A huge spike in the Earth’s atmospheric oxygen about 800 million years ago, the story goes, paved the way for the Cambrian explosion a couple hundred million years later, and with it the rise of complex life. But a new study out in Nature says that picture is incomplete. Researchers found evidence of substantial oxygen 1.2 billion years ago, meaning that the conditions needed for complex life appeared much earlier than scientists knew, and that perhaps something else was required to set off the explosion of biodiversity.
The geologists led by John Parnell hunted in the Scottish Highlands for clues in ancient rocks, where evidence of ancient bacteria could reveal how much oxygen was around 1.2 billion years ago.
Before there was a useful amount of free oxygen around, these bacteria used to get energy by converting sulfate, a molecule with one sulfur atom and four oxygens, to sulfide, a sulfur atom that is missing two electrons. Geologists can get a glimpse of how efficient the bacteria were by looking at two different sulfur isotopes, versions of the same element that have different atomic masses. Converting sulfate to sulfide leaves the rock with a lot more of the isotope sulfur-32 than would be there without the bacteria’s help. [Wired.com]
(more…)
The planet’s tumult never ceases. Hurricane Tomas is bearing down on Haiti right now, and an erupting volcano continues to wreak destruction on Indonesia.
At 8 a.m. EDT on Nov. 5, Tomas’ center was about 80 miles south-southeast of Guantanamo, Cuba and 160 miles west of Port Au Prince Haiti…. Tomas is moving to the northeast near 10 mph, and is expected to speed up over the next couple of days. [NASA Press release]
The hurricane is currently a category one, with sustained winds of 85 miles per hour, and is expected to continue strengthen throughout Friday before weakening on Saturday. The hurricane’s strong winds and flooding may hit the country hard: Haiti’s earthquake in January left the country particularly susceptible to land slides.
“Haiti has a really serious history of big landslides, almost all of them caused by tropical storm or hurricane rainfall,” said geologist David Petley, the Wilson Professor of Hazard and Risk at Durham University in England. [LiveScience]
If the hurricane stays on its current course it will pass just to the west of the small island nation, but there may still be plenty of damage and human misery. Many Haitians whose homes were destroyed in the earthquake are still living in temporary homes that won’t be able to stand up to the winds.
(more…)
The retreat of the ice covering “Snowball Earth” 700 million years ago might have been the key to the Cambrian explosion that seeded our planet with diverse forms of life. But the trigger may not have been the changes to the climate, but rather the release of phosphorus into the ocean.
During this time period, called the Cryogenian or Snowball Earth stage, the entire planet was covered in snow and ice, and the oceans may even have been frozen. Many researchers believe that the ice receded twice during this freezing period, first around 700 million years ago and then again around 635 million years ago. In a paper published in Nature this week, a team of researchers propose that these receding sheets released phosphorus into the oceans.
In the scheme offered by [Noah] Planavsky and his colleagues, the snowball ice sheets would, as their modern counterparts do, grind up continental rock that would release phosphorus when the glaciers retreated. That phosphorus would wash into the ocean, where it would fertilize algal blooms that could drive a surge in the production of organic matter and oxygen. And the added organic matter that settled into the mud on the ocean bottom would leave additional oxygen behind, eventually boosting atmospheric and oceanic oxygen. [ScienceNOW]
(more…)
A huge bounty of amber unearthed in India is giving researchers a peak at the wildlife that inhabited the area 50 million years ago, via the insects that are trapped inside it. The findings, published in the Proceedings of the National Academy of Sciences, suggest that the Indian subcontinent was not as isolated as previously thought.
“We know India was isolated, but … the biological evidence in the amber deposit shows that there was some biotic connection,” says David Grimaldi, curator in the Division of Invertebrate Zoology at the [American Museum of Natural History]. [Press release]
About 150 million years ago, the Indian tectonic plat separated from the African plate and began its 100 million year journey to Asia. During that long journey the subcontinent was isolated from all other continents, giving its wildlife the chance to evolve in distinctly different ways (much like the evolution of marsupials in Australia). Since the amber was deposited in the form of sticky tree resin 50 million years ago, it gives researchers insight into the insects that were adrift on the subcontinent.
