Sunday 28 February 2021

Large iceberg calves from the Brunt Ice Shelf, Antarctica.

A huge iceberg (1270 km² or the size of the county of Bedfordshire) has broken off the 150m thick Brunt Ice Shelf, according to a press release issued by the British Antarctic Survey on 26 February 2021, almost a decade after scientists first detected growth of vast cracks in the ice.

The Brunt Ice Shelf is the location of British Antarctic Survey’s Halley Research Station. British Antarctic Survey glaciologists, who have been expecting a big calving event for at least a decade, say that the research station is unlikely to be affected by the current calving.  The 12 person team working at the station left mid-February by British Antarctic Survey Twin Otter aircraft.  The station is now closed for the Antarctic winter.

North Rift crack photographed by Halley team in January 2021. British Antarctic Survey,

The first indication that a calving event was imminent came in November 2020 when a new chasm, called North Rift, headed towards another large chasm near the Stancomb-Wills Glacier Tongue 35 km away. North Rift is the third major crack through the ice shelf to become active in the last decade.

During January, this rift pushed northeast at up to 1 km per day, cutting through the 150 m thick floating ice shelf.  The iceberg was formed when the crack widened several hundred metres in a few hours on the morning of 26 February, releasing it from the rest of floating ice shelf.

Map of Brunt ice shelf and Halley Research Station. British Antarctic Survey.

The glaciological structure of this vast floating ice shelf is complex, and the impact of ‘calving’ events is unpredictable.  In 2016, the British Antarctic Survey took the precaution of relocating Halley Research Station 32 km inland to avoid the paths of ‘Chasm 1’ and ‘Halloween Crack’.

Since 2017, staff have been deployed to the station only during the Antarctic summer, because during the dark winter months evacuation would be difficult.  ‘Chasm 1’ and ‘Halloween Crack’ have not grown in the last 18 months.

Jane Francis, Director of the British Antarctic Survey said 'Our teams at the British Antarctic Survey have been prepared for the calving of an iceberg from Brunt Ice Shelf for years. We monitor the ice shelf daily using an automated network of high-precision GPS instruments that surround the station, these measure how the ice shelf is deforming and moving.  We also use satellite images from European Space Agency, NASA and the German satellite TerraSAR-X.  All the data are sent back to Cambridge for analysis, so we know what’s happening even in the Antarctic winter, when there are no staff on the station, it’s pitch black, and the temperature falls below minus 50 °C. Over coming weeks or months, the iceberg may move away; or it could run aground and remain close to Brunt Ice Shelf.  Halley Station is located inland of all the active chasms, on the part of the ice shelf that remains connected to the continent. Our network of GPS instruments will give us early warning if the calving of this iceberg causes changes in the ice around our station.'

Simon Garrod, Director of Operations at the British Antarctic Survey added 'This is a dynamic situation.  Four years ago we moved Halley Research Station inland to ensure that it would not be carried away when an iceberg eventually formed.  That was a wise decision.  Our job now is to keep a close eye on the situation and assess any potential impact of the present calving on the remaining ice shelf.  We continuously review our contingency plans to ensure the safety of our staff, protect our research station, and maintain the delivery of the science we undertake at Halley.'

Halley VI Research Station is an internationally important platform for, atmospheric and space weather observation in a climate-sensitive zone.  In 2013, the station attained the World Meteorological Organization Global Atmosphere Watch Global station status, becoming the 29th in the world and 3rd in Antarctica.  

Halley VI Research Station sits on Antarctica’s Brunt Ice Shelf, which is up to 150 m thick. This floating ice shelf flows at a rate of up to 2 km per year west towards the sea where, at irregular intervals, it calves off as icebergs.  

Long-term monitoring of the natural changes that occur in the ice shelf has revealed changes, including  growth of a recently-formed chasm, the North Rift. Halley VI Research Station has been unoccupied during the last four winters because of the complex and unpredictable glaciological situation. 

Change in the ice at Halley is a natural process and there is no connection to the calving events seen on Larsen C Ice Shelfand no evidence that climate change has played a significant role.

