*In “The Great Dying” 250 million years ago, the end came slowly*
The deadliest mass extinction of all took a long time to kill 90 percent of Earth’s marine life–and it killed in stages–according to a newly published report.
It shows that mass extinctions need not be sudden events.
Thomas Algeo, a geologist at the University of Cincinnati, and 13 colleagues have produced a high-resolution look at the geology of a Permian-Triassic boundary section on Ellesmere Island in the Canadian Arctic. (more…)
What’s the best way to study the Antarctic’s ecosystem? Follow the penguins.
Scientists are tracking penguins on land, under the sea, and even from space to unravel the environmental dynamics in the West Antarctic Peninsula as the region experiences climate change.
“We’re not just down there bird watching,” said Matthew Oliver, assistant professor of oceanography in UD’s College of Earth, Ocean, and Environment. “This is a concerted effort to put the whole ecosystem together.” (more…)
Nearly one-third of CO2 emissions due to human activities enters the world’s oceans. By reacting with seawater, CO2 increases the water’s acidity, which may significantly reduce the calcification rate of such marine organisms as corals and mollusks, resulting in the potential loss of ecosystems. The extent to which human activities have raised the surface level of acidity, however, has been difficult to detect on regional scales because it varies naturally from one season and one year to the next, and between regions, and direct observations go back only 30 years.
By combining computer modeling with observations, an international team of scientists concluded that anthropogenic CO2 emissions, resulting from the influence of human beings, over the last 100 to 200 years have already raised ocean acidity far beyond the range of natural variations. The study is published in the January 22, 2012 online issue of Nature Climate Change. (more…)
Woods Hole Oceanographic Institution (WHOI) scientists have discovered that bacterial communication could have a significant impact on the planet’s climate.
In the ocean, bacteria coalesce on tiny particles of carbon-rich detritus sinking through the depths. WHOI marine biogeochemists Laura Hmelo, Benjamin Van Mooy, and Tracy Mincer found that these bacteria send out chemical signals to discern if other bacteria are in the neighborhood. If enough of their cohorts are nearby, then bacteria en masse commence secreting enzymes that break up the carbon-containing molecules within the particles into more digestible bits. It has been suggested that coordinated expression of enzymes is very advantageous for bacteria on sinking particles, and Hmelo and her colleagues have uncovered the first proof of this in the ocean. (more…)
A NASA-led research team has confirmed what Walt Disney told us all along: Earth really is a small world, after all.
Since Charles Darwin’s time, scientists have speculated that the solid Earth might be expanding or contracting. That was the prevailing belief, until scientists developed the theory of plate tectonics, which explained the large-scale motions of Earth’s lithosphere, or outermost shell. Even with the acceptance of plate tectonics half a century ago, some Earth and space scientists have continued to speculate on Earth’s possible expansion or contraction on various scientific grounds.
Now a new NASA study, published recently in Geophysical Research Letters, has essentially laid those speculations to rest. Using a cadre of space measurement tools and a new data calculation technique, the team detected no statistically significant expansion of the solid Earth. (more…)
A new analysis of data from NASA’s Galileo spacecraft has revealed that beneath the surface of Jupiter’s volcanic moon Io is an “ocean” of molten or partially molten magma.
The finding, from a study published May 13 in the journal Science, is the first direct confirmation of such a magma layer on Io and explains why the moon is the most volcanic object known in the solar system. The research was conducted by scientists from UCLA, UC Santa Cruz and the University of Michigan–Ann Arbor. (more…)
*Study Finds Connection between Atmospheric Events and the Deep Ocean*
Researchers from Woods Hole Oceanographic Institution (WHOI) and their colleagues have discovered that massive, swirling ocean eddies–known to be up to 500 kilometers across at the surface–can reach all the way to the ocean bottom at mid-ocean ridges, some 2,500 meters deep, transporting tiny sea creatures, chemicals, and heat from hydrothermal vents over large distances.
The previously unknown deep-sea phenomenon, reported in the April 28 issue of the journal Science, helps explain how some larvae travel huge distances from one vent area to another, said Diane K. Adams, lead author at WHOI and now at the National Institutes of Health. (more…)
A North Carolina State University researcher is part of a team which has found that methane from “cold seeps” – undersea areas where fluids bubble up through sediments at the bottom of the ocean – could be contributing to the oceans’ increasing acidity and stressing already delicate undersea ecosystems.
Oceanic microorganisms and bacteria survive by consuming dissolved organic carbon, or DOC. A byproduct of this consumption is CO2 – carbon dioxide – which, in large enough concentrations, makes seawater more acidic.(more…)
