About 252 million years ago, more than 90 percent of all animal life on Earth went extinct. This event, called the “Permian-Triassic mass extinction,” represents the greatest catastrophe in the history of life on Earth. Ecosystems took nearly five million years to recover and many aspects of the event remain a mystery.
A research team, led by scientists from Arizona State University and funded by NASA and the National Science Foundation, is helping to understand why this extinction event happened and why it took life so long to recover. The study, published in Science Advances, was led by ASU School of Earth and Space Exploration graduate student Feifei Zhang, with direction from school faculty member Ariel Anbar.
Scientists now have a clearer picture of the Earth’s mantle, thanks to Michigan State University research published in the current issue of Nature Communications (…)
A new 53 million-year-old insect fossil called a scorpionfly discovered at B.C.’s McAbee fossil bed site bears a striking resemblance to fossils of the same age from Pacific-coastal Russia, giving further evidence of an ancient Canada-Russia connection.
Little is known about the ice age human occupation of the Pacific Coast of Canada. Here we present the results of a targeted investigation of a late Pleistocene shoreline on Calvert Island, British Columbia. Drawing upon existing geomorphic information that sea level in the area was 2–3 m lower than present between 14,000 and 11,000 years ago, we began a systematic search for archaeological remains dating to this time period beneath intertidal beach sediments (…)
• We quantitatively analyse pre-eruptive intrusion-induced surface deformation from 33 scaled laboratory experiments resulting in eruptions.
• A robust proxy extracted from surface deformation geometry enables systematic predictions of the locations of a subsurface intrusion and imminent eruption.
• Forecasting an eruption location is possible without geodetic modeling but requires volcano monitoring at high spatiotemporal resolution.
A new theory about how oceans and volcanoes interacted during the early history of Mars supports the idea that liquid water was once abundant and may still exist underground. Geophysicists propose that the oceans originated several hundred million years earlier than thought, as the volcanic province Tharsis formed, and that greenhouse gases enabled the oceans. The theory predicts smaller oceans, more in line with estimates of water underground and at the poles today.
Early modern humans living in South Africa around 74,000 years ago prospered through the cataclysmic eruption of the Toba supervolcano in Sumatra. The Toba eruption was one of the Earth’s most explosive volcanic events. The environmental effects of this event have been heavily debated, with some researchers having previously proposed that the eruption led to a worldwide volcanic winter that devastated contemporaneous human populations.
An eruption a hundred times smaller than Mount Toba — that of Mount Tambora, also in Indonesia, in 1815 — is thought to have been responsible for a year without summer in 1816. The impact on the human population was dire — crop failures in Eurasia and North America, famine and mass migrations. The effect of Mount Toba, a super-volcano that dwarfs even the massive Yellowstone eruptions of the deeper past, would have had a much larger, and longer-felt, impact on people around the globe (…)
A UNLV scientist has discovered the first direct evidence that fluid water pockets may exist as far as 500 miles deep into the Earth’s mantle.
Groundbreaking research by UNLV geoscientist Oliver Tschauner and colleagues found diamonds pushed up from the Earth’s interior had traces of unique crystallized water called Ice-VII.
Researchers have provided new insights into how molten rock (magma) moves through the Earth’s crust to feed volcanic eruptions. Using laboratory experiments involving water, jelly and laser imaging, researchers were able to demonstrate how magma magma flows through the Earth’s crust to the surface through magma-filled cracks called dykes.
A new study on the timescale of plant evolution has concluded that the first plants to colonize the Earth originated around 500 million years ago — 100 million years earlier than previously thought.
For the first four billion years of Earth’s history, our planet’s continents would have been devoid of all life except microbes.
In popular culture, asteroids play the role of apocalyptic threat, get blamed for wiping out the dinosaurs — and offer an extraterrestrial source for mineral mining. But for one researcher, asteroids play an entirely different role: that of time capsules showing what molecules originally existed in our solar system. Having that information gives scientists the starting point they need to reconstruct the complex pathway that got life started on Earth.