During the 2016-17 Antarctic Summer season (Nov-March), in anticipation of calving, the eight station modules were uncoupled and transported by tractor to a safer location upstream of Chasm-1.

Over the summer 18/19, the British Antarctic Survey installed an autonomous power generation and management system, Halley Automation project, which provides a suite of scientific instruments with power even when we have no staff at the station. This system has proved effective in running through more than eight months of darkness, extreme cold, high winds and blowing snow and delivering important data back to UK.

There have been six Halley research stations on the Brunt Ice Shelf since 1956. 

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Magnitude 5.5 Earthquake off the coast of Peru.

The United States Geological Survey recorded a Magnitude 5.5 Earthquake at a depth of 9.7 km, roughly 81 km off the coast of Islay Province in Peru, slightly after 9.15 pm local time on Saturday 27 February 2021 (slighty after 2.15 am on Sunday 28 February, GMT). There are no reports of any damage or casualties associated with this event, although it was felt on the coast of southern Peru.

The approximate location of the 27 February 2021 Islay Earthquake. USGS.

Peru is on the west coast of South America and the western margin of the South American Plate, close to where the Nazca Plate, which underlies part of the east Pacific, is being subducted along the Peru-Chile Trench. The Nazca Plate passes under the South American Plate as it sinks into the Earth, this is not a smooth process and the plates repeatedly stick together then break apart as the pressure builds up, causing Earthquakes. As the Nazca Plate sinks further it is partially melted by the friction and the heat of the Earth's interior. Some of this melted material then rises through the overlying South American Plate, fuelling the volcanoes of Peru and neighbouring countries.

The subduction of the Nazca Plate beneath the South American Plate, and how it causes Earthquakes and volcanoes. Pacific Earthquake Engineering Research Center.

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Four-wheeled ceremonial chariot unearthed in an area of Pompeii targetted by looters.

The Archaeological Park of Pompeii and the Public Prosecutor’s Office of Torre Annunziata have released a press statement announcing the discovery of an extraordinary find, which has emerged intact from the excavation of the suburban Villa of Civita Giuliana, beyond the walls to the north of the ancient city of Pompeii, as part of the joint operations launched in 2017 and in accordance with the Memorandum of Understanding signed in 2019, which sought to combat illegal activities which had been conducted in the area. A large ceremonial chariot with four wheels, along with its iron components, beautiful bronze and tin decorations, mineralised wood remains and imprints of organic materials (from the ropes to the remains of floral decoration), has been discovered almost intact in the portico facing the stable where, in 2018, the remains of 3 Equids, including a Horse still in its harness, had already been found.

Ceremonial chariot unearthed at the suburban Villa of Civita Giuliana, Pompeii. Archaeological Park of Pompeii.

This is an exceptional discovery, not only because it adds an additional element to the history of this dwelling and the story of the last moments in the lives of those who lived in it, as well as more generally to our understanding of the ancient world, but above all because it represents a unique find, which has no parallel in Italy thus far, in an excellent state of preservation.

The ongoing excavation project has a dual objective: firstly, to cooperate with the investigations of the Public Prosecutor’s Office of Torre Annunziata, in order to bring an end to the looting of cultural heritage by perpetrators who had dug several tunnels in the area in order to intercept archaeological treasures, and secondly, to reveal one of the most significant villas of the Vesuvian area and to protect it from further looting.

The excavations, which have also allowed the Archaeological Park of Pompeii to verify the extent of the illegal tunnels and the damage they have inflicted on cultural heritage, have been constantly accompanied by stabilisation and restoration operations on what has steadily emerged. Indeed, from the start, the excavation has been characterised by considerable technical-operational complexity, since the rooms to be studied are partially below and alongside modern dwellings, with all of the consequent structural and logistical difficulties such a situation entails.

The interventions which have been carried out over recent months have required careful planning on the part of an interdisciplinary team composed of archaeologists, architects, engineers, restorers, vulcanologists and specialised workers but also, as the excavation proceeded, archaeobotanists and anthropologists. An excavation was subsequently carried out which reached a depth of 6 metres relative to the road level, with stabilisation both of the excavation fronts and the robust masonry structures - which were preserved up to a level of 4 metres - that emerged over the course of the investigations.

