Saturday 26 February 2022

Sixty people killed by explosion at gold mine in Burkina Faso.

Sixty people are believed to have died and over a hundred more to have been injured following an explosion at a storage site associated with a mine at Gbomblora in Poni Province, Burkina Faso, on Monday 21 February 2022. The explosion is thought to have happened at about 2.00 pm local time, at a store used to house explosives and chemicals used in the mining industry, and to have ripped through a crowded market and residential area, flattening houses and uprooting trees.

 
The aftermath of an explosion at a mine store in Gbomblora, Burkina Faso on Monday 21 February 2022, which tore through a residential district and a crowded market. Reuters.

The gold industry has expanded significantly in recent years, overtaking cotton as the country's main export in 2019. This has included a number of large multinational mining companies running major operations, but also smaller, locally run mines such as Gbomblora. This fast-growing industry has been very poorly regulated, particularly at smaller mines, where reports of poor safety conditions and the use of child labourers are common. This general lawlessness has attracted gold smugglers, who ship metal across the country's borders into neighbouring states without paying any revenue to the Burkinabe government, as well a militant groups, often affiliated to al Qaeda and Islamic State, who both run mines of their own and extort 'taxes' from other miners, as well as carrying out attacks on mines owned by foreign mining companies and others that they perceive as being aligned with the government, foreign interests, or simply rival militia groups. However, the Gbomblora blast happened in an area hundreds of kilometres from any known militia activity, and is thought to have been accidental in nature.

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Acanthaspis rafiqi: A new species of Assassin Bug from Pakistan.

The Assassin Bugs, Reduviidae, are carnivorous True Bugs, often noted for their ability as mimics, which enables them to strike rapidly at unsuspecting prey with their enlarged, stabbing proboscis. The Reduviinae is one of the largest subfamilies within the Reduviidae, currently comprising over 1070 species within 141 genera. However, it is probably paraphyletic (i.e. not all descendants of the most recent common ancestor of all members of the group are included in the group), despite the high level of similarity seen between members of the group, suggesting that it represents a sort of 'basic' Assassin Bug bodyplan from which more specialised groups have derived. The genus Acanthaspis currently contains 124 species, making it the second largest within the Reduviinae, and is particularly diverse in South Asia, making up 42 of the 98 species of Assassin Bug found in India.

In a paper published in the Pakistan Journal of Zoology on 9 February 2022, Syed Ishfaq Ali Shah of the Department of Entomology at the China Agricultural University, and the Entomology Section at the Central Cotton Research Institute, Azaz Ahmad of the Department of Entomology at the University of Agriculture, and Wanzhi Cai, also of the Department of Entomology at the China Agricultural University, describe a new species of Acanthaspis from Pakistan.

The new species is named Acanthaspis rafiqi, in honour of Muhammad Rafiq, the former head of the Entomology Section and Principal Scientific Officer at the Central Cotton Research Institute. The species is described from five specimens, a males and a female collected from the village of Arja in the Bagh district of Azad Jammu and Kashmir by Khifza Niaz and placed in the collection of the Pakistan Museum of Natural History, a male specimen collected from the Margalla Hills of Islamabad by Azaz Ahmad, and two further specimens found in the collection of the Pakistan Museum of Natural History, which were collected in the 1980s and bear the legend 'Arbro'; one of these was also collected in Islamabad, and the other has no collection data.

Acanthaspis rafiqi, male specimen in dorsal view. Scale bar is 3.00 mm. Shah et al. (2022).

Male specimens of Acanthaspis rafiqi range from 16.00 to 16.20 mm in length, while females range from 16.16 to 16.24 mm, both are black to dark chocolate-brown in colour, with contrasting beige spots. The bodies of these insects are roughly elliptical, with females being more rectangular, they have some hairs on their underside, but the upper side is generally hairless and smooth.

 
Acanthaspis rafiqi, female specimen in (A) dorsal and (B) ventral views. Scale bar is 3.00 mm. Shah et al. (2022).

