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Large topographic features are caused by subtle changes in the uppermost mantle

From Department of Earth Sciences. Published on Oct 01, 2020.

Brazil’s Borborema Plateau is in the middle of the South American plate - well away from the dynamic tectonic forces of subduction in the Andes Volcanic Belt. Plate theory suggests that passive areas like Borborema should be flat and stable, with little movement of the crust. But the region, which is thousands of kilometres across and a domed shape, has actually risen by up to a kilometre over the last 30 million years.

Could there be life on Venus? Dr Paul Rimmer explains

By Erin Martin-Jones from Cambridge Earth Sciences blog. Published on Sep 21, 2020.

A UK-led team of astronomers recently discovered a rare molecule – phosphine – in the clouds of Venus that could have been created by microbes. We caught up with one of the co-authors of the study – Dr Paul Rimmer, a postdoctoral researcher at the Department of Earth Sciences Cambridge with affiliations at Cavendish Astrophysics …

Phosphine clouds suggest Venus could host life

From Department of Earth Sciences. Published on Sep 14, 2020.

A UK-led team of astronomers involving Dr Paul Rimmer, a postdoctoral researcher at the Department of Earth Sciences with affiliations at Cavendish Astrophysics and the MRC Labratory of Molecular Biology, has discovered a rare molecule – phosphine – in the clouds of Venus, hinting to the possibility of extra-terrestrial life.

Hints of life discovered on Venus

By sc604 from University of Cambridge - Department of Earth Sciences. Published on Sep 14, 2020.

Synthesized false colour image of Venus

Astronomers have speculated for decades that high clouds on Venus could offer a home for microbes – floating free of the scorching surface, but tolerating very high acidity. The detection of phosphine molecules, which consist of hydrogen and phosphorus, is an important step in the search for life beyond Earth, a key question in science. The results are reported in the journal Nature Astronomy.

The discovery was made by Professor Jane Greaves while she was a visitor at the University of Cambridge’s Institute of Astronomy. Greaves and her collaborators used the James Clerk Maxwell Telescope (JCMT) in Hawaii to detect the phosphine, and followed up their discovery on the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. Both facilities observe Venus at a wavelength of about 1 millimetre, much longer than the human eye can see.

“This was an experiment made out of pure curiosity, really – taking advantage of JCMT’s powerful technology, and thinking about future instruments,” said Greaves, who is based at Cardiff University. “I thought we’d just be able to rule out extreme scenarios, like the clouds being stuffed full of organisms. When we got the first hints of phosphine in Venus’ spectrum, it was a shock!”

Luckily, conditions were good at ALMA for follow-up observations while Venus was at a suitable angle to Earth. Processing the data was challenging, however, as ALMA isn’t usually looking for subtle effects in bright objects like Venus.

“In the end, we found that both observatories had seen the same thing – faint absorption at the right wavelength to be phosphine gas, where the molecules are backlit by the warmer clouds below,” said Greaves.

Using existing models of the Venusian atmosphere to interpret the data, the researchers found that phosphine is present but scarce – only about twenty molecules in every billion. The astronomers then ran calculations to see if the phosphine could come from natural processes on Venus. They caution that some information is lacking – in fact, the only other study of phosphorus on Venus came from one lander experiment, carried by the Soviet Vega 2 mission in 1985.

On Earth, phosphine is only made industrially or by microbes that thrive in oxygen-free environments. Co-author Dr William Bains from MIT led the work on assessing natural ways to make phosphine on Venus. Ideas included sunlight, minerals blown upwards from the surface, volcanoes, or lightning, but none of these could make anywhere near enough. Natural sources were found to make at most one ten-thousandth of the amount of phosphine that the telescopes saw.

To create the observed quantity of phosphine on Venus, terrestrial organisms would only need to work at about 10% of their maximum productivity, according to calculations by co-author Dr Paul Rimmer of Cambridge’s Department of Earth Sciences. Any microbes on Venus will likely be very different from their Earth cousins though, to survive in hyper-acidic conditions.

“This discovery brings us right to the shores of the unknown,” said Rimmer, who is also affiliated with Cambridge's Cavendish Laboratory. “Phosphine is very hard to make in the oxygen-rich, hydrogen-poor clouds of Venus and fairly easy to destroy. The presence of life is the only known explanation for the amount of phosphine inferred by observations.

“Both of these facts lie at the edge of our knowledge: the observations could be caused by an unknown molecule, or could be caused by chemistry we’re not aware of. Ultimately, the only way to find out what's really happening is to send a mission into the clouds of Venus to take a sample of the droplets and look at them to see what's inside.”

Earth bacteria can absorb phosphate minerals, add hydrogen, and ultimately expel phosphine gas. It costs them energy to do this, so why they do it is not clear. The phosphine could be just a waste product, but other scientists have suggested purposes like warding off rival bacteria.

