̽��ֱ�� of Cambridge - ̽��ֱ�� of Bern

Carbon dioxide ‘pulses’ are a common feature of the carbon cycle

cmm201 — Thu, 20 Aug 2020 18:00:00 +0000

Ice cores from Antarctica show that, in the span of less than two centuries, atmospheric levels of carbon dioxide jumped repeatedly at the end of the last ice age, when the Atlantic was continuously disturbed by melting ice sheets.

Whether these CO₂ jumps might occur in today’s conditions, when we are already seeing the impact of human-driven CO₂ emissions and rapidly melting polar ice sheets, has remained unknown.

̽��ֱ��study, published in the journal Science and by researchers from the Universities of Cambridge, Bern and Grenoble Alpes, reveals that rapid CO₂ jumps also occurred during a period from 450,000 to 330,000 years ago, a key time in Earth’s history covering more than a full glacial cycle.

“By looking back further in time, to previous glacial and interglacial conditions, we find the same CO₂jumps - irrespective of whether the climate was cold or warm,” said first author Dr Christoph Nehrbass-Ahles from Cambridge’s Department of Earth Sciences, who conducted the research while based at the ̽��ֱ�� of Bern.

These rapid CO₂ rises seem to be a common feature of the carbon cycle in the past. But, said Nehrbass-Ahles, human activities are releasing carbon a rate ten times faster than during CO₂ increases in the past. “What is unclear is how a future jump in carbon may interact with or exacerbate anthropogenic carbon emissions,” he said.

Central to the team’s finding was their detailed analysis of Antarctic ice from the EPICA ( ̽��ֱ��European Project for Ice Coring in Antarctica) Dome C ice core.

“Our previous understanding of rapid CO₂ changes has been hampered by a lack of detailed data over this interval – so these events were often missed,” said Nehrbass-Ahles. Thanks to a new gas extraction method and detailed sampling campaign, the team was able to identify subtle changes occurring at centennial timescales.

̽��ֱ��study marks an important step in understanding what causes such abrupt increases and possible feedbacks in the Earth’s climate system. “Scientists are uncertain as to the mechanism behind the CO₂ jumps, but think a combination of factors, including ocean circulation, changing wind patterns, and terrestrial processes, are likely responsible,” said co-author Professor David Hodell, also from the Department of Earth Sciences.

̽��ֱ��researchers combined the new ice core data with detailed information on ocean circulation from marine sediments collected off the coast of Portugal. ̽��ֱ��site, which was drilled as part of the International Ocean Discovery Program (IODP), is unique for its high accumulation of sediments and is ideally situated for monitoring the changes in ocean circulation triggered when ice sheets collapsed.

̽��ֱ��isotopic signal of the marine sediments showed the same pattern as the ice cores. “ ̽��ֱ��abrupt changes are clearly represented in both the marine and ice records, telling us that they must be connected to major changes in the surface and deep circulation of the Atlantic Ocean,” said Hodell.

According to Nehrbass-Ahles, the key is the high resolution of the ice and marine sediments records, making observations of these rapid changes in both records possible. “Understanding these centennial-scale changes is crucial because they operate at a similar pace to the anthropogenic changes altering our planet,” he said.

Reference:
C. Nehrbass-Ahles et al. ‘Abrupt CO2 release to the atmosphere under glacial and early interglacial climate conditions.’ Science (2020). DOI: 10.1126/science.aay8178

Researchers have found that pulse-like releases of carbon dioxide to the atmosphere are a pervasive feature of the carbon cycle and that they are closely connected to major changes in Atlantic Ocean circulation.

Understanding these centennial-scale changes is crucial because they operate at a similar pace to the anthropogenic changes altering our planet

Christoph Nehrbass-Ahles

Thibaut Vergoz, Institut polaire français

Concordia research station in Antarctica

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

A feather in your cap: inside the symbolic universe of Renaissance Europe

tdk25 — Thu, 02 Nov 2017 08:50:40 +0000

Later, an eyewitness recalled that officials thought the Duchess had fainted at the sight of blood trickling from her husband’s mouth. Only the Archduke himself seemed to realise that she, too, had been hit. “Sophie dear! Don’t die! Stay alive for our children!” Franz Ferdinand pleaded. Then, “he seemed to sag down himself,” the witness remembered. “His plumed general’s hat… fell off; many of its green feathers were found all over the car floor.”