From the very beginning, the excavation of the room where the chariot was found revealed its exceptional nature: the area in question is in fact a double-level portico which opens onto an uncovered courtyard, and which features the carbonised wooden ceiling with its network of beams, preserved in its entirety.

A carbonised wooden ceiling with a network of beam that emerged during excavations at the Villa of Civita Giuliana. Archaeological Park of Pompeii.

In keeping with the interdisciplinary perspective consistently adopted in the excavations of the Archaeological Park of Pompeii, archaeobotanical analyses have been carried out on the wood, which have shown that the ceiling was constructed of deciduous Oak wood (Quercus cf. robur, or English Oak), a timber which was frequently used in the Roman age for structural elements. The carbonised wooden structure of the door on the southern side of the room, which connected the portico to the stable where the three Equids were  recently discovered, was also preserved, and upon analysis was identified as Beechwood.

The wooden ceiling was carefully consolidated, cleaned, and removed from the excavation area in order to permit the investigations to continue.

On 7 January 2021 an iron artefact, the shape of which suggested the presence of a significant buried artefact, emerged from the covering of volcanic material which had flooded into the portico, just below the removed wooden ceiling.

Excavation work at the Villa of Civita Giuliana. Archaeological Park of Pompeii.

The excavation, which proceeded slowly over the following weeks due to the fragility of the elements which were progressively emerging, unearthed a ceremonial chariot, which  had miraculously been spared by both the collapse of the walls and ceiling of the room and by the illegal activities, with tunnels passing it by on two sides, but without compromising the structure.

Chariot emerging from volcanic ash at the Villa of Civita Giuliana. Archaeological Park of Pompeii.

From the moment it was identified, the excavation of the chariot has proved to be particularly complex due to the fragility of the materials involved and the difficult working conditions; as a result, it was necessary to proceed by means of a micro-excavation conducted by the restorers of the Park, who are specialised in the treatment of wood and metals. At the same time, whenever a void was discovered, plaster was poured in as part of an attempt to preserve the imprint of the organic material that was no longer present. Consequently, it has been possible to preserve the shaft and platform of the chariot, as well as the imprints of ropes, thus revealing the chariot in all of its complexity.

Micro-excavation work being carried out to expose the chariot at Villa of Civita Giuliana. Archaeological Park of Pompeii.

Given the extreme fragility of the chariot and the risk of possible illegal operations and damage caused by news leaks, the team has worked every weekend since mid-January, both to guarantee its conservation but also to send a strong signal of the Park’s action to protect the heritage, alongside the Public Prosecutor’s Office of Torre Annunziata and officers of the Naples Carabinieri Headquarters for the Protection of Cultural Heritage, assisted by investigators of the Carabinieri Group Command of Torre Annunziata. This collaboration also led to the participation of Park technicians in the ongoing trial of the alleged illegal excavators, who have struck this villa severely in recent years.

With the in situ micro-excavation completed, the various elements of the chariot have been transported to the laboratory of the Archaeological Park of Pompeii, where the restorers are working to complete the removal of volcanic material which still engulfs certain metal elements, and to begin the lengthy restoration and reconstruction of the chariot.

What has emerged has been systematically recorded via careful photographic documentation and through laser scanner surveying. 

Photographic documentation and laser scanner surveying of the archaeological site at Villa of Civita Giuliana. Archaeological Park of Pompeii.

'Pompeii continues to amaze with all of its discoveries, and it will continue to do so for many years yet, with twenty hectares still to be excavated. But above all, it demonstrates that valorisation can occur, and tourists can be attracted from all over the world, whilst at the same time research, education and studies are being conducted, and a young director like Zuchtriegel will develop this commitment.' Commented the Minister of Culture Dario Franceschini on the discovery of the chariot in the excavations of Civita Giulia. 'What has been announced today is a discovery of great scientific value. A round of applause and thanks to the Archaeological Park of Pompeii, the Public Prosecutor’s Office of Torre Annunziata and to the officers of the Carabinieri Headquarters for the Protection of Cultural Heritage for the collaboration which has averted the theft and illegal sale of these extraordinary finds on the black market. It is an extraordinary discovery for the advancement of our knowledge of the ancient world', declared Massimo Osanna, outgoing Director of the Archaeological Park, 'At Pompeii vehicles used for transport have been found in the past, such as that of the House of Menander, or the two chariots discovered at Villa Arianna (one of which can be admired at the new Stabian Antiquarium), but nothing like the Civita Giuliana chariot.

