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

Earth's iron core is surprisingly weak, Stanford researchers say

2013-05-20
(Press-News.org) The massive ball of iron sitting at the center of Earth is not quite as "rock-solid" as has been thought, say two Stanford mineral physicists. By conducting experiments that simulate the immense pressures deep in the planet's interior, the researchers determined that iron in Earth's inner core is only about 40 percent as strong as previous studies estimated.

This is the first time scientists have been able to experimentally measure the effect of such intense pressure – as high as 3 million times the pressure Earth's atmosphere exerts at sea level – in a laboratory. A paper presenting the results of their study is available online in Nature Geoscience.

"The strength of iron under these extreme pressures is startlingly weak," said Arianna Gleason, a postdoctoral researcher in the department of Geological and Environmental Sciences, and lead author of the paper. Wendy Mao, an assistant professor in the department, is the co-author.

"This strength measurement can help us understand how the core deforms over long time scales, which influences how we think about Earth's evolution and planetary evolution in general," Gleason said.

Until now, almost all of what is known about Earth's inner core came from studies tracking seismic waves as they travel from the surface of the planet through the interior. Those studies have shown that the travel time through the inner core isn't the same in every direction, indicating that the inner core itself is not uniform. Over time and subjected to great pressure, the core has developed a sort of fabric as grains of iron elongate and align lengthwise in parallel formations.

The ease and speed with which iron grains in the inner core can deform and align would have influenced the evolution of the early Earth and development of the geomagnetic field. The field is generated by the circulation of liquid iron in the outer core around the solid inner core and shields Earth from the full intensity of solar radiation. Without the geomagnetic field, life – at least as we know it – would not be possible on Earth.

"The development of the inner core would certainly have some effect on the geomagnetic field, but just what effect and the magnitude of the effect, we can't say," said Mao. "That is very speculative."

Gleason and Mao conducted their experiments using a diamond anvil cell – a device that can exert immense pressure on tiny samples clenched between two diamonds. They subjected minute amounts of pure iron to pressures between 200 and 300 gigapascals (equivalent to the pressure of 2 million to 3 million Earth atmospheres). Previous experimental studies were conducted in the range of only 10 gigapascals.

"We really pushed the limit here in terms of experimental conditions," Gleason said. "Pioneering advancements in pressure-generation techniques and improvements in detector sensitivity, for example, used at large X-ray synchrotron facilities, such as Argonne National Lab, have allowed us to make these new measurements."

In addition to intense pressures, the inner core also has extreme temperatures. The boundary between the inner and outer core has temperatures comparable to the surface of the sun. Simultaneously simulating both the pressure and temperature at the inner core isn't yet possible in the laboratory, though Gleason and Mao are working on that for future studies. (For this study, Gleason mathematically extrapolated from their pressure data to factor in the effect of temperature.)

Gleason and Mao expect their findings will help other researchers set more realistic variables for conducting their own experiments.

"People modeling the inner core haven't had many experimental constraints, because it's so difficult to make measurements under those conditions," Mao said. "There really weren't constraints on how strong the core was, so this is really a fundamental new constraint."

### Louis Bergeron is a science writer based in San Francisco.


ELSE PRESS RELEASES FROM THIS DATE:

Immune protein could stop diabetes in its tracks

2013-05-20
Melbourne researchers have identified an immune protein that has the potential to stop or reverse the development of type 1 diabetes in its early stages, before insulin-producing cells have been destroyed. The discovery has wider repercussions, as the protein is responsible for protecting the body against excessive immune responses, and could be used to treat, or even prevent, other immune disorders such as multiple sclerosis and rheumatoid arthritis. Professor Len Harrison, Dr Esther Bandala-Sanchez and Dr Yuxia Zhang led the research team from the Walter and Eliza ...

Competition in the quantum world

2013-05-20
This news release is available in German. "When water boils, its molecules are released as vapor. We call this change of the physical state of matter a phase transition," explains Sebastian Diehl from the Institute of Theoretical Physics at the University of Innsbruck. Together with his colleagues from the Institute for Experimental Physics and the theorist Markus Mueller from the Complutense University of Madrid, he studied the transition between two quantum mechanical orders in a way never before observed. The quantum physicists in Innsbruck use a new device ...

Diabetes drug tested in Parkinson's disease patients

2013-05-20
Parkinson's disease (PD) is a degenerative neurological disorder marked by a progressive loss of motor control. Despite intensive research, there are currently no approved therapies that have been demonstrated to alter the progression of the disease. In this issue of the Journal of Clinical Investigation, Dr. Thomas Foltynie and colleagues at the National Hospital for Neurology and Neurosurgery in London investigated the use of a drug approved for diabetes care, Exenatide, in PD patients. PD patients were divided into two groups: 20 patients received Exenatide injections ...

Women with severe injuries are less likely than men to be treated in a trauma center

2013-05-20
ATS 2013, PHILADELPHIA - Women are less likely than men to receive care in a trauma center after severe injury, according to a new study of almost 100,000 Canadian patients. "Gender-based disparities in access to healthcare services in general have been recognized for some time and evidence is emerging that these disparities extend to the treatment of severe injuries in trauma centers," says lead author Andrea Hill. MSc, PhD, a post-doctoral fellow at Sunnybrook Health Sciences Centre and the University of Toronto in Ontario, Canada. "Our study confirms and expands on ...