̽��ֱ��assassination of Archduke Franz Ferdinand on 28 June 1914, had such seismic repercussions in precipitating the First World War that it is easy to disregard the curious little detail of feathers on the floor. In such context, they seem trivial. Rewind a few moments more, to the famous final photograph of the couple leaving Sarajevo town hall, and the plumage sprouting from the Archduke’s hat looks positively absurd; as if amid all the other mortal perils of that day – the bomb that narrowly missed his car, the bullets from a semi-automatic – he somehow also sustained a direct hit from a large bird.

Today, we generally associate feathers with women’s fashion, and a peculiarly ostentatious brand at that, reserved for Royal Ascot, high-society weddings and hen parties. Among men, wearing feathers is typically seen as provocatively effete – the domain of drag queens, or ageing, eyelinered devotees of the Manic Street Preachers.

Yet a cursory glance at military history shows that Franz Ferdinand was far from alone in his penchant for plumage. ̽��ֱ��Bersaglieri of the Italian Army, for example, still wear capercaillie feathers in their hats, while British fusiliers have a clipped plume called a hackle. Cavaliers in the English Civil War adorned their hats with ostrich feathers.

“Historically, feathers were an incredibly expressive accessory for men,” observes Cambridge historian Professor Ulinka Rublack. “Nobody has really looked at why this was the case. That’s a story that I want to tell.”

Rublack is beginning to study the use of featherwork in early modern fashion as part of a project called ‘Materialized Identities’, a collaboration between the Universities of Cambridge, Basel and Bern, and funded by the Swiss National Science Foundation.

To the outsider, its preoccupations (her co-researchers are studying gold, glass and veils) might seem surprising. Yet such materials are not just mute artefacts; they sustained significant economies, craft expertise and, she says, “entered into rich dialogue with the humans who processed and used them”. Critically, they elicited emotions, moods and attitudes for both the wearer and the viewer. In this sense, they belonged to the ‘symbolic universe’ of communities long since dead. If we can understand such resonances, we come closer to knowing more about how it felt to be a part of that world.

Rublack has spotted that something unusual started to happen with feathers during the 16th century. In 1500, they were barely worn at all; 100 years later they had become an indispensable accessory for the Renaissance hipster set on achieving a ‘gallant’ look.

In prosperous trading centres, the locals started sporting hats bedecked with feathers from parrots, cranes and swallows. Headgear was manufactured so that feathers could be inserted more easily. By 1573, Plantin’s Flemish–French dictionary was even obliged to offer words to describe people who chose not to wear them, recommending such verbiage as: ‘the featherless’ and ‘unfeathered’.

Featherworking became big business. From Prague and Nuremberg to Paris and Madrid, people started to make a living from decorating feathers for clothing. Impressive efforts went into dyeing them. A 1548 recipe recommends using ashes, lead monoxide and river water to create a ‘very beautiful’ black, for example.

Why this happened will become clearer as the project develops. One crucial driver, however, was exploration – the discovery of new lands, especially in South America. Compared with many of the other species that early European colonists encountered, exotic birds could be captured, transported and kept with relative ease. Europe experienced a sudden ‘bird-craze’, as birds such as parrots became a relatively common sight on the continent’s largest markets.

Given the link with new territories and conquest, ruling elites wore feathers partly to express their power and reach. But there were also more complex reasons. In 1599, for example, Duke Frederick of Württemberg held a display at his court at which he personally appeared as ‘Lady America’, wearing a costume covered in exotic feathers. This was not just a symbol of power, but of cultural connectedness, Rublack suggests: “ ̽��ֱ��message seems to be that he was embracing the global in a duchy that was quite insular and territorial.”

Nor were feathers worn by the powerful alone. In 1530, a legislative assembly at Augsburg imposed restrictions on peasants and burghers adopting what it clearly felt should be an elite fashion. ̽��ֱ��measure did not last, perhaps because health manuals of the era recommended feathers as protecting the wearer from ‘bad’ air – cold, miasma, damp or excessive heat – all of which were regarded as hazardous. During the 1550s, Eleanor of Toledo had hats made from peacock feathers to protect her from the rain.

