Showing 20 articles starting at article 601
< Previous 20 articles Next 20 articles >
Categories: Geoscience: Oceanography, Paleontology: Climate
Published Kill dates for re-exposed black mosses


Scientists have used radiocarbon ages (kill dates) of previously ice-entombed dead black mosses to reveal that glaciers advanced during three distinct phases in the northern Antarctic Peninsula over the past 1,500 years.
Published What crocodile DNA reveals about the Ice Age


What drives crocodile evolution? Is climate a major factor or changes in sea levels? Determined to find answers to these questions, researchers discovered that while changing temperatures and rainfall had little impact on the crocodiles' gene flow over the past three million years, changes to sea levels during the Ice Age had a different effect.
Published Malformed seashells, ancient sediment provide clues about Earth's past


Shrunken seashells and unusually dark sediment cores have helped geoscientists better understand the chronology and character of events that led to Ocean Anoxic Event 2, nearly 100 million years ago.
Published In the Neanderthal site of Combe-Grenal, France, hunting strategies were unaffected by changing climate


Neanderthals in Combe-Grenal (France) preferred to hunt in open environments, and their hunting strategies did not alter during periods of climatic change, according to a new study.
Published Global warming reaches central Greenland


A temperature reconstruction from ice cores of the past 1,000 years reveals that today's warming in central-north Greenland is surprisingly pronounced. The most recent decade surveyed in a study, the years 2001 to 2011, was the warmest in the past 1,000 years, and the region is now 1.5 °C warmer than during the 20th century, as researchers report. Using a set of ice cores unprecedented in length and quality, they reconstructed past temperatures in central-north Greenland and melting rates of the ice sheet.
Published Study offers most detailed glimpse yet of planet's last 11,000 summers and winters


An international team of collaborators have revealed the most detailed look yet at the planet's recent climactic history, including summer and winter temperatures dating back 11,000 years to the beginning of what is known as the Holocene.
Published Rodent extinctions in Hispaniola may have been caused by humans


Hispaniola once had among the highest diversity of rodents in the Caribbean. Today, only one rodent species remains, and its prospects for survival are uncertain. New carbon dates place the blame squarely on humans.
Published Climate change could cause 'disaster' in the world's oceans



Climate change will slow down deep overturning ocean circulation in the coming centuries. Using three dozen Earth system models, researchers have concluded that the Southern Meridional Overturning Circulation could completely shut down by 2300, causing disaster to the marine ecosystem on a large portion of the planet.
Published Bering Land Bridge formed surprisingly late during last ice age


A new study that reconstructs the history of sea level at the Bering Strait shows that the Bering Land Bridge connecting Asia to North America did not emerge until around 35,700 years ago, less than 10,000 years before the height of the last ice age (known as the Last Glacial Maximum). The findings indicate that the growth of the ice sheets -- and the resulting drop in sea level -- occurred surprisingly quickly and much later in the glacial cycle than previous studies had suggested.
Published Early forests did not significantly change the atmospheric CO2



Scientists have discovered that the atmosphere contained far less CO2 than previously thought when forests emerged on our planet, the new study has important implications for understanding how land plants affect the climate.
Published New theory on timing for human settlement of some parts of tropical Pacific


Spread across vast distances, the islands of the tropical Pacific Ocean are thought to have been populated by humans in two distinct migrations beginning approximately 3,330 years ago. The first followed a northern route out of what is today the Philippines and the second followed a southern route from Taiwan and New Guinea. People arrived on the islands between these routes -- now making up the Federated States of Micronesia -- about 1,000 years later. But a new finding by sea-level researchers suggests that the islands in Micronesia were possibly settled much earlier than supposed and that voyagers on the two routes may have interacted with one another.
Published Linking fossil climate proxies to living bacteria helps climate predictions


Fossilized microbial skins can give us a glimpse of how the climate was in the deep geological past. By discovering the 'missing link' between such fossil skins and the skins of living bacteria, researchers have greatly improved the accuracy of climate reconstructions and predictions.
Published Climate change played key role in dinosaur success story


Climate change, rather than competition, played a key role in the ascendancy of dinosaurs through the Late Triassic and Early Jurassic periods.
Published Increasing forest cover in the Eifel region 11,000 years ago resulted in the local loss of megafauna


Sediment cores obtained from Eifel maar sites provide insight into the presence of large Ice Age mammals in Central Europe over the past 60,000 years: Overkill hypothesis not confirmed. Herds of megafauna, such as mammoth and bison, have roamed the prehistoric plains in what is today's Central Europe for several tens of thousands of years. As woodland expanded at the end of the last Ice Age, the numbers of these animals declined and by roughly 11,000 years ago, they had completely vanished from this region. Thus, the growth of forests was the main factor that determined the extinction of such megafauna in Central Europe.
Published Changes in Earth's orbit may have triggered ancient warming event


Changes in Earth's orbit that favored hotter conditions may have helped trigger a rapid global warming event 56 million years ago. Researchers found the shape of Earth's orbit, or eccentricity, and the wobble in its rotation, or precession, favored hotter conditions at the onset of the PETM and that these orbital configurations together may have played a role in triggering the event.
Published Assessing El Nino 'flavors' to unravel past variability, future impact


By assessing so-called 'flavors' of El Nino events in past climate records and model simulations, researchers have a clearer picture of El Nino patterns over the past 12,000 years and are able to more accurately project future changes and impacts of this powerful force.
Published Climate whiplash increased wildfires on California's west coast about 8,000 years ago


Researchers have been studying the effects of the sudden decrease in global temperatures that occurred about 8,200 years ago, the so-called 8.2-kiloyear event, with the help of mineral deposits present in White Moon Cave in Northern California. New indications show that oscillations between extreme wetness and aridity in California were closely linked with the occurrence of wildfires. The researchers have concluded that such events are likely to become more common in the face of human-induced climate change.
Published Climate archives under the magnifying glass


How is the weather changing as a consequence of global warming? Climate archives provide valuable glimpses into past climate changes, especially into the processes that drive our planet from one climate setting to the next. For humans and ecosystems, however, time spans of just weeks to years, which are the scope of weather events, are often most important. Using an newly developed and tested analytical method these two aspects have now been merged, and the impacts of the most recent global warming on seasonal temperature fluctuations have been described.
Published Discovery of world's oldest DNA breaks record by one million years


Two-million-year-old DNA has been identified -- opening a 'game-changing' new chapter in the history of evolution. Microscopic fragments of environmental DNA were found in Ice Age sediment in northern Greenland. Using cutting-edge technology, researchers discovered the fragments are one million years older than the previous record for DNA sampled from a Siberian mammoth bone. The ancient DNA has been used to map a two-million-year-old ecosystem which weathered extreme climate change.
Published Fresh understanding of ice age frequency


A chance find of an unstudied Antarctic sediment core has led researchers to flip our understanding of how often ice ages occurred in Antarctica.