Co-author Dr Clara Sousa Silva from MIT was also thinking about searching for phosphine as a ‘biosignature’ gas of non-oxygen-using life on planets around other stars because normal chemistry makes so little of it. “Finding phosphine on Venus was an unexpected bonus,” she said. “The discovery raises many questions, such as how any organisms could survive. On Earth, some microbes can cope with up to about 5% acid in their environment – but the clouds of Venus are almost entirely made of acid.”

Other possible biosignatures in the Solar System may exist, like methane on Mars and water venting from the icy moons Europa and Enceladus. On Venus, it has been suggested that dark streaks where ultraviolet light is absorbed could come from colonies of microbes. The Akatsuki spacecraft, launched by the Japanese space agency JAXA, is currently mapping these dark streaks to understand more about this unknown ultraviolet absorber.

The team believes their discovery is significant because they can rule out many alternative ways to make phosphine, but they acknowledge that confirming the presence of ‘life’ needs a lot more work. Although the high clouds of Venus have temperatures up to a pleasant 30 degrees Celsius, they are incredibly acidic – around 90% sulphuric acid – posing major issues for microbes to survive there. The researchers are investigating the possibility that the microbes could shield themselves inside droplets.

The team is now awaiting more telescope time to establish whether the phosphine is in a relatively temperate part of the clouds and to look for other gases associated with life. New space missions could also travel to our neighbouring planet, and sample the clouds to search for signs of life.

Professor Emma Bunce, President of the Royal Astronomical Society, said: “A key question in science is whether life exists beyond Earth, and the discovery by Professor Jane Greaves and her team is a key step forward in that quest. I’m particularly delighted to see UK scientists leading such an important breakthrough – something that makes a strong case for a return space mission to Venus.”

Reference:
Jane S. Greaves et al. ‘Phosphine Gas in the Cloud Decks of Venus.’ Nature Astronomy (2020). DOI: 10.1038/s41550-020-1174-4

Adapted from an RAS press release.

A UK-led team of astronomers has discovered a rare molecule – phosphine – in the clouds of Venus, pointing to the possibility of extra-terrestrial ‘aerial’ life.

The presence of life is the only known explanation for the amount of phosphine inferred by observations
Paul Rimmer
Synthesized false colour image of Venus

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Seismology in schools

By Rory Cockshaw from Cambridge Earth Sciences blog. Published on Sep 14, 2020.

Throughout July, Gemma Shaw, Hero Bain, and myself (all Earth Sciences students at varying levels) set out on an internship spearheaded by Dr Jenny Jenkins of the Deep Earth Seismology Group. Our aim was to bring the latest research from Cambridge Earth Sciences to secondary schools across the country.  Very few science or maths teachers …

New record of Earth’s Cenozoic climate reveals defining role of polar ice

From Department of Earth Sciences. Published on Sep 10, 2020.

Research published today in Science presents a new record of Earth’s temperature and glaciation since the end of the age of the dinosaurs, revealing the changing state of the climate system through the last 66 million years.

Atomic-scale imaging of uranium dioxide reveals how nuclear waste breaks down

From Department of Earth Sciences. Published on Sep 01, 2020.

A recent study, led by Dr Aleksej Popel and directed by Professor Ian Farnan, both at the Department of Earth Sciences and Cambridge Nuclear Energy Centre, has observed the surface breakdown of uranium dioxide, the primary component of nuclear fuel, shedding light on the mechanism and rate of waste leaching.

Scelidosaurus finally makes its way into the dinosaur family tree

From Department of Earth Sciences. Published on Aug 27, 2020.

The first complete dinosaur skeleton ever identified has finally been studied in detail and found its place in the dinosaur family tree, completing a project that began more than a century and a half ago.

Scelidosaurus: ready for its closeup at last

By sc604 from University of Cambridge - Department of Earth Sciences. Published on Aug 26, 2020.

The first complete dinosaur skeleton ever identified has finally been studied in detail and found its place in the dinosaur family tree, completing a project that began more than a century and a half ago.

Abrupt changes in Earth’s past climate occurred synchronously

From Department of Earth Sciences. Published on Aug 20, 2020.

An international study, involving Professor Eric Wolff at the Department of Earth Sciences, University of Cambridge, has found that the onset of past climate changes was synchronous over an area extending from the Arctic to the low latitudes.

Carbon dioxide pulses are a common feature of the carbon cycle

From Department of Earth Sciences. Published on Aug 20, 2020.

A multi-institutional study, involving researchers at the Department of Earth Sciences, University of Cambridge, has 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.

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

By cmm201 from University of Cambridge - Department of Earth Sciences. Published on Aug 20, 2020.

Concordia research station in Antarctica

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.

