Sunday, 30 April 2017

Heliconia berguidoi: A new species of Lobster-claw from Panama.

Lobster-claws, Heliconiaceae, are large Banana-like plants closely related to the Bird-of-Paradise Plants, Strelitziaceae, and sometimes known as 'False Bird-of-Paradise Plants'. The family comprises a single genus, Heliconia, found in the American tropics from Mexico through Central America and into the tropical forests of South America, as well as the islands of the Caribbean and Pacific, and parts of Indonesia, and have become naturalised in some other parts of the world, notably Florida, Thailand, and West Africa.

In a paper published in the journal Phytotaxa on 7 February 2017, Rodolfo Flores of the Programa de Maestría en Biología Vegetal at the Universidad Autónoma de Chiriquí, Carla Black of Volcán in Chiriquí Province, Panama. and Alicia Ibáñez of Gamboa in Colón Province, Panama, describe a new species of Lobster-claw from the Chucantí Private Forest Reserve in Chiriquí Province, Panama.

The new species is named Heliconia berguidoi, where 'berguidoi' in honour of the Panamanian biologist and conservationist Guido Cesar Berguido. The Plants reach 4.5-5.0 m in height, with clusters of up to five stems, each bearing a single large leaf. Flowers are born on pendant stems up to 220 cm in length, with clusters of about 25 red flowers up to 12 cm in length.

(A) Habit of Heliconia berguidoi. (B) Inflorescences touching the ground. Flores et al. (2017).

The new species was found only within the reserve, growing in the Serranía de Majé at an altitude of 800 m. It is possible that the Plant is also found in the surrounding area, though the forests outside the reserve are vulnerable to agriculture, Cattle ranching and logging. As the known range of the species is only four square kilometres, Flores et al. recomend that Heliconia berguidoi be listed as Critically Endangered under the terms of the International Union for the Conservation of Nature’s Red List of Threatened Species.

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Magnitude 1.7 Earthquake in Cumbria, northwest England.

The British Geological Survey recorded a Magnitude 1.7 Earthquake at a depth of about 4 km, close to the village of Aspatria, roughly 20 km to the south west of Carlisle in Cumbria, England, slightly before 10.40 am British Summertime (slightly before 9.40 am GMT) on Thursday 27 April 2017. There are no reports of any damage or injuries associated with this event, and nor would they be expected from such a small event, though it is possible it was felt locally.
 The approximate location of the 27 April 2017 Aspatria 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. However, while quakes in southern England are less frequent, they are often larger than events in the north, as tectonic pressures tend to build up for longer periods of time between events, so that when they occur more pressure is released.
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.  
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Asteroid 2017 GK4 passes the Earth.

Asteroid 2017 GK4 passed by the Earth at a distance of about 13 800 000 km (35.9 times the average distance between the Earth and the Moon, or 9.2% of the distance between the Earth and the Sun), slightly after 9.00 am GMT on Sunday 23 April 2017. There was no danger of the asteroid hitting us, though were it to do so it would have presented a considerable threat. 2017 GK4 has an estimated equivalent diameter of 90-280 m (i.e. it is estimated that a spherical object with the same volume would be 90-280 m in diameter), and an object towards the upper end of this size range 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 60 000 times as powerful as the Hiroshima bomb. Such an impact would result in an impact crater about 4 km in diameter and devastation on a global scale, as well as climatic effects that would last decades or even centuries.

The calculated orbit of 2017 GK4. Minor Planet Center.

2017 GK4 was discovered on 1 April 2017 (22 days after its closest approach to the Earth) by the University of Hawaii's PANSTARRS telescope on Mount Haleakala on Maui. The designation 2017 GK4 implies that it was the 111th asteroid (asteroid GK4) discovered in the first half of April 2017 (2017 G).

2017 GK4 has a 554 day orbital period and an eccentric orbit tilted at an angle of 16.4° to the plane of the Solar System, which takes it from 0.81 AU from the Sun (i.e. 81% of he average distance at which the Earth orbits the Sun) to 1.82 AU from the Sun (i.e. 182% of the average distance at which the Earth orbits the Sun, and considerably outside the orbit of 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). This means that close encounters between the asteroid and Earth are extremely common, with the last having occurred in April 2014 and the next predicted in May 2020 As an asteroid probably larger than 150 m in diameter that occasionally comes within 0.05 AU of the Earth, (474231) 2001 HZ7 is also classified as a Potentially Hazardous Asteroid. 

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Saturday, 29 April 2017

Landslide kills 24 in Osh Region of Kyrgyzstan.

