Study find physical weathering of rock breakdown more important than previously recognized
(Press-News.org) Research led by the University of Wyoming shows that physical weathering is far more important than previously recognized in the breakdown of rock in mountain landscapes. Because it is difficult to measure, physical weathering has commonly been assumed to be negligible in previous studies.
Cliff Riebe, a professor in UW's Department of Geology and Geophysics, headed a research group that discovered that climate and erosion rates strongly regulate the relative importance of subsurface physical and chemical weathering of saprolite, the zone of weathered rock that retains the relative positions of mineral grains of the parent bedrock and lies between the layer of soil and harder rock underneath. Saprolite is much like the weathered granite found on the flat areas surrounding the hard granite of Vedauwoo.
"Our work shows that physical strain can no longer be ignored in studies of subsurface weathering. It's not just a chemical process. It is physical as well," Riebe says. "What we found is that anisovolumetric weathering is much more common than previously thought, and that variations in this process can be explained by climate and erosion."
Riebe is lead author of a paper, titled "Anisovolumetric Weathering in Granitic Saprolite Controlled by Climate and Erosion Rates," which was published in the Jan. 12 issue of Geology. The journal publishes timely, innovative and provocative articles relevant to its international audience, representing research from all fields of the geosciences.
The study looked at three sites -- with differing climates and elevations of granitic bedrock -- of the Sierra Nevada, a mountain range in California.
In the lingo of geochemists, weathering has long been assumed to be "isovolumetric," meaning without a change in volume caused by physical strain.
"Our work shows that, to the contrary, weathering is commonly 'anisovolumetric,' meaning that strain caused by physical weathering is important," Riebe says.
Riebe credits some of the tools and instruments that were purchased from the Wyoming Center for Environmental Hydrology and Geophysics (WyCEHG) EPSCoR (Established Program to Stimulate Competitive Research) project that ended a few years ago as the reason his team could measure both physical and chemical weathering at several sites in California.
"The reason why weathering was difficult to measure in the past is you have to be able to access the deep subsurface and sample it without disturbing it," Riebe explains. "You need a Geoprobe push coring system, which is basically a big track-mounted drill rig, to do this.
"It's expensive work, especially if you do not happen to own a Geoprobe and have to hire someone to do the work," he continues. "Fortunately, we have access to this equipment and the expertise to operate it through Wyoming's Near Surface Geophysics facility, which is ably managed by Brad Carr, one of the study's co-authors."
The research was funded by grants from the National Science Foundation (NSF), NASA and the Natural Sciences and Engineering Research Council of Canada.
Riebe says there is a direct correlation between the research in this paper and the $5.33 million NSF grant he received last September. The grant focuses on connections among rock, water and life at Earth's surface.
"This research is partly supported by that grant and also helped inspire it," Riebe says.
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
A compound developed at Oregon Health & Science University appears to protect nerve fibers and the fatty sheath, called myelin, that covers nerve cells in the brain and spinal cord.
The discovery, published in the Journal of Neuroimmunology, could be important in treating or preventing the progression of multiple sclerosis and other central nervous system disorders. The new research in a mouse model advances earlier work to develop the compound - known as sobetirome - that has already showed promise in stimulating the repair of myelin.
"Sobetirome and related drugs are effective at stimulating myelin repair after damage has occurred. Our new findings now suggest that these drugs could also prove ...
Earth gets blasted by mild short gamma-ray bursts (GRBs) most days. But sometimes a giant flare like GRB 200415A arrives at our galaxy, sweeping along energy that dwarfs our sun. In fact, the most powerful explosions in the universe are gamma-ray bursts.
Now scientists have shown that GRB 200415A came from another possible source for short GRBs. It erupted from a very rare, powerful neutron star called a magnetar.
Previous detected GRB's came from relatively far away from our home galaxy the Milky Way. But this one was from much closer to home, in cosmic terms.
GRB explosions can disrupt mobile phone reception on earth, but they can also be messengers from ...
(Boston)--What percent of patients with Alzheimer's Disease (AD) currently have severe dementia? Do more people have mild disease? Or are the majority suffering with moderate dementia? A new study using data from the Framingham Heart Study (FHS) sheds light on these trends.
