Sunday, 7 February 2016

Eruption on Sakurajima volcano, Japan.

Sakurajima, an active volcano on Kyushu Island, Japan, underwent a spectacular eruption on Friday 5 February 2015, producing an ash column about 2.2 km in height as well as throwing incandescent material (glowing hot ash and/or rocks) several hundred meters from the crater. There are no reports of any damage or injuries following the event, but local authorities have placed a 2 km exclusion zone around the volcano as a precaution. 

An incandescent eruption on Sakurajima on 5 February 2016. ANP.

Sakurajima is one of Japan's most active volcano's with around 700 eruptions last year (the exact figure is hard to derive as eruptions often occur close together and may run into one another), though there have been no major events since September. This high level of activity is impressive, but prevents Sakurajima from becoming a major hazard, partly because people tend not to build homes or other structures too close to very active volcanoes, but also because the high levels of activity tend to prevent pressure within the volcano from building up to dangerous levels, which can lead to sudden very large and destructive eruptions on less obviously active volcanoes.

The location of the Sakurajima volcano. Google Maps.

Japan has a complex tectonic situation, with parts of the country on four different tectonic plates. Kyushu Island lies at the northeast end of the Ryukyu Island Arc, which sits on top of the boundary between the Eurasian and Philippine Plates. The Philippine Plate is being subducted beneath the Eurasian Plate, in the Ryukyo Trench, to the Southeast of the Islands. As it is drawn into the interior of the Earth, the tectonic plate is partially melted by the heat of the Earth's interior, and liquid magma rises up through the overlying Eurasian Plate to form the volcanos of the Ryukyu Islands and Kyushu.

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

See also... and pyroclastic flow on Sakurajima, Kyushu.                                             The Sakurajima Volcano, situated on an island in Kagoshima Bay, Kyushu, underwent a large explosive eruption on the morning of Friday 4 October 2013, producing a 4 km high ash column and triggering... city covered in ash by eruption on Sakurajima Volcano.                                      An eruption on Sakurajima Volcano, situated on an island in Kagoshima Bay, Kyushu, has coated the city of Kagoshima in a layer of ash. The eruption... on Sakurajima.                              On 9 August 2013 the Japan Meteorological Agency reported a 50 minute eruption on Sakurajima Volcano, which is one of Japan's most active and sits on an island in Kagoshima Bay, Kyushu Island, which produced a 3.5 km high ash column, as well...
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Twenty four confirmed deaths following Taiwan Earthquake.

Twenty four people have been confirmed dead and over five hundred have been injured with over a hundred more are still missing following an Earthquake in Taiwan that led to the collapse of a seventeen story residential building. The event happened slightly before 4.00 am local time on Saturday 6 February 2016 (slightly before 8.00 pm on Friday 5 February GMT), and was measured by the United States Geological Survey as having a magnitude of 6.7 and occurring at a depth of 10 km beneath the eastern part of the city of Tianan in the southern part of the country.

Rescue workers at the scene of the 6 February 2016 Tianan building collapse. Ashley Pon/Getty Images.

Taiwan has a complex tectonic setting, lying on the boundary between the Eurasian and Philippine Plates, with the Eurasian Plate being subducted beneath the Philippine Plate in the South and the Philippine Plate being subducted beneath the Eurasian in the East. Subduction is not a smooth process even in simple settings, with plates typically sticking together as pressure from tectonic expansion elsewhere builds up, then suddenly breaking apart and shifting abruptly, causing Earthquakes.

 The motion of the tectonic plates beneath Taiwan. The University of Memphis.
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.
 The approximate location of the 6 February 2016 Tainan Earthquake. Google Maps.
See also... 4.7 Earthquake in central Taiwan. The Taiwan Central Weather Bureau reported a Magnitude 4.7 Earthquake at a depth of 7.4 km in the countries Central Mountain Range, slightly before 0.45 am local time on Wednesday 15 January 2014... least one person killed by Taiwan Earthquake.                                                    A Magnitude 6.2 Earthquake at a depth of about 20 km struck central Taiwan slightly before 1.45 pm local time (slightly before 5.45 am GMT) on Sunday 2 June... least one person dead following Magnitude 6.0 Earthquake in Taiwan.                          Central Taiwan was struck by a Magnitude 6.0 Earthquake at a depth of 20.7 km, slightly after 10.00 am local time (slightly after 2.00 am GMT) on Wednesday 27 March 2013, according to the...
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Three still missing following collapse at South African gold mine.