The 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 CO2 jumps - 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 University 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 (The 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.

The 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.

The researchers combined the new ice core data with detailed information on ocean circulation from marine sediments collected off the coast of Portugal. The 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.

The isotopic signal of the marine sediments showed the same pattern as the ice cores. “The 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
Concordia research station in Antarctica

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Abrupt changes in Earth’s past climate occurred synchronously

By cmm201 from University of Cambridge - Department of Earth Sciences. Published on Aug 20, 2020.

Speleothems in the Corchia Cave, Central Italy

The Last Glacial Period, between 115,000 and 11,700 years ago, was punctuated by a series of severe climate changes: warm periods where temperatures in Greenland spiked by 8-16°C over the course of a decade.

Data from the Greenland and Antarctic ice cores suggests that these warming events, known as Greenland Interstadials, occurred at least 25 times over this period. Their imprint has also been observed in climate records collected from mid to low latitudes, leading scientists to question whether these widespread changes were simultaneous, or whether warming in some regions lagged behind others.

But resolving this question has proved challenging because precisely dated records of past climate are relatively rare. And dating is key. If scientists could exactly pinpoint the relative timing of warming in different regions, they could answer whether the climate changed synchronously. 

The study, published in the journal Science and led by University of Melbourne PhD student Ellen Corrick, uses detailed climate data from stalagmites (speleothems) to compare the timing of climate changes between regions. Stalagmites take in detailed information on regional temperature and rainfall as they grow, and they can also be dated accurately, often to decadal resolution, using the uranium-thorium technique.

Corrick compiled climate data from 63 speleothem records collected from caves across Asia, Europe and South America - a dataset amounting to 20 years’ of published research from scientific teams around the world. The onset of many Greenland Interstadials was clearly recognisable in the speleothem data, each event marked by a shift in the contents of stable oxygen isotope, δ18O.

To test if the changes were synchronous, the team used statistical methods to compare the age of onset for the interstadials. Once they were sure that intraregional changes were simultaneous, the team looked at the relative timing of interstadials between Asia, Europe and South America. The wider comparison showed that, out of the 25 interstadials studied, 23 were synchronous.

According to co-author Professor Eric Wolff from Cambridge’s Department of Earth Sciences, the findings “provide confirmation of a persistent but, until now, unsubstantiated assumption that climate changes between the tropics and the Arctic were synchronous.”

The team went on to compare their speleothem data with model simulations of future abrupt climate changes. An interesting feature of this study is how well the climate model outputs agree with the stalagmite data. This gives us increased confidence in the climate models weve built,” said co-authro Professor Xu Zhang from Lanzhou University China, who conducted model experiments at the Alfred Wegener Institute in Germany.

The findings shed light on the patterns and timing of these warming phases, also known as Dansgaard-Oeschger events. But their cause, whether external factors, such the ice sheet height, greenhouse gases, meltwater and volcanism, or internal oscillations in Atlantic Ocean circulation, remains, as yet, an open question.

Reference:
E. Corrick et al.Synchronous timing of abrupt climate changes during the last glacial period.’ Science (2020). DOI: 10.1126/science.aay5538

Adapted from a press release by The University of Melbourne

A study from the Universities of Cambridge and Melbourne has found that the onset of past climate changes was synchronous over an area extending from the Arctic to the low latitudes.

These findings provide confirmation of a persistent but, until now, unsubstantiated assumption that climate changes between the tropics and the Arctic were synchronous
Eric Wolff
Speleothems in the Corchia Cave, Central Italy

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Studying in lockdown (or a lack thereof)

By James Craig from Cambridge Earth Sciences blog. Published on Jul 15, 2020.

Of all the cities to be locked down in away from Cambridge, my hometown of Durham wouldn’t normally make for too much of a contrast. Winding cobbled streets, hordes of students with a penchant for college stash and absolutely no sign of the 21st century are ordinarily staples of both cities. Yet when I headed …

Addressing racial inequality and inclusion in the Department of Earth Sciences

From Department of Earth Sciences. Published on Jun 10, 2020.

This post is a response on behalf of the Department of Earth Sciences to an open letter sent by undergraduates, postgraduates and post-docs prompted by the current vocalisation around racial injustice, and in particular the Black Lives Matter movement. The letter raises concerns about the Department and wider Earth science sector’s track records on diversity and inclusion, and urges a substantial and comprehensive shift in the approaches taken to addressing this. To date, more than 120 people have signed the letter.

Research in Lockdown: Labs Closed

By Will Knapp from Cambridge Earth Sciences blog. Published on Jun 08, 2020.

It’s been just shy of two months (I think) since I cleared my desk and left Cambridge as a result of the ongoing COVID-19 pandemic. This blog is a bit of a summary of my life in lockdown, my thoughts about my PhD progress, and my aims for the future. I started my PhD in …

Ozone depletion blamed for the end-Devonian mass extinction

From Department of Earth Sciences. Published on Jun 03, 2020.

