Category: Earth Sciences
Saturday, November 23, 2013
There are two types of pole shift. The terrestrial kind is where the land masses actually move from their current positions to new ones sometimes thousands of kilometers away. Then there’s magnetic pole shift, a flip in the Earth’s magnetic field where the north and south poles exchange places.
Adam Maloof, associate professor of geosciences at Princeton University has believed in terrestrial pole shift since his student days. Years of research has not fully proven that terrestrial pole shift does occur at all, but his research has shown there is no possible way it could happen the way he envisioned it would.
Maloof aired his theory on a National Geographic television program in 2009. The geological evidence discovered during the show found rocks in Australia that were ‘born’ thousands of miles away, and Maloof saw this as evidence of violent upheaval.
The rocks had the ‘wrong’ polarity for their situation. As a geologist he knew that rocks maintain their original polarity from the time they are pushed up from the bowels of the earth until they crumble away to dust millions of years later. Finding rocks that originated thousands of miles north on an island in the southern hemisphere offered further proof to him that his theories were correct.
Closer inspection presented him with a major problem though.
There was no evidence of any violent upheaval, none, nothing at all to explain how the rocks had arrived in their current location. The pattern was repeated at other sites around the globe. He and his team turned up dozens of examples of rocks that just shouldn’t be where they were finding them. Rocks that originated near the north pole were marooned in Australia and formations that were known for sure to have started their lives in the southern hemisphere were now located thousands of miles to the north.
Maloof immediately concluded that a terrestrial pole shift couldn’t have happened …but that didn’t explain the out-of-place rocks
After thinking about the issue for some time he hypothesized that terrestrial pole shift could occur after all, but on a scale so slow that we can’t feel it happening. You can hear his explanation on Listen To The story: Talk Of The Nation.
Many scientists do not follow his theory, preferring to believe that the rocks with opposing polarity just came up from the Earth’s interior when the magnetic poles were in their opposite position, or that they arrived where they are due to continental drift.
Magnetic pole shift is a different thing entirely. The Earth’s crust stays in place, there is no movement of rocks or anything else on the surface of the earth. What changes is the Earth’s magnetic field.
The magnetic field around the Earth is generated by the movement of molten iron in the outer core. When working properly it protects us from particle storms, cosmic rays, UV type B radiation and subatomic particles flying in from deep space. Without it the ozone layer would be eroded, and we would be exposed to almost everything the universe has to throw at us.
Every few hundred thousand years the force of the magnetic field reduces until it is almost not there at all, and at this point the magnetic poles flip over, the poles exchange places. The geological record tells us that there have been many such reversals. The last one is thought to have happened about 780,000 years ago.
Our magnetic field has been weakening for 150 years now, but the weakening is not uniform. Professor Elgil Friis-Christensen former director of Denmark’s National Space Institute told the BBC:
We talk about the weakening of the global field but in some local areas, such as in the South Atlantic, the field has gone down 10% in just the last 20 years. But we do not know whether we will go into a reversal or whether the global field will recover.
Pole shift is not synchronized; for a while we may have two, or more south poles, or north poles, as the field adjusts and settles into its new position. It’s a total unknown as to how long the planet would not have the shielding effects of the field.
No one has yet even guesstimated how long it takes to complete the reversal and for the field to return to normal operating levels.
How Far Will Sea Levels Rise? In Miami, They Drew Lines On The Pavement To Find Out
Sea Level Rise in Miami Beach
A woman rides a bike along the chalk outline showing how far inland 3 feet of sea level rise would reach in Miami Beach, Fla. (Courtesy Jayme Gershen/High Water Line)
Looking ahead to a future shaped by Earth’s changing climate, it’s tempting to minimize the impact of a few feet of sea level rise or temperatures a couple degrees higher than today’s, especially when the numbers seem so small.
But in a place like Miami, numbers like those will make a huge difference in the lives of the more than 5 million people who live there – in fact, whether they’ll be able to live there at all.
Visualizing what this future might look like – and sparking conversations about it on the street – is what New York artist Eve Mosher, project co-director Heidi Quante and some 300 volunteers had in mind last week, when they laid down 26 miles of chalk lines through the streets of downtown Miami and Miami Beach.
It was all part of the latest installment in the High Water Line project, which started in New York City back in 2007 and aims to show how rising sea levels will impact life in major cities like Miami, Philadelphia and London this year and next.
“It’s really like a very large performance, with many different people, passing it off from one person to another,” explained project co-coordinator Marta Viciedo. “And the communication, the dialogue that happens [when people ask] hey, what are you doing?”
The lines, drawn with a chalk line marker you’d find at a baseball field, show how far the Atlantic Ocean and Biscayne Bay would encroach if sea levels rose by 3 feet and by 6 feet, reflecting optimistic (and pessimistic) forecasts for sea level rise in Miami by 2100.