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Magnitude 6.2 Earthquake beneath West Sumatra, killing at least seven.

The Indonesian Meteorological, Climatological, and Geophysical Agency recorded a Magnitude 6.2 Earthquake at a depth of about 10 km, beneath West Sumatra Province, Indonesia slightly before 8.40 am Western Indonesian Time (slightly before 1.40 am GMT) on Friday 25 February 2022. There have been seven reported fatalities following this incident, including two children, with another 85 injured and damage to about 410 buildings. The event was felt across West Sumatra and Riau provinces, as well as much of Peninsula Malaysia and Singapore, with about 6000 people being temporarily evacuated from their homes in Sumatra and Malaysia.

 
The approximate location of the 25 February 2022 West Sumatra Earthquake. USGS.

The Indo-Australian Plate, which underlies the Indian Ocean to the west of Sumatra, is being subducted beneath the Sunda Plate, a breakaway part of the Eurasian Plate which underlies Sumatra and neighbouring Java, along the Sunda Trench, passing under Sumatra, where friction between the two plates can cause Earthquakes. As the Indo-Australian Plate sinks further into the Earth it is partially melted and some of the melted material rises through the overlying Sunda Plate as magma, fuelling the volcanoes of Sumatra.

 
The Subduction zone beneath Sumatra. NASA/Earth Observatory.

This does not happen at a 90° angle, as occurs in the subduction zones along the western margins of North and South America, but at a steeply oblique angle. This means that as well as the subduction of the Indo-Australian plate beneath the Sunda, the two plates are also moving past one-another. This causes rifting within the plates, as parts of each plate become stuck to the other, and are dragged along in the opposing plate's direction. The most obvious example of this is the Sumatran Fault, which runs the length of Sumatra, with the two halves of the island moving independently of one-another. This fault is the cause of most of the quakes on the island, and most of the island's volcanoes lie on it.

 
The movement of the tectonic plates around Sumatra. NASA/Earth Observatory.

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São Tomé and Príncipe: Possibly the last country on Earth never to have been visited by a working archaeologist.

Small oceanic islands have become sites of great interest to archaeologists in recent years, presenting opportunities to study how cultures interacted with one-another, often on very unequal terms, and how Humans impacted on unique island ecologies, within a limited geographical space. This has led to many archaeological expeditions to the islands of the Mediterranean, Caribbean, and Pacific. However, oceanic islands associated with the African continent have been less well studied, and one island nation, São Tomé and Príncipe, located in the Gulf of Guinea about 200 km off the west coast of Central Africa, has never been the subject of any archaeological fieldwork at all, possibly making it the last country on Earth about which this can be said.

In a paper published in the journal World Archaeology on 27 January 2022, Peter Mitchell of the School of Archaeology at the University of Oxford, and the Rock Art Research Institute at the University of the Witwatersrand, and Samuel Lunn-Rockliffe of the Institute for Global Prosperity at University College London, present a brief overview of the history of São Tomé and Príncipe and outline why they feel the country should be a future focus for archaeological fieldwork.

The islands of São Tomé and Príncipe form part of the Cameroon Line, a chain of volcanoes that passes from the African continent out into the Gulf of Guinea. The two islands are separated from one-another by about 160 km, from the African mainland by about 200 km, have a combined area of 1001 km², and a total population of 214 000, of whom 96% live on the larger island, São Tomé. The islands are volcanic in origin, with mountainous interiors, although they are no longer a site of active volcanism. Both islands lie very close to the Equator, and have wet tropical climates with the highest rainfall between October and May. Most of the country's population are dependent on subsistence farming and fishing, with the largest export being Cacao.

 
Map of São Tomé and Príncipe showing its location within the Gulf of Guinea. Mitchell & Lunn-Rockliffe (2022).