359 million years ago, at the end of Devonian times, life on Earth suffered a catastrophic extinction—the cause of which has puzzled geologists for decades. Land plants and freshwater life were affected particularly badly. However, unlike other major extinctions, there is no evidence to suggest that major volcanic eruptions or asteroid impacts were to blame. Now a team of Earth scientists, including Sarah Wallace-Johnson from the University of Cambridge’s Sedgwick Museum, has found the cause.

Research in Lockdown: Fieldwork Disrupted

By Nick Barber from Cambridge Earth Sciences blog. Published on May 26, 2020.

My PhD concerns a longstanding question—how do valuable metals move through volcanic systems? Since starting my PhD in September 2018, I’ve been looking forward to testing my hypotheses on this topic in the field, on a six-week expedition called the Metals in Magmas field campaign. Like many Earth scientists, I spent months planning the project’s …

WACSWAIN: Sherman Island Drilling—Part Three

By Isobel Rowell from Cambridge Earth Sciences blog. Published on May 06, 2020.

In the final instalment of this WACSWAIN fieldwork diary, Isobel Rowell describes the heartbreak of ending her fieldwork earlier than planned, as drilling takes a dramatic turn. In case you missed them, Part One and Part Two are available on the blog. The Bad Day The weather eased a little over the next couple of …

The Royal Society announces election of new Fellows 2020

By jg533 from University of Cambridge - Department of Earth Sciences. Published on Apr 29, 2020.

Fellows are chosen for their outstanding contributions to scientific understanding. The 62 newly elected Fellows embody the global nature of science, and are elected for life through a peer review process based on excellence in science. Past Fellows and Foreign Members include Isaac Newton, Charles Darwin, Dorothy Hodgkin and Stephen Hawking.

The Royal Society is a self-governing Fellowship made up of the most eminent scientists, engineers and technologists from the UK and the Commonwealth. Its Foreign Members are drawn from the rest of the world. The Society’s fundamental purpose is to recognise, promote and support excellence in science and to encourage the development and use of science for the benefit of humanity.

Sir Venki Ramakrishnan, President of the Royal Society, said: “At this time of global crisis, the importance of scientific thinking, and the medicines, technologies and insights it delivers, has never been clearer. Our Fellows and Foreign Members are central to the mission of the Royal Society, to use science for the benefit of humanity.

"While election to the Fellowship is a recognition of exceptional individual contributions to the sciences, it is also a network of expertise that can be drawn on to address issues of societal, and global significance. This year’s Fellows and Foreign Members have helped shape the 21st century through their work at the cutting-edge of fields from human genomics, to climate science and machine learning. 

"It gives me great pleasure to celebrate these achievements, and those yet to come, and welcome them into the ranks of the Royal Society.”

 

The Cambridge scientists announced today as Royal Society Fellows are:

Professor Kevin Brindle FMedSci, Department of Biochemistry and Cancer Research UK Cambridge Institute. His current research is focused on novel imaging methods for detecting cancer progression and to monitor early tumour responses to treatment, with an emphasis on translating these techniques to the clinic.

Professor Vikram Deshpande, Department of Engineering, for his seminal contributions in microstructural mechanics. His works include developing ‘metallic wood’, sheets of nickel as strong as titanium, but four-times lighter thanks to their plant-like nanoscale pores.

Professor Marian Holness, Department of Earth Sciences. She has created a new approach to decoding rock history, and concentrates on understanding the evolution of bodies of magma trapped in the crust, which ultimately controls the eruptive behaviour of any overlying volcano. 

Professor Giles Oldroyd, Russell R Geiger Professor of Crop Science, Crop Science Centre and Group Leader, Sainsbury Laboratory. He is leading an international research programme attempting to achieve more equitable and sustainable agriculture through the enhanced use of beneficial microbial associations.  

Professor Hugh Osborn, Department of Applied Mathematics and Theoretical Physics for work in theoretical physics on quantum field theory and in particular conformal field theory. 

Professor Didier Queloz, Cavendish Laboratory, for his part in the discovery of the first planet beyond our solar system, for which he shared the Nobel Prize in Physics last year. Hundreds more exoplanets have since been revealed by his pioneering observational techniques.

Dr Sarah Teichmann FMedSci, Director of Research, Cavendish Laboratory and Senior Research Fellow, Churchill College, for her contributions to computational biology and genomics, including her role in founding and leading the Human Cell Atlas international consortium to map all cell types in the human body.

Professor Stephen Young, Department of Engineering, for pioneering the statistical approach to language processing - namely, treating conversation as a reinforcement learning problem - that made the speech-recognition products in millions of homes a reality.