“The amber shows, similar to an old photo, what life looked like in India just before the collision with the Asian continent,” says Jes Rust, professor of Invertebrate Paleontology at the Universität Bonn in Germany. “The insects trapped in the fossil resin cast a new light on the history of the sub-continent.” [Press release]
(more…)
Rare earth metals are a hot commodity in today’s high-tech world. Until recently these elements were fairly obscure members of the periodic table; now, their usefulness in everything from hybrid cars to solar panels has boosted their profile.
The 17 rare earth metals, some with exotic names like lanthanum and europium, form unusually strong lightweight magnetic materials. Lanthanum is used in the batteries of hybrid cars, neodymium is used in magnets in the electric generators of wind turbines and europium is used in colored phosphors for energy-efficient lighting. [Reuters]
Their new necessity has also provided a boost to China, where the vast majority of these elements are currently mined. China’s dominance has been brought into sharp focus over the past three weeks, when China blocked all shipments of rare earth metals to Japan in response to a diplomatic incident concerning a Chinese fishing boat in territorially disputed waters.
Beijing has denied the embargo, yet the lack of supply may soon disrupt manufacturing in Japan, trade and industry minister Akihiro Ohata told reporters Tuesday. [Technology Review]
(more…)
Earlier this week we brought you news of water woes in the American southwest, where reservoir levels have dropped dangerously low, and in China, where the government is spending $60 billion to route water to parched cites like Beijing. Now comes news of just how widespread the world’s water problems really are. A study in Nature reports that nearly 80 percent of the world’s population lives in areas where the fresh water supply isn’t secure. And while industrialized nations have made massive investments in infrastructure to keep the faucets flowing, those projects have taken a toll on the environment.
[The researchers] say that in western countries, conserving water for people through reservoirs and dams works for people, but not nature. They urge developing countries not to follow the same path. Instead, they say governments should to invest in water management strategies that combine infrastructure with “natural” options such as safeguarding watersheds, wetlands and flood plains. [BBC News]
Related Content:
80beats: Water Woes: The Southwest’s Supply Dwindles; China’s Behemoth Plumbing Project Goes On
80beats: Saudi to Use Plentiful Resource (Sunlight) to Produce Scarce Resource (Fresh Water)
80beats: From 300 Miles Up, Satellites See Water Crisis in India’s Future
DISCOVER: How Big Is Your Water Footprint?
DISCOVER: Dams, From Hoover to Three Gorges to the Crumbling Ones
Images: Nature / C. J. Vörösmarty et al.
The glaciers that form atop mountains can act like a saw or sandpaper, wearing away material as they slide and preventing the peaks from ascending too high. Until now, that’s been the consensus notion of how glaciers shape mountains. But whatever your tool shop metaphor of choice might be, neither saws nor sanders work if the glaciers don’t move. That might explain what’s happening in the far reaches of southern South America, where, scientists led by Stuart Thomson report in Nature, glaciers are not wearing down the Andes Mountains but are actually protecting them from erosion.
In the more temperate part of the range, from 38˚ to 49˚ south latitude, the glacial grinder has shaved off as much as 1000 meters from the mountains’ peaks, flattened their slopes, and smoothed their surfaces. But farther south, between 49˚ and 56˚ latitude, the mountains have been spared: The peaks are higher—some nearly 4000 meters—and the ridges are much more rugged. [ScienceNOW]
(more…)
Had compass-toting Boy Scouts existed around fifteen million years ago, they may have had a fun time making it through the forest. New geological research questions if the Earth’s magnetic field changed, at that time, at the remarkable pace of one degree per week, leading to a particularly fast magnetic pole flip.
In a paper to appear in Geophysical Research Letters, Scott Bogue and Jonathan Glen suggest that the Earth’s magnetic field changed 53 degrees in one year’s time, based on their study of preserved lava flows in Nevada. As the solid rock formed from cooling liquid lava, it preserved a pattern corresponding to the “super-fast” geomagnetic field reversal, the researchers believe. This is the second time that Bogue has controversially argued for the existence of such speedy flips, finding hints of a faster one in 1995.
In 1995 an ancient lava flow with an unusual magnetic pattern was discovered in Oregon. It suggested that the field at the time was moving by 6 degrees a day–at least 10,000 times faster than usual. “Not many people believed it,” says Scott Bogue of Occidental College in Los Angeles. [New Scientist]
(more…)
As Tropical Storm Earl grew into Hurricane Earl this past weekend, NASA had a plan: Fly a plane into it. A DC-8 aircraft, used for NASA’s new Genesis and Rapid Intensification Processes (GRIP) project, darted around the storm to trace the movement of atmospheric aerosols–particles suspended in the air–and to drop weather sensors, giving NASA researchers data on how such storms form and strengthen.