Source of infection affects hospital mortality in septic shock patients in the ICU

2013-05-20
In ICU patients who have septic shock, the anatomic source of infection has a strong effect on the chances of survival, according to a new study from researchers in Canada. "Understanding the local infection source in patients with septic shock may influence treatment strategies and clinical outcomes," said researcher Peter Dodek, MD MHSc, professor of critical care medicine at the University of British Columbia in Vancouver. "Accordingly, we examined the relationship between anatomic source of infection and hospital mortality in nearly 8,000 patients who had septic ...

New study identifies risk factors for depression among COPD patients

2013-05-20
ATS 2013, PHILADELPHIA ─ Patients suffering from chronic obstructive pulmonary disease (COPD) typically suffer from depression more frequently than those without COPD, resulting in higher levels of disability and illness and increasing the overall healthcare burden for the COPD population. Now, a study from researchers in Argentina indicates female COPD patients and patients who experience significant shortness of breath may have the greatest risk for developing depression. The results of the study will be presented at the ATS 2013 International Conference. "About ...

Stress test may help predict increased mortality risk in sleep apnea patients

2013-05-20
ATS 2013, PHILADELPHIA – Many studies have shown that men and women who suffer from obstructive sleep apnea (OSA) - a disorder that causes breathing to halt intermittently during sleep – have a higher mortality rate than those who do not have the disorder. Now, a study from researchers at the Cleveland Clinic shows that OSA patients who also have poor functional capacity have an even greater risk of mortality and suggests that an assessment of functional capacity in this population can help physicians identify patients most at risk for death. The results of the study ...

Metabolic biomarkers can predict mortality in the ICU

2013-05-20
ATS 2013, PHILADELPHIA – A metabolic profile of intensive care unit (ICU) patients based on biomarkers of four metabolites can be used to accurately predict mortality, according to a new study. "Existing models for predicting mortality in the ICU may not always be accurate and they can also be cumbersome to use," said researcher Angela J. Rogers MD, MPH, Instructor in Medicine at Channing Laboratory, Brigham and Women's Hospital, Harvard Medical School in Boston. "Levels of lactate, a metabolite from the carbohydrate pathway, are an established biomarker for ICU mortality. ...

Food laboratory accuracy remains a concern

2013-05-20
Food microbiology laboratories continue to submit false negative results and false positive results on a routine basis. A retrospective study of nearly 40,000 proficiency test results over the past 14 years, presented today at the 113th General Meeting of the American Society for Microbiology, examined the ability of food laboratories to detect or rule out the presence of Escherichia coli O157:H7, Salmonella, Listeria monocytogenes, and Campylobacter. "There is concern when laboratories report that pathogens are not found in a food sample, when in fact they are there," ...

Pharmaceutical advances offer new options for health outcomes

2013-05-20
Orlando, FL (May 20, 2013) — Research presented at Digestive Disease Week® (DDW) explores pharmaceutical advances for treating irritable bowel syndrome with diarrhea (IBS-D) and hepatitis C. An international study holds promising results for patients suffering from IBS-D. In the phase II study, researchers found that the drug ibodutant significantly improved symptoms in more than 50 percent of the individuals treated. "While there's been a lot of progress in medicines for IBS with constipation, we haven't seen the same in IBS with diarrhea," said Jan Tack, MD, professor ...

LAST 30 PRESS RELEASES:

Thirty-year mystery of dissonance in the “ringing” of black holes explained

Less intensive works best for agricultural soil

Arctic rivers project receives “national champion” designation from frontiers foundation

Computational biology paves the way for new ALS tests

Study offers new hope for babies born with opioid withdrawal syndrome

UT, Volkswagen Group of America celebrate research partnership

New Medicare program could dramatically improve affordability for cancer drugs – if patients enroll

Are ‘zombie’ skin cells harmful or helpful? The answer may be in their shapes

University of Cincinnati Cancer Center presents research at AACR 2025

Head and neck, breast, lung and survivorship studies headline Dana-Farber research at AACR Annual Meeting 2025

AACR: Researchers share promising results from MD Anderson clinical trials

New research explains why our waistlines expand in middle age

Advancements in muon detection: Taishan Antineutrino Observatory's innovative top veto tracker

Chips off the old block

Microvascular decompression combined with nerve combing for atypical trigeminal neuralgia

Cutting the complexity from digital carpentry

Lung immune cell type “quietly” controls inflammation in COVID-19

Fiscal impact of expanded Medicare coverage for GLP-1 receptor agonists to treat obesity

State and sociodemographic trends in US cigarette smoking with future projections

Young adults drive historic decline in smoking

NFCR congratulates Dr. Robert C. Bast, Jr. on receiving the AACR-Daniel D. Von Hoff Award for Outstanding Contributions to Education and Training in Cancer Research

Chimpanzee stem cells offer new insights into early embryonic development

This injected protein-like polymer helps tissues heal after a heart attack

FlexTech inaugural issue launches, pioneering interdisciplinary innovation in flexible technology

In Down syndrome mice, 40Hz light and sound improve cognition, neurogenesis, connectivity

Methyl eugenol: potential to inhibit oxidative stress, address related diseases, and its toxicological effects

A vascularized multilayer chip reveals shear stress-induced angiogenesis in diverse fluid conditions

AI helps unravel a cause of Alzheimer's disease and identify a therapeutic candidate

Coalition of Autism Scientists critiques US Department of Health and Human Services Autism Research Initiative

Structure dictates effectiveness, safety in nanomedicine

[Press-News.org] Earth's iron core is surprisingly weak, Stanford researchers say