Professor Jack Thorne, Department of Pure Maths and Mathematical Statistics for multiple breakthroughs in diverse areas of algebraic number theory. At age 32, he becomes the youngest living member of the Fellowship.

In addition, Dr William Schafer at the MRC Laboratory of Molecular Biology, based at the Cambridge Biomedical Campus, has been elected as a Fellow.

 

 

Nine Cambridge scientists are among the new Fellows announced today by the Royal Society. 

At this time of global crisis, the importance of scientific thinking, and the medicines, technologies and insights it delivers, has never been clearer.
Venki Ramakrishnan

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Coronavirus pandemic: making safer emergency hospitals

By lw355 from University of Cambridge - Department of Earth Sciences. Published on Apr 28, 2020.

Simple, low-cost ventilation designs and configuration of wards can reduce the dispersal of airborne virus in emergency COVID-19 hospitals, say Cambridge researchers.

WACSWAIN: Sherman Island Drilling—Part Two

By Isobel Rowell from Cambridge Earth Sciences blog. Published on Apr 27, 2020.

In part two of her three-part series, Isobel Rowell describes her daily routine as part of the WACSWAIN team, drilling into the Antarctic ice sheet and sampling ice chippings from the borehole in search of ice from the last interglacial. In case you missed it, Part One is available on the blog. The Sherman Island …

WACSWAIN: Sherman Island Drilling—Part One

By Isobel Rowell from Cambridge Earth Sciences blog. Published on Apr 14, 2020.

In a three-part series of blog posts, Isobel Rowell describes her experiences on the second field campaign of the WACSWAIN project. Part one outlines the motives behind the Sherman Island drilling project, and details the team’s journey to their drill site. Introduction The Sherman Island Drilling Project is the second of two field campaigns under …

Origins of Earth's magnetic field remain a mystery

From Department of Earth Sciences. Published on Apr 08, 2020.

Zircons, and their microscopic mineral inclusions, from an ancient outcrop of Jack Hills, Western Australia, have been at the centre of an intense geological debate: When did the Earth first create a magnetic field? Previous studies have suggested that these minerals record traces of Earth’s magnetic field dated as far back as 4.2 billion years ago (Ga). However, an international team led by MIT, and including Professor Richard Harrison (Dept of Earth Sciences, University of Cambridge), has now found evidence to the contrary.

Imaging of North-Sulawesi subduction in the Celebes Sea

By ChuanChuan Lü from Cambridge Earth Sciences blog. Published on Mar 30, 2020.

How does subduction start? The answer to this question remains enigmatic and controversial. The process of subduction, which drives global plate tectonics and helps to shape the Earth as we know it, began as early as 4.1 Ga, but how the first subduction zone initiated remains unknown. Some have argued that the plate tectonic cycle …

‘Wonderchicken’ fossil from the age of dinosaurs reveals origin of modern birds

By sc604 from University of Cambridge - Department of Earth Sciences. Published on Mar 18, 2020.

The oldest fossil of a modern bird yet found, dating from the age of dinosaurs, has been identified by an international team of palaeontologists.

Half billion-year-old 'social network' observed in early animals

By sc604 from University of Cambridge - Department of Earth Sciences. Published on Mar 05, 2020.

Some of the first animals on Earth were connected by networks of thread-like filaments, the earliest evidence yet found of life being connected in this way.

Deep Earth Explorers

By Jess Bartlet from Cambridge Earth Sciences blog. Published on Feb 24, 2020.

In this blog post, Jess Bartlet answers questions about her experiences as a Public Engagement Coordinator within Dr Sanne Cottaar’s deep Earth research group. Together, they seek to unravel and expose the mysteries of the Earth, thousands of kilometres beneath our feet. Working with the Sedgwick Museum of Earth Sciences, Jess is developing a series …

Taking a dinosaur's temperature

From Department of Earth Sciences. Published on Feb 14, 2020.

New chemical analyses of dinosaur eggshell by Dr Robin Dawson (Yale University), Dr Daniel Field (University of Cambridge), and colleagues from the US, Canada and Israel, show that representatives of all three major dinosaur groups were endothermic (i.e., warm-blooded). As such, thermal-regulation is likely to have been the ancestral condition for dinosaurs, and helps explain their remarkably successful occupation of Earth’s Mesozoic landscapes from pole to pole.

WACSWAIN: the hard slog of analysis

By Eric Wolff from Cambridge Earth Sciences blog. Published on Feb 05, 2020.

The last time I blogged about WACSWAIN was in January 2019, when we were in the euphoria of having drilled to the bedrock at Skytrain Ice Rise, and retrieved 651 metres of ice.  So what have we been doing since then? Well, firstly the ice had to travel safely (i.e., cold) to Cambridge. Our 130 …

Sand dunes can ‘communicate’ with each other

By sc604 from University of Cambridge - Department of Earth Sciences. Published on Feb 04, 2020.

