Monday, 30 May 2016

Magnitude 1.3 Earthquake in the northwest Highlands.

The British Geological Survey recorded a Magnitude 1.3 Earthquake at a depth of about 7 km about 5 km to the southeast of the village of Gairloch in the northwest of the Highland Region of Scotland, at about 5.10 am British Summertime (about 4.10 am GMT) on Monday 30 May 2016. This was not a major event, and presented no threat to human life or property, but may have been felt locally.
 The approximate location of the 30 May 2016 Gairloch 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... 1.3 Earthquake in the Highland Regionof Scotland.                                 The British Geological Survey recorded a Magnitude 1.3 Earthquake at a depth of about 3 km about 2 km to... 1.3 Earthquake near Glencoe, Scotland.                                             The British Geological Survey recorded a Magnitude 1.3 Earthquake at a depth of about 10 km about 5 km to the west of Glencoe in the district of Lochaber in... 2.2 Earthquake to the south of Loch Shiel, Scotland.                              The British Geological Survey recorded a Magnitude 2.2 Earthquake at a depth of about 11 km to the south...
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Friday, 27 May 2016

Garra lorestanensis: A new species of Blind Cave Fish from Loven Cave in Lorestan Province, Iran.

Many cave systems around the world are home to Cave Fish, populations of Fish that have become isolated within subterranean waterways, and both evolved adaptations to living in these systems and lost adaptations to life in sunlit waterways, most obviously manifested in the absence of pigment and eyes. Loven Cave in the Ab-e Sirum or Ab-e Serum Valley in Lorestan Province, Iran, has been known to be an outlet of a limestone cave system beneath the Zagros Mountains since the mid-twentieth century. Two species of unique Cave Fish have been describd from this cave, both blind and pigmentless; a species of Sucker-mouthed Barb, Garra typhlops, and an Asian Stone Loach, Paracobitis smithi.

In a paper published in the journal FishTaxa on 22 March 2016, Hamed Mousavi-Sabet of the Department of Fisheries at the University of Guilan and Soheil Eagderi of the Department of Fisheries at the University of Tehran, describe a new species of Cave Fish from the Loven Cave.

The new species is also placed in the genus Garra and is given the specific name lorestanensis, meaning 'From Loristan'. The species is described from six adult specimens ranging in size from 27.2-58 mm in length. It differs from Garra typhlops in having a mental disk (disk-shaped structure on the lower jaw, used to attach to the substrate during feeding), which the previously described species lacks; a genetic analysis supported the idea that this was a digannostic for a separate species rather than a variable trait within the species (as with some other species of Garra).

Garra lorestanensis, 55 mm SL; Iran: Loven Cave. Mousavi-Sabet & Eagderi (2016).

See also... nanningensis: A fossil Loach from the Middle Oligocene of Guangxi Province, China.                                                     Loaches, Corbitidae, are freshwater Cypriniform Fish related to Carp and Minnows, found across Eurasia... new species of River Loach from Rakhine State, Myanmar.                                         River Loaches (Nemacheilidae) are ubiquitous members of the Eurasian freshwater fauna, with at least 704 species in 46 genera... new species of blind Cavefish from Indiana.                                                   Cavefish (Amblyopsidae) are a group of predominantly cave-dwelling Perciform Fish from North America. Of the eight currently described species three are found at the surface, predominantly around springs, and...
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Thursday, 26 May 2016

Dozens of cars swallowed by sinkhole in Florence, Italy.

Dozens of cars have been swallowed by a giant sinkhole that opened up on the Lungarno Torrigiani beside the Arno River in Florence on Wednesday 25 May 2016. The whole measured 182 m in length, but only about 7 m across, and opened slightly before 6.15 am local time, swallowing a row of parked cars but not causing any injuries.

The scene of the 25 May 2016 Florence sinkhole. Vigu del Fuoco.

Sinkholes are generally caused by water eroding soft limestone or unconsolidated deposits from beneath, causing a hole that works its way upwards and eventually opening spectacularly at the surface. Where there are unconsolidated deposits at the surface they can infill from the sides, apparently swallowing objects at the surface, including people, without trace.