NASA’s DC-8 aircraft left Fort Lauderdale at 10:05 a.m. EDT on Saturday heading for St. Croix for a multi-day deployment that targeted (at that time) Tropical Storm Earl…. On Sunday, August 29, the DC-8 completed an 8.5-hour science flight over (then) Hurricane Earl west of St. Croix. The research aircraft flew at altitudes of 33,000 feet and 37,000 feet and descended to 7,000 feet northwest of the storm area to collect measurements of atmospheric aerosols. The flight originated in St. Croix but diverted to land in Fort Lauderdale, Fla., due to the degrading weather forecast for St. Croix associated with the approaching hurricane. [NASA]
(more…)
The United States currently holds around half of the world’s helium supply and we’re selling it, for cheap.
We’ve known this for a while. We started stockpiling the stuff near Amarillo, Texas in 1925, in part for dirigible use, and stepped up reserves in the 1960s as a Cold War asset. In 1996, Congress passed the Helium Privatization Act mandating that the United States sell the gas at artificially low prices to get rid of the stockpile by 2015. This February, the National Research Council published a report estimating that, given increasing consumption, the world may run out of helium in 40 years. That’s bad news given helium’s current applications in science, technology, and party decorations–and possible future applications in fusion energy.
Now physicist Robert Richardson, who won a 1996 Nobel Prize for work using helium-3 to make superfluids, has come forward to stress the folly of underselling our supply of the natural resource. He suggested in several interviews that the gas’s price should mirror its actual demand and scarcity. He estimates that typical party balloons should cost $100 a pop.
“They couldn’t sell it fast enough and the world price for helium gas is ridiculously cheap,” Professor Richardson told a summer meeting of Nobel laureates…. “Once helium is released into the atmosphere in the form of party balloons or boiling helium it is lost to the Earth forever, lost to the Earth forever,” he emphasised. [The Independent]
If we don’t heed Richardson’s warning, here are some sources the United States might have to tap when we run out:
(more…)
Originally scientists believed that one earthquake had set off the deadly tsunami that struck Samoa, American Samoa, and Tonga in September of 2009. But two studies to appear tomorrow in Nature argue that instead of one there were really two earthquakes that took place in rapid succession.
For some scientists, the studies clear up odd behavior that didn’t fit with the originally blamed “normal-fault” earthquake in the Pacific Northwest.
“We knew right off the bat that something was weird about this earthquake,” says geophysicist Eric Geist of the U.S. Geological Survey in Menlo Park, Calif. Geist wasn’t involved in the current studies but has puzzled over the anomalous signs produced by the quake. “This is a very complicated event, and these studies, for me, really helped explain a lot.” [Science News]
John Beaven, lead author of one of the studies, told Nature News the researchers expected the Tongan island to move about three inches to the west as a result of the quake, but GPS showed it had moved nearly a foot east. They also expected the sea bed to drop but instead it rose, a sign of a different kind of “megathrust” quake. A separate study led by Thorne Lay confirmed signs of this alternate type of earthquake from seismic readings.
Though both studies point to two different types of earthquakes, they disagree on which earthquake came first and caused the other. Ronald Burgmann, a geophysicist at the University of California, Berkeley, who was not involved in either study says, overall, they both make a good case:
“As in all good chicken-and-egg mysteries,” he says, “there is merit to both views.” [Nature News]
Related content:
80beats: Toads—Yes, Toads—May Know When an Earthquake Is Coming
80beats: Haiti Earthquake May Have Released 250 Years of Seismic Stress
80beats: Science Via Twitter: Post-Earthquake Tweets Can Provide Seismic Data
80beats: Major Earthquakes Can Weaken Faults Around the Globe
80beats: A Major Quake Could Release Plutonium from Los Alamos Lab
Image: Mick Finn, GNS Science
Way up in the Great White North, beneath Canada’s Baffin Island, lies material from the very beginning of the planet.