Sand dune

Using an experimental dune ‘racetrack’, the researchers observed that two identical dunes start out close together, but over time they get further and further apart. This interaction is controlled by turbulent swirls from the upstream dune, which push the downstream dune away. The results, reported in the journal Physical Review Letters, are key for the study of long-term dune migration, which threatens shipping channels, increases desertification, and can bury infrastructure such as highways.

When a pile of sand is exposed to wind or water flow, it forms a dune shape and starts moving downstream with the flow. Sand dunes, whether in deserts, on river bottoms or sea beds, rarely occur in isolation and instead usually appear in large groups, forming striking patterns known as dune fields or corridors.

It’s well-known that active sand dunes migrate. Generally speaking, the speed of a dune is inverse to its size: smaller dunes move faster and larger dunes move slower. What hasn’t been understood is if and how dunes within a field interact with each other.

“There are different theories on dune interaction: one is that dunes of different sizes will collide, and keep colliding, until they form one giant dune, although this phenomenon has not yet been observed in nature,” said Karol Bacik, a PhD candidate in Cambridge’s Department of Applied Mathematics and Theoretical Physics, and the paper’s first author. “Another theory is that dunes might collide and exchange mass - sort of like billiard balls bouncing off one another - until they are the same size and move at the same speed, but we need to validate these theories experimentally.”

Now, Bacik and his Cambridge colleagues have shown results that question these explanations. “We’ve discovered physics that hasn’t been part of the model before,” said Dr Nathalie Vriend, who led the research.

Most of the work in modelling the behaviour of sand dunes is done numerically, but Vriend and the members of her lab designed and constructed a unique experimental facility which enables them to observe their long-term behaviour. Water-filled flumes are common tools for studying the movement of sand dunes in a lab setting, but the dunes can only be observed until they reach the end of the tank. Instead, the Cambridge researchers have built a circular flume so that the dunes can be observed for hours as the flume rotates, while high-speed cameras allow them to track the flow of individual particles in the dunes.

Bacik hadn’t originally meant to study the interaction between two dunes: “Originally, I put multiple dunes in the tank just to speed up data collection, but we didn’t expect to see how they started to interact with each other,” he said.

The two dunes started with the same volume and in the same shape. As the flow began to move across the two dunes, they started moving. “Since we know that the speed of a dune is related to its height, we expected that the two dunes would move at the same speed,” said Vriend, who is based at the BP Institute for Multiphase Flow. “However, this is not what we observed.”

Initially, the front dune moved faster than the back dune, but as the experiment continued, the front dune began to slow down, until the two dunes were moving at almost the same speed.

Crucially, the pattern of flow across the two dunes was observed to be different: the flow is deflected by the front dune, generating ‘swirls’ on the back dune and pushing it away. “The front dune generates the turbulence pattern which we see on the back dune,” said Vriend. “The flow structure behind the front dune is like a wake behind a boat, and affects the properties of the next dune.”

As the experiment continued, the dunes got further and further apart, until they form an equilibrium on opposite sides of the circular flume, remaining 180 degrees apart.

The next step for the research is to find quantitative evidence of large-scale and complex dune migration in deserts, using observations and satellite images. By tracking clusters of dunes over long periods, we can observe whether measures to divert the migration of dunes are effective or not.

Reference:
Karol A. Bacik et al. ‘Wake-induced long range repulsion of aqueous dunes.’ Physical Review Letters (2020). DOI: 10.1103/PhysRevLett.124.054501

Even though they are inanimate objects, sand dunes can ‘communicate’ with each other, researchers have found. A team from the University of Cambridge has found that as they move, sand dunes interact with and repel their downstream neighbours.

We’ve discovered physics that hasn’t been part of the model before
Nathalie Vriend
Sand dune

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'All the world's a stage'

From Department of Earth Sciences. Published on Feb 03, 2020.

According to Cambridge geologist Neil S. Davies and colleagues, Shakespeare was on the right track—again. Earth’s surface is indeed the stage upon which life has strutted its stuff, and has done so for the last 3.8 billion years. Billions of organisms have graced this stage, making their entrances and exits, but what was the impact of these ‘actors’? The answer has been locked up in Earth’s sedimentary record until now.

A top avian predator’s surprising past

From Department of Earth Sciences. Published on Jan 20, 2020.

A single fossil bone found in Japan is ruffling a few feathers in the world of avian palaeontology. It belongs to a relative of the little auk or dovekie, today the most common seabird and top avian predator in the Atlantic and Arctic Oceans. At around 700,000 years old, the fossil’s presence in Japan indicates that during the ‘Ice Age’, the little auk had a much wider range that extended into the Pacific. Discovered by Junya Watanabe of the Department of Earth Sciences in the University of Cambridge and colleagues from Japan’s Kyoto University, the find raises the question of why such a successful, competitive and adaptive seabird should have suffered such a significant reduction in range.