Three people are still missing following a collapse at the Vantage Goldfields operated Makonjwaan Lily Gold Mine near Low's Creek in Mpumalanga at about 8.40 am local time on Friday 5 February 2015. The incident was reportedly caused by the failure of an underground pillar, which in turn led to a roof collapse, trapping 87 miners below ground. All of these workers have now been rescued successfully with only miner injuries, however the collapse also led to the formation of a sinkhole (surface hole created by the formation of a void bellow ground)which swallowed a mobile office building in which two women and a man were working, It is these three mine employees, understood to have been involved in issuing miners with safety equipment, that are still missing and are still being actively sought by rescue teams. All production at the mine has ceased until further notice, and workers are being offered trauma counseling.

Friends and relatives of the missing mineworkers waiting for news at the Makonjwaan Lily Gold Mine. AP.

The Makonjawaan Lily Gold Mine is a shallow pit mine with an estimated reserve of about 0.35 million ounces of gold and an annual production of about 35 000 ounces per year. It accesses an ore body within the Barberton Greenstone Belt, an ancient (more than 3 billion years old) section of basement rocks underlying parts of South Africa and Swaziland, which forms the eastern part of the Kaapvaal Craton, one of the ancient blocks from which the continent of Africa was assembled. 

The approximate location of the Makonjwaan Lily Gold Mine.  Google Maps.

See also... miners rescued safely after fire at South African gold mine.                                            All the workers who were bellow ground at the Harmony Gold operated Kusasalethu Mine, at Carletonville near Johannesburg in South Africa, when an underground fire broke out on Sunday 22 February 2015 have... least one fatality following Magnitude 5.5 Earthquake in northern Free State, South Africa.                                                          The South African Council for Geoscience recorded... potential for geothermal energy in Limpopo Province, South Africa.                    South Africa is the largest producer of carbon dioxide on the African continent, and as such has committed itself to ambitious emission reduction plans, aiming to cut production of the gas by 40% by 2050. At the same...
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Saturday, 6 February 2016

Asteroid 2016 AK193 passes the Earth.

Asteroid 2016 AK193  passed by the Earth at a distance of 9 157 000 km (23.8 times the average distance between the Earth and the Moon, or 6.12% of the average distance between the Earth and the Sun), slightly before 2.00 a m GMT on Saturday 30 January 2016. There was no danger of the asteroid hitting us, though had it done so it would have presented a considerable threat. 2016 AK193 has an estimated equivalent diameter of 71-240 m (i.e. a spherical body with the same mass would be 71-240 m in diameter), and an object towards the upper end of this range would pass through the atmosphere and directly impact the ground with a force of about 500 megatons (about 30 000 times the explosive energy of the Hiroshima bomb), causing devastation over a wide area and creating a crater over 3 km across, and resulting in global climatic problems that could last for years or even decades.

 Image of 2016 AK193 on 15 January 2016 from Monteviasco in Italy. The asteroid is the point in the center of the picture. The longer lines are stars, their elongation being caused by the telescope tracking the asteroid over the length of the exposure. Stazione Astronimica di Monteviasco.

2016 AK193 was discovered on 15 January 2016 (fifteen days before 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 2016 AK193 implies that it was the 4836th asteroid (asteroid K193) discovered in the first half of January 2016 (period 2016 A).

