Tuesday, 30 August 2016

Magnitude 3.8 Earthquake rattles Anchorage, Alaska.

The United States Geological Survey recorded a Magnitude 3.8 Earthquake at a depth of 35.1 kmabout 40 km to the east of Anchorage, Alaska, slightly before 4.30 am local time (slightly before 12.30 pm GMT) on Tuesday 30 May 2016. There are no reports of any damage or casualties associated with this event, but people have reported feeling it locally.

The approximate location of the 30 August 2016 Anchorage Earthquake. Earthquake Report/Google Maps.

Alaska lies on the North American Plate, with the Pacific Plate underlying the ocean to the south. The Aleutian Trench runs along much of the south coast of Alaska, with the Pacific Plate being subducted beneath this and passing under Alaska as it sinks into the Earth. The 4 January quake occurred in the far southeast of the state; east of the extent of the Aleutian Trench. Off the coast of southeast Alaska the Pacific and North American Plates pass one-another horizontally, with the Pacific Plate moving northward and the North American to the south (a transform plate margin). This is not a smooth process, and the plates frequently stick together, then break apart as the pressure builds up, causing Earthquakes.

Model of the subduction of the Pacific Plat beneath the North American Plate along the southern coast of Alaska and the Aleutians. United States Geological Survey.


Witness accounts of quakes can help geologists to understand these events and the rock structures 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 the USGS here.

See also...

Landslide deisplaces about 150 000 tonnes of debris in Glacier Bay in southeast Alaska.   About 150 000 tonnes of debris are believed to have been displaced following a landslide onto Lamplugh Glacier in Glacier Bay in southeast Alaska on...


Eruption on Mount Pavlof causes severe disruption to flights over Alaska.               Mount Pavlof, a 2.5 km high stratovolcano (cone-shaped volcano made up of layers of ash and lava) on the Alskan Peninsula, underwent a significant...

Eruptions on Mount Pavlof, on the Alaskan Peninsula.                                                  Mount Pavlof, a 2.5 km high stratovolcano began erupting on Saturday 31 May 2014, for the first time since the preceding September, according to the Alaska Volcano Observatory. This...



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Lightning kills 323 Reindeer in Norwegian national park.

A total of 323 Reindeer have been killed by a lightning strike during a thunder storm on the Hardanangervidda National Park on Friday 26 August 2016, according to the Norwegian Environment Agency. The Reindeer migrate across the park, which is a mountainous plateau, at this time of year, and are believed to have huddled together during the storm, an action which helps to protect the younger members of the herd (which included 70 calves) from the worst of the elements, but which makes them particularly vulnerable to (rare) lightning strikes.

Reindeer killed by lightning on the Hardangervidda Plateau on 26 August 2016. Håvard Kjøntvedt/Norwegian Environment Agency.

Thunderstorms occur when warm, moist bodies of air encounter cooler, drier air packages. The warm air rises over the cooler air until it rises above its dew point (the point where it cools to far to retain its water content as vapor), and the water precipitates out, falling as rain, sleet or hail.

Warm moist air passing over the surface of the Earth acts as an electrical generator, creating a negative charge in the cloud tops and a positive charge at the ground (or occasionally in a second cloud layer). The atmosphere acts as an electrical insulator, allowing this potential to build up, until water begins to precipitate out. This allows a channel of ionized air to form, carrying a current between the clouds and the ground, which we perceive as lightning.

See also...

Thirteen dead after helicopter crashes during flight from Norwegian oilfield.                 Thirteen people have died after a helicopter crashed to the west of Bergen, Norway, on Friday 29 April 2016, during a return flight from the Gullfaks Oil Field in...


Magnitude 3.8 Earthquake off the west coast of Norway.                                          The British Geological Survey recorded a Magnitude 3.8 Earthquake at a depth of 10 kmabout 30 km offshore of the town of Florø in Sogn og Fjordane County...