The search for primordial stuff—rocks that have survived 4.5 billion years since the formation of the Earth without being changed by forces that shook and scrambled our planet—is one of geology’s long-running quests. In Nature this week, Matthew Jackson says he may have done it. Jackson’s team found lava rocks in Canada with a signature that matches that of the newly formed Earth, suggesting there is material below the snowy surface that has endured unchanged throughout the planet’s history.
They have the highest proportion of the isotope helium-3 relative to helium-4 of any rocks known. This suggests that the rocks came from a “primitive” region of Earth, as, unlike helium-4, helium-3 can’t be replenished and thus must have come from the original building blocks of the planet. What’s more, the ratio of two isotopes of the element neodymium match what geochemists would expect for a residue from Earth’s early ocean of molten magma [ScienceNOW].
(more…)
Researchers camped on the Greenland ice sheet hit bedrock this week after almost three years of drilling, reaching a depth of 8,000 feet. They hope that the ice they’ve uncovered from some 120,000 years ago, might give them a better understanding of what a warmer future might look like, if Greenland has less ice and the sea level rises.
The team, which is part of the North Greenland Eemian Ice Drilling (NEEM) project, is looking to learn more about carbon dioxide levels during the Eemian period, when global temperatures were over 2-3 degrees Celsius warmer and sea level was about 15 feet higher. They believe these conditions might mirror effects caused by the earth’s changing climate during the next century.
Scientists believe that by the end of the 21st century the planet will experience similar conditions again. Over the Greenland ice sheet, temperatures at the height of the Eemian may have been around 5 degrees Celsius warmer–mirroring the Arctic amplification of modern climate change. . . There are large uncertainties concerning the response of ice sheets to warming air and ocean temperatures. Understanding what happened to the Greenland ice sheet during the Eemian could help constrain projections of future sea level rise. [Nature]
(more…)
You can’t rise from the primordial ooze if that ooze is frozen. But about three billion years ago the sun was around thirty percent dimmer, meaning our planet should have been a snowball. The puzzle has haunted scientists for decades, but a study in Science has a new answer: It argues that a dense cloud of “fractal haze” enveloped the Earth.
Old Theories
This isn’t the first attempt to solve the early Earth conundrum. Carl Sagan, for one, had a few ideas. First, in 1972, he speculated that the atmosphere had ammonia which could trap heat, but later work showed that the sun’s ultraviolet radiation would have broken that ammonia down. In 1996 he tried again, saying that Earth might have had a thick haze, perhaps a nitrogen-methane mix, that blocked the ultraviolet but let in enough of the sun’s then-meager rays to warm the planet. Unfortunately, that too was a no go:
Early models assumed the haze particles were spheres, and that when individual particles collided, they globbed together to make bigger spheres. These spheres blocked visible light as well as ultraviolet light, and left the Earth’s surface even colder. “It basically led us to a dead end where we couldn’t have a warm early Earth,” said Eric Wolf, a graduate student in atmospheric sciences at the University of Colorado at Boulder and the first author of the new study. [Wired]
(more…)
The sheer jarring starkness of it makes this photo look Photoshopped. But the massive sinkhole that collapsed into being in Guatemala City this weekend is deadly real.
The seemingly never ending hole appears to be about 200 feet deep, according to numerous reports [Los Angeles Times].
Tropical Storm Agatha pounded the Central American country, and as of this afternoon the death toll stands around 175. Some of that death and destruction came via mudslides and flooding. However, this gaping hole has captured the world’s attention.
In the northern part of Guatemala City, the downpour created a sinkhole the size of a street intersection. Residents told CNN that a three-story building and a house fell into the hole [CNN].
Unfortunately, the sight is not unfamiliar in Guatemala. The country experienced a similarly daunting sinkhole in 2007 (see photos). A ruptured sewer line caused that one by releasing too much water and softening the ground. It’s not out of the question that the same thing could have happened here, hydrogeologist James Currens says.
A burst sanitary or storm sewer may have been slowly saturating the surrounding soil for a long time before tropical storm Agatha added to the inundation. “The tropical storm came along and would have dumped even more water in there, and that could have been the final trigger that precipitated the collapse,” Currens said [National Geographic].
Related Content:
80beats: Why Chile’s Massive Earthquake Could Have Been Much Worse
DISCOVER: Rock-a-pedia, the open source map that could save you from a sinkhole
Bad Astronomy: Top 10 Astronomy Pictures of 2007, featuring something like a sinkhole on Mars
Image: Guatemalan government