Arts Council England funding announced for the Sedgwick Museum

From Department of Earth Sciences. Published on Dec 18, 2019.

Arts Council England has announced that the Sedgwick Museum of Earth Sciences is among 28 organisations to be awarded Designation Development Funding. A total of £2.1 million has been awarded across the country, drawn from the National Lottery, with the Sedgwick Museum receiving £89,406

Above and beyond: measuring volcanic emissions with drones

By lw355 from University of Cambridge - Department of Earth Sciences. Published on Dec 06, 2019.

Dr Emma Liu travels to some of the world's most active volcanoes to understand what makes them erupt. Her latest work is helping a Pacific community to monitor the restless mountain they live with.

Sifting through the sediment

By Issy Baker from Cambridge Earth Sciences blog. Published on Dec 03, 2019.

While many of my friends spent their summer vacation swanning off to remote corners of the world for some well-deserved rest and relaxation, I decided that it would be fun to spend August doing some lab work in Cambridge—I was actually pleasantly surprised. I was working for Nick Butterfield on some lake sediments from Idaho, …

A ‘wet’ Summer: Cambridge and Tenerife

By Nikki Sridhar from Cambridge Earth Sciences blog. Published on Oct 08, 2019.

This summer I was lucky enough to complete an internship in Environmental Consultancy with Mott MacDonald followed by a Hydrology Field Training Programme run by GeoTenerife. As a geologist, it can be hard to see how an Earth Sciences degree can be directly used outside of academia or the traditional field of Oil and Gas: …

UKRI fellowship enables further research on the origins and evolution of birds

From Department of Earth Sciences. Published on Sep 20, 2019.

Announced today, Dr Field, University Lecturer in Evolutionary Palaeobiology, has been named a recipient of a Future Leaders Fellowship by UK Research and Innovation (UKRI). Dr Field is an expert on the origins and evolution of birds, and his award, entitled 'Modernisation, diversification, and domination: Macroevolutionary origins of living bird diversity', will fund his research for the next several years.

Mussels could 'tough out' climate change

From Department of Earth Sciences. Published on Aug 21, 2019.

Global environmental change is generally bad news for life on Earth. But the future may not be entirely doom and gloom. Cambridge biologist Luca Telesca and colleagues have conducted the first large-scale examination of natural variation in biomineralisation in ecologically and economically important Atlantic mussel species Mytilus edulis and M. trossulus within their natural habitats. Little is known about the processes, which allow species such as these to vary regionally. So the researchers tested the mussels ability to vary the production and composition of their calcareous shells which provides them with a resilience to the impacts of climate change in their shallow marine habitat.

More Impressions from ‘not a geologist’ – the Part III Spain field trip 2018

By Sarah Humbert from Cambridge Earth Sciences blog. Published on Jul 22, 2019.

The last field trip that our undergraduates take is the fourth year, Part III trip to Spain. Run in the break between Lent & Easter term the trip aims to gather all the aspects of the course and put them together as a cohesive whole. Other trips focus on specific research areas: e.g. Sedimentology and …

Professor Richard Harrison appointed Head of Department

From Department of Earth Sciences. Published on Jul 18, 2019.

Richard Harrison (Fitzwilliam 1990), Professor of Earth and Planetary Materials and Fellow of St Catharine’s College, will take over as Head of Department on 1st August 2019.

Perched for take-off

From Department of Earth Sciences. Published on Apr 02, 2019.

Perching birds, ranging from sparrows, tits and jays to the South African White-bellied Sunbird, form the largest and most diverse group of living birds. With over 6,000 species belonging to 143 families, the passerines, as they are technically known, have had astonishing evolutionary and geographical success. Within the last 45 million years they have spread out around the world. Now, for the first time the evolutionary tree of all major groups of perching birds has been mapped out in a study involving Daniel Field of the Department of Earth Sciences in Cambridge and led by Carl Oliveros and Brant Faircloth of Louisiana State University.

Geological Society awards for Cambridge researchers

From Department of Earth Sciences. Published on Mar 04, 2019.

Congratulations to Professor Marian Holness, Dr Nigel Woodcock and Dr Brendan McCormick Kilbride who each received awards from the Geological Society of London. The awards were presented on President's Day on 6 June 2019.

Historic Quito-Galápagos Alumni trip

By Sally Gibson from Cambridge Earth Sciences blog. Published on Feb 27, 2019.