What we have is a ceremonial chariot, probably the Pilentum referred to by some sources, which was employed not for everyday use or for agricultural transport, but to accompany community festivities, parades and processions. This type of chariot, which has never before emerged from Italian soil, bears comparison with finds uncovered around fifteen years ago inside a burial mound in Thrace (in northern Greece, near the Bulgarian border). One of the Thracian chariots is particularly similar to ours, even if it lacks the extraordinary figurative decorations that accompany the Pompeian find.  The scenes on the medallions which embellish the rear of the chariot refer to Eros (Satyrs and nymphs), while the numerous studs feature erotes. Considering that the ancient sources allude to the use of the Piletum by priestesses and ladies, one cannot exclude the possibility that this could have been a chariot used for rituals relating to marriage, for leading the bride to her new household. If the entire operation had not been initiated courtesy of the synergy with the Public Prosecutor’s Office of Torre Annunziata, with which a memorandum of understanding was signed in order to combat the criminal phenomena of looting archaeological sites and trafficking finds and works of art, we would have lost extraordinary testimonies which enhance our understanding of the ancient world.'

'In recent years the Public Prosecutor’s Office at the Court of Torre Annunziata has paid constant attention to the protection of the immense archaeological heritage present in our jurisdiction,' declared the Chief Prosecutor of Torre Annunziata, Nunzio Fragliasso. 'The fight against the looting of archaeological sites, both inside and outside the urban area of ancient Pompeii, is certainly one of the primary objectives of the Office.  It is in this context that the memorandum signed by this Public Prosecutor’s Office in 2019 with the Archaeological Park of Pompeii is placed, which represents a ‘pilot agreement’ in the field of synergy between Institutions for safeguarding national artistic heritage. The collaboration between the Public Prosecutor’s Office of Torre Annunziata and the Archaeological Park of Pompeii has proved itself to be a formidable instrument, not only for bringing finds of exceptional historical and artistic value to light, but also for halting the criminal actions of individuals who for years have been the protagonists in a systematic looting of the priceless archaeological heritage preserved in the vast area of the Civita Giuliana Villa, which is still largely buried and to which the recent exceptional findings bear witness.  The criminal activities of which the Public Prosecutor’s Office of Torre Annunziata had been made aware, and which had to be fully confirmed, specifically the digging of a complex network of tunnels at a depth of over 5 metres, and the looting and partial destruction of illegally explored areas, required an investigative operation which could not have been carried out other than by a planned archaeological excavation, which was consequently conducted alongside the Archaeological Park of Pompeii. The excavation operations carried out on the site by the Archaeological Park of Pompeii with the aid, for investigative purposes, of officers of the Carabinieri Headquarters for the Protection, under the constant coordination of Assistant Prosecutor Filippelli, made it possible to gather decisive and irrefutable evidence of serious and repeated incidents of  the theft and trafficking of precious archaeological finds by ‘grave robbers’. Among other things, it has been established that the very chariot which has now been unearthed had miraculously escaped the looting of grave robbers, despite being literally touched by the tunnels dug by the perpetrators at a depth of over 5 metres.  As we speak, the criminal trial against two defendants suspected of being the chief architects of the aforementioned criminal activity, whose dwelling still now stands on the site of a plundered Ancient Roman villa, is proceeding before the Court of Torre Annunziata. The investigations have allowed us to ascertain that the network of over 80 metres of tunnels used for the systematic looting of the archaeological area originated at the property of the two defendants. Over the coming years, the work of this Office in the protection of artistic, archaeological and cultural heritage of the area will be constant and will be given the highest priority, giving particular attention to the operation aimed at the recovery of precious archaeological finds which have been stolen and exported abroad, and their return'. 

Plan of the tunnels investigated as of 8 February 2021. Archaeological Park of Pompeii.