The island of São Tomé was discovered by Portuguese explorers João de Santarém and Pêro Escobar on 21 December 1471, the feast day of St Thomas, after whom the island was named, with Principe being discovered the following year. The first settlement on São Tomé was established in 1493, and that on Principe in 1500, both with the intention of providing supplies to Portuguese ships and bases on the African mainland. These early colonists found the climate difficult; European crops would not grow, and the colonies quickly became home to a range of tropical diseases, making it hard to attract workers to the islands. To supplement their numbers, the first forced deportations to the colonies were made, of Jews and criminals from Portugal, but another source of labour was quickly found, slaves from the Kingdom of Benin in what is now Edo State, Nigeria, who were later joined by further captives from the Kingdom of Kongo in Angola, and the area around the Congo delta. These slaves had advantages over deportees form Portugal, in that they has a degree of resilience to tropical diseases, and were familiar with African crops which would grow in the island's climate. 

This slave economy proved to be highly profitable, with São Tomé and Príncipe becoming the world's largest exporter of sugar by 1550, and the system was exported to Portuguese and Spanish colonies in the Caribbean and Brazil, along with large numbers of African slaves, who passed through the islands on the way to the New World. The export of sugar and slaves for a while made São Tomé and Príncipe one of the most important colonies in the Portuguese Empire, but by the end of the sixteenth century it had been eclipsed as a slave exporter by direct shipments from Angola, and as a sugar producer by the new colonies in Brazil, to which many of the islands planters had emigrated. The production of sugar on the islands declined through the next century, and had almost ended by 1700. During this time the European population of the islands dwindled to the point of almost vanishing, and while the colonies remained nominally part of the Portuguese Empire, local political power effectively passed to people of African or mixed descent. 

In 1787 Coffee production was introduced to the islands, followed by Cocao in 1820, and with them came a new wave of Portuguese colonists, and a new colonial system. With the islands being divided into a series of plantations, each of which acted as an independent and self-governing unit, with their own hospitals, schools, chapels, railways, and harbours. By the early 1900s São Tomé and Príncipe had become the world's largest producer of Cocao, though little of the wealth this generated remained in the islands, instead being divided amongst a series of absentee landlords and large corporations. The plantations which grew Coffee and Cacao were also dependent on slave labour to operate, and following the abolition of slavery throughout the Portuguese Empire in 1875, this was replaced by a system of forced labour which differed from it in little beyond the payment of a nominal wage to the now 'free' workers, recruited more-or-less forcibly from Cape Verde, Angola and Mozambique. This system only ended with the independence of São Tomé and Príncipe from Portugal in 1975, which was followed by agrarian reforms, nationalisation of the plantations, and the granting of land rights to former labourers.

The first academic studies of São Tomé and Príncipe's cultural heritage were made while the islands were still a Portuguese colony, following a 1958 decree by the Estado Novo regime of António de Oliveira Salazar, which demanded the classification, conservation, and repair of monuments in Portugal’s overseas colonies. Following this decree Luís Benavente, the director of the National Monuments Service, visited São Tomé city, and identified two historic churches and two forts as being worthy of conservation, as examples of structures dating from the heyday of Portuguese rule in the islands in the sixteenth and seventeenth centuries. One of these, Fort São Sebastião, built between 1566 and 1575 to defend the colony against attacks by other European powers and uprisings by the local slave population, subsequently became the new nation's National Museum following independence in 1975.

 
Fort São Sebastião, São Tomé, from the landward side. Mitchell & Lunn-Rockliffe (2022).

Fort São Sebastião is one of the oldest buildings in the islands, and has been recognised as being a significant structure in the history of the slave trade UNESCO's Slave Route Project, although this side of its heritage is not (perhaps understandably) not featured in the modern museum. 

Some limited studies of the architecture of São Tomé have been made by Portuguese universities in the past decade, including an attempt to pinpoint the locations of the captain’s tower constructed in 1493, which served as the first seat of government on the island, and examinations of other civic buildings, as well as looking at the potential for restoring the island's plantations. These restoration projects have not considered the potential for archaeological investigations at these sites, nor apparently considered the possibility of examining narratives other than those left by the colony's estate owners and ruling class.

