Around 717 million years ago, the Earth turned into a snowball. Most of the ocean, if not all of it, was frozen at its surface. The land, which was aggregated into one big supercontinent, was also covered in mile-thick ice. And then, everything changed. Volcanoes released enough carbon dioxide into the atmosphere to trap the sun’s heat and trigger global warming. The ice melted, and the surface of the sea reached temperatures of 120 to 140 degrees Fahrenheit. By 659 million years ago, the world had transformed from snowball to greenhouse. And just 14 million years later, the ice returned and the planet became a snowball for the second time.
New research using DNA from the fish bone remains of Viking-era meals reveals that north Norwegians have been transporting -- and possibly trading -- Arctic cod into mainland Europe for a millennium.
ELKO, Nev. -- A fossil found in northeastern Nevada shows a newly discovered fish species that scientists believe looked, and ate, like a shark. The fossil is what remains of a bony, sharp-toothed fish that would have been about six-feet-long (1.83 meters) with long jaws and layers of sharp teeth. The type of jaw and teeth on the fish suggest it would have chomped down on its prey before swallowing it whole, like a shark, the Reno Gazette-Journal reported.
In 2014, a team of researchers led by a paleobiologist from the University of Missouri found that clams from the Holocene Epoch (that began 11,700 years ago) contained clues about how sea level rise due to climate change could foreshadow a rise in parasitic trematodes, or flatworms. The team cautioned that the rise could lead to outbreaks in human infections if left unchecked. Now, an international team from Mizzou and the Universities of Bologna and Florida has found that rising seas could be detrimental to human health on a much shorter time scale. Findings from their study in northern Italy suggest that parasitic infections could increase in the next century, if history repeats itself.
For three years, Tara Djokic, a Ph.D. student at the University of New South Wales Sydney, scoured the forbidding landscape of the Pilbara region of Western Australia looking for clues to how ancient microbes could have produced the abundant stromatolites that were discovered there in the 1970s. Stromatolites are round, multilayered mineral structures that range from the size of golf balls to weather balloons and represent the oldest evidence that there were living organisms on Earth 3.5 billion years ago.
Benjamin Horton remembers being in Southeast Asia just months after the devastating 2004 Indian Ocean tsunami. “They were still dealing with a disaster,” he says. “The roads were in a terrible state.” But in those days, the formerly niche field of tsunami research had taken on new urgency. Horton, who studies sea levels at Rutgers University and Nanyang Technological University, was just one of dozens of researchers who came in search of answers: Had this happened before? Would it happen again?
Using a combination of fossils and chemical markers, scientists have tracked how a period of globally low ocean-oxygen turned an Early Jurassic marine ecosystem into a stressed community inhabited by only a few species. The research was led by Rowan Martindale, an assistant professor at The University of Texas at Austin Jackson School of Geosciences, and published in print in Palaeogeography, Palaeoclimatology, Palaeoeconology on July 15. The study was co-authored by Martin Aberhan, a curator at the Institute for Evolution and Biodiversity Science at the Natural History Museum in Berlin, Germany.
Scientists are getting a much clearer picture of the retreat of the West Antarctic Ice Sheet over thousands of years, and of the forces driving it. New research indicates that warm waters pulled up from the deep by strong winds sharply undercut glaciers from about 11,000 years ago to 7,500 years ago. This incursion then stopped until it got under way again in the 1940s. The findings are important because they inform our understanding about how the ice may respond in the future.
Paleontologists investigating the sea bed off the coast of southern California have discovered a lost ecosystem that for thousands of years had nurtured communities of scallops and shelled marine organisms called brachiopods. These brachiopods and scallops had thrived along a section of coast stretching approximately 250 miles from San Diego to Santa Barbara for at least 4,000 years. But they had died off by the early 20th century, replaced by the mud-dwellling burrowing clams that inhabit this seabed today. Paleontologists Adam Tomašových of the Slovak Academy of Sciences and Susan Kidwell of the University of Chicago examine the lost ecosystem in a study published online June 7 in the Royal Society Proceedings B.
The Arctic Ocean was once a gigantic freshwater lake. Only after the land bridge between Greenland and Scotland had submerged far enough did vast quantities of salt water pour in from the Atlantic. With the help of a climate model, researchers from the Alfred Wegener Institute have demonstrated how this process took place, allowing us for the first time to understand more accurately how Atlantic circulation, as we know it today came about. The results of the study have now been published in the journal Nature Communications.
The Amazon rainforest is a treasure trove of biodiversity, containing 10% of the planet’s species in its 6.7 million square kilometers. How it got to be that way has been fiercely disputed for decades. Now, a new study suggests that a large section of the forest was twice flooded by the Caribbean Sea more than 10 million years ago, creating a short-lived inland sea that jump-started the evolution of new species. But the new evidence still hasn’t convinced scientists on the other side of the debate.
It is as if a child has been doodling with large coloured crayons. What you see are actually the great gouge marks left on the seafloor when the keel of a giant block of ice has dragged through the sediments. The arcs and loops record the movement of the berg as it turns about, caught in the wind, currents and tides. This "ice art" is from a stunning new collection of images that detail how glacial action has shaped the ocean floor in Earth's polar regions. The atlas is the work of more than 250 scientists from 20 countries and represents our most comprehensive view yet of what the seabed looks like at high latitudes.