The chariot was found inside a double-level portico which probably faced onto an uncovered courtyard, not far from the already-investigated stable, to which it was connected by a door.

The layer of cinerite which entombed the chariot had allowed the preservation of its original dimensions and of the individual parts which mark out the connected structure.

Location of the Civita Giuliana Villa to the north of Pompeii. Archaeological Park of Pompeii.

The four-wheeled chariot, on the basis of information recorded by ancient sources and the few archaeological traces that have otherwise been found to date, can probably be identified as a pilentum, a transport vehicle used in the Roman world by the elites in ceremonial contexts.

The Civita Giuliana Villa chariot during excavation.  Archaeological Park of Pompeii.

Atop high iron wheels, connected by an advanced mechanical system, rests the light carriage (0.90 x 1.40 m), or the main part of the chariot, where the seat was located, surrounded by metal arm and backrests, for either one or two individuals.

One of the wheels of the Civita Giuliana Villa chariot.  Archaeological Park of Pompeii.

The carriage is richly decorated along both sides with alternating engraved bronze sheet and red and black painted wooden panels, whilst at the rear there is a complex and extensive decorative system featuring three distinct registers with a succession of bronze and tin medallions with figurative scenes.

These medallions, set in bronze sheet and surrounded by decorative motifs, represent male and female figures in relief, depicted in erotic scenes.

The Civita Giuliana Villa chariot during excavation. Archaeological Park of Pompeii.

The bronze sheet is also decorated in its upper section with small medallions, also in tin, which depict cupids engaged in various activities. In the lower section of the chariot there is a small female herm in bronze with a crown.

Bronze medalion on the Civita Giuliana Villa chariot during excavation. Archaeological Park of Pompeii.

Archaeobotanical analyses were also conducted in this instance, which showed that the wood used to create the side structures and rear of the chariot, to which the bronze decorative elements were fixed with small nails and clamps, was beech, which is particularly suitable for this kind of production.

This kind of chariot is entirely unique in Italy, not only on account of its state of preservation, as we have not only individual decorations but the entire vehicle, but also because it is not a chariot used for the transport of agricultural products or the activities of daily life, as is already attested both at Pompeii and Stabiae.

In the adjacent stable, which had already been investigated, it was possible to create casts not only of the trough, but also of a large horse, which bore a rich bronze harness.

In the same room two other horses were discovered, one lying on its right side and the other on its left, of which it was sadly not possible to make a cast as a result of the damage caused by the tunnels of the grave robbers, and subsequent overbuilding of the cavities, which destroyed the context of the discovery. Nevertheless, other bronze harness elements were recovered, relating to a saddle and other parade elements, which can certainly be connected to the newly discovered chariot.

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Surveying the Brachyuran Mangrove Crabs of Kerala State, India.

Brachyurans are the most prominent group of Crabs, because of their great diversity; comprising of about 6793 species, 1721 genera, and 93 families recorded globally. Brachyuran Crabs perform a significant role in the Mangrove ecosystems and are commercially valuable with high culture and fattening potential. Mangrove ecosystems warrant more attention as it is diminishing day by day, especially along Kerala coastline and its importance protecting the environment from natural catastrophes are increasing. Mangroves are fragile ecosystem having highly variable conditions of life style, which make them profusely rich in biodiversity. The ecosystem value of Mangroves overwhelms any other ecosystem as it gives very many services, including biodiversity richness. Distribution studies of Brachyuran Crabs, especially the Mangrove Crab in Indian Mangroves are scanty and the available literature generally discusses the distribution of both marine and estuarine/Mangrove Crabs together.

Literature regarding Crabs of Mangrove ecosystems of Kerala was comparatively meager apart from that of few individual report and citations of each Crab species. In 2008 Muthiah Kathirvel reported 990 species of marine Brachyuran Crabs belonging to 281 genera and 36 families from Indian waters. Thirty-six Brachyuran Crab species were identified from Pichavaram Mangroves by another study in 2008. Another study in 2013 revealed that 33 Mangrove Crab species belonging to the family Grapsidae and Ocypodidae were found in the state of Tamil Nadu. A comprehensive approach to document the diversity and abundance of true Mangrove Crabs is lacking especially fromvKerala, which is considered to be one of the Crab-rich states.