Fireball over northern Europe.       Eyewitnesses across much of northern Europe reported seeing a bright fireball in the sky moving southwest to northeast at about 6.05 pm GMT on Saturday 31 October 2015. The event was seen from the Netherlands, Germany, Denmark...



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Worker dead after landslide at Kuala Lumpur construction site.

One worker is being treated for injuries and another has died following a landslide in Kuala Lumpur on Tuesday 30 August 2016. The incident happened in the north of the city slightly before 4.00 pm, following a period of heavy rain. Neither of the men has been named, though the dead man has been identified as a Bangladeshi national and the injured man as a 28-year-old Malaysian.

The scene of the 30 August 2016 Kuala Lumpur landslide. The Coverage.

Malaysia has become increasingly landslip-prone in recent years due to extensive deforestation, which leaves soil exposed to heavy tropical rainfall. 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. August is one of the driest months in Kuala Lumpur, where the monsoon season lasted from October to March, however the city has a wet tropical climate, and heavy storms can happen at any time of year.

See also...

http://sciencythoughts.blogspot.co.uk/2014/06/three-workers-killed-by-landslide-at.htmlThree workers killed by landslide at Phuket landslide.                                                    Three workers were killed by a landslide at a construction site on the Thai island of Phuket at about 4.30 pm local time on Tuesday...
http://sciencythoughts.blogspot.co.uk/2014/05/about-150-people-forced-to-leave-their.htmlAbout 150 people forced to leave their homes by landslide in Perak State, Malaysia. Around 150 people have been forced to leave their homes after a landslide in Ipoh, the capital of Perak State in Malaysia. The incident took place at about...
http://sciencythoughts.blogspot.co.uk/2014/04/truck-swallowed-by-singapore-sinkhole.htmlTruck swallowed by Singapore sinkhole.      A truck carrying sand for the construction industry was partially swallowed by a sinkhole in Singapore on Thursday 24 April 2014. The incident happened at about 8.30 am local time when the driver of the truck...
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Monday, 29 August 2016

Ceratocaryum argenteum: A plant producing dung-mimicing seeds.

Ceratocaryum argenteum is a large Rush-like Grass native to Cape region in South Africa. It produces lage, hard seeds which Dung Beetles have been observed burrying, despite the fact that they do not appear to be a suitable food source for either the Beetles or their larvae, which has led to suggestions that the seeds somehow mimic the dung of a large Antelope, fooling the Beetles into burrying the seeds.

In a paper published in the South African Journal of Science on 26 July 2016, Jeremy Midgley and Joseph White of the Department of Biological Sciences at the University of Cape Town describe the results of an investigation into the relationship between the seeds of Ceratocaryum argenteum and the Dung Beetles.

Midgley and White placed piles of Ceratocaryum argenteum seeds beside a sand road in the De Hoop Nature Reserve in early in the morning after heavy rain events in February 2016. They found that two species of Dung Beetle, Epirinus flagellatus and Scarabaeus spretus, arrived at the seed stations within a few minutes of placing the seeds, and immediately began rolling the seeds away and burrying them. One specimen of Scarabaeus spretus even flew into a bag containing the seeds before they could be placed. Flesh Flies, Sarcophagidae, and Lesser Dung Flies, Sphaeroceridae, were also attracted to the seeds.

(a) Epirinus flagellatus rolling a Ceratocaryum argenteum seed; (b) Scarabaeus spretus rolling a seed (the arrow indicates a Sphaerocerid Lesser Dung Fly); (c) the large hole made by Scarabaeus spretus for burying several seeds (the arrow indicates the location of the Dung Beetle); and (d) a female Sarcophagid Fly on a seed. Midgley & White (2016).

Two Antelope species present in the De Hoop Nature Reserve, the Eland, Taurotragus oryx, and the Bontebok, Damaliscus pygargus. The two species have different diets, with the Bontenok favouring Grasses and the Eland being a browser with a mixed diet. 

