Earth

Overfishing of sharks is harming coral reefs

A team of scientists from Canada and Australia has discovered that a decline in shark populations is detrimental to coral reefs.

"Where shark numbers are reduced due to commercial fishing, there is also a decrease in the herbivorous fishes which play a key role in promoting reef health," said Jonathan Ruppert, a recent University of Toronto PhD graduate. Ruppert was part of a team engaged in long-term monitoring of reefs off Australia's northwest coast.

Densest array of carbon nanotubes grown to date

WASHINGTON, D.C. Sept. 20, 2013 -- Carbon nanotubes' outstanding mechanical, electrical and thermal properties make them an alluring material to electronics manufacturers. However, until recently scientists believed that growing the high density of tiny graphene cylinders needed for many microelectronics applications would be difficult.

Lithosphere interprets earth

Boulder, Colo., USA -- The October 2013 Lithosphere is now online. Locations studied include the Central Iberian Massif in Spain; Arctic Alaska; the Wet Mountains of Central Colorado, USA; the Basgo Formation in northwest India; Crystal Geyser in southeastern Utah, USA; Knight Inlet in the southwestern Coast Mountains Batholith, British Columbia, Canada; and three crustal-scale shear zones in the western Canadian Shield of northern Saskatchewan. Lithosphere is published bimonthly in hardcopy; articles are posted online as they become available.

Testing sequence stratigraphic models by drilling Miocene foresets on the New Jersey shallow shelf

Kenneth Miller and colleagues present seismic, core, log, and chronologic data on three early to middle Miocene sequences sampled across a transect of seismic clinothems (prograding sigmoidal sequences) in topset, foreset, and bottomset locations beneath the New Jersey shallow continental shelf (Integrated Ocean Drilling Program Expedition 313, Sites M27-M29). They recognize stratal surfaces and systems tracts by integrating seismic stratigraphy, lithofacies successions, gamma logs, and foraminiferal paleodepth trends.

Warming ocean thawing Antarctica glacier, researchers say

Fairbanks, Alaska— For the first time, researchers completed an extensive exploration of how quickly ice is melting underneath a rapidly changing Antarctic glacier, possibly the biggest source of uncertainty in global sea level projections.

Martin Truffer, a physics professor at the University of Alaska Fairbanks, and Tim Stanton, an oceanographer with the Naval Postgraduate School, were able to look underneath the Pine Island Glacier on the West Antarctic Ice Sheet and take exact measurements of the undersea melting process.

Container's material properties affect the viscosity of water at the nanoscale

Water pours into a cup at about the same rate regardless of whether the water bottle is made of glass or plastic.

But at nanometer-size scales for water and potentially other fluids, whether the container is made of glass or plastic does make a significant difference. A new study shows that in nanoscopic channels, the effective viscosity of water in channels made of glass can be twice as high as water in plastic channels. Nanoscopic glass channels can make water flow more like ketchup than ordinary H2O.

After the storms, a different opinion on climate change

Extreme weather may lead people to think more seriously about climate change, according to new research. In the wake of Hurricanes Irene and Sandy, New Jersey residents were more likely to show support for a politician running on a "green" platform, and expressed a greater belief that climate change is caused by human activity.

Study suggests overfishing of sharks is harming coral reefs

A team of scientists from Canada and Australia have discovered that the decline in shark populations is detrimental to coral reefs.

"Where shark numbers are reduced due to commercial fishing, there is also a decrease in the herbivorous fishes which play a key role in promoting reef health," said Jonathan Ruppert, a recent University of Toronto PhD graduate. Ruppert was part of a team engaged in long-term monitoring of reefs off Australians northwest coast.

Beyond quantum simulation: JILA physicists create 'crystal' of spin-swapping ultracold gas molecules

Physicists at JILA have created a crystal-like arrangement of ultracold gas molecules that can swap quantum "spin" properties with nearby and distant partners. The novel structure might be used to simulate or even invent new materials that derive exotic properties from quantum spin behavior, for electronics or other practical applications.

X-ray science taps bug biology to design better materials and reduce pollution

Bug spray, citronella candles, mosquito netting – most people will do anything they can to stay away from insects during the warmer months. But those creepy crawlers we try so hard to avoid may offer substantial solutions to some of life's problems.

Undersea mountains provide crucial piece in climate prediction puzzle

A mystery in the ocean near Antarctica has been solved by researchers who have long puzzled over how deep and mid-depth ocean waters are mixed. They found that sea water mixes dramatically as it rushes over undersea mountains in Drake Passage - the channel between the southern tip of South America and the Antarctic continent. Mixing of water layers in the oceans is crucial in regulating the Earth's climate and ocean currents.

Beyond quantum simulation: JILA physicists create 'crystal' of spin-swapping ultracold molecules

BOULDER, Colo.- Physicists at JILA have created a crystal-like arrangement of ultracold gas molecules that can swap quantum "spin" properties with nearby and distant partners. The novel structure might be used to simulate or even invent new materials that derive exotic properties from quantum spin behavior, for electronics or other practical applications.

Today's worst watershed stresses may become the new normal, study finds

Nearly one in 10 U.S. watersheds is "stressed," with demand for water exceeding natural supply, according to a new analysis of surface water in the United States. What's more, the lowest water flow seasons of recent years -- times of great stress on rivers, streams, and sectors that use their waters -- are likely to become typical as climates continue to warm.

Nanocrystal catalyst transforms impure hydrogen into electricity

UPTON, NY -- The quest to harness hydrogen as the clean-burning fuel of the future demands the perfect catalysts -- nanoscale machines that enhance chemical reactions. Scientists must tweak atomic structures to achieve an optimum balance of reactivity, durability, and industrial-scale synthesis. In an emerging catalysis frontier, scientists also seek nanoparticles tolerant to carbon monoxide, a poisoning impurity in hydrogen derived from natural gas. This impure fuel -- 40 percent less expensive than the pure hydrogen produced from water -- remains largely untapped.

Stronger winds explain puzzling growth of sea ice in Antarctica

Much attention is paid to melting sea ice in the Arctic. But less clear is the situation on the other side of the planet. Despite warmer air and oceans, there's more sea ice in Antarctica now than in the 1970s – a fact often pounced on by global warming skeptics.

A University of Washington researcher says the reason may lie in the winds. A new modeling study to be published in the Journal of Climate shows that stronger polar winds lead to an increase in Antarctic sea ice, even in a warming climate.