 The proximity of the 25 May 2016 sinkhole to the Arno River. Vigu del Fuoco.

In this case the sinkhole is thought to have been caused by the collapse of a water supply pipe, which was 60 cm in diameter and provided water to homes in the area. An initial split in the pipe is thought to have allowed water to wash away surrounding sediments, causing the overlaying road to collapse onto the pipe. Part of the city around the sinkhole is currently without water, and buildings close to the incident have been evacuated as a precaution.

See also... people evacuated from homes after massive sinkhole opens on Naples Street. Approximately 380 people from 95 families had to be evacuated from their homes after a massive sinkhole opened up in a residential district of Naples on Sunday 22 February 2015. Nobody was injured by the incident, in which a 10 m section of road collapsed abruptly...
Four people are known to have died following landslides in the southern Alps this weekend. On Saturday 15 November 2014 a landslide destroyed... dead in Italian flash flood.                  Four people are known to have died and about twenty more have been injured after a thunderstorm caused a flash flood near Refrontolo in the Veneto Region of northern Italy slightly before midnight on Saturday 2...
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Anebodon luoi: A new species of Zhangheotherid Mammal from the Early Cretaceous of Liaoning Province.

Zhangheotherids are a small group of Mammals known only from the Early Cretaceous of Asia. They have traditionally been placed within the Symmetrodonta, a wider group of Mesozoic Mammals thought to have given rise to the Therians (Marsupials and Placental Mammals), though this group is now considered to be paraphyletic (i.e. not all members share a common ancestor). However more recent examinations of relationships among Mesozoic Mammals have suggested that the Zhangheotherids are closely related to the Therians, with the two groups being placed together to form a higher classification, the Trechnotheria.

In a paper published in the journal Scientific Reports on 24 May 2016, Shundong Bi of the Department of Biology at the Indiana University of Pennsylvania and the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences, Xiaoting Zheng of the Shandong Tianyu Museum of Nature and the Institute of Geology and Paleontology at Linyi University, Jin Meng of the Division of Paleontology at the American Museum of Natural History and the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences, Xiaoli Wang, also of the Shandong Tianyu Museum of Nature and the Institute of Geology and Paleontology at Linyi University, Nicole Robinson, also of the Department of Biology at the Indiana University of Pennsylvania and Brian Davis of the Department of Anatomical Sciences and Neurobiology at University of Louisville, describe a new species of Zhangheotherid Mammal from the Early Cretaceous Yixian Formation of Liaoning Province, China.

The new species is named Anebodon luoi, where 'Anebodon'  means 'young-tooth', in reference to the last premolar, which appears to have been replaced by an adult tooth late in the development if the animal, and 'luoi' honours palaeontologist Zhe-Xi Luo of the Univeristy of Chigaco for his work on Mesozoic Mammals. The species is decribed from a single partial skull and jaw, showing complete dentition.

Stereophotographs of the skull of the Zhangheotheriid Anebodon luoi, in dorsal (a), ventral (b), right lateral (c) and left lateral (d) views; illustrations of the skull in dorsal (e), ventral (f), and left lateral (g) views. Illustrations are enlarged to show detail and are not to same scale as photographs. Dotted fill represents matrix. Abbreviations: al, anterior lamina of petrosal; as, alisphenoid; ax, axis; bs, basisphenoid; ef, ethmoidal foramen; fdv, foramen for frontal diploic vein; fr, frontal; if, incisive foramen; iof, infraorbital foramen; lac, lacrimal; lf, lateral flange of petrosal; mapf, major palatine foramen; mpf, minor palatine foramen; mx, maxilla; na, nasal; os, orbitosphenoid; otc, anterior opening of orbitotemporal canal; pa, parietal; pal, palatine; pmx, premaxilla; smx, septomaxilla; spf, sphenopalatine foramen. Bi et al. (2016).