Twenty four people, including nine children,are believed to have been killed when a landslide hit a village in the Osh Region of Kyrgyzstan on Saturday 29 April 2017. The landslip hit the village of Ayu in the Uzgen District at about 6.40 am local time, burying seven buildings beneath about a million cubic meters of mud and rubble. A further forty families living close to the area have been evacuated following the incident, and over 250 rescue workers are searching the area, but there is not thought to be any hope of recovering any of the victims alive.

The scene of the 29 April 2017 Ayu landslide. Red Crescent Society of Kyrgyzstan/AFP.

The incident happened following several days of heavy rainfall in the area; 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. Local authorities report that the village had been evacuated in March this year due to concerns about the stability of the hillslope, but people had begun to return to the area. The Uzgen District has a strongly seasonal climate, with a dry summer lasting from June to September, but high rainfall for most of the rest of the year. April is the wettest month, with rainfall typically exceeding 80 mm.

Wider view of the 29 April 2017 Ayu landslide. KABAR.

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Göbekli Tepe: Does an ancient Anatolian stone carving depict a cometary impact at the onset of the Younger Dryas.

The Younger Dryas is the name given to a period of abrupt cooling at the end of the last ice age, when temperatures, which had been rising for several thousand years, abruptly dropped for about a thousand years, and glaciers spread back into many areas from which they had disappeared. The cause of this cooling is unclear, and this uncertainty has led to several theories, with no evidence having emerged which strongly supports any one theory. One notable hypothesis is the proposition that the onset of the Younger Dryas may have been caused by a comet impacting into the Earth, an idea which has considerable popular appeal, despite being viewed with some scepticism by much of the scientific community. A number of lines of evidence have been put forward to suit this idea, but most are essentially self-referential, for example the extinction of the North American Megafauna and disappearance of the Clovis Culture, again in North America, events associated with the end of the Pleistocene and which are the sort of events we would expect around an abrupt change in climate, whatever the cause of that change (the extinction of the North American Megafauna was almost certainly the result of Human activity, but this does not rule out climate as an ultimate cause, as a sharp change in climate is likely to result in a similarly abrupt change in Human behaviour).

In a paper published in the journal Mediterranean Archaeology and Archaeometry on 16 March 2017, Martin Sweatman and Dimitrios Tsikritsis of the School of Engineering at the University of Edinburgh, examine the possibility that a series of carvings on a series of stone pillars at the Göbekli Tepe archaeological site in southeastern Turkey depict a comet or swarm of comets impacting the Earth.

Sweatman and Tsikritsis’ theory rests upon several lines of evidence. First of these is the date of the complex. This is based upon a carbon isotope date obtained from material from a plaster wall connecting the pillars at the site, which gives an age of about 11 530 before the present; or about 9515 BC.

Secondly Sweatman and Tsikritsis propose that several animal symbols on the stone pillars at the site are representations of asterisms (constellations), i.e. groups of stars which appear close to one another in the sky, and which people have long interpreted as representations of animals or other important objects, for example a Scorpion is identified as a representation of the constellation of Scorpius, while a Vulture- or Eagle-like Bird as a representation of the constellation of Sagittarius. Furthermore, a disk-shaped marking is close to the wing of the Sagittarius-Bird, which Sweatman and Tsikritsis interpret to indicate that the Sun was in the constellation of Sagittarius at one of the solstices or equinoxes. They observe that the Sun is currently in Sagittarius during the Winter Solstice, that it was in Sagittarius during the Autumnal Equinox around 4350 BC, that it was in Sagittarius during the Summer Solstice in 10 950 BC and the Spring Equinox around 18 000 BC. Moreover, they note that three other symbols present (a Frog, an Ibex and a Bird) represent the constellations Virgo, Gemini and Pisces, constellations which would have fallen on the Spring Equinox, Winter Solstice and Autumn Equinox, respectively. 

Pillar 43, Enclosure D, also known as the Vulture Stone of Göbekli Tepe. Sweatman & Tsikritsis (2017).

Finally Sweatman and Tsikritsis provide several lines of evidence that they suggest may represent cometary impacts on the Earth. These include the shape of a belt buckle worn by a human figure, which resembles the shockwave generated by a bolide moving at hypersonic speeds. Secondly a Fox symbol on one of the pillars could potentially represent a comet, the tails of Foxes having been used to symbolise comets in some (much later) art (though Sweatman and Tsikritsis admit this is dubious). Thirdly several Snakes are present on pillars at the site, which may be symbols of death and destruction (Snakes have a poor representation in mythology; in Ancient Egypt, a Snake was the symbol of Set, who murdered the fertility god Osiris, while in Judeo-Christian mythology a Snake tempted Adam and Eve to eat from the tree of forbidden knowledge, leading to their being expelled from paradise). Fourthly the belt symbol has an H-shaped motif, which may represent the stars around the pole around 10 950 BC combined with crescent shapes which may represent phases of the Moon, which taken together could indicate the night sky or divine beings in the sky. Fifthly a broach or pendant has a symbol which appears to represent an eclipse, which Sweatman and Tsikritsis suggest should not be taken as a literal indication of an eclipse, but rather a symbolic representation of a darkening of the Sun, possibly caused by a cometary impact. Finally, a headless human figure is present on one of the pillars, which may represent an event leading to massive loss of life. 

