For the entire history of our species, humans have lived on a planet capped by a chunk of ice at each pole. But Earth has been ice-free for about 75 percent of the time since complex life first appeared. This variation in background climate, between partly glaciated and ice-free, has puzzled geologists for decades.
Over the last 540 million years, the Earth has weathered three major ice ages -- periods during which global temperatures plummeted, producing extensive ice sheets and glaciers that have stretched beyond the polar caps. Now scientists at MIT, the University of California at Santa Barbara, and the University of California at Berkeley have identified the likely trigger for these ice ages.
Every year earthquakes worldwide claim hundreds or even thousands of lives. Forewarning allows people to head for safety and a matter of seconds could spell the difference between life and death. UTokyo researchers demonstrate a new earthquake detection method -- their technique exploits subtle telltale gravitational signals traveling ahead of the tremors. Future research could boost early warning systems.
Using cores of rock, scientists have mapped out the tracks of several planets that influence the orbit, and thus the climate, of Earth, in a period 200 million years ago. This vastly expands the time period for which such calculations have been made, opening a window onto the evolution of our climate, and of the solar system itself.
New results from the Gulf of Corinth, Greece, a continental rift zone where the first stage of ocean basin formation is taking place, show how the environmental conditions and sediment input into the rift basin changed as the Earth alternated between non-glaciated to glaciated conditions over the last 500 thousand years.
Research shedding light on the internal 'plumbing' of volcanoes may help scientists better understand volcanic eruptions and unrest. The University of Queensland-led study analyzed crystals in Italy's famous Mount Etna to reveal how quickly magma moves to the surface.
Princeton geoscientists Blair Schoene and Gerta Keller led an international team of researchers who have assembled the first high-resolution timeline for the massive eruptions in India's Deccan Traps, determining that the largest eruption pulse occurred less than 100,000 years before the mass extinction that killed the (non-avian) dinosaurs.
Understanding the global carbon cycle provides scientists with vital clues about the planet's habitability.
UC Berkeley scientists have obtained more precise dates for the Deccan Traps volcanic lava flows, linking peak activity more closely to the asteroid or comet impact 66 million years ago and the coincident mass extinction. But if greenhouse gases emitted before the impact created a hothouse climate that set life up for a fall when the impact cooled the planet, those gases did not coincide with the largest lava flows from the Deccan Traps.
A major volcanic event could have triggered one of the largest glaciations in Earth's history -- the Gaskiers glaciation, which turned the Earth into a giant snowball approximately 580 million years ago. Researchers from Heidelberg University and colleagues from Mexico have discovered remnants of such a large igneous province that resulted from vast lava flows.