The calculated orbit of  2016 AK193JPL Small Body Database.
2016 AK193 has a 296 day orbital period, with an elliptical orbit tilted at an angle of 17.4° to the plain of the Solar System which takes in to 0.63 AU from the Sun (63% of the distance at which the Earth orbits the Sun and considerably inside the orbit of the planet Venus) and out to 1.11 AU (11% further away from the Sun than the Earth). This means that close encounters between the asteroid and Earth are fairly common, with the last thought to have happened in August 2015 and the next predicted in October 2019. 2016 AK193 also has frequent close encounters with the planet Venus, with the last thought to have occurred in August 2015 and the next predicted for June 2022. Although it does cross the Earth's orbit and is briefly further from the Sun on each cycle, 2015 XX169 spends most of its time closer to the Sun than we are, and is therefore classified as an Aten Group Asteroid. As an asteroid probably larger than 150 m in diameter with an orbit that brings it to within 0.05 AU (750 000 km) of the Earth, 2016 AK193 is also classified as a Potentially Hazardous Asteroid. 

See also... (438661) 2008 EP6 passes the Earth.                                                         Asteroid (438661) 2008 EP6 passed by the Earth at a distance of 7 505 000 km (19.5 times the average distance between the Earth and the Moon, or 5.02% of the average distance between the Earth and the... 2016 AH164 passes the Earth. Asteroid 2016 AH164 passed by the Earth at a distance of 26 660 km (0.08 times the average distance between the Earth and the Moon, or 0.02% of the average distance between the Earth and the Sun; 6660 km above the orbit at which the satellites supporting... 2016 AO8 passes the Earth.     Asteroid 2016 AO8 passed by the Earth at a distance of 18 950 000 km (49.4 times the average distance between the Earth and the Moon, or 12.7% of the average distance between the Earth and the Sun), slightly before 0.55 am GMT on Saturday 2...

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Friday, 5 February 2016

Butterflies 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 found more-or-less exclusively in Eurasia, and are thought to have been closely related to Neuropteran groups such as Antlions, Owlflies, Silky-winged Lacewings, and Spoon and Thread-winged Lacewings. However they show a suite of features unlike any other Neuropteran group, including large conspicuous wings (with the largest species reaching 160 mm in wingspan), scales on the wings, eyespots, and siphoning mouthparts, features which have led many to compare them to modern Butterflies, a group which appeared in the fossil record during the Early Eocene about 56 million years ago, but which are estimated from molecular studies to have appeared between 70 and 80 million years ago in the Late Cretaceous. Neuropterans (Lacewings) and Lepidopterans (Butterflies and Moths) are related, but are thought to have diverged in the Middle Carboniferous, about 320 million years ago, so any similarities between Kalligrammatid Lacewings and Butterflies must have evolved convergently in the two groups in response to similar ecological pressures. 

In a paper published in the Proceedings of the Royal Society Series B: Biological Sciences on 3 February 2016, a team of scientists led by Conrad Labandeira of the College of Life Sciences at Capital Normal University and the departments of Paleobiology and Mineral Sciences at the National Museum of Natural History examine a series of Kalligrammatid Lacewings from three Mesozic Insect-bearing deposits.

The three localities examined are all fine-grained lake deposits in Asia. The oldest is the Jiulongshan Formation of Inner Mongolia, dated to 164-165 million years ago (late Middle Jurassic), the middle deposit is the Karabastau Formation of eastern Kazakhstan, thought to be about 155 million years old (Late Jurassic), while the youngest locality is the Yixian Formation of Liaoning Province, which produces Insects ranging in age from about 128.2 to 121.6 million years, with the majority of the specimens dated to about 125 million years ago (Early Cretaceous).