Boston University School of Medicine researchers have found that slightly more than half (50.4 percent) of cases are mild, just under one-third (30.3 percent) of cases are moderate and 19.3 percent are severe cases. Among all participants with mild cognitive impairment (MCI) and AD, the pooled percentage was 45.2 percent for the combined group of mild AD dementia and MCI that later ...
In 2007, an increase in world food prices led to a global rush for land in the form of land grabs or large-scale land acquisitions. Over the last two decades, such acquisitions have resulted in millions of hectares of land changing hands in developing nations. Although such changeover can increase the cultivation of crops needed to feed the world's growing population and spark new agricultural practices and technologies, it can also lead to environmental degradation, increased carbon emissions and threats to the livelihoods of smallholder farmers.
The socioeconomic ...
Financial responsibility means managing money in a relatively sensible way by minimizing superfluous or unnecessary spending. But according to new research from the University of Notre Dame, people think they are more financially responsible than they actually are.
Even when people consistently spend their money superfluously, they still believe that they manage their money in a responsible fashion, according to " END ...
New Rochelle, NY, January 13, 2021--Aggressive video games are not a risk factor for mental health problems, according to a new study of more than 3,000 youth. This study is part of a special issue on the effects of violent video games published in the peer-reviewed journal Cyberpsychology, Behavior, and Social Networking. Click here to read the issue now.
Christopher Ferguson, PhD, Stetson University, and C.K. John Wang, PhD, Nanyang Technological University, examined whether early exposure to aggressive games was predictive of anxiety depression, somatic symptoms, or ...
Apart from black holes, magnetars may be the most extreme stars in the universe. With a diameter less than the length of Manhattan, they pack more mass than that of our sun, wield the largest magnetic field of any known object -- more than 10 trillion times stronger than a refrigerator magnet -- and spin on their axes every few seconds.
A type of neutron star -- the remnant of a supernova explosion -- magnetars are so highly magnetized that even modest disturbances in the magnetic field can cause bursts of X-rays that last sporadically for weeks or months.
These exotic, compact stars are also thought to be the source of some types of short gamma ray bursts (GRBs): bright flashes of highly energetic radiation that have ...
Primary amoebic meningoencephalitis (PAM), a deadly disease caused by the "brain-eating amoeba" Naegleria fowleri, is becoming more common in some areas of the world, and it has no effective treatment. Now, researchers reporting in ACS Chemical Neuroscience have found that a compound isolated from the leaves of a traditional medicinal plant, Inula viscosa or "false yellowhead," kills the amoebae by causing them to commit cell suicide in lab studies, which could lead to new treatments.
PAM, characterized by headache, fever, vomiting, hallucinations and seizures, is almost always fatal within a couple of weeks of developing symptoms. Although the disease, which is usually contracted ...
New probes allow scientists to see four-stranded DNA interacting with molecules inside living human cells, unravelling its role in cellular processes.
DNA usually forms the classic double helix shape of two strands wound around each other. While DNA can form some more exotic shapes in test tubes, few are seen in real living cells.
However, four-stranded DNA, known as G-quadruplex, has recently been seen forming naturally in human cells. Now, in new research published today in Nature Communications, a team led by Imperial College London scientists have created new probes that can see how G-quadruplexes are interacting ...
On April 15, 2020, a brief burst of high-energy light swept through the solar system, triggering instruments on several NASA and European spacecraft. Now, multiple international science teams conclude that the blast came from a supermagnetized stellar remnant known as a magnetar located in a neighboring galaxy.
This finding confirms long-held suspicions that some gamma-ray bursts (GRBs) - cosmic eruptions detected in the sky almost daily - are in fact powerful flares from magnetars relatively close to home.
"This has always been regarded as a possibility, and several GRBs observed since 2005 have provided tantalizing evidence," said Kevin Hurley, a Senior Space Fellow with the Space Sciences Laboratory at the University of California, Berkeley, ...
LAST 30 PRESS RELEASES:
[Press-News.org] Study find physical weathering of rock breakdown more important than previously recognized