This is a useful difference, as many tropical Grases use a different photosynthetic method to most other plants (which enables them to use less water in the process), as a side affect of which they tend to fix more of the lighter carbon isotope Carbon 12 (12C) and less of the heavier isotope Carbon 13 (13C), which results in the  tissues of animals which eat these Grasses having a distinct isotope signature; useful to archaologists trying to understand the diets of ancient populations and ecologists trying to understand the diets of animals. 

The larvae of Dung Beetles feed on undigested plant tissues within dung balls burried by their parents. This means that a Dung Beetle should have a carbon isotope signature which matches the dung of the animal on which it fed. Midgley and White analysed dung from both the Antelope species as well as a number of individuals of both Dung Beetle. Both Beetles had a carbon isotope signature closely matching that of the Eland dung, suggesting that this is their natural diet. Since other large Dung Beetles are present in the De Hoop Nature Reserve which did not pay any attention to the Ceratocaryum argenteum seeds, Midgely & White suggest that the seeds must specifically be mimicing the Eland dung, presumably be emiting chemical signatures (scents) detectable by the Beetles.

See also...

http://sciencythoughts.blogspot.co.uk/2016/04/onthophagus-clavijeroi-onthophagus.htmlOnthophagus clavijeroi & Onthophagus martinpierai: Two new species of Scarab Beetles from the Trans-Mexican Volcanic Belt.                                                          Mexico has an essentially tropical climate, but is...
http://sciencythoughts.blogspot.co.uk/2015/05/ateuchus-cujuchi-new-species-of-scarab.htmlAteuchus cujuchi: A new species of Scarab Beetle from Rodent burrows in Bolivia. Tuco-tucos, Ctenomys spp., are small South American Rodents which live their entire lives underground within underground burrow systems, never venturing to the surface. Studies of other Rodents with similar...
http://sciencythoughts.blogspot.co.uk/2014/09/a-new-species-of-scarab-beetle-from.htmlA new species of Scarab Beetle from Hardap Province, Namibia.                                    There are currently eight species of Scarab Beetles in the genus Scapanoclypeus, which is known from Namibia and western South Africa. They are... 
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Magnitude 5.7 Earthquake in Papua Province, Indonesia.

The United States Geological Survey recorded a Magnitude 5.7 Earthquake at a depth of 28.43 km, in the Van Rees Mountains of Papua Province, Indonesia, slightly after 4.20 pm local time (slightly after 7.20 am GMT) on Sunday 28 August 2016.An Earthquake of this size has the potential to cause considerable damage, however the area where it occurred is very remote and there are no reports of any damage or casualties at this time.

The approximate location of the 28 August 2016 Van Rees Mountains Earthquake. Google.

The tectonic situation underlying Papua Province is complex, with the island being made up of a number of small tectonic plates being squeezed between the larger Pacific and Australian plates. The area affected by the 6 April quake lies on the boundary between the Maoke Plate, which underlies much of Papua Province and the Woodlark Plate, which underlies much of the east of the island. Other parts of the island lie on the Bird's Head, Australian and South Bismarck Plates. To the north of Papua Province the Caroline Plate is being subducted in the Manus Trench, which is parallel to the northern shore of the island.

 The plates underlying Papua Province and the surrounding area, along with their directions and rates of movement. Wikipedia.

Witness accounts of Earthquakes can help geologists to understand these events, and the structures that cause them. The international non-profit organization 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/2015/08/injuries-reported-after-eruption-on.htmlInjuries reported after eruption on Manam Moto, Papua New Guinea.                    The Rabaul Volcano Observatory reported an eruption on Manam Motu, a volcanic island 13 km off the north coast of Papua New Guinea on Friday 31 July 2015, which started at about 11.30 am local time...
http://sciencythoughts.blogspot.co.uk/2013/11/landslides-kills-nine-in-papua-new.htmlLandslides kills nine in Papua New Guinea. Nine people have died after two landslides swept through the village of Kenagi, in Papua New Guinea's Eastern Highlands, late in the evening of Saturday 2 November 2013, and early in the morning of Sunday...
http://sciencythoughts.blogspot.co.uk/2013/05/another-worker-killed-in-fresh-grasberg.htmlAnother worker killed in fresh Grasberg Mine cave in.                                                            A worker has been killed in a cave in at the Freeport-McMoRan Copper & Gold operated Grasberg Mine in Indonesian West Papua, less than two weeks after an incident on 14 May 2013, in which 38 workers...
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Using zircon uranium-lead geochronology to understand the origins of the Miocene Sanya Formation beneath the South China Sea.