Kalligrammatid structural diversity. Specimens are from the late-Middle Jurassic Jiulongshan Formation (JIU), China; Late Jurassic Karabastau Formation (KAR), Kazakhstan; and mid-Early Cretaceous Yixian Formation (YIX), China. At (a–i) are nine species showing general habitus. Arrows indicate proboscis tips. (a) Kalligramma circularia (JIU); (b) Affinigramma myrioneura (JIU); (c) Affinigramma myrioneura (JIU); (d) Kallihemerobius feroculus (JIU); (e) Oregramma aureolusa (YIX); (f) Ithigramma multinervia (YIX); (g) Abrigramma calophleba (JIU); (h) Kalligramma brachyrhyncha (JIU); and (i) Oregramma illecebrosa (YIX). (i–k) Lateral views of ovipositor structure in Oregramma illecebrosa above: (i) intact specimen; (j) complete ovipositor and posteriormost abdominal segments; and (k) lateral valve pairs. (l–q): five Kalligrammatid wing eyespot and spot types. (l ) Type 1 wing eyespot with two outer rings and ca 15 contiguous ocules surrounding a central pigmented disc (Oregramma illecebrosa, YIX); (m) Type 2 wing eyespot with a single outer ring, light-hued inner area, and uninterrupted, pigmented central disc with surrounding, non-contiguous ocules (Kallihemerobius almacellus, JIU); (n) Type 2 eyespot similar to (M) (Kallihemerobius feroculus, JIU); (o) Type 3 wing eyespot with a light-hued circular area and a few, variably sized ocules in a darkly pigmented central disc (Ithigramma multinervia, YIX); (p) Type 4 wing eyespot contains a few ocules and others surrounding a pigmented central disc, a light-hued inner area and surrounding, dark outermost ring (Kalligramma circularia, JIU); and (q) Type 5 wing spot of a circular, pigmented central disc (Kallihemerobius aciedentatus, JIU). Scale bars: solid, 10 mm; striped, 1 mm. Labandeira et al. (2016).

Labandeira et al. began by examining the distribution of Butterfly-like features among different Kalligrammatid groups. The earliest and most primitive group to appear were the Sophogrammatinae. These retain mandibles similar to those seen in other Lacewings, and lack any of the other Butterfly-like features seen in more derived members of the group, but are apparently the group from which other, more advanced Kalligrammatids are derived.

Four more derived groups of Kalligrammatids have been identified; the Kalligrammatinae, comprising five genera including the specious Kalligramma, which retain small mandibles as well as having siphon-like proboscises. These mandibles are thought to have been used for pollen handling, in a similar way to those of the modern Spoon and Thread-winged Lacewings and Micropterigid Moths. The more derived Kallihemerobiinae comprises six genera, while the Meioneurinae comprises the single genus Meioneurites, and the Oregrammatinae comprises three genera including the highly derived Oregramma.

Eyespots are found in all the Kalligrammatid groups except the Sophogrammatinae. In modern Butterflies these are a defensive mechanism used against predators such as Mantises and Birds, which can be used to either startle a would-be predator or deflect an attack away from the body (Butterflies can lose fairly large proportions of their wings and still fly). Labandeira et al. divided these into six levels of complexity, ranging from simple dark patches to more complex forms with central disks surrounded by rings of pigment and whitish, oval-shaped ocules and rings. However these different spot patterns appeared to have no particular distribution within the derived Kalligrammatid groups, suggesting that once spots had appeared, gaining and losing complexity was accomplished numerous times within different lineages. This at first seems a non-useful result, as it does not allow the tracing of developing complexity within the group, however this is also the pattern seen within Butterflies, strongly supporting the idea that Kalligrammatids shared a similar ecology to Butterflies.

Phylogenetic context of wing spots and eyespots in mid-Mesozoic Kalligrammatids, with comparisons to modern Lepidopterans. The best preserved fossil material was used for this analysis. (a) Most parsimonious tree of Kalligrammatidae phylogeny, with right forewing eyespot/spot condition mapped onto terminal clades and likely wing spot and eyespot origins. Wing eyespot and spot type symbols are at upper-left; crosses are eyespot/spot absences. (b–g) Examples of right forewings with wing eyespots or spots from mid-Mesozoic Kalligrammatidae (b–f ), and modern Psychopsidae (g). These taxa correspond to a Type 1 eyespot (b), Type 2 eyespot (c), Type 3 eyespot (d ), Type 4 eyespot (e) and two Type 5 double spots (f ) matched by two spots in modern Psychopsid (red arrows) in (g). Kalligrammatid wing eyespots and spots are compared to modern Lepidoptera in (h–k), of butterfly species with Type 6 eyespots (h) and multiple Type 5 spots (i); moth lacking wing spots or eyespots ( j ); and modern Owl Butterfly eyespot (k), showing pigmentation similar to Type 2 and 3 eyespots (b), indicated by arrow pointing to an ocule series and longitudinal wing vein. Scale bars: solid, 10 mm; striped, 1 mm. Labandeira et al. (2016).