 
Mock-medieval stable façade at Roça Sundy, Príncipe. Mitchell & Lunn-Rockliffe (2022).

São Tomé and Príncipe itself is a poor, underdeveloped, island nation, which understandably has higher priorities for its limited resources than developing its archaeological heritage. The remote location of the islands has led to it being largely overlooked by the international archaeological community, something not helped by the official language (and most of the historical documentation) of the islands being Portuguese rather than English or French (the two languages most used by archaeologists working in Africa. 

There is no evidence for São Tomé and Príncipe having been inhabited before the arrival of the Portuguese in 1471. This means that it should be possible, at least in theory, to find historical documentation for the entire of the islands' inhabited history, a significant aid to any archaeologists carrying out survey work on the islands. Furthermore, the landscape of the islands provides a very good guide to the places where particular types of settlements are likely to have been located. The elevated broken terrain of the islands' interiors is unsuitable for plantation agriculture, so that plantations have always been concentrated in low lying areas with good access to the coast. The interior of the islands, meanwhile, was an excellent location for people escaping from slavey, and a number of long-term settlements built by such communities of escapees are known to have existed there.

Many areas where Europeans settled in the earlier stages of colonial expansion were 'seeded' with familiar Plants and Animals in order to make them more inhabitable for colonists. In the case of São Tomé and Príncipe that was simply not possible; the islands' equatorial climate was unsuitable for any crops familiar to Portuguese settlers, which made the import of African workers (and in particular female African workers) skilled in the cultivation of crops that would grow in the climate a priority, and leading to the development of the plantation system which was then repeated across much of the New World by Portuguese and other European colonists. 

The precarious nature of the early colony (no doubt combined with genuine conviction on the part of the settlers) seems to have made religious architecture an important part of the colony's identity from very early in its history, with records showing the city of São Tomé already had five churches and a monestery in the early 1500s, a time when there were only about 250 houses. 

São Tomé and Príncipe are unusual in that they appear to have been uninhabited before the arrival of European explorers, something they share in the Atlantic region only with the Falklands, Annobón, St Helena, Ascension Island, Bermuda, Cape Verde, Madeira, the Azores, and Iceland. Several of these other islands also adopted the plantation system developed in São Tomé and Príncipe, leaving potential for archaeologists to explore the spread of this system through early Portuguese colonies and then into the wider Atlantic economy, and to compare the way this system developed on uninhabited islands in the Atlantic to how it developed on previously inhabited islands such as those of the Caribbean, or on previously uninhabited islands in other parts of the world, such as the Seychelles or Mascarine islands in the Indian Ocean, where different patterns of colonial control emerged.

When the Portuguese first arrived, the islands of São Tomé and Príncipe were largely covered by primary rainforest, but the establishment of plantations required clearing of large swaths of this forest, as did a need for firewood, used not just for domestic purposes, but also for the processing of Sugar Cane, with historical records showing that much of the primary rainforests had been cleared by 1540. Later in the sixteenth century, as the Sugar industry declined, secondary forests regrew in many of the areas cleared for plantations, only to be felled again in the eighteenth and nineteenth centuries for the new Coffee and Cacao plantations. 

This is unfortunate, as the distance between São Tomé and Príncipe and the African mainland makes in likely that the islands were home to a high level of endemic biodiversity. Even today, after 500 years of Human habitation and contact with the outside world, 17 of the 45 Bird species found on the islands are found nowhere else, and another three are found additionally only on Annobón, another oceanic island on the Cameroon Line, to the south of São Tomé and Príncipe, and a territory of Equatorial Guinea. Thus, the historic (and ongoing) loss of forests on the islands represents the loss of an unknown, and unrecorded biodiversity heritage, something which archaeological investigations could help to uncover.