The Miocene Shanya Formation forms part of the geological sequence in the Yinggehai Basin, which underlies part of the northwestern South China Sea. The formation is 2950 m thick at its maximum, and is known to host a number of hydrocarbon reserves, making it of great interest to exploration geologists. The formation comprises shallow marine sedimentary deposits formed by the deposition of material washed from nearby terrestrial environments, however, like many offshore deposits, the processes that led to the formation of the Shanya Formation are poorly understood, making it hard to make predictions about where hydrocarbons might be found within these beds.

In a paper published in the journal Acta Geologica Sinica in February 2016, Wang Ce of the State Key Laboratory of Isotope Geochemistry at the Guangzhou Institute of Geochemistry and the University of the Chinese Academy of Sciences, Liang Xinquan, also of the State Key Laboratory of Isotope Geochemistry at the Guangzhou Institute of Geochemistry, and Fu Jiangang, Jiang Ying and Dong Chaoge, again of the State Key Laboratory of Isotope Geochemistry at the Guangzhou Institute of Geochemistry and the University of the Chinese Academy of Sciences, describe the results of a study in which zircon uranium-lead geochronology was used to develop an understanding of the origins of sedimentary material in the Shanya Formation.

Zircon is a mineral formed by the crystallization of cooling lavas. When it forms it often contains trace amounts of uranium, which decays into (amongst other things) lead at a known rate. Since lead (which has a much lower melting point) will not have been present in the original lava, it is possible to calculate the age of a zircon crystal from the ratio between these elements.

 A ziron crystal, about 250 µm in length. Wikipedia.

This has obvious uses for the dating of igneous rocks, but can also be useful in sedimentary geology, since it enables geochemists to link zircons found in sedimentary rocks to their sources (i.e. the igneous rocks from which they were eroded before being deposited in the sedimentary strata).

Wang et al. collected zircons from sandstones attributed to the Sanya Formation from drill cores in the northern, northeaster and eastern parts of the Yinggehai Basin. The first sample (from the north) yielded zircon uranium-lead dates with a very wide range of dates, though the most abundant were 274, 432 and 957 million years old, with smaller peaks in abundance at 793, 1966 and 2481. The second site (from the northeast) yielded a similar range of dates, with the commonest dates being 156 and 428 million years old and smaller peaks at 41, 239 and 733 million years old. The third site (the one in the east) produced zircons with a smaller range of dates, being much younger, with peaks at 99 and 238 million years old.

The youngest zircons present, the 41 million-year-old crystals in the second sample, are approximately the right age to be associated with melting and exhumation during a period of motion on the Red River Fault Zone, which runs through Yunnan Province and Vietnam, and which is a fault within the Yangtze Block that accommodates movement by the Indo-Australian Plate.

The zircons aged 99 and 156 million years old, found in the second and third drill cores, are consistent with the formation of the Yanshanian Granites on Hainan Island in the Late Jurassic-Cretaceous.

Zircons with dates of 230-250 million years old, again found in the second and third samples, are likely to have originated during the collision of the Indochina and Yangtze Blocks, and could have come from a wide range of sources in South China, Vietnam or Hainan Island.

Samples dating to about 430 million years ago, found in the first and second samples, are thought likely to be associated with the Caledonian Orogen, when the ancient continents of Laurentia, Baltica and Avalonia collided during the closure of the Iapetus Ocean; grains of this age are common in South China, but very rare on Hainan.

Grains 700-1000 million years old, again found in the first and second samples only, are likely to have formed during the Jinningian Movement, part of the breakup of the ancient supercontinent of Rodinia, and originated on the Yangtze Block.