Wing scales were absent in the Sophogrammatinae but present in all the derived Kalligrammatid groups, as well as in all Lepidoptera (Butterflies and Moths). Scales seem to have appeared early in the history of the Kalligrammatinae and are present in all later members of derived groups. These scales take two forms, larger elongate scales on the major wing veins, and smaller flatter scales between the veins. This is different to the pattern seen in modern Lepidoptera, where scales are absent from the major veins.

Proboscises are found in many Insect groups, but those of Kalligrammatids are notably similar to those of Butterflies in a number of ways; they were long (8-20 mm) and appear to have been flexible and lacked stylets or other piercing structures, with some specimens being hair covered and others smooth. This similarity to the range of shapes found in Butterflies is taken as evidence of a similar lifestyle, sucking nectar or a similar substance from flowers or another plant organ. Kalligrammatids even appear to have had pump-like sucking organs in the frontal part of the head, similar to those of Butterflies.

Gross mouthpart diversity and proboscis variation in Kalligrammatid Lacewings from the Middle Mesozoic of Eastern Asia. Drawings and digital images of Kalligrammatid taxa from the late Middle Jurassic (Jiulongshan Formation, 165 Ma, JIU) of northeastern China (c, d, f, h, m, o–t, v–x), middle Late Jurassic (Karabastau Formation, 155 Ma, KAR) of Kazakhstan (l), and middle Early Cretaceous (Yixian Formation, 125 Ma, YIX) of northeastern China (a, b, e, g, i–k, n). All overlay drawings are standardized to a scale of 5 mm (double diamond scale bar) to show size relationships; head and mouthpart elements are color identified to legend at upper left. (a, g) Abrigramma calophleba (YIX, dorsal view); (b, e) Oregramma illecebrosa (YIX, dorsal view), with food canal and subterminal constriction (arrow); (c, q) Kallihemerobius aciedentatus (JIU, dorsal view); (d, m) Kallihemerobius almacellus (JIU, dorsal view); (f, s) Affinigramma myrioneura (Jiulongshan, dorsal view); (h, w) Kalligramma brachyrhyncha (Jiulongshan, dorsal view); (i) Oregramma aureolusa (YIX, ventral view), with prominent maxillary stipites (mxst); (j) Oregramma sp. (YIX, oblique lateral view); (k) Ithigramma sp. (YIX, lateral view); (l) Meioneurites spectabilis (KAR, left lateral view); (n) Ithigramma multinervia (YIX, right oblique view); (o) Kalligramma circularia (JIU, right lateral view); (p) Kallihemerobiinae gen. et sp. indet. (JIU, dorsal view); (r) Affinigramma myrioneura (JIU, left lateral view); (s) Affinigramma myrioneura (JIU, frontal view); (t) Kallihemerobius feroculus (JIU, ventral view), with modified mandibles (md) adjacent the labial plate (la) and associated bisaccate pollen, probably Pinaceae, near the left mandible; (u) Ventral view of mandibles and labial plate of an extant, pollinating South African species of Nemopteridae, for comparison to (T); (v) Another specimen of Kalligramma circularia (JIU, dorsal view); (x) Kalligramma sp. (JIU, dorsal view). Scale bars: striped, 1 mm; dotted, 10 mm. Labandeira et al. (2016).

Angiosperms (Flowering Plants) have a long symbiotic relationship with Butterflies (and some other Insect groups), but are unlikely to have been ecological partners with Kalligrammatids, a group which appeared in the Middle Jurassic and disappeared as the Angiosperms came to prominence in the Cretaceous. Of the three formations examined in the study only the youngest, the Yixian Formation, has produced Angiosperm fossils at all, and these were small aquatic plants without tubular flowers that would require probing proboscises. However a number of other Plants with flower-like structures were present in the Mesozoic, including the extant Cycads and the extinct Bennettitaleans (Cycadoids) and Caytonialeans (Seed Ferns), all of which produced tube-like structures.