Gradually, feathers came to indicate that the wearer was healthy, civilised and cultured. Artists and musicians took to wearing them as a mark of subtlety and style. “They have a certain tactility that was seen to signal an artistic nature,” Rublack says.

Like most fads, this enthusiasm eventually wore off. By the mid-17th century, feathers were out of style, with one striking exception. Within the armies of Europe what was now becoming a ‘feminine’ fashion choice elsewhere remained an essential part of military costume.

Rublack thinks that there may have been several reasons for this strange contradiction. “It’s associated with the notion of graceful warfaring,” she says. “This was a period when there were no standing armies and it was hard to draft soldiers. One solution was to aestheticise the military, to make it seem graceful and powerful, rather than simply about killing.” Feathers became associated with the idea of an art of warfare.

They were also already a part of military garb among both native American peoples and those living in lands ruled by the Ottomans. Rublack believes that just as some of these cultures treated birds as gods, and therefore saw feathers as having a protective quality, European soldiers saw them as imparting noble passions, bravery and valiance.

In time, her research may therefore reveal a tension about the ongoing use of feathers in this unlikely context. “It has to do with a notion of masculinity achieved both through brutal killing, and the proper conduct of war as art,” she says. But, as she also notes, she is perhaps the first historian to have spotted the curious emotional resonance of feathers in military fashion at all. All this shows a sea-change in methodologies: historians now chart the ways in which our identities are shaped through deep connections with ‘stuff’. Further work is needed to understand how far these notions persisted by 1914 when, in his final moments, Franz Ferdinand left feathers scattered across the car floor.

Inset image: Hendrick Goltzius, soldier, c. 1580; credit: ̽��ֱ��Rijsmuseum, Amsterdam.

Today, feathers are an extravagant accessory in fashion; 500 years ago, however, they were used to constitute culture, artistry, good health and even courage in battle. This unlikely material is now part of a project that promises to tell us more not only about what happened in the past, but also about how it felt to be there.

Historically, feathers were an incredibly expressive accessory for men. Nobody has really looked at why this was the case. That’s a story that I want to tell.

Ulinka Rublack

Achille Beltrame

Assassination of the feather-hatted Archduke Franz Ferdinand

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

Yes

Cambridge app maps decline in regional diversity of English dialects

sjr81 — Thu, 26 May 2016 09:26:27 +0000

̽��ֱ��English Dialects App (free for Android and iOS) was launched in January 2016 and has been downloaded more than 70,000 times. To date, more than 30,000 people from over 4,000 locations around the UK have provided results on how certain words and colloquialisms are pronounced. A new, updated version of the app – which attempts to guess where you’re from at the end of the quiz – is available for download from this week.

Based on the huge new dataset of results, researchers at Cambridge, along with colleagues at the universities of Bern and Zurich, have been able to map the spread, evolution or decline of certain words and colloquialisms compared to results from the original survey of dialect speakers in 313 localities carried out in the 1950s.

One of the major findings is that some features of regional accents, such as pronouncing the 'r' in words like 'arm' – a very noticeable pronunciation feature which was once normal throughout the West Country and along much of the south coast – are disappearing in favour of the pronunciations found in London and the South-East (see map slideshow).

Lead researcher Dr Adrian Leemann, from Cambridge’s Department of Theoretical and Applied Linguistics, said: “When it comes to language change in England, our results confirm that there is a clear pattern of levelling towards the English of the south-east; more and more people are using and pronouncing words in the way that people from London and the south-east do.

Professor David Britain from the ̽��ֱ�� of Bern added: “People in Bristol speak much more similarly to those in Colchester now than they did fifty years ago. Regional differences are disappearing, some quite quickly. However, while many pockets of resistance to this levelling are shrinking, there is still a stark north-south divide in the pronunciation of certain key words.”

Dialect words are even more likely to have disappeared than regional accents, according to this research. Once, the word ‘backend’ instead of ‘autumn’ was common in much of England, but today very few people report using this word (see map slideshow).