Zircons 1966 and 2481 million years old, found only in the first sample, are likely to have formed during the origin of the Yangtze block.

Thus zircons in the sediments from the first and second drill cores are dominated by grains that originated from the Yangtze Block to the north (i.e. mainland China), while the third sample appears to contain mostly zircons that originated on Hainan Island, a source which also provided a significant minority of the material in the second sample.

Possible provenance directions of the Lower Miocene Sanya Formation in the Yinngehai Basin. Wang et al. (2016).

See also...

http://sciencythoughts.blogspot.co.uk/2016/08/significant-new-gold-deposits.htmlSignificant new gold deposits discovered on the Jiaodong Peninsula in Shandong Province, China.                                           The Jiaodong Peninsula of Shandong Province in northeast China...
http://sciencythoughts.blogspot.co.uk/2016/04/assessing-impact-of-land-reclamation-in.htmlAssessing the impact of land reclamation in the Spratly Islands.                                      The Spratly Islands are a widely distibuted archipelago of over 750 coral reefs, atols and islands in the South China Sea. Ownership of the islands is disputed between surrounding nations, with China, Taiwan, Thailand, Vietnam, Malaysia, the Philippines and...
http://sciencythoughts.blogspot.co.uk/2016/03/predicting-eruptions-in-monogenetic.htmlPredicting eruptions in monogenetic volcanic fields.                                                        Seismic activity and fumerol (gas) emissions are well established as predictors of eruptions on stratovolcanoes (volcanic mountains which undergo repeated eruptions), but predicting eruptions in...
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Sunday, 28 August 2016

Paleosisyra minor: A new species of Spongefly from Baltic Amber.

Spongeflies, Sisyridae, are Neuropteran Insects related to Dustywings and Brown Lacewings. The adults closely resemble Brown Lacewings, but the larvae are very different, being aquatic, which is unusual in Neuropterans, and parasitic on Freshwater Sponges and Bryozoans. There are about 60 species living today, but like other Neuropterans the group is ancient, with a fossil record going back to the Crecaceous, and modern Spongeflies are probably less diverse than the ancient members of the group.

In a paper published in the journal Zootaxa on 26 August 2016, Wilfried Wichard of the Institute of Biology at the University of Koeln, Sonja Wedmann of the Senckenberg Forschungsstation Grube Messel, and Thomas Weiterschan of Höchst im Odenwald describe a new species of Spongefly from Eocene Baltic Amber.

The new species is placed in the genus Paleosisyra, which includes two previous species described from Baltic Amber, and given the specific name minor, meaning 'small' in Latin, due to the small size of the specimen, which has a forewing length of only 3.5 mm (compared to 4.0-5.2 for other members of the genus. The species is described from a single well preserved male specimen preserved in a piece of almost clear Baltic Amber.

Paleosisyra minor. Male in dorsal view; right forewing apically distored, left forewing length 3.5 mm. Wichard et al. (2016).

See also...

http://sciencythoughts.blogspot.co.uk/2016/02/butterflies-of-jurassic-convergent.htmlButterflies of the Jurassic: Convergent evolution between Mesozoic Kalligrammatid Lacewings and modern Butterflies. Kalligrammatid Lacewings first appeared in the fossil record in the Middle Jurassic, about 160 million years ago, and disappeared in the Early Cretaceous about 115 million years ago. They were...
http://sciencythoughts.blogspot.co.uk/2015/12/glenochrysa-minima-new-species-of-green.htmlGlenochrysa minima: A new species of Green Lacewing from Western Australia.   The Neuroptera, or Net-winged Insects, first appeared in the Permian and reached their maximum diversity in the Permian, when they were the most numerous Insects...
http://sciencythoughts.blogspot.co.uk/2014/07/a-silky-lacewing-from-eocene-of.htmlA Silky Lacewing from the Eocene of Washington State.                                       Silky Lacewings (Psychopsidae) are a group of Neuropteran Insects that are rare today, with only...
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