Tag Archives: oceans

Ganymede May Harbor ‘Club Sandwich’ of Oceans and Ice

The largest moon in our solar system, a companion to Jupiter named Ganymede, might have ice and oceans stacked up in several layers like a club sandwich, according to new NASA-funded research that models the moon’s makeup.

Previously, the moon was thought to harbor a thick ocean sandwiched between just two layers of ice, one on top and one on bottom. (more…)

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Exoplanet study finds ‘super-Earths’ likely have oceans and continents

Massive terrestrial planets, called “super-Earths,” are known to be common in Earth’s galaxy, the Milky Way. Now a Northwestern University astrophysicist and a University of Chicago geophysicist report the odds of these planets having an Earth-like climate are much greater than previously thought.

Nicolas B. Cowan and Dorian Abbot’s new model challenges the conventional wisdom, which says super-Earths actually would be very unlike Earth—each would be a waterworld, with its surface completely covered in water. They conclude that most tectonically active super-Earths—regardless of mass—store most of their water in the mantle and will have both oceans and exposed continents, enabling a stable climate such as Earth’s. (more…)

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From obscurity to dominance: Tracking the rapid evolutionary rise of ray-finned fish

ANN ARBOR — Mass extinctions, like lotteries, result in a multitude of losers and a few lucky winners. This is the story of one of the winners, a small, shell-crushing predatory fish called Fouldenia, which first appears in the fossil record a mere 11 million years after an extinction that wiped out more than 90 percent of the planet’s vertebrate species.

The extinction that ended the Devonian Era 359 million years ago created opportunities quickly exploited by a formerly rare and unremarkable group of fish that went on to become—in terms of the sheer number of species—the most successful vertebrates (backboned animals) on the planet today: the ray-finned fish. (more…)

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Before Dinosaurs’ Era, Volcanic Eruptions Triggered Mass Extinction

Increase in atmospheric carbon dioxide, global warming, ocean acidification killed 76 percent of species on Earth

More than 200 million years ago, a massive extinction decimated 76 percent of marine and terrestrial species, marking the end of the Triassic period and the onset of the Jurassic.

The event cleared the way for dinosaurs to dominate Earth for the next 135 million years, taking over ecological niches formerly occupied by other marine and terrestrial species.

It’s not clear what caused the end-Triassic extinction, although most scientists agree on a likely scenario. (more…)

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Antarctic and Arctic Insects Use Different Genetic Mechanisms to Cope With Lack of Water

Genomic techniques facilitate discovery that gene expression causes disparity

Although they live in similarly extreme ecosystems at opposite ends of the world, Antarctic insects appear to employ entirely different methods at the genetic level to cope with extremely dry conditions than their counterparts that live north of the Arctic Circle, according to National Science Foundation- (NSF) funded researchers.

Writing in the Proceedings of the National Academy of Sciences, the researchers concluded, “Polar arthropods have developed distinct… mechanisms to cope with similar desiccating conditions.” (more…)

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Environmental Issues: How True the Climate Changes Affecting Biodiversity

A changing climate has implications on biodiversity without any doubt. Species in the past have been sensitive to changes in the climate; that has been proved time and again by the fossilized remains and pollen distribution studies. It has been seen or can be concluded safely that climate changes have led to extinction of species in one area and colonization in another.

It is improbable that all species can or will be able to adapt to changing conditions specially the sudden changes. This leads to impact in ecosystem dynamics and also on community composition. (more…)

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Sailing in a Sea of Microbes

Researchers led by Matt Sullivan at the UA are among the first to dive into the world of viruses drifting through the world’s oceans.

Surrounded by the deep blue of the Pacific Ocean stretching from horizon to horizon, a lonely dot is glinting in the sun. It is the aluminum hull of a sailboat, a 118-foot schooner with white sails billowing from two masts.

On the deck, crewmembers and scientists are milling about. Commands are flying back and forth, and soon a strange contraption consisting of tubes clustered around an array of sensors dangling from a crane is lowered into the water, until it disappears in the clear blue depths. (more…)

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Scientists Look to Microbes to Unlock Earth’s Deep Secrets

*To find answers, oceanographers install observatories beneath remote seafloor*

Of all the habitable parts of our planet, one ecosystem still remains largely unexplored and unknown to science: the igneous ocean crust.

This rocky realm of hard volcanic lava exists beneath ocean sediments that lie at the bottom of much of the world’s oceans.

While scientists have estimated that microbes living in deep ocean sediments may represent as much as one-third of Earth’s total biomass, the habitable portion of the rocky ocean crust may be 10 times as great. (more…)

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