In addition to the major cash crops, Sugar Cane, Coffee, and Cacao, a number of other crops were introduced to the islands for local consumption, including Bananas and Plantains, Musa spp., Maize, Zea mays, Manioc, Manihot esculenta, Sweet Potato, Ipomoea batatas, Pineapple, Ananas comosus, Coconuts, Cocos nucifera, and Ginger, Zingiber officinale. Furthermore, a number of Animals were also introduced to the islands, either as livestock or Human commensals, including Pigs, Sus domesticus, Cats, Felis catus, Rats, Rattus spp., and Mona Monkeys, Cercopithecus mona. All of these are likely to have changed the local ecology to some extent, and some of the crops probably helped Human population growth on the islands, in turn affecting labour patterns and other aspects of Human behaviour.

Directly tracking changes in Plant cover in the tropics is difficult, as most plant matter breaks down quickly in hot, wet environments, but changes in foodstuffs can be reflected in the tools that Humans choose to use, although this will have, at least for the ruling class, also be impacted by a desire to maintain cultural links with the culture of the wider Portuguese Empire, even at times when the European population was minimal and the island's leadership was largely of African or mixed ancestry.

The development of a Sugar Cane industry in São Tomé and Príncipe in the sixteenth century required the presence of a large workforce able to carry out physical labour in the island's tropical climate, and reasonably resilient to the illnesses associated with that climate. Since, unlike earlier Iberian conquests such as the Canary Islands, São Tomé and Príncipe lacked any indigenous population to be exploited, this led to the (involuntary) recruitment of large numbers of workers from Africa, who were then unable to return home due to the distance between the islands and the mainland. Thus the islands became the first tropical plantation colony, laying the foundations of a system that then spread to the Caribbean, North and South America, and the western Indian Ocean. Thus, studying the history and archaeology of São Tomé and Príncipe has the potential to shed light on the early development of this system, the ways in which the European and African populations intermixed, and how early forms of colonial slavery were enforced and fought.

Archaeology can help us to understand the material infrastructure of the plantation colonies, and the way in which the different groups within these societies lived and worked. The plantations seem to have been created with a conscious desire to maintain Portuguese models of estate-management, typically with a large house at the end of a long approach, faced by a barracks type building used to house the workers facing the main building across an open courtyard, thus enabling the surveillance of the workers. Workshops and other ancillary buildings would be located to one side, a chapel near the main house, while any medical facility would be further away. These buildings tended to be constructed in a way that emphasised the differences between the groups on the plantation, with the main house, and other structures used primarily by Europeans (such as stables), being built on a much more impressive scale than buildings used by the workforce.

 
Map of the location of roças (plantations) on São Tomé and Príncipe. Mitchell & Lunn-Rockliffe (2022).

The society of São Tomé and Príncipe has never been homogeneous, reflecting the different locations from which slaves and forced labourers were sourced at different points in the islands' colonial history. The oldest documented creole language on São Tomé is Lungwa Santome, a mixture of the Kikongo spoken around the Congo Delta and the Edoid languages spoken around Benin in southern Nigeria, languages spoken by the earliest slaves brought to the island; from Benin in the 1520s and Kongo in the mid 1500s. The Lung’yie language of Principe is much more closely aligned to the Edoid languages, although the people who speak it have been shown to have a similar genetic make-up to people elsewhere in São Tomé and Príncipe, with roughly half their DNA derived from West Africa and half from Central Africa. The Lunga Ngolá language of the Angolares of São Tomé's south and interior is closely related to the Kimbundu language of Angola. Genetic studies of this group suggest that it shows distinctly reduced male diversity, with all speakers descended fairly recently from a small group of related men. Local legend has it that these men were survivors from a slave ship from Angola shipwrecked in the mid 1500s, although it is possible that they simply escaped from slavery on the island. Either way, this group retained its independence in the island's interior until the late 1800s, with a community centred on the town of São João dos Angolares. 

