PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Scientists discover new variability in iron supply to the oceans with climate implications

2013-07-19
(Press-News.org) The supply of dissolved iron to oceans around continental shelves has been found to be more variable by region than previously believed – with implications for future climate prediction.

Iron is key to the removal of carbon dioxide from the Earth's atmosphere as it promotes the growth of microscopic marine plants (phytoplankton), which mop up the greenhouse gas and lock it away in the ocean.

A new study, led by researchers based at the National Oceanography Centre Southampton, has found that the amount of dissolved iron released into the ocean from continental margins displays variability not currently captured by ocean-climate prediction models. This could alter predictions of future climate change because iron, a key micronutrient, plays an important role in the global carbon cycle.

Previously assumed to reflect rates of microbial activity, the study found that the amount of iron leaking from continental margins (the seafloor sediments close to continents) is actually far more varied between regions because of local differences in weathering and erosion on land. The results of the study are published this week in Nature Communications.

"Iron acts like a giant lever on marine life storing carbon," says Dr Will Homoky, lead author and postdoctoral research fellow at University of Southampton Ocean and Earth Science, which is based at the Centre. "It switches on growth of microscopic marine plants, which extract carbon dioxide from our atmosphere and lock it away in the ocean."

Continental margins are a major source of dissolved iron to the oceans and therefore an important factor for climate prediction models. But until now, measurements have only been taken in a limited number of regions across the globe, all of which have been characterised by low oxygen levels and high sedimentation rates. The present study focussed on a region with contrasting environmental conditions – in Atlantic waters off the coast of South Africa.

"We were keen to measure iron from this region because it is so different to areas studied before. The seawater here contains more oxygen, and sediments accumulate much more slowly on the seafloor because the region is drier and geologically less active," says Professor Rachel Mills, co-author at the University of Southampton.

The team found substantially smaller amounts of iron being supplied to seawater than measured anywhere before – challenging preconceptions of iron supply across the globe.

The researchers also identified that there are two different mechanisms by which rocks are dissolving on the seafloor. They did this by measuring the isotopic composition of the iron, using a technique developed with co-authors based at the University of South Carolina.

"We already knew that microbial processes dissolve iron in rocks and minerals," says Dr Homoky, "but now we find that rocks also dissolve passively and release iron to seawater. A bit like sugar dissolving in a cup of tea.

"The fact that we have found a new mechanism makes us question how much iron is leaking out from other areas of the ocean floor. If certain rocks are going to dissolve irrespective of microbial processes, suddenly there are whole regions that might be supplying iron that are presently unaccounted for."

But how much can this one factor really affect changes in the Earth's climate? Dr Homoky explains: "Model simulations indicate that the presence or absence of iron supply from continental margins may be enough to drive Earth's transition between glacial and interglacial periods," he says. "Therefore these findings could certainly have implications for global climate modelling – to what extent, is yet to be determined.

"Our study shows that the amount of iron coming off different margins might vary by up to ten thousand times. In some regions we are probably overestimating – and in others underestimating – the influence of sedimentary iron supply on the ocean's carbon cycle. The goal now is to refine this knowledge to improve ocean-climate models."



INFORMATION:

The study formed part of the international GEOTRACES programme (http://www.geotraces.org). The UK contribution was funded by the UK's Natural Environment Research Council (NERC), including the two UK-led research expeditions across the Atlantic Ocean.

Notes for editors

1. Reference: Homoky, W. B. et al. Distinct iron isotopic signatures and supply from marine sediment dissolution. Nat. Commun. 4:2143 doi: 10.1038/ncomms3143 (2013).

2. The image shows a satellite-captured view of a productive ocean margin in the western South Atlantic Ocean. Visible milky-blue swirls of ocean colour are blooms of tiny phytoplankton taking up carbon dioxide in the surface ocean. These blooms are caused by ocean currents, which stir nutrient laden waters from the continental margins into the sunlit surface ocean. Rivers, like the South American Río de la Plata or River Plate shown here, are an important source of nutrient-rich material to shelf systems. Credit: NASA http://visibleearth.nasa.gov/view.php?id=75351

3. Dr Will Homoky is a NERC funded Postdoctoral Research Fellow at the University of Southampton, and Professor Rachel Mills is the Principal Investigator at the University of Southampton leading on the NERC funded GEOTRACES programme.

