Sunday, 20 May 2018

Magnitude 5.1 Earthquake in Petorca Province, Chile.

The United States Geological Survey recorded a Magnitude 5.1 Earthquake at a depth of 32.7 km, 39 km to the northeast of the city of La Ligua in the Chilean province of Petorca slightly before 2.45 am local time (slightly before 6.45 am GMT) on Saturday 19 May 2018. There are no reports of any damage or injuries associated with this event, but people have reported feeling the event across much of central Chile, and parts of western Argentina.

The approximate location of the 19 May 2018 Petorca Earthquake. USGS.

Chile is located on the west coast of South America, which is also the convergent margin between the Nazca and South American Plates. The Nazca Plate is being subducted beneath the South American Plate and is sinking beneath the South American Plate. This is not a smooth process, the rocks of the two plates continuously stick together then, as the pressure builds up, break apart again, causing Earthquakes. As the Nazca Plate sinks deeper it is partially melted by the heat of the Earth's interior. Some of the melted material then rises up through the overlying South American Plate as magma, fuelling the volcanoes of the Chilean Andes.
 
 The subduction of the Nazca Plate beneath the South American Plate, and how it causes Earthquakes and volcanoes. Pacific Earthquake Engineering Research Center.
 
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.
 
See also...
 
http://sciencythoughts.blogspot.co.uk/2018/01/eruptive-activity-on-volcan-arrau-peak.htmlhttp://sciencythoughts.blogspot.co.uk/2017/12/landslide-kills-at-least-five-in.html
http://sciencythoughts.blogspot.co.uk/2017/11/magnitude-49-earthquake-in-petorca.htmlhttp://sciencythoughts.blogspot.co.uk/2017/10/magnitude-54-earthquake-in-el-loa.html
http://sciencythoughts.blogspot.co.uk/2017/09/magnitude-58-earthquake-off-coast-of.htmlhttp://sciencythoughts.blogspot.co.uk/2017/07/magnitude-51-earthquake-in-antofagasta.html
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Meganodontia haunuiensis, Elliptiolucina neozelandica, and Lucinoma saetheri: Three new species of Lucinid Bivalves from Miocene hydrocarbon seeps on eastern North Island, New Zealand.

Ludinid Bivalces, Lucinidae, are large marine Bivalves which lack syphons, but which have an elongate foot with a long chanel that serves the same purpose. All modern Lucinids host colonies of symbiotic sulfur-oxidizing Bacteria in their gills, which enable them to colonise and thrive in sulphur-rich subtidal sediments. The first Lucinids appeared in the Silurian, though they remained a minor constituent of Bivalve faunas until the Late Cretaceous, when they underwent a major radiation at roughly the same time as Mangroves and Seagrass meadows appeared, which may have been when they acquired their symbiont Bacteria. Lucinids also form a significant part of the communities that live around hydrocarbon seeps (areas where hydrocarbons escape into the sea from exposed deposits).

In a paper published in the journal Acta Palaeontologica Polonica on 28 March 2018,  Kazutaka Amano of the Department of Geoscience at Joetsu University of Education, Crispin Little of the School of Earth and Environment at the University of Leeds, and Kathleen Campbell of the School of Environment at the University of Auckland, describe three new species of Lucinid Bivalves from Early and Middle Miocene hydrocarbon seeps from the area around Hawke Bay on eastern North Island, New Zealand.

The first new species is placed in the genus Meganodontia, which currently contains two described species, a living species found off the coast of Taiwan, and a fossil species from Miocene seep-carbonates from Italy, as well as an undescribed species from the Miocene of Cuba, and is given the specific name haunuiensis, meaning 'from Haunui', in reference to the location where it was found. This species is smaller than other members of the genus, with described specimens ranging from 40.2 to 84.6 mm in length, and are subcircular and highly inflated in shape, and a broad, toothed hinge. The species was found in the Early Miocene Ihungia Limestone to the south of Hawke Bay,

