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

Valley networks suggest ancient snowfall on Mars

2013-07-24
(Press-News.org) PROVIDENCE, R.I. [Brown University] — Valley networks branching across the Martian surface leave little doubt that water once flowed on the Red Planet. But where that ancient water came from — whether it bubbled up from underground or fell as rain or snow — is still debated by scientists. A new study by researchers at Brown University puts a new check mark in the precipitation column.

The study finds that water-carved valleys at four different locations on Mars appear to have been caused by runoff from orographic precipitation — snow or rain that falls when moist prevailing winds are pushed upward by mountain ridges. The new findings are the most detailed evidence yet of an orographic effect on ancient Mars and could shed new light on the planet's early climate and atmosphere.

A paper describing the work has been accepted by Geophysical Research Letters and published online in June.

Kat Scanlon, a geological sciences graduate student at Brown, led the research and is well-acquainted with the orographic effect. She did graduate work in meteorology in Hawaii, which is home to a quintessential orographic pattern. Moist tropical winds from the east are pushed upward when they hit the mountains of Hawaii's big island. The winds lack the kinetic energy to reach the mountain summit, so they dump their moisture on the eastern side of the island, making parts of it a tropical jungle. The western side, in contrast, is nearly a desert because it sits in a rain shadow cast by the mountain peak.

Scanlon thought similar orographic patterns might have been at play on early Mars and that the valley networks might be an indicator. "That's what immediately came to mind in trying to figure out if these valleys on Mars are precipitation related," she said.

The researchers, including Jim Head, professor of geological sciences, started by identifying four locations where valley networks were found along tall mountain ridges or raised crater rims. To establish the direction of the prevailing winds at each location, the researchers used a newly developed general circulation model (GCM) for Mars. The model simulates air movement based on the gas composition scientists think was present in the early Mars atmosphere. Next, the team used a model of orographic precipitation to determine where, given the prevailing winds from the GCM, precipitation would be likely to fall in each of the study areas.

Their simulations showed that precipitation would have been heaviest at the heads of the densest valley networks. "Their drainage density varies in the way you would expect from the complex response of precipitation to topography," Scanlon said. "We were able to confirm that in a pretty solid way."

The atmospheric parameters used in the GCM are based on a new comprehensive general circulation model that predicts a cold climate, so the precipitation modeled in this study was snow. But this snow could have been melted by episodic warming conditions to form the valley networks, and indeed some precipitation could have been rain during this period, Scanlon and Head say.

"The next step is to do some snowmelt modeling," she said. "The question is how fast can you melt a giant snowbank. Do you need rain? Is it even possible to get enough discharge [to carve the valleys] with just the snowmelt?"

With the knowledge from this study that precipitation was important in carving the valleys, the answers to those additional questions could provide important insight into the climate on Mars billions of years ago.



INFORMATION:



Editors: Brown University has a fiber link television studio available for domestic and international live and taped interviews, and maintains an ISDN line for radio interviews. For more information, call (401) 863-2476.



ELSE PRESS RELEASES FROM THIS DATE:

New species of Hero Shrew found in equatorial Africa

2013-07-24
Scientists at Chicago's Field Museum and international collaborators have described a new species of Hero Shrew – the mammal with the most bizarre lower spine on Earth. The interlocking vertebrae of the Hero Shrew render the spine four to five times more robust relative to body mass, a condition not found in any other mammal. The spine has been an enigma to evolutionary biologists, with no known adaptive significance. This new species of Hero Shrew, named Scutisorex thori, possesses features that may represent intermediate character states between the only other known ...

When bar fights get mean, bystanders intervene

2013-07-24
People are more likely to try to break up a bar fight when they believe the conflict is too violent, or has the potential to become more violent, according to an international team of researchers. Bystanders break up about a third of the fights that occur in bars and are most likely to intervene in conflicts between males, said Michael Parks, who recently earned his doctorate in sociology at Penn State. These bystanders used nonaggressive interventions to break up about 65 percent of the fights between two aggressive males. Most bystander interventions were classified ...