4. GEOTRACES is an international programme, which aims to improve the understanding of biogeochemical cycles and large-scale distribution of chemical elements and their isotopes in the marine environment. Scientists from approximately 35 nations have been involved in the programme, which is designed to study all major ocean basins over the next decade. The UK is leading research efforts in the Atlantic Ocean, with funding provided by the Natural Environment Research Council (NERC).

5. The National Oceanography Centre (NOC) is the UK's leading institution for integrated coastal and deep ocean research. NOC operates the Royal Research Ships James Cook and Discovery and develops technology for coastal and deep ocean research. Working with its partners NOC provides long-term marine science capability including: sustained ocean observing, state-of-the-art numerical ocean models, mapping and surveying, data management and scientific advice.

NOC operates at two sites, Southampton and Liverpool, with the headquarters based in Southampton.

Among the resources that NOC provides on behalf of the UK are the British Oceanographic Data Centre (BODC), the Marine Autonomous and Robotic Systems (MARS) facility, the National Tide and Sea Level Facility (NTSLF), the Permanent Service for Mean Sea Level (PSMSL) and British Ocean Sediment Core Research Facility (BOSCORF).

The National Oceanography Centre is wholly owned by the Natural Environment Research Council (NERC).

6. University of Southampton School of Ocean and Earth Science is based at the National Oceanography Centre Southampton.

Contact details

Catherine Beswick, Communications and Public Engagement, National Oceanography Centre, catherine.beswick@noc.ac.uk, +44 238 059 8490

The National Oceanography Centre has an ISDN-enabled radio broadcast studio.



ELSE PRESS RELEASES FROM THIS DATE:

Cheaper anti-cancer drug as effective as expensive drug in treating wet AMD

2013-07-19
An anti-cancer drug has been proven to be equally as effective in treating the most common cause of blindness in older adults as a more expensive drug specifically formulated for this purpose. The results of a two-year trial, led by Queen's scientist Professor Usha Chakravarthy, and published in The Lancet today (Friday 19 July), show that two drug treatments Lucentis and Avastin are equally effective in treating neovascular or wet age-related macular degeneration (wet AMD). Wet AMD is a common cause of sight loss in older people with at least 23,000 older people diagnosed ...

Overnights away from home affect children's attachments, U.Va. study shows

2013-07-19
Babies have an innate biological need to be attached to caregivers, usually their parents. But what happens when babies spend a night or more per week away from a primary caregiver, as increasingly happens in cases where the parents share custody, but do not live together? In a new national study, University of Virginia researchers found that infants who spent at least one night per week away from their mothers had more insecure attachments to the mother compared to babies who had fewer overnights or saw their fathers only during the day. The finding is reported in the ...

The hair of the dog

2013-07-19
Just over a century ago, Harvey Cushing published an account of a young woman who showed unusual symptoms because her glands were making excessive amounts of something. Subsequent research has shown that the thing in question is a set of hormones known as glucocorticoids that are produced by the adrenal glands, so "Cushing's disease" is now more commonly known as hyperadrenocorticism, at least by those who can pronounce it. The condition is particularly common in dogs, particularly as the animals grow older. Most cases result from a tumor in the pituitary gland but some ...

Haste and waste on neuronal pathways

2013-07-19
This news release is available in German. To write this little piece of text, the brain sends commands to arms and fingers to tap on the keyboard. Neuronal cells with their cable-like extensions, such as axons, transfer this information as electrical pulses that trigger muscles to move. The axonal signal speed can be to up to 100m/s in myelinated axons along the spinal cord. For a long time, scientists assumed that axonal signal conduction is by and large digital: either there is a signal, "1", or there is no signal, "0". Strong propagation speed variations Now, ...

Disney Research develops method to provide tactile feedback in free air

2013-07-19
Depth cameras and other motion-tracking devices allow people to use natural gestures to play computer games, yet the experience remains unnatural because they can't feel what their eyes can see. Disney Research, Pittsburgh, has developed a solution, however, that could enhance not only games, but a variety of virtual experiences. Called AIREAL, the new technology uses controlled puffs of compressed air – something akin to smoke rings – to create the impression of a ball bouncing off a hand, of an arm tingling from the flutter of a butterfly's wings, or of the rippling ...

Disney researchers reconstruct detailed 3D scenes from hundreds of high-resolution 2D images

2013-07-19
Investigators at Disney Research, Zürich have developed a method for using hundreds of photographic images to build 3D computer models of complex, real-life scenes that meet the increasing demands of today's movie, TV and game producers for high-resolution imagery. Building 3D models from multiple 2D images captured from a variety of viewing positions is nothing new, but doing so for highly detailed or cluttered environments at high resolution has proved difficult because of the large amounts of data involved. The Disney Research, Zürich team, however, developed an algorithm ...