Of these groups the Bennettitaleans seem the most likely partners for the Kalligrammatids, with species known from all the Kalligrammatid-producing deposits and many specimens known from Eurasia within the Kalligrammatid time range that had tubular structures through which the ovules could be reached by an organ of similar size to a Kalligrammatid proboscis, and apparent secretary glands, tentatively identified as nectaries, positioned bellow the pollen sacs.

Plant associations of Kalligrammatids. (a–f) are palynomorphs associated with Kalligrammatid taxa; (a) cf. Chasmatosporites of possible Cycadales affiliation; (b) tetrad of Classopollis cf. Classopollis annulatus of the extinct conifer Cheirolepidaceae; (c) Cycadopites nitidus attributable to Bennettitales, Cycadales, Czekanowskiales, Ginkgoales or Pentoxylales; (d) Vitreisporites pallidus of Caytoniales; (e) epifluorescence image of a Classopollis cf. Classopollis annulatus on a foreleg tarsus of Meioneurites spectabilis (KAR); and (f) Gleicheniaceous Fern spore. (a–e) Are pollen macerated from sedimentary matrix adjacent to Kallihemerobius feroculus (JIU). (g) The Bennettitalean male strobilus Weltrichia sp. (h) The earlier occurring Bennettitalean female strobilus Williamsonia sp. (i) Reconstruction of specimen on a Bennettitalean host and probing a Williamsonia. Scale bars: solid, 10 mm; striped, 1 mm; dotted, 10 µm. Labandeira et al. (2016).

See also... new species of Osmylid from the Middle Jurassic Daohugou Biota of Inner Mongolia. Osmylids (Osmylidae) are a group of Neuropteran Insects with a fossil record dating back to the Early Jurassic and are still in existence today. They appear to have been at their most numerous and diverse in the Middle-Late Jurassic, with a number of lineages apparently disappearing at the... new species of Snakefly from the Middle Jurassic of Inner Mongolia.                    Snakeflies (Raphidioptera) are a group of carnivorous flying insects related to the Lacewings, Antlions and Alderflies. They have long life cycles, with a number of larval stages, but still feed as adults. Modern Snakeflies are found throughout Europe and Temperate Asia... new species of Split-foot Lacewing from the Middle Jurassic of Inner Mongolia.                 The Split-foot Lacewings (Nymphidae) are the oldest group of...
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Thursday, 4 February 2016

Lycopsid Trees from the earliest Late Devonian of Svalbad Island, Norway.

The evolution of Trees is considered to be a key development in the colonization of land by life, creating a range of new habittats as well as raising oxygen levels and stabilizing soils for the first time. The earliest known fossil forest comes from the late Middle Devonian of Gilboa in New York State, and comprises a diverse assemblage of trees including Archaeopteridaleans (trees with woody trunks and leafy branches probably related to living Conifers), Pseudosporochnaleans (small to medium trees showing some morphological similarity to living Tree Ferns and Palms), and Lycopsids (Giant Club Mosses). Lycopsid Trees are known from a variety of other fossil forest sites, as well as individual floated Trees in marine sediments through the Late Devonian, and were a major part of the flora of the Carboniferous Coal forests.

In a paper published in the journal Geology on 24 November 2015, Christopher Berry of the School of Earth and Ocean Sciences at Cardiff University and John Marshall of the National Oceanography Centre at the University of Southampton discuss a fossil Lycopsid forest from the Plantekløfta Formation at Munindalen on Svalbard Island in the Norwegian Arctic.

The Plantekløfta Formation has previously been described as being Latest Devonian in age, but examination of palynological evidence (preserved pollen and spores) by Berry and Marshall leads them to conclude that the deposits in fact date from the earliest Late Devonian, making these deposits only a little younger than those at Gilboa.

The formation is exposed at three localities, each showing numerous Lycopsid stumps preserved in situ, many having extensive root systems as well as variable amounts of upright trunk, with the largest trunks being about  100 mm across. These have previously been described as Archaeosigillaria, but which Berry and Marshall consider to belong to the species Protolepidodendropsis pulchra, which has previously only been described from isolated specimens from marine deposits identified as floating logs.