Lucinid Bivalve Meganodontia haunuiensis from the lower Miocene Ihungia Limestone at Haunui and Ugly Hill, North Island, New Zealand. (A) Specimen UOA L4777, edentulous hinge plate of left valve (A₁,), left valve (A₂). (B) Specimen UOA L4581, dorsal view (B₁) and frontal view (B₂) of right valve. (C) Specimen UOA L4791, edentulous hinge plate of right valve. (D) Specimen UOA L4790, right valve of small specimen. (E) Specimen UOA L4782, dorsal view of slightly compressed specimen (E₁), left valve (E₂). (F) Specimen UOA L4792, dorsal view showing symmetric lunule in both valves (F₁), right valve showing internal mould (F₂), enlargement of the anterior adductor muscle scar of F₂ (F₃). (G) Specimen UOA L 4789, right valve, showing internal mould of small specimen. Scale bars 10 mm. Amano et al. (2018).

The second new species is placed in the genus Elliptiolucina, which currently contains five living species from the Indo-Pacific region, and given the specific name neozelandica, meaning New Zealand. This is a small species, with described specimens ranging from 17.1 to 34.9 mm in length, with a thin, flattened shell. It was found in the Middle Miocene Bexhaven Limestone at the Moonlight North seep sight, to the north of Hawke Bay.

Lucinid Bivalve Elliptiolucina neozelandica from the Middle Miocene Bexhaven Limestone at Moonlight North, North Island, New Zealand. (A) Specimen UOA L4771, dorsal view (A₁), right (A₂) and left (A₃) valves. (B) Specimen UOA L4783, dorsal view (B₁), right valve (B₂), internal mould of left valve (B₂), enlargement of anterior adductor muscle scar in B₂ (B₄). (C). Specimen UOA L4775, edentulous hinge plate of right valve (C₁), left valve (C₂). (D) Specimen UOA L4774, dorsal view (D₁), right (D₂) and left (D₃) valves. Scale bars 10 mm. Amano et al. (2018).

The third new species described is placed in the genus Lucinoma, whuch has 38 described living species as well as two previously described Miocene ones, from Italy and New Zealand, and is given the specific name saetheri, in honour of Kristian Saether of the University of Auckland, for his work on the hydrocarbon seep fauna of New Zealand. This is a large species, with measured specimens ranging from 39.6 to 67.4 mm in length, with a thick, subcircular shell, with is moderately inflated with week ribs and a straight antero-dorsal margin. The species was found in the Early Miocene Ihungia Limestone to the south of Hawke Bay, and the Middle Miocene Bexhaven Limestone at the Moonlight North seep sight, to the north.

 Lucinid Bivalve Lucinoma saetheri from the lower Miocene Ihungia Limestone at Ugly Hill and the middle Miocene Bexhaven Limestone at Moonlight North, North Island, New Zealand. (A) Specimen UOA L4773, internal mould of right valve. (B) Specimen UOA L 4772, hinge plate of right valve. (C) Specimen UOA L4785, left (C₁) and right (C₂) valves. (D) Specimen UOA L4780, dorsal view (D₁), right (D₂) and left (D₃) valves. (E) Specimen UOA L4786, right valve. (F) Specimen UOA L 4779, left valve showing lamellated commarginal riblets (F₁), dorsal view (F₂). Scale bars 10 mm. Amano et al. (2018).

See also...

http://sciencythoughts.blogspot.co.uk/2017/08/a-hydrocarbon-seep-from-late-triassic.htmlhttp://sciencythoughts.blogspot.co.uk/2017/05/kuphus-polythalamia-can-giant-free.html
http://sciencythoughts.blogspot.co.uk/2016/09/borniopsis-mortoni-new-species-of.htmlhttp://sciencythoughts.blogspot.co.uk/2015/12/evidence-for-middle-permian-extinction.html
http://sciencythoughts.blogspot.co.uk/2015/03/the-reaction-of-marine-invertebrates-to.htmlhttp://sciencythoughts.blogspot.co.uk/2015/01/a-new-probably-fossil-species-of.html
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Asteroid 2018 HL2 passes the Earth.

