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Rescooped by Joslyn from Amazing Science
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Earth's crust was unstable in the Archean eon and dripped down into the mantle

Earth's crust was unstable in the Archean eon and dripped down into the mantle | Science | Scoop.it
Earth's mantle temperatures during the Archean eon, which commenced some 4 billion years ago, were significantly higher than they are today. According to recent model calculations, the Archean crust that formed under these conditions was so dense that large portions of it were recycled back into the mantle. This is the conclusion reached by Dr. Tim Johnson who is currently studying the evolution of the Earth's crust as a member of the research team led by Professor Richard White of the Institute of Geosciences at Johannes Gutenberg University Mainz (JGU). According to the calculations, this dense primary crust would have descended vertically in drip form. In contrast, the movements of today's tectonic plates involve largely lateral movements with oceanic lithosphere recycled in subduction zones. The findings add to our understanding of how cratons and plate tectonics, and thus also the Earth's current continents, came into being.Because mantle temperatures were higher during the Archean eon, the Earth's primary crust that formed at the time must have been very thick and also very rich in magnesium. However, as Johnson and his co-authors explain in their article recently published in Nature Geoscience, very little of this original crust is preserved, indicating that most must have been recycled into the Earth's mantle. Moreover, the Archean crust that has survived in some areas such as, for example, Northwest Scotland and Greenland, is largely made of tonalite–trondhjemite–granodiorite complexes and these are likely to have originated from a hydrated, low-magnesium basalt source. The conclusion is that these pieces of crust cannot be the direct products of an originally magnesium-rich primary crust. These TTG complexes are among the oldest features of our Earth's crust. They are most commonly present in cratons, the oldest and most stable cores of the current continents.With the help of thermodynamic calculations, Dr. Tim Johnson and his collaborators at the US-American universities of Maryland, Southern California, and Yale have established that the mineral assemblages that formed at the base of a 45-kilometer-thick magnesium-rich crust were denser than the underlying mantle layer. In order to better explore the physics of this process, Professor Boris Kaus of the Geophysics work group at Mainz University developed new computer models that simulate the conditions when the Earth was still relatively young and take into account Johnson's calculations.More information: Tim E. Johnson et al. Delamination and recycling of Archaean crust caused by gravitational instabilities, Nature Geoscience 7, 47–52. Published online 1 December 2013. DOI: 10.1038/ngeo2019
Via Dr. Stefan Gruenwald
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Climate Change 2013: Where We Are Now - Not What You Think | Truth-Out.org

Climate Change 2013: Where We Are Now - Not What You Think | Truth-Out.org | Science | Scoop.it
We are in the midst of an era of frightening contradictions, when it comes to public understandings of climate change. While climate changes are occurring more quickly than scientists have ever predicted, most people’s knowledge of these realities remains hazy and clouded by political overtones.Because of both the counter-intuitive nature of climate change and the massive misinformation campaigns created by the fossil fuel industry, the general population is 20 years behind most climate scientists when it comes to the straightforward fact of "believing in" climate change.This is an ominous statistic: Now that scientists are predicting that even worse impacts than previously understood will happen significantly sooner, a rapid global response will be necessary for any attempt to stave them off. We are likely closer to irreversible dangerous climate change - if it has not begun already - and to take action, there must be a basic public consensus. There is, however, some hopeful news on the technological front if action is taken soon.In 1976, Wallace Broeker was one of the first to suggest climate change could alter our planet harmfully within our lifetimes. Even though a few scientists said in the '70s we could be headed for an ice age, Broeker had already made the connection, and those few climate scientists have not talked about a coming ice age in nearly 40 years. Broeker is arguably the grandfather of climate science: He's been at it for 55 years.One of his first jobs was under Willard Libby, who was awarded the Nobel Prize in 1949 for discovering carbon-14 dating. This rare but predictable form of carbon is radioactive, and it completely decays in about 55,000 years. It is because of carbon-14 dating that we know for absolutely certain that the extra carbon dioxide in our atmosphere came from burning fossil fuels.There are many other ways that we know for sure. The physics of the greenhouse effect are easily demonstrated in the lab, and even the simplest models from the early 1980s prove their effect. Surprisingly, the complicated high resolution climate models of today yield results that are quite similar to those of the simplest models of the early 1980s.But how are we supposed to trust the models when weather people can't even get the seven-day forecast correct?Click headline to read more--
Via Chuck Sherwood, Senior Associate, TeleDimensions, Inc
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Rescooped by Joslyn from Jeff Morris
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Algae to crude oil: Million-year natural process takes minutes in the lab

Algae to crude oil: Million-year natural process takes minutes in the lab | Science | Scoop.it
“ Engineers at the Department of Energy’s Pacific Northwest National Laboratory (PNNL) have created a continuous process that produces useful crude oil minute...”
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Rescooped by Joslyn from Solar Energy projects & Energy Efficiency
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Researchers create a low cost thin film photovoltaic device with high energy efficiency

Researchers create a low cost thin film photovoltaic device with high energy efficiency | Science | Scoop.it
The solar cell developed by the researchers of the ICMol consists of a thin perovskite film sandwiched in between two very thin organic semiconductors. The total thickness of the device is less than half a micrometer. The hybrid organic-inorganic perovskite material can be prepared easily and at low cost.
Via Pol Bacquet
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Rescooped by Joslyn from Longevity science
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Edible Batteries Could Power a Range of Smart Pills and Medical Devices

Edible Batteries Could Power a Range of Smart Pills and Medical Devices | Science | Scoop.it
How can we safely power electronic technology inside the body? A number of researchers are aggressively seeking answers to that question. For instance, Singularity Hub has covered an electronic pill that, when activated by stomach acid, generates enough power to signal an external device that then registers that the pill has been taken.
Via Ray and Terry's
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