Choosing a wave could accelerate airplane maintenance

2013-07-24
Ultrasonic waves can find bubbles and cracks in adhesive bonds holding airplane composite parts together, and now aerospace engineers can select the best frequencies to detect adhesive failures in hard-to-reach places more quickly, thanks to Penn State researchers. Different ultrasonic modes work best for different materials and configurations using the right one will locate more flaws with higher precision, according to the researchers. The selection process could save time and effort for engineers who perform maintenance on complex structures made from composite materials ...

Estée Lauder clinical trial finds link between sleep deprivation and skin aging

2013-07-24
In a first-of-its-kind clinical trial, physician-scientists at University Hospitals (UH) Case Medical Center found that sleep quality impacts skin function and aging. The recently completed study, commissioned by Estée Lauder, demonstrated that poor sleepers had increased signs of skin aging and slower recovery from a variety of environmental stressors, such as disruption of the skin barrier or ultraviolet (UV) radiation. Poor sleepers also had worse assessment of their own skin and facial appearance. The research team, led by Primary Investigator Elma Baron, MD, presented ...

Researcher develops peer-led program to help individuals with HIV adhere to treatment plans

2013-07-24
COLUMBIA, Mo. –Individuals diagnosed with HIV nowadays can live long, healthy lives if they follow their medical treatment plans; however, nearly half of individuals with the virus fail to get needed medical help or to continue treatment, according to previous research. Now, a nursing researcher at the University of Missouri has developed a peer-led intervention that helps individuals with HIV adhere to their treatment plans that can improve their quality of life. "Being 'peered' is different from being doctored, nursed or counseled," said Maithe Enriquez, an associate ...

Pathways activated in most K9 bone tumors not driving the worst bone tumors

2013-07-24
Many cancers show inappropriate activation of a cell signaling pathway called NOTCH. In the developing body, NOTCH tells brain cells to grow and proliferate. It should be quiet in the adult body, but cancers restart NOTCH to drive their own growth, far and beyond the rate of healthy tissues. A Colorado State University and University of Colorado Cancer Center study expected to find NOTCH signaling elevated in K9 osteosarcoma samples, gathered from patients at the CSU Flint Animal Cancer Center. What they found surprised the researchers: overall, NOTCH signaling was elevated ...

Researchers reveal the clearest new pictures of immune cells

2013-07-24
Scientists from The University of Manchester have revealed new images which provide the clearest picture yet of how white blood immune cells attack viral infections and tumours. They show how the cells, which are responsible for fighting infections and cancer in the human body, change the organisation of their surface molecules, when activated by a type of protein found on viral-infected or tumour cells. Professor Daniel Davis, who has been leading the investigation into the immune cells, known as natural killers, said the work could provide important clues for tackling ...

Hospital mammography recall rates higher

2013-07-24
OAK BROOK, Ill. – The rate at which women get called back for additional imaging after screening mammography may be higher at hospitals than at community office practices, mostly due to differences among the patients, according to a new study published online in the journal Radiology. The findings highlight the limitations of recall rates as a quality measure for breast cancer screening, the researchers said. Recall rates for mammography refer to the percentage of women who undergo screening and are called back for additional testing. Since recalls involve anxiety for ...

RI Hospital study finds differences in mammography recall rate between 2 centers

2013-07-24
PROVIDENCE, R.I. – A new study at Rhode Island Hospital has found that academic medical centers have higher rates of recall following mammography than community radiology centers. The recall rate is the frequency at which a radiologist interprets an examination as positive and the patient is instructed to return for more testing. The study is published online in advance of print in the journal Radiology. "Recalling a patient for a mammogram has an impact on both the patient, and on the hospital," said lead researcher and author Ana Lourenco, M.D., a radiologist at Rhode ...

New research findings highlight benefits of human-animal interaction

2013-07-23
Chicago, US (July 22, 2013) --- Positive results from three new studies on human-animal interaction (HAI) are being presented today at the triennial conference of the International Association of Human-Animal Interaction Organizations (IAHAIO) in Chicago, IL. The studies, supported by funding from Mars and the WALTHAM® Centre for Pet Nutrition (WALTHAM®), examined how pets impact our physical and emotional well-being and our social relationships and community connectedness. WALTHAM® is the state-of-the-art petcare science centre for Mars Petcare and provides the science ...

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] Valley networks suggest ancient snowfall on Mars