As much as two-thirds of Earth's carbon may be hidden in the inner core, making it the planet's largest carbon reservoir, according to a new model that even its backers acknowledge is "provocative and speculative." In a recent paper, Univ. of Michigan researchers and their colleagues suggest that iron carbide, Fe7C3, provides a good match for the density and sound velocities of Earth's inner core under the relevant conditions.
A National Science Foundation-funded research team has successfully tested an autonomous underwater vehicle (AUV) that can produce high-resolution, 3-D maps of Antarctic sea ice. SeaBED, as the vehicle is known, measured and mapped the underside of sea-ice floes in three areas off the Antarctic Peninsula that were previously inaccessible.
New findings by a Johns Hopkins Univ.-led team reveal long unknown details about carbon deep beneath the Earth’s surface and suggest ways this subterranean carbon might have influenced the history of life on the planet. The team also developed a new, related theory about how diamonds form in the Earth’s mantle.
Ample evidence of ancient rivers, streams and lakes make it clear that Mars was at some point warm enough for liquid water to flow on its surface. While that may conjure up images of a tropical Martian paradise, new research published in Nature Geoscience throws a bit of cold water on that notion.
Here’s another reason to pay close attention to microbes: Current climate models probably overestimate the amount of carbon that will be released from soil into the atmosphere as global temperatures rise, according to research from Lawrence Berkeley National Laboratory. The findings are from a new computer model that explores the feedbacks between soil carbon and climate change.
While astronomers have observed the protoplanetary disk evolution throughout our galaxy, the mechanism by which planetary disks evolve at such a rapid rate has eluded scientists for decades. Now researchers have provided the first experimental evidence that our solar system’s protoplanetary disk was shaped by an intense magnetic field that drove a massive amount of gas into the sun within just a few million years.
The continental margins of plates on either side of the Atlantic Ocean are thinner than expected, and an international team led by a Rice Univ. scientist is using an array of advanced tools to understand why. The viscous bottom layers of the continental shelves beneath the Gibraltar arc and northeastern South America are literally being pulled off by adjacent subducting oceanic plates.
The rapidly melting ice sheets on the coast of West Antarctica are a potential major contributor to rising ocean levels worldwide. Although warm water near the coast is thought to be the main factor causing the ice to melt, the process by which this water ends up near the cold continent is not well understood. Using robotic ocean gliders, Caltech researchers now have a better understanding of the cause.
The bones and teeth of two—possibly related—Ice-Age infants, who were buried more than 11,000 years ago in central Alaska, constitute the youngest human remains ever found in the North American Arctic, according to a new paper published by National Science Foundation-funded researchers.
Scientists believe that until about 2.4 billion years ago there was little oxygen in the atmosphere. Evidence in support of this hypothesis comes from studies of sulfur isotopes preserved in the rock record. But the sulfur isotope story has been uncertain because of the lack of key information that has now been provided by a new analytical technique developed by a team of Caltech geologists and geochemists.
Geologists are letting the air out of a nagging mystery about the development of animal life on Earth. Scientists have long speculated as to why animal species didn’t flourish sooner, once sufficient oxygen covered the Earth’s surface.
Wisconsin is famous for its ice fishers. Less well known are the state’s big-league ice drillers. Hollow coring drills designed and managed by the Univ. of Wisconsin-Madison have been instrumental to new research published this week documenting carbon dioxide in the atmosphere between 23,000 and 9,000 years ago, based on data from an 11,000-foot hole in Antarctica.
Scientists have long speculated as to why animal species didn’t flourish sooner, once sufficient oxygen covered the Earth’s surface. Animals began to prosper at the end of the Proterozoic period, about 800 million years ago. But what about the billion-year stretch before that, when most researchers think there also was plenty of oxygen? Well, it seems the air wasn’t so great then, after all.
It’s not as bizarre as it sounds. Earth’s magnetic field has flipped many times throughout the planet’s history. Its dipole magnetic field, like that of a bar magnet, remains about the same intensity for thousands to millions of years, but for incompletely known reasons it occasionally weakens and, presumably over a few thousand years, reverses direction.
Methane-breathing microbes that inhabit rocky mounds on the seafloor could be preventing large volumes of the potent greenhouse gas from entering the oceans and reaching the atmosphere, according to a new study. The rock-dwelling microbes represent a previously unrecognized biological sink for methane and as a result could reshape scientists' understanding of where this greenhouse gas is being consumed in subseafloor habitats.
Washington State University undergraduate Kellie Wall, 21, recently looked for evidence that water influenced crystal formation in basalt, the dark volcanic rock that covers most of eastern Washington and Oregon. She then compared this with volcanic rock observations made by the rover Curiosity on Mars’ Gale Crater, inventing a new method for detecting water on Mars.
For decades, planetary geologists have speculated that glaciers might once have crept through Valles Marineris, the 2000-mile-long chasm that constitutes the Grand Canyon of Mars. A research team has now identified what could be the first mineralogical evidence of past glaciers within the Valles Marineris: a layer of mixed sulfate minerals halfway up three-mile-high cliffs in the canyon system.
Up to half of the water on Earth is likely older than the solar system itself, Univ. of Michigan astronomers theorize. The researchers' work helps to settle a debate about just how far back in galactic history our planet and our solar system's water formed. Were the molecules in comet ices and terrestrial oceans born with the system itself—in the planet-forming disk of dust and gas that circled the young sun 4.6 billion years ago?
Conditions on Earth for the first 500 million years after it formed may have been surprisingly similar to the present day, complete with oceans, continents and active crustal plates. This alternate view of Earth’s first geologic eon, called the Hadean, has gained substantial new support from the first detailed comparison of zircon crystals that formed more than 4 billion years ago with those formed contemporaneously in Iceland.
Scientists at NIST have determined that polonium-209, the longest-lived isotope of this radioactive heavy element, has a half-life about 25% longer than the previously determined value, which had been in use for decades. The new NIST measurements could affect geophysical studies such as the dating of sediment samples from ocean and lake floors.
Picture the fearsome creatures of "Jurassic Park" crossed with the shark from "Jaws." Then super-size to the biggest predator ever to roam Earth. Now add a crocodile snout as big as a person and feet like a duck's. The result gives you some idea of a bizarre dinosaur scientists unveiled Thursday. This patchwork of critters, a 50-foot predator, is the only known dinosaur to live much of its life in the water.
A new study published in The Journal of Geology provides support for the theory that a cosmic impact event over North America some 13,000 years ago caused a major period of climate change known as the Younger Dryas stadial, or “Big Freeze.” The key to the mystery of the Big Freeze lies in nanodiamonds scattered across Europe, North America, and portions of South America.
When a segment of a major fault line goes quiet, it can mean one of two things: The “seismic gap” may simply be inactive, or the segment may be a source of potential earthquakes, quietly building tension over decades until an inevitable seismic release. Researchers from Massachusetts Institute of Technology and Turkey have found evidence for both types of behavior on different segments of the North Anatolian Fault.
A high-tech survey reveals that there is more to Stonehenge than meets the eye, finding previously unknown monuments. Researchers have produced digital maps of what's beneath the World Heritage Site, using ground-penetrating radar, high-resolution magnetometers and other techniques to peer deep into the soil. And they have found some surprises.
In the typical textbook picture, volcanoes, such as those that are forming the Hawaiian islands, erupt when magma gushes out as narrow jets from deep inside Earth. But that picture is wrong, according to a new study from researchers at Caltech and the Univ. of Miami. New seismology data are now confirming that such narrow jets don't actually exist.