In-situ Lycopsid fossils. (H) Locality AF3, partial trunk in situ, base sheared by small fault (arrow), showing variation of level of preservation in cortex from oval leaf base parenchyma at base to diamond-shaped leaf bases at top. (I) Locality AF1, upright trunk with slightly flared base. (J,K) Locality AF2 Sandstone cast base removed from loose shale, showing flaring of extreme basal portion and separation of diamond leaf bases by secondary expansion. Scale bars are 50 mm. Berry & Marshall (2015).

Although it is located within the Arctic Circle today, during the Devonian Svalbad was close to the equator, so that the forests of Plantekløfta would have been tropical in nature. The roots of the trees are preserved in a palaeosol (fossil soil), but the upper parts are preserved in a conglomerate; a sedimentary deposit comprising a mixture of rock types, typically associated with landslides, floods or similar catastrophic events. The upper layers of this contain amorphous organic matter, thought to have been formed in an anoxic lake. Berry and Marshall interpret this as being a rapidly subsiding lake basin with aluvial sediments being deposited by a river or river entering from the west and forming a fan or delta.

The trees apparently lived in monospecific stands (stands of a single species of tree), quite unlike the forests of Gilboa, which were diverse in nature with a diverse range of trees living alongside one another. Since the Gilboan forest is slightly older, this cannot imply that the Plantekløfta forest predates the evolution of a wider range of trees, suggesting that this a reflection of the forests ecology. This is contrary to modern expectations, with a diverse tree assemblage in Gilboa, thought to have had a dry temperate climate, but a low diversity forest in the wet tropics at Plantekløfta.

See also... first leaves; leafy plant fossils from the Early Devonian of South China.                 Plant leaves are split into two groups by botanists; microphylls, which are simple plates of undifferentiated cells, as found in Mosses and Liverworts, and megaphylls, or true leaves, which have cellular differentiation and veins; such structures... new species of Moss from the Permian of Brazil.                                                   Mosses (Bryophytes) are simple plants which lack vascular systems to pump water and nutrients from a root system, instead relying on what they can absorb through their leaves, and generally only reaching a few cm in height. This means that they are at their... Permian forest preserved in volcanic ash. Plants are an important part of all terrestrial ecosystems on Earth, and are abundant in the fossil record, but the relationship between plants in ancient environments is often unclear, since most plant fossils represent disarticulated specimens, removed from their life...
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Wednesday, 3 February 2016

Ethiopia experiences a rain of Fish.

The According to Dire Dawa Agriculture, Water, Mining and Energy Bureau has reported a ran of Fish falling in a number of locations in and around the city of Dire Diwa in northeastern Ethiopia which fell about 11.30 pm on Wednesday 20 January 2015. This has been widely proclaimed as a miracle locally, though experts from organizations such as the Ethiopian Agricultural Research Institute and Department of Meteorology at Haromaya University have been a pains to explain that this is a natural, if somewhat uncommon, phenomenon.

Fish which fell as rain in Dire Diwa, Ethiopia, on 20 January 2015. ECADForum.

Rains of Fish (and occasionally other small aquatic animals such as Amphibians) occur when tornadoes over bodies of water suck up volumes of water including the Fish. That this could lead to rains of Fish very far from the site seems counterintuitive, but tornadoes are capable of lifting heavy objects such as cars and even houses and throwing them considerable distances, and small animals such as Fish can be thrown kilometers into the air by such events, falling to Earth a long way from the site where they were picked up. 

The location of Dire Diwa.  Google Maps..

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. 

See also... house carried 100 m by tornado.          A house in Burnet County, Texas, has been lifted off its foundations by a tornado, then deposited 100 m away in a field with its occupants unharmed. The incident happened on the evening of Thursday 12 June 2014, when a tornado touched down close to the house... after Mumbai hit by freak waves. Parts of the Indian city of Mumbai are suffering from flooding after being hit by a series of freak waves on Thursday 12 June 2014. The waves occurred around high tide, and rose over four meters above expected levels, inundating low lying coastal parts of the city... in Namibia                                     The borders of modern Namibia were drawn up on a map at the Berlin conference of 1884, named of South West Africa, and given to Germany as a colony. The germans ruled it from then until 1915, when it was invaded by South African troops during the First World War.
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