In a paper published in the Journal of Threatened Taxa on 26 November 2020, Kurian Mathew Abraham and Apreshgi Kolothuthara Prakasan of the Department of Aquatic Biology and Fisheries at the University of Kerala present the results of a study which aimed to create a check list of the Brachyuran Crabs  of the Mangroves of Kerala, and photo-document that diversity, along with revalidation of Crab nomenclature.
A survey of Crabs of different estuarine mangrove ecosystems along the western coastline of Kerala was carried out from June 2016 to May 2017. Crabs were collected live by handpicking, opening of burrows, bait trap and normal traditional trap kept overnight.
The sampling locations of mangrove crabs from Kerala. Abraham & Prakasan (2020).
A total of 18 species of true Mangrove Crabs under four families (Portunidae, Grapsidae, Sesarmidae, and Ocypodidae) and 11 genera were identified and documented in the present study. Highest number species was recorded from the family Sesarmidae (seven species) followed by Portunidae and Ocypodidae with four species each and Grapsidae with three species. Scylla serrata, Scylla olivacea, and Thalamita crenata were the economically valuable crab species. Parasesarma bengalense was reported for the first time from the western coast of India and Clistocoeloma lanatum was reported for the first time from Kerala Mangroves. Pseudosesarma glabrum was one of the rarer species and was recently reported from Cochin in southwestern India. Parasesarma plicatum was the most common Crab species encountered throughout west coastline Mangrove ecosystems of Kerala.

Checklist of Mangrove Brachyuran Crabs from Kerala. Abraham & Prakasan (2020).

Studiess in the 1950s reported the occurrence of Crabs from Mangrove habitats around Travancore and Bombay respectively without much of its taxonomic identity. After a long gap, a 1980s study reported the presence of 20 species of Crabs from Pichavaram Mangroves, which includes true Mangrove as well as estuarine Crabs. There are several taxonomic works on the Brachyuran Crabs of estuarine and Mangrove ecosystems of India. A total of 55 species of Brachyuran Crabs represented under 31 genera have been reported earlier from different Mangrove habitats of India. But none of the above reports exclusively documented Mangrove Crabs, in fact they included estuarine, marine forms in addition to Mangrove Crabs. Eighteen species of Brachyuran Crabs under nine genera and four families were identified exclusively from Sunderban Mangrove ecosystems. A study of the Mangrove fauna of the Andaman & Nicobar Islands listed 31 species of Crabs from Andaman Mangroves and briefly dealt with zonation and annual breeding pattern of some of the Crabs.

Mangrove Brachyuran Crabs from Kerala. Abraham & Prakasan (2020).

The nomenclature of many Crabs has been changed by different taxonomists, with the genus name of four Crabs has been changed or revalidated recently; Perisesarma bengalense has been changed to Parasesrma, the genus Uca has been renamed as Austruca for Uca annulipes and Uca perplexa and Uca vocans has been renamed as Gelasimus vocans. Many taxa belonging to the genus Perisesarma have been changed to Parasesarma, however, Perisesarma dussumieri, without any name changes is the type species of the genus Perisesarma owing to its original characters of the genus. All the Crabs by Abraham and Prakasan are listed as ‘Least Concern’ status on the International Union for the Conservation of Nature's Red List of Threatened Species, which may be due to lack of baseline data about abundance and distribution the true Mangrove Crabs.

Mangrove Brachyuran Crabs from Kerala. Abraham & Prakasan (2020).

Abraham and Prakasan's investigation revealed 18 true Brachyuran Mangrove Crab species along estuarine mangroves of western coast of Kerala. Family Sesarmidae constitute the major diversity (seven species) followed by Portunidae (four species) and Ocypodidae (four species), and least in Grapsidae (three species) of Mangrove Crabs. Among the 18 Brachyuran Crabs, four crabs have been revalidated by change in genus or species name and provided in a checklist along with photo-documention of true Mangrove crabs of Kerala estuarine systems.

Mangrove Brachyuran Crabs from Kerala. Abraham & Prakasan (2020).

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