Earth | Page 1359 | Science Codex

Study shows continued spread of 'dead zones'

A global study led by Professor Robert Diaz of the Virginia Institute of Marine Science, College of William and Mary, shows that the number of "dead zones"—areas of seafloor with too little oxygen for most marine life—has increased by a third between 1995 and 2007.

Diaz and collaborator Rutger Rosenberg of the University of Gothenburg in Sweden say that dead zones are now "the key stressor on marine ecosystems" and "rank with over-fishing, habitat loss, and harmful algal blooms as global environmental problems."

Northwestern chemists take gold, mass-produce Beijing Olympic logo

EVANSTON, Ill. --- Northwestern University nanoscientist Chad A. Mirkin has mass-produced the 2008 Summer Olympics logo -- 15,000 times. All the logos take up only one square centimeter of space.

Mirkin and his colleagues printed the logos as well as an integrated gold circuit using a new printing technique, called Polymer Pen Lithography (PPL), that can write on three different length scales using only one device.

Drinking water in Gaza Strip contaminated with high levels of nitrate

Gaza/Leipzig. Palestinian and German scientists have recommended to the authorities in the Gaza Strip that they take immediate measures to combat excessive nitrate levels in the drinking water. 90 per cent of their water samples were found to contain nitrate concentrations that were between two and eight times higher than the limit recommended by the World Health Organization (WHO), say the researchers from the University of Heidelberg and the Helmholtz Centre for Environmental Research (UFZ) writing in the specialist journal Science of the Total Environment.

A recipe for saving the world's oceans from an extinction crisis

Jeremy Jackson, senior scientist emeritus of the Smithsonian Tropical Research Institute and the Scripps Institution of Oceanography, asserts in the Aug. 12 issue of the journal Proceedings of the National Academy of Sciences, that the following steps, if taken immediately, could reverse the demise of the oceans: Establish marine reserves, enforce fishing regulations, implement aquaculture, remove subsidies on fertilizer use, muster human ingenuity to limit fossil fuel consumption, buy time by establishing local conservation measures.

Turning waste material into ethanol

AMES, Iowa – Say the word "biofuels" and most people think of grain ethanol and biodiesel. But there's another, older technology called gasification that's getting a new look from researchers at the U.S. Department of Energy's Ames Laboratory and Iowa State University. By combining gasification with high-tech nanoscale porous catalysts, they hope to create ethanol from a wide range of biomass, including distiller's grain left over from ethanol production, corn stover from the field, grass, wood pulp, animal waste, and garbage.

Oceans on the precipice: Scripps scientist warns of mass extinctions and 'rise of slime'

Human activities are cumulatively driving the health of the world's oceans down a rapid spiral, and only prompt and wholesale changes will slow or perhaps ultimately reverse the catastrophic problems they are facing.

Smells like bees' spirit

Bumblebees choose whether to search for food according to how stocked their nests are, say scientists from Queen Mary, University of London.

When bumblebees return to the nest from a successful foraging mission, they produce a pheromone which encourages their nest mates to also go out and find food. Scientists had originally thought that these pheromones elicited a standard response from all bees. But new research from Queen Mary's School of Biological and Chemical Sciences has shown that bees' response to the pheromone changes according to their situation.

Robot vehicle surveys deep sea off Pacific Northwest

The first scientific mission with Sentry, a newly developed robot capable of diving as deep as 5,000 meters (3.1 miles) into the ocean, has been successfully completed by scientists and engineers from the Woods Hole Oceanographic Institution (WHOI) and the University of Washington (UW).

The vehicle surveyed and helped pinpoint several proposed deep-water sites for seafloor instruments that will be deployed in the National Science Foundation (NSF)'s planned Ocean Observatories Initiative (OOI).

Climate change may boost Middle East rainfall

The prospect of climate change sparking food and water shortages in the Middle East is less likely than previously thought, with new research by an Australian climate scientist suggesting that rainfall will be significantly higher in key parts of the region.

Southern Ocean seals dive deep for climate data

Elephant seals are helping scientists overcome a critical blind-spot in their ability to detect change in Southern Ocean circulation and sea ice production and its influence on global climate.

According to a paper published today by a team of French, Australian, US and British scientists in the Proceedings of the National Academy of Sciences, elephant seals fitted with special oceanographic sensors are providing a 30-fold increase in data recorded in parts of the Southern Ocean rarely observed using traditional ocean monitoring techniques.

X-rays use diamonds as a window to the center of the Earth

Diamonds from Brazil have provided the answers to a question that Earth scientists have been trying to understand for many years: how is oceanic crust that has been subducted deep into the Earth recycled back into volcanic rocks? A team of researchers, led by the University of Bristol, working alongside colleagues at the STFC Daresbury Laboratory, have gained a deeper insight into how the Earth recycles itself in the deep earth tectonic cycle way beyond the depths that can be accessed by drilling.

AGU journal highlights -- Aug. 12, 2008

1. Fast rise of scorching days predicted

Old growth giants limited by water-pulling ability

CORVALLIS, Ore. – The Douglas-fir, state tree of Oregon, towering king of old-growth forests and one of the tallest tree species on Earth, finally stops growing taller because it just can't pull water any higher, a new study concludes.

This limit on height is somewhere above 350 feet, or taller than a 35-story building, and is a physiological tradeoff between two factors in the tree's wood - a balance between efficiency and safety in transporting water to the uppermost leaves.

If a street tree falls... what does it take to make sound policy?

BLOOMINGTON, Ind. -- There's little debate that, when a tree falls near a city street, it makes a sound. But other questions are more difficult to answer: Who is affected by the falling tree and how? Who is liable for the damage? And who is responsible for deciding how to replace the tree?

A paper written by an Indiana University professor and doctoral student, and presented at two international conferences, argues that thinking of street trees as a "common-pool resource" can help lead to better management of an under-appreciated community asset.

Surviving the revolution, easier than withstanding human use and abuse

Inwood Hill Park survived the drastic modifications of Revolutionary War patriots, but preserving this last bastion of large-growth, mature trees in New York City is difficult with the proliferation of invasive species and hard human use, according to biologists. They suggest the situation warrants a plan in collaboration with those studying the park.