Asteroid 2018 HL2 passed by the Earth at a distance of about 18 775 000 km (48.9 times the average distance between the Earth and the Moon, or 12.5% of the distance between the Earth and the Sun), slightly before 5.55 pm GMT on Sunday 13 May 2018. There was no danger of the asteroid hitting us, though were it to do so it would have presented a significant threat. 2018 HL2 has an estimated equivalent diameter of 110-340 m (i.e. it is estimated that a spherical object with the same volume would be 110-340 m in diameter), and an object of this size would be predicted to be capable of passing through the Earth's atmosphere relatively intact, impacting the ground directly with an explosion that would be 600 to 75 000 000 times as powerful as the Hiroshima bomb. Such an impact would result in an impact crater 1.5-5 km in diameter and devastation on a global scale, as well as climatic effects that would last years or even decades.
 
 The calculated orbit of 2018 HL2. Minor Planet Center.
 
2018 HL2 was discovered on 26 April 2018 (17 days before its closest approach to the Earth) by the University of Arizona's Mt. Lemmon Survey at the Steward Observatory on Mount Lemmon in the Catalina Mountains north of Tucson. The designation 2018 HL2 implies that the asteroid was the 61st object (object L2) discovered in the second half of April 2018 (period 2018 H).   
 
2018 HL2 has a 788 day orbital period and an eccentric orbit tilted at an angle of 33.5° to the plane of the Solar System, which takes it from 0.89 AU from the Sun (i.e. 89% of he average distance at which the Earth orbits the Sun) to 2.45 AU from the Sun (i.e. 245% of the average distance at which the Earth orbits the Sun, and much further from the Sun than the planet 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). As an asteroid probably larger than 150 m in diameter that occasionally comes within 0.05 AU of the Earth, 2018 HL2 is also classified as a Potentially Hazardous Asteroid. 2018 HL2 has occasional close encounters with the planet Earths, with the next predicted for May 2154.
 
See also...
 
http://sciencythoughts.blogspot.co.uk/2018/05/asteroid-2018-jg3-passes-earth.htmlhttp://sciencythoughts.blogspot.co.uk/2018/05/asteroid-2017-wy14-passes-earth.html
http://sciencythoughts.blogspot.co.uk/2018/05/comet-c2016-r2-panstarrs-reaches.htmlhttp://sciencythoughts.blogspot.co.uk/2018/04/asteroid-2018-hv-passes-earth.html
http://sciencythoughts.blogspot.co.uk/2018/04/asterpid-2018-hc1-passes-earth.htmlhttp://sciencythoughts.blogspot.co.uk/2018/04/asteroid-2018-hm-passes-earth.html
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Cougar kills cyclist in Washington State, USA.

A cyclist has died after being attacked by a Cougar (or Mountain Lion, or Puma), Puma concolor, to the northeast of Snoqualmie, in King County, Washington, on Saturday 19 May 2018. The dead man was one of two mountain bikers who apparently disturbed the animal while out cycling, and who were initially able to drive off the Cougar by making themselves look larger and waving their arms about. However the Cat returned and attacked one of the men, causing his companion to dismount and try to tackle it. When the Cougar turned on him the man fled on foot (generally considered the worse course of action since Cougars can easily outpace us and typically attack prey from behind), leaving his injured friend to escape and seek help. The man's body was later found by trackers from the Washington Dapartment of Fish & Wildlife, who shot and killed the animal. The injured man was airlifted to Harborview Medical Center, where his condition is now described as satisfactory.

Officers from the Washington Department of Fish & Wildlife with the body of a Cougar, which was tracked and shot after killing a cyclist on 19 May 2018. Seattle Times.

Cougars were formerly found throughout the Americas, with the exception of northern Canada and Alaska, however they are now largely restricted to the western parts of North America, where Human populations are lower and more of their original habitat remains. Nevertheless, Cougars are not thought to be a particularly threatened species, with a population of about 2100 adults in Washington State alone, where the population is 'controled' by licenced hunting. 