See also... transylvanicus: A red-toothed Multituberculate Mammal from the Late Cretaceous of Haţeg Island.                                 Small, isolated islands often produce distinctive... Eutherian Mammal from the Late Cretaceous of Kazakhstan.                    Biologists studying modern mammals divide them into three groups, the egg-laying Monotremes, the pouched Marsupials, and the large-baby-producing... Eutherian Mammal from the Jurassic of China.                                                      Modern mammals are divided into three groups by biologists: the monotremes which lay eggs, the marsupials which give birth to underdeveloped live young then raise these young in pouches, and the placental mammals which give birth to large, well developed young. Palaeontologists rarely get the... 
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Wednesday, 25 May 2016

Multicellular Eukaryotic organisms from the 1.56-billion-year-old Gaoyuzhuang Formation of North China.

Sediments across the Earth contain numerous macrofossils (fossils of big things that can be found with the naked eye, as opposed to smaller microfossils which are found by sieving sediments or examining thin slices of rock under a microscope) from the Cambrian Explosion (542 million years ago) onwards, with numerous such fossils also now known from the Ediacaran Period (635-542 million years ago) and even some from the later part of the Cryogenian (720-635 million years ago). Earlier than this the fossil record is harder to interpret, with several disputed claims of multicellular organisms, as well as uncertainty as to whicj are the earliest cells that can be described as tuly Eukaryotic (having cells with a nulceus like animals and plants, as opposed to Prokaryotic cells which lack such nuclei, as in Bacteria and Archeans).

In a paper published in the journal Nature Communications on 17 May 2016, Shixing Zhu of the Tianjin Institute of Geology and Mineral Resources of the China Geological Survey and the State Key Laboratory of Biogeology and Environmental Geology at the China University of Geosciences, Maoyan Zhu of the State Key Laboratory of Palaeobiology and Stratigraphy at the Nanjing Institute of Geology and Palaeontology, Andrew Knoll of the Department of Organismic and Evolutionary Biology at Harvard University, Zongjun Yin and Fangchen Zhao, also of the State Key Laboratory of Palaeobiology and Stratigraphy at the Nanjing Institute of Geology and Palaeontology, Shufen Sun, aslo of the Tianjin Institute of Geology and Mineral Resources of the China Geological Survey, Yuangao Qu of the Centre for Geobiology at the University of Bergen, Min Shi, also of the State Key Laboratory of Biogeology and Environmental Geology at the China University of Geosciences and Huan Liu, again of the Tianjin Institute of Geology and Mineral Resources of the China Geological Survey, describe a series of Multicellular Eukaryotic fossils from the 1.56-billion-year-old Gaoyuzhuang Formation of North China.

At 1.56-billion years old the Gaoyuzhuang Formation is considered to be Calymmian, or Early Mesoproterozoic, in age, though these are definations based upon age rather fossil content as with later geologic periods. It comprises a series of calcarous shales and mudstones that outcrop across a wide area of North China, though fossils were found only at two locations, one in Qianxi County in Guizhou Province and the other in Kuancheng County in Hebei Province.

Zhu et al. found four different fossil forms, linear forms with parallel sides but no preserved ends, leaf-shaped forms which taper at one end, oblong forms with rounded ends and parallel sides, and tounge-shaped forms. All forms show well defined margins on at least two sides, unlike algal mats which spread amorphously, and one small example of a leaf-shaped form was found to have a stipe (stem) and holdfast similar to that seen in modern seaweeds. 

 Macroscopic fossils from the Gaoyuzhuang Formation. (a) Linear fossil without preservation of either end (a(1)) and fragment of tongueshaped fossil (a(2)), Qg98017. (b) Linear fossil without preservation of either end (b(1)) and tongue-shaped fossil with longitudinal striations (b(2)), Qg20011; (c,d) Cuneate fossils, 07kg1332 (c), Qg20017 (d). (e) Oblong fossil with possible holdfast, 07 kg1331. (f) Cuneate fossil preserved with differentiated holdfast, Qg98021; (g) linear fossil without preservation of either end. Scale bars, 5 cm (in a,b,g), 20mm (in c), 40mm (in d) and 5mm (in e,f). Zhu et al. (2016).