However, the research has shown some areas of resistance to the patterns of overall levelling in dialect. Newcastle and Sunderland stood out from the rest of England with the majority of people from those areas continuing to use local words and pronunciations which are declining elsewhere. For example, many people in the North-East still use a traditional dialect word for 'a small piece of wood stuck under the skin', 'spelk' instead of Standard English 'splinter'.

Other dialect words, like ‘shiver’ for ‘splinter’, are still reported in exactly the same area they were found historically—although they are far less common than they once were (see map slideshow).

̽��ֱ��data collected to date shows that one northern pronunciation has proved especially robust: saying words like 'last' with a short vowel instead of a long one. In this case, the northern form actually appears to have spread southwards in the Midlands and the West Country compared with the historical survey.

In other cases, new pronunciations were found to be spreading. Pronouncing words like 'three' with an 'f' was only found in a tiny region in the south east in the 1950s, but the data from today show this pronunciation is much more widespread – 15% of respondents reported saying 'free' for 'three', up from just 2% in the old Atlas.

Cambridge PhD student Tam Blaxter, who worked alongside Dr Leemann to map the 30,000 responses supplied by the public, suggests that greater geographical mobility is behind the changes when compared to the first systematic nationwide investigation of regional speech, the Survey of English Dialects from the 1950s.

“There has been much greater geographical mobility in the last half century,” said Blaxter. “Many people move around much more for education, work and lifestyle and there has been a significant shift of population out of the cities and into the countryside.

“Many of the results have confirmed what language experts might predict – but until now we just didn’t have the geographical breadth of data to back up our predictions. If we were to do the survey in another 60-70 years we might well see this dialect levelling expanding further, although some places like the north-east seem to have been especially good at preserving certain colloquialisms and pronunciations.”

When the app was originally launched in January, users were quizzed about the way they spoke 26 different words or phrases. ̽��ֱ��academics behind the app wanted to see how English dialects have changed, spread or levelled out since the Survey of English Dialects. ̽��ֱ��1950s project took eleven years to complete and captured the accents and dialects of mainly farm labourers.

Perhaps one of the most surprising results of the data provided so far is how the use of ‘scone’ (to rhyme with ‘gone’ rather than ‘cone’) is much more common in the north of England that many might imagine (see map slideshow).

Adrian Leemann said: “Everyone has strong views about how this word is pronounced but until we launched the app in January, we knew rather little about who uses which pronunciation and where. Our data shows that for the North and Scotland, ‘scone’ rhymes with ‘gone’, for Cornwall and the area around Sheffield it rhymes with ‘cone’ – while for the rest of England, there seems to be a lot of community-internal variation. In the future we will further unpick how this distribution is conditioned socially.”

̽��ֱ��launch of the English Dialects App in January has also allowed language use in Wales, Scotland and Northern Ireland to be compared with language use in England (the original 1950s survey was limited to England and similar surveys of the other parts of the UK were not undertaken at the same time or using the same methods).

̽��ֱ��huge levels of feedback have also meant the team have improved the prediction of where users might be from. ̽��ֱ��app now correctly places 25 per cent of respondents within 20 miles, compared with 37 miles for the old method.

Regional diversity in dialect words and pronunciations could be diminishing as much of England falls more in line with how English is spoken in London and the south-east, according to the first results from a free app developed by Cambridge researchers.

More and more people are using and pronouncing words in the way that people from London and the south-east do.

Adrian Leemann

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

Yes

Do you say splinter, spool, spile or spell? English Dialects app tries to guess your regional accent

sjr81 — Mon, 11 Jan 2016 00:06:31 +0000

Along with colleagues from the universities of Zurich and Bern, Cambridge’s Adrian Leemann has developed the free app English Dialects (available on iOS and Android), which asks you to choose your pronunciation of 26 different words before guessing where in England you’re from.

̽��ֱ��app also encourages you to make your own recordings in order to help researchers determine how dialects have changed over the past 60 years. ̽��ֱ��English language app follows the team’s hugely successful apps for German-speaking Europe, which accumulated more than one million hits in 4 days on Germany’s Der Spiegel website, and more than 80,000 downloads of the app by German speakers in Switzerland.

