the End Permian Extinction. They had conical shells with opercula (lids), and sometimes a pair of curved horns called 'helens'. The exact nature of Hyoliths was for a long time considered a mystery, with most palaeontologists considering them to be either a form of Mollusc or an extinct phylum of animals of unknown affinities. However, recent studies of Hyoliths with preserved soft tissues and shell microstrucure has led to the conclusion that they were lophophorate animals closely related to Brachiopods.

In a paper published in the European Journal of Taxonomy on 24 January 2019, Martin Valent of the Palaeontological Department at the National Museum in Prague, Oldřich Fatka of the Institute of Geology and Palaeontology at Charles University, and the late Ladislav Marek of the Institute of Geology of the Czech Academy of Sciences (Ladislav Marek died in 1995, but is included as a co-author by Valent and Fatka because he began work on the paper before he died), describe a new species of Hyolith from the Middle Cambrian Buchava Formation of the Skryje-Týřovice Basin in the Barrandian area of the Czech Republic.

The new species is named Alfaites romeo, where 'Alfaites' derives from the Greek letter alpha (Α), which the species resembles, and 'romeo' refers to the character Romeo Montague from Shakespeare's play Romeo and Juliet; Marek originally planned to slit the specimens assigned to the genus into two species, Alfaites romeo and Alfaites juliet, but Valent and Fatka could find no justification for this analysis. The species is described from seven specimens collected by Ladislav Marek and Petr Šlehofer in the 1970s and 1980s. These have almost flat sided shells with rounded lateral edges.

Alfaites romeo. (A)-(B) Holotype (NM L46640). (A) Outer mould of internal side of operculum. (B) Detail of outer mould of internal side of operculum with marked cardinal teeth. (C)–(I) Paratypes. (C) Outer mould of internal side of operculum (NM L46642). (D) Outer mould of external side of operculum (NM L46646). (E) Outer mould of external side of operculum (NM L46641). (F) Outer mould of apertural part of conch – lateral view (NM L46645). (G) Inner mould of apertural part of conch – dorsal view (NM L46645). (H) Subtrigonal cross-section of conch (NM L46643). (I) Outer mould of dorsal side of conch with distinct asymmetrical ribs (NM L46644). Scale bar is 1 mm. Valent et al. (2019).

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Epitomapta simentalae: A new species of Sea Cucumber from Acapulco Bay, Mexico.

Sea Cucumbers (Holothuroidea) are a class of Echinoderms that have become elongated and worm-like, effectively becoming secondarily bilaterally symmetrical. Like all Echinoderms they have a calcareous exoskeleton, but this is greatly reduced, typically only occurring as ossicles within the epidermis. The muscle structure of Sea Cucumbers is instead supported by a layer of modified collegen that can be stiffened or relaxed at will, allowing for a more flexible body than that of other Echinoderms. 

In a paper published in the journal ZooKeys on 15 January 2018, Francisco Alonso Solís-Marín of the Colección Nacional de Equinodermos 'Dra. Ma. Elena Caso Muñoz' at the Universidad Nacional Autónoma de México, Carlos Andrés Conejeros-Vargas of Posgrado en Ciencias del Mar y Limnología at the Universidad Nacional Autónoma de México, Andrea Alejandra Caballero-Ochoa of the Facultad de Ciencias at the Universidad Nacional Autónoma de México, and Julio Adrian Arriaga-Ochoa, also of Posgrado en Ciencias del Mar y Limnología at the Universidad Nacional Autónoma de México, describe a new species of Sea Cucumber from Acapulco Bay on the Pacific Coast of Guerrero State, Mexico.

The new species is placed in the genus Epitomapta, which currently contains two species of small, worm-like Sea Cucumbers from the Atlantic Coast of the United States and the Pacific Coast of Mexico, and given the specific name simentalae, in honour of Delia Rosalba Simental Crespo, for her contributions to the study and conservation of Echinoderms on the coasts of Mexico. The species is described from 127 specimens collected from well aerated sandy sediments at depths of between four and ten meters. These specimens are pink to light purple in colour and less than 2 cm long, with smooth skin and twelve tentacles, each with two or three pairs of digits and a terminal digit, plus up to six sensory cups.

Epitomapta simentalae. Lateral view of preserved specimen. Solís-Marín et al. (2019).

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Hundreds feared dead after collapse of mine tailings dam in Minas Gerais State, Brazil.

Ten people have now been confirmed dead and over 200 more are missing, following the collapse of a tailings dam at a Vale mining operated iron mine in Minas Gerais State, Brazil, on Friday 25 January 2019. The incident happened close to the Alegria Mine site where a similar tailings dam collapse in November 2015, resulting in 19 deaths and a major environmental catastrophe which is still causing problems today. The dam that collapsed this week is only about a fifth of the size of that dam, and is not thought likely to cause environmental problems on the same scale, but it is feared that the number of deaths will be much greater, as the dam was uphill of an encampment used by workers at the mine.

The remains of a mine camp in Minas Gerais State, Brazil, where it is feared over 200 people died when the camp was hit by a wave of slurry following the collapse of a tailings dam on 25 January 2019. Leo Drumond/Nitro/AP.

Tailings ponds are used to store sediment-laden waters from mines; such waters typically contain a high proportion of fine silt and clay particles, which take time to settle out of the water. The resulting water may be fairly clean, or may contain other pollutants (typically acids, either generated by the local geology or used in the mining process), and need further treatment. In some instances acid is added to such pools in order to dissolve the product, which is then released from the resultant chemical slurry by further treatment, however this is not a typical procedure at iron ore mines.

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Three confirmed deaths and two people missing after tornadoes and flash floods hit the Mediterranean coast of Anatolia.

Three people have been confirmed dead and two more are missing after a series of tornadoes and flood events in southwestern Anatolia, Turkey, on Friday 25 January 2019. The Kumluca and Finike districts of Antalya Province were hit by a series of tornadoes, that are known to have killed two people, schoolgirl Berivan Karakeçi, 13, and an as yet unnamed 40-year-old man described as a municipality employee, while student Busa Acar, 20, is also feared to have died after the car she was travelling was picked up and thrown into a river. On the Bodrum Peninsula in neighbouring Muğla Province teacher Billur Atik, 23, drowned after a car she was travelling in was caught in a flash flood, and her fiance, electrician Çağlar Bilecik, 27, is still missing, with little hope of being found alive. A further fifteen people were injured in storm related incidents across the region.

Turkish student Busa Acar, 20, who is feared to have died after her car was thrown into a river in Antalya Province on 25 January 2019. Hürriyet Daily News.

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. 

Damage caused by a tornado in Antalya Province on 25 January 2019. Hürriyet Daily News.

Like many dry areas, Anatolia, while generally experiencing low rainfall, is prone to occasional severe flooding. This stems from two causes; firstly the arid climate prevents the development of a thick soil layer which would be expected in less dry areas, so that in much of the area (non-porous) bedrock is either exposed or close to the surface, and secondly the hot climate leads to heavy evaporation from nearby seas and oceans, so that if the wind changes direction and brings water-laden air to the area, it brings a lot of precipitation with it. This combination of heavy rainfall and low ground absorbency leads to large amounts of water at the surface, typically moving downhill at some speed. Wadis, dry channels or ravines through which these sudden floods are channelled, can be particularly dangerous at these times, particularly as they often appear to resemble natural pathways or even camp sites to people unfamiliar with the climate.
 The car in which young Turkish couple Çağlar Bilecik, 27, and Billur Atik, 23, were caught in a flash flood on the Bodrum Peninsula on Friday 25 January 2019. Sputnik Türkiye.
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