Tag Archives: erosion

Earthquakes, ‘Marsquakes,’ and the possibility of life

A new study shows that rocks formed by the grinding together of other rocks during earthquakes are rich in trapped hydrogen — a finding that suggests similar seismic activity on Mars may produce enough hydrogen to support life. (more…)

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Huge waves measured for first time in Arctic Ocean

As the climate warms and sea ice retreats, the North is changing. An ice-covered expanse now has a season of increasingly open water that is predicted to extend across the whole Arctic Ocean before the middle of this century. Storms thus have the potential to create Arctic swell – huge waves that could add a new and unpredictable element to the region. (more…)

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Anthropozän: Das Erdzeitalter der menschlichen Einflussnahme

Geograph Ronald Pöppl zu landschaftlichen Eingriffen und deren geomorphologischen Konsequenzen mit Beispielen aus Niederösterreich

Die Auswirkungen menschlichen Handelns auf die geologischen, biologischen und atmosphärischen Prozesse haben insbesondere seit Beginn der Industrialisierung enorme Ausmaße angenommen. WissenschafterInnen haben deshalb das Zeitalter des “Anthropozäns” ausgerufen. Ronald Pöppl, Geograph an der Universität Wien, zeigt anhand von Beispielen aus Niederösterreich  auf, wie sehr die Menschheit mit flussbaulichen Maßnahmen und durch Veränderung der Vegetationsbedeckung das Erdrelief verändert. Im Rahmen der heuer in Wien stattfindenden Konferenz der “European Geosciences Union” liefert Pöppl im Rahmen einer Pressekonferenz zum Thema “The Anthropocene: are we living in the age of humans?” einen Beitrag zum geomorphologischen Erbe von Staudämmen. (more…)

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Post-Sandy Survey Shows a Polluted but Generally Intact Barrier System off Long Island

AUSTIN, Texas — As coastal communities continue to rebuild in the wake of Hurricane Sandy, scientists at last week’s annual meeting of the American Geophysical Union offer some encouraging news: The storm did not seriously damage the offshore barrier system that controls erosion on Long Island. Long-term concerns remain about the effects on the region of sea-level rise, pollutants churned up by the storm within back-barrier estuaries, and the damage closer to shore, but in the near-term, Long Island residents can rebuild knowing that Hurricane Sandy did not significantly alter the offshore barrier systems that control coastal erosion on the island. (more…)

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Bodenlose Verluste

Erosion vernichtet jährlich 24 Milliarden Tonnen Boden. / WWF warnt vor massiven Verlust fruchtbarer Agrarflächen.

Fruchtbarer Boden ist die wortwörtliche Grundlage unserer Ernährung. Trotzdem gehen jährlich weltweit mehr als 24 Milliarden Tonnen durch Erosion verloren. Davor warnt die Umweltschutzorganisation WWF anlässlich einer Konferenz zum Schutz fruchtbarer Böden in Berlin. „Die Menschheit zieht sich selbst den Boden unter den Füßen weg“, sagt Birgit Wilhelm WWF-Landwirtschaftsreferentin. Dabei seien fruchtbare Anbauflächen Grundvoraussetzung für 90 Prozent aller Lebensmittel – und nicht unendlich vorhanden. Laut Schätzungen bestehen nur zwölf Prozent der Erdoberfläche aus landwirtschaftlich nutzbarem Boden. Ist die gerade einmal 2,5 cm dicke fruchtbare Oberschicht durch Erosion verloren, dauert es 500 Jahre, um sie zurück zu bringen. (more…)

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Coral reefs’ collapse isn’t inevitable, researchers say

Coral reefs are in decline, but their collapse can still be avoided with local and global action.

That’s according to findings reported in the Cell Press journal Current Biology on May 9th based on an analysis that combines the latest science on reef dynamics with the latest climate models.

“People benefit by reefs having a complex structure – a little like a Manhattan skyline but underwater,” said Peter Mumby of The University of Queensland and University of Exeter. “Structurally-complex reefs provide nooks and crannies for thousands of species and provide the habitat needed to sustain productive reef fisheries. They’re also great fun to visit as a snorkeler or diver. If we carry on the way we have been, the ability of reefs to provide benefits to people will seriously decline.” (more…)

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Invasive crabs help Cape Cod marshes

Ecologists are wary of non-native species, but along the shores of Cape Cod where grass-eating crabs have been running amok and destroying the marsh, an invasion of a predatory green crabs has helped turn back the tide in favor of the grass. The counter-intuitive conclusions appear in a new paper in the journal Ecology.

PROVIDENCE, R.I. [Brown University] — Long vilified, invasive species can sometimes become an ecosystem asset. New Brown University research published online in the journal Ecology reports exactly such a situation in the distressed salt marshes of Cape Cod. There, the invasive green crab Carcinus maenas is helping to restore the marsh by driving away the Sesarma reticulatum crabs that have been depleting the marsh grasses. (more…)

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Mars Rock Takes Unusual Form

On Mars, as on Earth, sometimes things can take on an unusual appearance. A case in point is a shiny-looking rock seen in a recent image from NASA’s Curiosity Mars rover.

Some casual observers might see a resemblance to a car door handle, hood ornament or some other type of metallic object. To Ronald Sletten of the University of Washington, Seattle, a collaborator on Curiosity’s science team, the object is an interesting study in how wind and the natural elements cause erosion and other effects on various types of rocks. (more…)

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