The joint Cambridge-Oxford Universities Alumni trip to Historic Quito and Galápagos in September 2018 was the first time I’ve acted as a Trip Scholar. From the outset, I was intrigued as to who would be in the group and how the dynamics would work. I could not have been more pleased with the way things …

Magnetic properties of meteorite ‘cloudy zones’ revealed

From Department of Earth Sciences. Published on Feb 12, 2019.

A team led by Cambridge Earth Sciences' Joshua Einsle and Richard Harrison have used advanced microscopy techniques and numerical simulations to gain new insight into the formation, composition and magnetic behaviour of the meteoritic composite known as the ‘cloudy zone’.

Tales from Bear Island: a month of Arctic fieldwork (or, four weeks without a phone)

By Sean Herron from Cambridge Earth Sciences blog. Published on Feb 05, 2019.

In August 2018 I was lucky enough to join a CASP expedition to Bear Island, in the Norwegian High Arctic, as a field assistant and as part of my Part III project. My journey to the arctic began as so many do, in Heathrow airport. We unloaded the minivan-sized taxi required to get all our …

Interning at the Bermuda Institute of Ocean Sciences

By Anna Prescott from Cambridge Earth Sciences blog. Published on Jan 31, 2019.

Over the summer, I was fortunate enough to complete a research internship at the Bermuda Institute of Ocean Sciences (BIOS), known by locals as the ‘Biological Station’. I was therefore off to a tiny island in the middle of the Atlantic Ocean for two months to research the effects of climate change and swim with …

Research shows what it takes to be a giant shark

From Department of Earth Sciences. Published on Jan 24, 2019.

Have you ever wondered why the Megalodon shark became to be so big? Or wondered why some other sharks are much smaller?

Cambridge team reach bedrock to complete Antarctic ice core

From Department of Earth Sciences. Published on Jan 09, 2019.

WACSWAIN Drill Log: ice core complete!

By Eric Wolff from Cambridge Earth Sciences blog. Published on Jan 08, 2019.

The aim of our fieldwork in Antarctica is to retrieve an ice core reaching through the entire depth of the ice cap on Skytrain Ice Rise, to obtain ice extending at least 130,000 years back in time. Last night, on Tuesday 7 January, we succeeded. The feeling of elation is all around me, with all …

WACSWAIN Drill Log: Christmas in Antarctica

By Eric Wolff from Cambridge Earth Sciences blog. Published on Dec 31, 2018.

We’ve now been at Skytrain Ice Rise in Antarctica for about 6 weeks. In previous blogs, I have written about the life in camp and the drilling. Now, just after Christmas, it’s time to take stock of what we have achieved, and what we are aiming to do. The target is to drill an ice …

WACSWAIN Drill Log: ice core drilling begins

By Eric Wolff from Cambridge Earth Sciences blog. Published on Dec 10, 2018.

In order to achieve our goal of retrieving ice that is 130,000 years old, we need to drill a core to the bottom of the ice cap we’re camping on, through about 620 m of ice. All the work so far has been preparation for drilling, so what does the drilling actually involve? The end …

Liz Hide appointed as first full-time Director of the Sedgwick Museum

From Department of Earth Sciences. Published on Nov 28, 2018.

The Sedgwick Museum of Earth Sciences, the oldest of the University of Cambridge museums, has appointed its first full-time director.

Taking to the skies: measuring volcanic gas emissions using drones

From Department of Earth Sciences. Published on Oct 17, 2018.

Many of the world’s most hazardous volcanoes are either too remote or too active to make measurements safely from the ground. Cambridge Earth Scientists are now taking to the skies to investigate the gases being released by these elusive volcanoes.

Metals mark magma for life

From Department of Earth Sciences. Published on Sep 03, 2018.

Gases erupted by volcanoes contain various volatile metal products. New research by Marie Edmonds and Emma Liu in Cambridge and Tamsin Mather in Oxford has discovered that different kinds of volcanoes have distinctive metal ‘signatures’, which reflect differences in how their magma forms.

Lessons about a future warmer world using data from the past

From Department of Earth Sciences. Published on Jun 25, 2018.

Selected intervals in the past that were as warm or warmer than today can help us understand what the Earth may be like under future global warming. A latest assessment of past warm periods, by an international team of 59 scientists from 17 nations including Cambridge Earth Sciences' Professor Eric Wolff, shows that in response to the warming ecosystems and climate zones will spatially shift and on millennial time scales ice sheets will substantially shrink.

Dating the emplacement of the Shap granite using zircon

From Department of Earth Sciences. Published on Jun 07, 2018.

G5a - the distinctive coarse-grained, pink granite exposed at Shap in Cumbria - has long been a favourite igneous hand specimen for Earth Sciences teaching in Cambridge. New research uses the age of zircon crystal formation to suggest a long gestation period in the mid-crust before its final emplacement 405 million years ago.