These morphologies strongly support the idea that these were photosynthetic multicellular organisms with pre-determined growth patterns, albeit simple ones, similar to moder marine Macro-Algae (Seaweeds). Of the three modern groups of Macro-Algae (Red, Green and Brown) two (Red and Green) have been predicted by some studdies to have shared a common ancestor in the Early Mesoproterozoic (Brown Algae are thought to be quite unrelated and much younger). The Gaoyuzhuang fossils could potentially be representatives of this ancestral Algal group, though the presence of similar morphologies in the unrelated Brown Algae indicates that this simple bodyplan has evolved at least twice in Eukaryotes, raising the possibility that similar forms could have arisen quite separately in an extinct group of Eukaryotes in the Early Mesoproterozoic.

In addition to examening macrofossils Zhu et al. took sediment samples from the Gaoyuzhuang Formation and treated them by acid maceration (mashing up and disolving in acid). This yielded a number of fragments of cellular material, up to 1 mm across, comprised of tightly packed masses of polyhedral cells 6–18 μm in diameter. These were found to be made of altered carbon-based material, strongly supporting the idea that these were remains of living material, though evidence of internal structure could not be found. These cannot be directly linked to the macrofossils, but they are large enough to be clearly Eukaryotic in origin, and in the absense of any other structures from which they might have come, are thought to provide further evidence for the idea that the macrofossils represent Multicellular Eukaryotic Algae.

Polygonal cells forming a multi-layered network from the Gaoyuzhuang Formation. Scale bar is 20 μm. Zhu et al. (2016).

See also... Earth’s earliest fossils.                           In the nineteenth century the origin of life seemed an intractable problem for palaeontologists, with large complex animal fossils appearing in the Cambrian explosion, but scientists having access to neither examples of earlier fossils nor the means with which to examine them... the primordial soup; did the first life emerge in volcanic pools?                          The blood plasma and lymph of modern animals is similar in chemical composition to seawater, strongly supporting the idea that animal life began in the oceans, but the liquid inside our cells has a quite different chemistry, suggesting that cells... oldest animals - Pre-Ediacaran Sponges from Namibia(?)                                     Sponges are curious creatures. They are considered to be animals as they are multicellular and some of them have fixed body shapes, however they show no...

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Landslide at Myanmar jade mine kills at least twelve.

Twelve people have been confirmed dead and another eleven have been injured following a landslide at a jade mine at Hpakant in Kachin State, Myanmar, on Tuesday 24 May 2016. It is feared that many more people may be trapped beneath the rubble following the event, which occurred on a spoil heap produced by a large mining concern that was itself being worked by smaller artisanal miners looking for pieces of jade missed by the larger operation.

The scene of the 24 May 2016 Hpakant landslip. AFP.

Myanmar is the world's largest producer of jade, though much of this is produced (along with other precious and semi-precious minerals such as amber) at unregulated (and often illegal) artisanal mines in the north of the country, from where it is smuggled into neighbouring China. Accidents at such mines are extremely common, due to the more-or-less total absence of any safety precautions at the site. At many sites this is made worse by the unregulated use of explosives to break up rocks, often leading to the weakening of rock faces, which can then collapse without warning. The majority of people in this industry are migrant workers from the surrounding countryside, not registered with any local authority, which can make it difficult for rescuers to identify victims following such events, or even gain accurate assessments of the number of people likely to have been involved in such accidents.

The approximate location of the Hpakant jade mines. Google Maps.

See also... kills at least five at mine in Kachin State, Myanmar.                                          Five people have been confirmed dead and as many as fifty more may be missing following a landslide at a jade mine at Hpakant in Kachin State, Myanmar, on Friday 25 December 2015. The precise number of people involved is unclear because the... feared dead following landslide at Myanmar jade mine.                                    One hundred and five people have now been confirmed dead and over a hundred are still thought to be missing following a landslide at a jade mine at Hpakant in Kachin State, Myanmar on Saturday... kills at least nine at Myanmar jade mine.                                                            Nine people have been confirmed dead and about twenty more are thought to still be missing following a rockslide on a spill heap at a jade mine at Hpakant in Kachin State, Myanmar, on Monday 20 March 2015. All the people caught in the landslide are understood...
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Dramatic rise in Cephalopod populations across the globe.