Attacks on Humans by Cougars are extremely rare, with less than a hundred fatalities recorded in the United States since 1890, and only a single other recorded fatality in Washington State in the last 94 years. The most recent Cougar-related fatality in the US was in New Mexico in 2008.

See also...

http://sciencythoughts.blogspot.co.uk/2018/04/tchadailurus-adei-new-species-of-sabre.htmlhttp://sciencythoughts.blogspot.co.uk/2018/04/woman-attacked-by-leopard-in-rajasthan.html
http://sciencythoughts.blogspot.co.uk/2018/04/german-tourist-attacked-by-leopard-in.htmlhttp://sciencythoughts.blogspot.co.uk/2018/04/german-tourist-attacked-by-leopard-in.html
http://sciencythoughts.blogspot.co.uk/2018/04/eleven-lions-poisoned-in-ugandan.htmlhttp://sciencythoughts.blogspot.co.uk/2018/03/lioness-kills-woman-at-south-african.html

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Saturday, 19 May 2018

Rosaliella svalbardensis: A new species of Ostracod from methane cold seeps on the western Svalbard margin.

Ostracods are small Crustaceans with a bivalved body plan; their body is sandwiched laterally between two large valves, with the animal using its legs to generate a current through the shell, enabling it to feed, and in many cases swim (check). Ostracods are small (seldom much over a millimetre) and can be very abundant, making them common fossils in many deposits. They also often have distinctive shell ornamentation, enabling the identification of species from valves alone, and are both fast-evolving and sensitive to a range of environmental conditions, making them useful in both biostratigraphy (dating rocks using fossils) and palaeoenvironmental reconstruction. Methane cold seeps are considered to be important environments for understanding past climate change, as methane hydrates (ice deposits with trapped methane) form extensive deposits in Arctic regions, which are thought to release large amounts of methane during times of rapid global warming, which, since methane is a far more powerful greenhouse gas than carbon dioxide, makes identifying methane seeps importanr for understanding past climate change. Since Ostracods are known to inhabit methane cold seeps, they are a potential useful tool for identifying past cold seep deposits, though at the moment Ostracods from these environments are little studded.

In a paper published in the Journal of Micropalaeontology on 5 January 2018, Moriaki Yasuhara of the School of Biological Sciences and Swire Institute of Marine Science at the University of Hong Kong, Kamila Sztybor and Tine Rasmussen of the Centre for Arctic Gas Hydrate, Environment and Climate at the Arctic University of Norway, Hisayo Okahashi, also of the School of Biological Sciences and Swire Institute of Marine Science at the University of Hong Kong, Runa Sato, again of the School of Biological Sciences and Swire Institute of Marine Science at the University of Hong Kong, and of the Department of Marine Biosciences at the Tokyo University of Marine Science and Technology, and Hayato Tanaka of the Research Center for Marine Education at the University of Tokyo, describe a new species of Ostracod from methane cold seeps on the western Svalbard margin.

The new species is named Rosaliella svalbardensis, where 'Rosaliella' honours Rosalie Maddocks of the University of Houston for her work on Ostracods from chemosynthetic environments, and 'svalbardensis' means 'from Svarlbad'. The species is 642-680 μm in length, with a reticulated surface covered in clusters of pores. Such clusters of pores have been areas where chemosynthetic Bacteria are found, and have been suggested to be used to house symbionts. 

Scanning electron microscopy images of Rosaliella svalbardensis. (a)–(e) Adult, female, 0–1 cm depth. (f)–(j) Adult, female, 0–1 cm depth. (k)–(n) Adult, female, 0–1 cm depth. (o)–(q) Adult, female, 0–1 cm depth. (a), (c), (f), (h), (l), (n), (o) Lateral views. (b), (d), (e), (g), (i), (j), (k), (p), (q) Internal views. Scale bars: 1mm for (a), (b), (f), (g), (l), (m), (o), (p); 100 μm for (d), (i); 50 μm for (c), (e), (h), (j), (k), (n), (q). 1mm scale bar in the middle part of the figure. Other scale bars in each panel. Yasuhara et al. (2018).