“We want to document how English dialects have changed, spread or levelled out,” said Dr Leemann, a researcher at Cambridge’s Department of Theoretical and Applied Linguistics. “ ̽��ֱ��first large-scale documentation of English dialects dates back 60-70 years, when researchers were sent out into the field – sometimes literally – to record the public. It was called the ‘Survey of English Dialects’. In 313 localities across England, they documented accents and dialects over a decade, mainly of farm labourers.”

̽��ֱ��researchers used this historical material for the dialect guessing app, which allows them to track how dialects have evolved into the 21st century.

“We hope that people in their tens of thousands will download the app and let us know their results – which means our future attempts at mapping dialect and language change should be much more precise,” added Leemann. “Users can also interact with us by recording their own dialect terms and this will let us see how the English language is evolving and moving from place to place.”

̽��ֱ��app asks users how they pronounce certain words or which dialect term they most associate with commonly-used expressions; then produces a heat map for the likely location of your dialect based on your answers.

For example, the app asks how you might say the word ‘last’ or ‘shelf’, giving you various pronunciations to listen to before choosing which one most closely matches your own. Likewise, it asks questions such as: ‘A small piece of wood stuck under the skin is a…’ then gives answers including: spool, spile, speel, spell, spelk, shiver, spill, sliver, splinter or splint. ̽��ֱ��app then allows you to view which areas of the country use which variations at the end of the quiz.

It also asks the endlessly contentious English question of whether ‘scone’ rhymes with ‘gone’ or ‘cone’.

“Everyone has strong views about the pronunciation of this word, but, perhaps surprisingly, we know rather little about who uses which pronunciation and where,” said Professor David Britain, a dialectologist and member of the app team based at the ̽��ֱ�� of Bern in Switzerland.

“Much of our understanding of the regional distribution of different accent and dialect features is still based on the wonderful but now outdated Survey of English Dialects – we haven’t had a truly country-wide survey since. We hope the app will harness people’s fascination with dialect to enable us to paint a more up-to-date picture of how dialect features are spread across the country.”

At the end of the 26 questions, the app gives its best 3 guesses as to the geography of your accent based on your dialect choices. However, while the Swiss version of the app proved to be highly accurate, Leemann and his colleagues have sounded a more cautious note on the accuracy of the English dialect app.

Dr Leemann said: “English accents and dialects are likely to have changed over the past decades. This may be due to geographical and social mobility, the spread of the mass media and other factors. If the app guesses where you are from correctly, then the accent or dialect of your region has not changed much in the last century. If the app does not guess correctly, it is probably because the dialect spoken in your region has changed quite a lot over time.”

At the end of the quiz, users are invited to share with researchers their location, age, gender, education, ethnicity and how many times they have moved in the last decade. This anonymous data will help academics understand the spread, evolution or decline of certain dialects and dialect terms, and provide answers as to how language changes over time.

“ ̽��ֱ��more people participate and share this information with us, the more accurately we can track how English dialects have changed over the past 60 years,” added Dr Leemann.

After taking part in the quiz, users can also listen to both historic and contemporary pronunciations, taking the public on an auditory journey through England and allowing them to hear how dialects have altered in the 21st century. ̽��ֱ��old recordings are now held by the British Library and were made available for use in the app. One of these recordings features a speaker from Devon who discusses haymaking and reflects on working conditions in his younger days.

Dr Leemann added: “Our research on dialect data collected through smartphone apps has opened up a new paradigm for analyses of language change. For the Swiss version nearly 80,000 speakers participated. Results revealed that phonetic variables (eg if you say ‘sheuf’ or ‘shelf’) tended to remain relatively stable over time, while lexical variables (eg if you say ‘splinter’, ‘spelk’, ‘spill’ etc.) changed more over time. ̽��ֱ��recordings from the Swiss users also showed clear geographical patterns; for example people spoke consistently faster in some regions than others. We hope to do such further analyses with the English data in the near future.”

̽��ֱ��findings of the German-speaking experiments were published last week in PLOS ONE.

An app that tries to guess your regional accent based on your pronunciation of 26 words and colloquialisms will help Cambridge academics track the movement and changes to English dialects in the modern era.

We hope that people in their tens of thousands will download the app and let us know their results.

Adrian Leemann

Screen grab of one of the app's questions

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

Yes

Licence type:

Attribution-Noncommercial-ShareAlike