When the seabed loses its stability and starts to move, it often happens in much larger dimensions than landslides ashore — and at slopes with very low gradients. At the same time, discplacement of large amounts of sediment under water scan cause devastating tsunamis. However, why and when submarine landslides develop is hardly understood. Marine scientists have now published possible causes based on observations on submarine landslides off the coast of northwest Africa.
A long-standing question in Earth Science is the extent to which seismic and volcanic activity can be regulated by tidal stresses, a repeatable and predictable external excitation induced by the Moon-Sun gravitational force. Fortnightly tides, a ~14-day amplitude modulation of the daily tidal stresses that is associated to lunar cycles, have been suggested to affect volcano dynamics. However, previous studies found contradictory results and remain mostly inconclusive. Here we study how fortnightly tides have affected Ruapehu volcano (New Zealand) from 2004 to 2016 by analysing the rolling correlation between lunar cycles and seismic amplitude recorded close to the crater. (…)
Though mass extinctions wiped out staggeringly high numbers of species, they barely touched the overall ‘functional’ diversity — how each species makes a living, be it filtering phytoplankton or eating small crustaceans, burrowing or clamping onto rocks.
In recent years, researchers have identified a small group of stalactites that appear to have calcified underwater instead of in a dry cave. The Hells Bells in the El Zapote cave near Puerto Morelos on the Yucatán Peninsula are just such formations. Scientists have recently investigated how these bell-shaped, meter-long formations developed, assisted by bacteria and algae.
How deep can seawater penetrate through cracks and fissures into the seafloor? By applying a new analysis method, an international team of researchers has now discovered that the water can penetrate to depths of more than 10 kilometers below the seafloor. This result suggests a stronger cooling effect on the hot mantle.
Earth’s Moon had a rough start in life. Formed from a chunk of Earth that was lopped off during a planetary collision, it spent its early years covered by a roiling global ocean of molten magma before cooling and forming the serene surface we know today.
The British Isles were once neither British nor isles
Things aren’t always what they seem on the surface. Looking at the area between mainland Europe and the eastern coast of Great Britain, you probably wouldn’t guess it had been anything other than a great expanse of ocean water. But roughly 12,000 years ago, as the last major ice age was reaching its end, the area was very different. Instead of the North Sea, the area was a series of gently sloping hills, marshland, heavily wooded valleys, and swampy lagoons: Doggerland.
A new geological record of the Yellowstone supervolcano’s last catastrophic eruption is rewriting the story of what happened 630,000 years ago and how it affected Earth’s climate. This eruption formed the vast Yellowstone caldera observed today, the second largest on Earth.
The results reveal that a lateral collapse can trigger a significant deflection of deep magma pathways in the crust, favouring the formation of a new eruptive centre within the collapse embayment. Our results have implications for the long-term evolution of intraplate volcanic ocean islands.
Anomalous peaks of nickel abundance have been reported in Permian-Triassic boundary sections in China, Israel, Eastern Europe, Spitzbergen, and the Austrian Carnic Alps. New solution ICP-MS results of enhanced nickel from P-T boundary sections in Hungary, Japan, and Spiti, India suggest that the nickel anomalies at the end of the Permian were a worldwide phenomenon.
Life on Earth began somewhere between 3.7 and 4.5 billion years ago, after meteorites splashed down and leached essential elements into warm little ponds, say scientists. Their calculations suggest that wet and dry cycles bonded basic molecular building blocks in the ponds’ nutrient-rich broth into self-replicating RNA molecules that constituted the first genetic code for life on the planet.
Expedition co-chief scientist Rupert Sutherland of Victoria University of Wellington in New Zealand said researchers had believed that Zealandia was submerged when it separated from Australia and Antarctica about 80 million years ago.
Big geographic changes across northern Zealandia, which is about the same size as India, have implications for understanding questions such as how plants and animals dispersed and evolved in the South Pacific.
The most productive volcanic systems on Earth are hidden under an average of 8,500 feet (2,600 m) of water. Beneath the oceans a global system of mid-ocean ridges produces an estimated 75% of the annual output of magma. An estimated 0.7 cubic miles (3 cubic kilometers) of lava is erupted. The magma and lava create the edges of new oceanic plates and supply heat and chemicals to some of the Earth’s most unusual and rare ecosystems.
La géologie, une science plus que passionnante … et diverse
