For corals adjusting to climate change, it’s survival of fattest and most flexible
The future health of the world’s coral reefs and the animals that depend on them relies in part on the ability of one tiny symbiotic sea creature to get fat — and to be flexible about the type of algae with which it cooperates. (more…)
By analyzing the speed of seismic waves generated by earthquakes, scientists have shown that temperature differences deep within Earth’s mantle control the elevation and volcanic activity along mid-ocean ridges, the colossal mountain ranges that line the ocean floor. Recent research sheds new light on how temperature in the depths of the mantle influences the contours of the Earth’s crust.
PROVIDENCE, R.I. [Brown University] — Scientists have shown that temperature differences deep within Earth’s mantle control the elevation and volcanic activity along mid-ocean ridges, the colossal mountain ranges that line the ocean floor. The findings, published April 4 in the journal Science, shed new light on how temperature in the depths of the mantle influences the contours of the Earth’s crust. (more…)
Salmon are beginning to swim up the Elwha River for the first time in more than a century. But University of Washington marine geologists are watching what’s beginning to flow downstream — sediments from the largest dam-removal project ever undertaken.
The 108-foot Elwha Dam was built in 1910, and after decades of debate it was finally dismantled last year. Roughly a third of the 210-foot Glines Canyon Dam still stands, holding back a mountain of silt, sand and gravel. (more…)
Study simulating pressures in mantle beneath the ocean floor shows that rocks can melt at depths up to 250 kilometers
Magma forms far deeper than geologists previously thought, according to new research results.
A team led by geologist Rajdeep Dasgupta of Rice University put very small samples of peridotite, rock derived from Earth’s mantle, under high pressures in a laboratory.
The scientists found that the rock can and does liquify, at least in small amounts, at pressures equivalent to those found as deep as 250 kilometers down in the mantle beneath the ocean floor. (more…)
EAST LANSING, Mich. — Warmer oceans in the future could significantly alter populations of phytoplankton, tiny organisms that could have a major impact on climate change.
In the current issue of Science Express, Michigan State University researchers show that by the end of the 21st century, warmer oceans will cause populations of these marine microorganisms to thrive near the poles and may shrink in equatorial waters. Since phytoplankton play a key role in the food chain and the world’s cycles of carbon, nitrogen, phosphorous and other elements, a drastic drop could have measurable consequences. (more…)
The most-studied mass extinction in Earth history happened 65 million years ago and is widely thought to have wiped out the dinosaurs. New University of Washington research indicates that a separate extinction came shortly before that, triggered by volcanic eruptions that warmed the planet and killed life on the ocean floor.
The well-known second event is believed to have been triggered by an asteroid at least 6 miles in diameter slamming into Mexico’s Yucatán Peninsula. But new evidence shows that by the time of the asteroid impact, life on the seafloor – mostly species of clams and snails – was already perishing because of the effects of huge volcanic eruptions on the Deccan Plateau in what is now India. (more…)
*Evidence of water mass moving south 70 million years ago shows how warmth was distributed*
COLUMBIA, Mo. – New research from the University of Missouri indicates that Atlantic Ocean temperatures during the greenhouse climate of the Late Cretaceous Epoch were influenced by circulation in the deep ocean. These changes in circulation patterns 70 million years ago could help scientists understand the consequences of modern increases in greenhouse gases.
“We are examining ocean conditions from several past greenhouse climate intervals so that we can understand better the interactions among the atmosphere, the oceans, the biosphere, and climate,” said Kenneth MacLeod, professor of geological sciences in the College of Arts and Science. “The Late Cretaceous Epoch is a textbook example of a greenhouse climate on earth, and we have evidence that a northern water mass expanded southwards while the climate was cooling. At the same time, a warm, salty water mass that had been present throughout the greenhouse interval disappeared from the tropical Atlantic.” (more…)