Controlling friction by tuning van der Waals forces

2013-07-19
This news release is available in German. For a car to accelerate there has to be friction between the tire and the surface of the road. The amount of friction generated depends on numerous factors, including the minute intermolecular forces acting between the two surfaces in contact – so-called van der Waals forces. The importance of these intermolecular interactions in generating friction has long been known, but has now been demonstrated experimentally for the first time by a research team led by Physics Professor Karin Jacobs from Saarland University and Professor ...

It's not just the heat -- it's the ozone: Study highlights hidden dangers

2013-07-19
During heat waves -- when ozone production rises -- plants' ozone absorption is curtailed, leaving more pollution in the air, and costing an estimated 460 lives in the UK in the hot summer of 2006. Vegetation plays a crucial role in reducing air pollution, but new research by the Stockholm Environment Institute (SEI) at the University of York shows that they may not protect us when we need it most: during extreme heat, when ozone formation from traffic fumes, industrial processes and other sources is at its worst. The reason, explained lead author Dr Lisa Emberson, is ...

Tuberculosis genomes recovered from 200-year old Hungarian mummy

2013-07-19
Researchers at the University of Warwick have recovered tuberculosis (TB) genomes from the lung tissue of a 215-year old mummy using a technique known as metagenomics. The team, led by Professor Mark Pallen, Professor of Microbial Genomics at Warwick Medical School, working with Helen Donoghue at University College London and collaborators in Birmingham and Budapest, sought to use the technique to identify TB DNA in a historical specimen. The term 'metagenomics' is used to describe the open-ended sequencing of DNA from samples without the need for culture or target-specific ...

Alternative target for breast cancer drugs

2013-07-19
HEIDELBERG, 19 July 2013 – Scientists have identified higher levels of a receptor protein found on the surface of human breast tumour cells that may serve as a new drug target for the treatment of breast cancer. The results, which are published today in EMBO Molecular Medicine, show that elevated levels of the protein Ret, which is short for "Rearranged during transfection", are associated with a lower likelihood of survival for breast cancer patients in the years following surgery to remove tumours and cancerous tissue. "Our findings suggest that Ret kinase might be an ...

LAST 30 PRESS RELEASES:

Pink skies

Monkeys are world’s best yodellers - new research

Key differences between visual- and memory-led Alzheimer’s discovered

% weight loss targets in obesity management – is this the wrong objective?

An app can change how you see yourself at work

NYC speed cameras take six months to change driver behavior, effects vary by neighborhood, new study reveals

New research shows that propaganda is on the rise in China

Even the richest Americans face shorter lifespans than their European counterparts, study finds

Novel genes linked to rare childhood diarrhea

New computer model reveals how Bronze Age Scandinavians could have crossed the sea

Novel point-of-care technology delivers accurate HIV results in minutes

Researchers reveal key brain differences to explain why Ritalin helps improve focus in some more than others

Study finds nearly five-fold increase in hospitalizations for common cause of stroke

Study reveals how alcohol abuse damages cognition

Medicinal cannabis is linked to long-term benefits in health-related quality of life

Microplastics detected in cat placentas and fetuses during early pregnancy

Ancient amphibians as big as alligators died in mass mortality event in Triassic Wyoming

Scientists uncover the first clear evidence of air sacs in the fossilized bones of alvarezsaurian dinosaurs: the "hollow bones" which help modern day birds to fly

Alcohol makes male flies sexy

TB patients globally often incur "catastrophic costs" of up to $11,329 USD, despite many countries offering free treatment, with predominant drivers of cost being hospitalization and loss of income

Study links teen girls’ screen time to sleep disruptions and depression

Scientists unveil starfish-inspired wearable tech for heart monitoring

Footprints reveal prehistoric Scottish lagoons were stomping grounds for giant Jurassic dinosaurs

AI effectively predicts dementia risk in American Indian/Alaska Native elders

First guideline on newborn screening for cystic fibrosis calls for changes in practice to improve outcomes

Existing international law can help secure peace and security in outer space, study shows

Pinning down the process of West Nile virus transmission

UTA-backed research tackles health challenges across ages

In pancreatic cancer, a race against time

Targeting FGFR2 may prevent or delay some KRAS-mutated pancreatic cancers

[Press-News.org] Scientists discover new variability in iron supply to the oceans with climate implications