In the past few decades marine biologists have become aware of many dramatic changes in the world's oceans, including dramatic falls in many commercially exploited Fish species, rising temperatures and widespread pollution and marine litter. During this time several studies have shown that as Fish populations have fallen in many areas, they have been replaced by rising Cephalopod numbers, leading some experts to wonder if this might be a global trend, though to date the data has not been examined to test this hypothesis.

In a paper published in the journal Current Biology on 23 May 2016, Zoë Doubleday and Thomas Prowse of the School of Biological Sciences and The Environment Institute at the University of Adelaide, Alexander Arkhipkin of the Fisheries Department of the Falkland Islands, Graham Pierce of the Oceanlab at the University of Aberdeen, Jayson Semmens of the Institute for Marine and Antarctic Studies at the University of Tasmania, Michael Steer of the South Australian Research and Development Institute, Stephen Leporati of the Department of Fisheries Western Australia, Sílvia Lourenço of the Instituto Português do Mar e Atmosfera, Antoni Quetglas of the Centre Oceanogràfic de les Balears of the Instituto Español de Oceanografía, Warwick Sauer of the Department of Ichthyology and Fisheries Science at Rhodes University and Bronwyn Gillanders, also of the School of Biological Sciences and The Environment Institute at the University of Adelaide, present a detailed analysis of Cephalopod population statistics from around the globe since 1953.

A Caribbean Reef Squid, Sepioteuthis sepioidea, on Bari Reef in the Caribbean Netherlands. Betty Wills/Wikimedia Commons.

Doubleday & Prowse et al. examined records from all major oceanographic regions in both hemispheres from 1953 to 2013, examining all key taxonomic groups (Squid, Octopus and Cuttlefish) and life history groups: demersal (living close to the bottom), benthopelagic (living on the bottom, but also swimming higher into the water column at times), and pelagic (living in the water column away from the bottom).

 A Two-spot Octopus, Octopus bimaculoides. Monterey Bay Aquarium.

In all cases Cephalopod numbers were found to have grown over the period examined. Doubleday & Prowse et al. suggest several possible explanations for this. Cephalopods are highly adaptable and intelligent, enabling them to colonise new areas and exploit novel resources, and have shorter life-cycles than comparably sized fish. In addition almost all Cephalopods, regardless of adult lifestyle, have a planktonic larval phase enabling them to reach suitable new habitats quickly. In addition recent studies have shown that rising temperatures tend to reduce generation times in Cephalopods (i.e. they reach maturity and reproduce more quickly). Furthermore many such larval Cephalopods are subject to predation by Fish species that have undergone dramatic population declines in recent years, potentially enabling more larval Cephalopods to survive to adulthood and reproduce.

Broadclub Cuttlefish, Sepia latimanus. Nick Hobgood/Wikipedia.

Doubleday & Prowse et al. note that such a rise in Caphalopod numbers is likely to have knock-on effects, most notably a rise in predation on species targeted by Cephalopods and an increase in food supply to species targeting Cephalopods (including many Humans). However they also observe that the current rise in Caphalopod numbers does not necessarily imply that in future Cephalopod populations will continue to rise, noting that the group are potentially vulnerable to future threats, such as rising ocean acidification and increased targeting by Human predation as Fish populations decline.

See also... the environments favored by Late Cretaceous Ammonites.              Ammonites are almost ubiquitous fossils in Mesozoic Marine deposits, and as such have been used extensively in interpreting and dating these deposits. They were free-swimming Cephalopods, related... behaviour in a Deep-sea Octopus.  Most Octopus reproduce only once in their life cycle, with the female undertaking an extended period of brooding in which she tends her eggs, keeping them clean and oxygenated and protected from predators, expiring at the end of this period. In most species the female does not feed at all during this... masses of the Diamond-shaped Squid in the Canary Islands.                                       The Diamond-shaped Squid, Thysanoteuthis rhombus, is a large (up to 100-130 cm, excluding tentacles) ocean-going Squid found in tropical and...

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