Close-ups of pillar 18, Enclosure D. Part (a) shows the belt and belt buckle), part (b) shows the Fox held under its right arm, while part (c) shows the ‘eclipse brooch’ under the head. Sweatman & Tsikritsis (2017).

From this evidence Sweatman and Tsikritsis conclude that symbols at the Göbekli Tepe complex represent a cometary impact around the Summer Solstice in 10 950 BC, which was constructed over a thousand years after the event, in about 9515 BC. Furthermore, they suggest such an impact could be associated with the Taurid Meteor Shower, which would have passed at about this time. 

However there are several problems with this scenario, both regarding the dating and the symbolism of the site.

Firstly the date ascribed to the site needs to be viewed with some suspicion, as it would make the Göbekli Tepe complex several thousand years older than any similar structure, with a complex pattern of carved relief images with apparent symbolic meaning. Such a remarkable claim requires exceptional evidence to support it, which is not provided by a single carbon date obtained from material within a wall. Isotope dating methods are generally considered to be extremely reliable, but not infalable, and a number of different readings would usually be used to establish a reliable date, whereas Sweatman and Tsikritis cite an earlier study which used only a single reading. If this were accepted, a date from a plaster wall would not be considered reliable unless it can be established that the wall does not contain any older material. Furthermorre, even if this date could be taken as reliable, it is a thousand years after the date of the supposed impact, requiring precise astronomical information to have been preserved through oral history for a thousand years, through a time of global cataclysm with radical changes in climate. 

Pillar 2 from Enclosure A, with three animal symbols in series. Sweatman & Tsikritsis (2017).

Next there is the symbolism of the carvings, which even if the interpretation of the symbols as constellations is accurate (and this does not seem unreasonable) cannot necessarily be used to imply a cometary strike on a precise date for a number of reasons. Firstly the dating implied from the inscriptions is somewhat speculative; a disk close to a symbol representing Sagittarius does not necessarily represent the Summer Solstice occurring in Sagittarius; potentially it could mean ‘when there is a Full Moon in Sagittarius’ or just ‘when the Sun is in Sagittarius’ (which could well have indicated a time of year to the monument-makers, who are unlikely to have known that the solstices progressed through the constellations over thousands of years); the positions of Virgo, Gemini and Pisces relative to Sagittarius cannot be used to make inferences about the age of the carvings or the events they depict, as these will always be three, six and nine months ahead and behind, regardless of where the solstices fall. 

Next there is the interpretation of the symbols. The interpretation of some of the symbols as representations of constellations does not seem unreasonable, but can only possibly be a hypothesis; there is no actual proof of this idea. The idea that all the symbols represent astronomical phenomena is even more untestable. None of the symbols appear to directly represent comets or meteors, and even if the inscriptions do represent a series of constellations combined with dire warnings about some terrible catastrophe (which in itself is largely speculation based upon the idea that figures such as Snakes represent something bad happening), then plenty of more recent peoples have made associations between the stars and strictly terrestrial disasters, and there would be no reason to assume that the builders of Göbekli Tepe would not have done the same.

Pillar 38 from Enclosure D, with three animal symbols in series. Sweatman & Tsikritsis (2017). 

Finally there is the belt buckle itself. A buckle is essentially a metal clip on a leather or cloth strip, which can hold the strip in place while bearing some strain, either to support the weight of weapons or tools hung from the belt or to hold garments up. This requires a reasonable level of metal-making skill; a weak metal buckle will rapidly snap or bend. In Europe this seems a familiar part of the ancient tool kit, both the Greeks and Romans used buckles, but older civilizations did not; buckles were unknown to the Egyptians of the Old Kingdom and the peoples of Ancient Mesopotamia, they were never invented in the New World, nor in Medieval Japan, where people had advanced metallurgical skills but a shortage of metals. Of course the interpretation of this object as a buckle could be questioned, but this seems a more reasonable interpretation than that ascribed to many other symbols at the site (an ovoid shape on a band separating the upper and lower parts of a Human body at the waist), which raises serious problems with the interpretation of Göbekli Tepe as a particularly ancient site. 

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