See also...

http://sciencythoughts.blogspot.co.uk/2017/09/cypria-lacrima-new-species-of-candonid.htmlhttp://sciencythoughts.blogspot.co.uk/2015/01/a-new-probably-fossil-species-of.html
http://sciencythoughts.blogspot.co.uk/2014/11/a-new-species-of-ostracod-from.htmlhttp://sciencythoughts.blogspot.co.uk/2014/09/a-new-species-of-freshwater-ostracod.html
http://sciencythoughts.blogspot.co.uk/2014/04/three-dimensional-soft-tissue.htmlhttp://sciencythoughts.blogspot.co.uk/2012/07/deep-sea-gastropods-from-miocene-cold.html
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Landslide destroys home in Roanoke County, Virginia.

A family of three were forced to flee their home when it slid off its foundations and slid about six metres down a hillslope after being hit by a mudslide on Friday 18 May 2018. The family were sleeping in the home in the town of Vinton in the east of the county, when the property began to shift, at about 4.45 am local time. The family were able to escape through a hoke that opened up in a brick wall as the property moved.


The scene of a landslide in Roanoke County, Virginia, which shifted a house off its foundations and six metres downslope. Roanoke County Fire and Rescue.

The incident happened after several hours of heavy rain in the area, which appears to have destabilized exposed sediment on a construction site upslope of the home. 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.

See also...

http://sciencythoughts.blogspot.co.uk/2018/03/meteorite-stolen-from-virginia-museum.htmlhttp://sciencythoughts.blogspot.co.uk/2017/10/two-injured-in-chemical-spill-at.html
http://sciencythoughts.blogspot.co.uk/2012/06/protest-group-appalachia-rising-occupy.htmlhttp://sciencythoughts.blogspot.co.uk/2011/08/virginia-earthquake-shakes-washington.html

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Magnitude 5.3 Earthquake beneath Chiba Prefecture, Japan.

The Japan Meteorological Agency recorded a Magnitude 5.3 Earthquake at a depth of about 50 km, beneath Chiba Prefecture on Honshū Island, slightly after 12.10 pm Japan Standard Time (slightly after 3.10 am GMT) om Thursday 17 May 2018. There are no reports of any damage or casualties associated with this event, people have reported feeling it across most of central and eastern Honshū.

Map showing the location of the 17 May 2018 Chiba Prefecture Earthquake, and areas where the event was felt. Japan Meteorological Agency.

Japan has a complex tectonic situation, with parts of the country on four different tectonic plates. Eastern Honshū area lies on the boundary between the Pacific, Eurasian and Philipine Plates, where the Pacific Plate is passing beneath the Eurasian and Philipine Plates as it is subducted into the Earth. This is not a smooth process; the rocks of the two plates constantly stick together, only to break apart again as the pressure builds up, causing Earthquakes in the process. 

The movement of the Pacific and Philippine Plates beneath eastern Honshū. Laurent Jolivet/Institut des Sciences de la Terre d'Orléans/Sciences de la Terre et de l'Environnement.

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.

See also...

http://sciencythoughts.blogspot.co.uk/2018/04/eruption-on-io-yama-volcano-japan.htmlhttp://sciencythoughts.blogspot.co.uk/2018/04/ongoing-eruptions-on-mount-shinmoedake.html
http://sciencythoughts.blogspot.co.uk/2018/03/further-eruptions-on-mount-shinmoedake.htmlhttp://sciencythoughts.blogspot.co.uk/2018/03/eruption-on-mount-shinmoedake.html
http://sciencythoughts.blogspot.co.uk/2017/10/eruption-on-mount-shinmoedake-kyushu.htmlhttp://sciencythoughts.blogspot.co.uk/2017/07/eleven-confirmed-deaths-in-japan.html
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