Resistance to, slavery, including both successful and failed attempts at escape, has a long history on São Tomé and Príncipe, with the first documented such escapes occurring in 1499, and free settlements, or mocambos, existing on the islands for most of their history. These survived principally by farming Yams, Oil Palm, and Plantains, all mainstays of the traditional Central African diet, but are also known to have raided, or sometimes with, other settlements for salt, iron, and weapons. Raids carried out on slave-plantations also typically sought new recruits, particularly female ones. Archaeological investigation of these settlements, however, is likely to be far harder than would be the case for plantations, as they are likely to have been far more ephemeral, moving regularly to escape any action by the Portuguese authorities, and therefore building few structures intended to last any length of time, although the long period for which these peoples were able to sustain their independence does raise the hope that they will have left some physical record of their activities. 

 
This view of Cão Grande, which rises to 663 m above sealevel, conveys a sense of the ruggedness and impenetrability of the interiors of São Tomé and Príncipe that favoured the survival of escaped slaves and their resistance to colonial control. Helena Van Eykeren/Wikimedia Commons in Mitchell & Lunn-Rockliffe (2022).

As well as a history of slavery and resistance to slavery, São Tomé and Príncipe also saw the development of unique creole cultures, arguably the first such cultures to appear in the Atlantic region, as European Portuguese culture blended with the African cultures of the Benin and Kongo areas (themselves quite different and distinct). This is visible today in cultural phenomena such as the Tchiloli and Auto de Floripes theatre traditions of São Tomé and Príncipe, which are rooted in Medieval European plays, but enhanced by African beliefs and customs. Activities such as street theatre are unlikely to have left much archaeological evidence, but such blending might leave visible traces in the form evidence of dietary changes, tool use, or the arrangement of domestic spaces. Mitchell and Lunn-Rockliffe speculate that any such cultural fusion might be particularly associated with the collapse of the Sugar industry on the islands, following which slavery persisted only really in domestic environments, with the slave owners themselves likely to have been of mixed or African descent. It is even possibly that some of the early plantations on the islands were originally owned by wealthy individuals from Benin or Kongo.

 
A scene from a performance of the Tchiloli in front of the church of São Pedro, São Tomé city. Wikimedia Commons in Mitchell & Lunn-Rockliffe (2022).

Following independence from Portugal, the roças (plantations) of São Tomé and Príncipe were first nationalised, then privatised in smaller fragments, creating an entirely new pattern of land use on the islands. The impact of this has never been formally studied, and has itself the potential for archaeological investigation. Some of the large plantation centres have been renovated for use as up-market holiday destinations, while others have simply fallen into disrepair or become the centre of new urban environments, being used in ways quite different to those intended by their original users. These changes are slowly obscuring the previous status of these sites, while at the same time creating new environments, the evolution of which has not been studied, with archaeology presenting a way to both better understand the past and assess the evolving present.

 
Re-use of the main plantation house at Roça Porto Alegre in the far south of São Tomé. Wikimedia Commons in Mitchell & Lunn-Rockliffe (2022).

African islands, and in particular the islands of the African Atlantic, have largely been overlooked by archaeologists, with São Tomé and Príncipe possibly being the last country on Earth never to have been explored by archaeologists. The history of the country is currently known almost exclusively from written records left by its Portuguese colonial masters. This is despite the historical significance of the islands, which were the first example of the plantation economy which was later transported to the Caribbean and Americas, fueling the trans-Atlantic slave trade for centuries. São Tomé and Príncipe was also the first Christian diocese south of the Equator (from 1534), and the first site if Coffee and Cocao production in Africa, where following the abolition of slavery, and indentured labour system was developed that was later transferred elsewhere in Africa as well as to European colonies in other parts of the world. São Tomé and Príncipe was also home to the first communities of escaped African slaves, which persisted for centuries despite the Portuguese dominance of the islands. 

This long history, and the impact which it had on the islands' previously untouched ecologies, deserves to be the subject of archaeological investigation, although this would need to be done with great sensitivity, given the probability of uncovering darker facets of the islands' histories. Such an investigation has the capacity to inform us about not just the history of the islands themselves, but also the wider Atlantic region, where a series of societies developed under a similar economic model, following the pattern developed on São Tomé and Príncipe.

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Sunday 20 February 2022

More than 100 people dead after a series of landslides and flash floods hit the city of Petrópolis in Rio de Janeiro State, Brazil.

One hundred and seventeen people are now known to have died and more than one hundred and forty more are still missing after a series of landslides and flash floods hit the Brazilian city of Petrópolis in Rio de Janeiro State on Tuesday 15 February 2022. The incident happened following a rainstorm which brought more than a month's rain in three hours, making it the worst such storm recorded in the state since 1932. 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. Approximately 90% of all landslides are caused by heavy rainfall. In the worst incident over 80 homes were destroyed by a single landslide that hit the neighbourhood of Morro da Oficina. In addition to the dead many hundreds more have been injured and/or displaced from their homes, with many of the displaced now staying in temporary accommodation in schools, sports centres, and other civic buildings.

 
A landlide which swept through the Morro da Oficina area of Petrópolis on 15 February 2022, destroying more than 80 homes. Reuters.

Southern Brazil has a rainy season that lasts from October to March, with peak rains from mid-November to mid-January, however, this year's rains have been exceptionally strong. Brazil has suffered a string of flood-related disasters in recent years, most notably in 2011, when over 800 people died. The country has a rapidly growing population, with little effective urban planning, which has led to sprawling urban developments springing up with little thought to natural hazards, and in particular poorer neighbourhoods often expanding up unstable hillsides, with the result that when floods occur (which is not unusual) communities are often quickly overwhelmed. This year's exceptional rains have led to more widespread flooding, which may also persist for longer, and there is a distinct danger that without determined action the death toll may exceed that of 2011. Such events are becoming increasingly common in Brazil, something which many climatologists are citing as direct evidence of global warming.

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Asteroid 2022 CL7 passes the Earth.

Asteroid 2022 CL7 passed by the Earth at velocity of 9.98 km per second and a distance of about 83 800 km (0.22 times the average distance between the Earth and the Moon, or 0.06% of the distance between the Earth and the Sun), slightly after 3.40 pm GMT on Monday 14 February 2022. There was no danger of the asteroid hitting us, though were it to do so it would not have presented a significant threat. 2022 CL7 has an estimated equivalent diameter of 2-7 m (i.e. it is estimated that a spherical object with the same volume would be 2-7 m in diameter), and an object of this size would be expected to explode in an airburst (an explosion caused by superheating from friction with the Earth's atmosphere, which is greater than that caused by simply falling, due to the orbital momentum of the asteroid) more than 36 above the ground, with only fragmentary material reaching the Earth's surface.

 
The relative positions of 2022 CL7 and the Earth on at 4.00 pm on 14 February 2022. JPL Small Body Database.

2022 CL7 was discovered on 14 February 2022 (the day of 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 2022 AY5 implies that it was the 188th asteroid (object L7 - in numbering asteroids the letters A-Y, excluding I, are assigned numbers from 1 to 25, with a number added to the end each time the alphabet is ended so that A = 1, A1 = 26, A2 = 51, etc., which means that L7 implies the 188th asteroid (L7 = (25 x 7) + 11 = 188) discovered in the first half of February 2022 (period 2022 C - the year being split into 24 half-months represented by the letters A-Y, with I being excluded).

 
The orbit and current position of 2022 CL7. The Sky Live 3D Solar System Simulator.

2022 CL7 has a 777 day (2.13 year) orbital period, with an elliptical orbit tilted at an angle of 6.99° to the plain of the Solar System which takes in to 0.90 AU from the Sun (91% of the distance at which the Earth orbits the Sun) and out to 2.0 AU (240% of the distance at which the Earth orbits the Sun, and more than the distance at which the planet Mars orbits the Sun). 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 Asteroid 2022 CL7 has occasional close encounters with the Earth, with the most recent having happened in October 2019, and the next predicted for March 2046.

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