Following maps based on sea level rise analysis by Climate Central, the volunteers laid down chalk through historic neighborhoods like Little Havana and right up to the doors of both American Airlines Arena, where the NBA’s Miami Heat play, and Marlins Park, the home of baseball’s Miami Marlins.
$900m Risk From Rising Sea Levels
This is what Earth will look like if we melt all the ice
National Geographic has a good, but disturbing, interactive map showing what 216 feet of sea level rise will do to coastlines around the world.
The maps here show the world as it is now, with only one difference: All the ice on land has melted and drained into the sea, raising it 216 feet and creating new shorelines for our continents and inland seas.
There are more than five million cubic miles of ice on Earth, and some scientists say it would take more than 5,000 years to melt it all. If we continue adding carbon to the atmosphere, we’ll very likely create an ice-free planet, with an average temperature of perhaps 80 degrees Fahrenheit instead of the current 58.
In 2010, the seismologists had set up two crossing lines of seismographs across Marie Byrd Land in West Antarctica. It was the first time scientists had deployed many instruments in the interior of the continent that could operate year-round even in the coldest parts of Antarctica.
The goal was essentially to weigh the ice sheet to help reconstruct Antarctica’s climate history. But to do this accurately the scientists had to know how the Earth’s mantle would respond to an ice burden, and that depended on whether it was hot and fluid or cool and viscous.
In the meantime, automated-event-detection software was put to work to comb the data for anything unusual.
In January 2010 and March 2011, the seismic network recorded two unusual bursts of seismic activity beneath Antarctica’s ice sheet.
“I started seeing events that kept occurring at the same location, which was odd. Then I realized they were close to some mountains, but not right on top of them,” explained PhD student Amanda Lough from Washington University in St. Louis, who is the lead author of the paper appearing in the journal Nature Geoscience.
“My first thought was, ‘OK, maybe it’s just coincidence.’ But then I looked more closely and realized that the mountains were actually volcanoes and there was an age progression to the range. The volcanoes closest to the seismic events were the youngest ones.”
The seismic events were weak and very low frequency, which strongly suggested they weren’t tectonic in origin.
While low-magnitude seismic events of tectonic origin typically have frequencies of 10 to 20 cycles per second, this shaking was dominated by frequencies of 2 to 4 cycles per second.
Ms Lough with colleagues used a global computer model of seismic velocities to relocate the hypocenters of the events to account for the known seismic velocities along different paths through the Earth. This procedure collapsed the swarm clusters to a third their original size. It also showed that almost all of the events had occurred at depths of 25 to 40 km.
Antarctica, a land of ice and FIRE: Active volcano is discovered under continent – and it could speed up melting
The volcano is buried 1km beneath the ice sheets of West Antarctica
Swarms of tremors were detected in January 2010 and February 2011
It was found near the extinct volcanoes of the Executive Committee Range
Ash found trapped in the ice came from an eruption 8,000 years ago
The volcano could cause the ice sheet to melt faster than first thought
Forget global warming, the ice sheets of Antarctica face a different and a potentially more imminent threat in the form an active volcano buried deep beneath.
Researchers from Washington University discovered the volcano – which is yet to be named – by accident in the Marie Byrd Land region of West Antarctica.
Swarms of tremors were detected in January 2010 and February 2011 and ash found trapped in the ice suggest it has been active for around 8,000 years.
The new volcano was found buried beneath an ice sheet in West Antarctica, close to the Executive Committee Range of mountains, pictured. While trying to establish the weight of the ice sheet in the region, seismometers measured two swarms of tremors suggesting the volcano is active
MOUNTAINS DEEP BENEATH THE ICE
The as yet unnamed volcano buried beneath the ice sheet in Marie Byrd Land, West Antarctica is believed to be located close to the Executive Committee Range of extinct volcanoes.
The Range is made up consisting of five major volcanoes which were found by the United States Antarctic Service expedition in 1940.
It is named after the Antarctic Service Executive Committee.
The mountains are called Mount Sidley, Mount Waesche, Mount Hampton, Mount Cumming and Mount Hartington and are named after members of the committee.
Further mountains, thought to be extinct volcanoes, were discovered in East Antarctica in 1958.
This range is called the Gamburtsev Mountain Range and is covered by around 6 kilometres of snow and ice.
It is thought to be similar in size to the Alps.
Like with the new volcano, and the Executive Committee range, it is unclear exactly what caused these mountains to form.
Scientists now believe that a large eruption could cause the ice sheet to melt faster than first thought and cause sea levels to rise.
In January 2010, a team of scientists from the St. Louis-based university set up two crossing lines of seismographs across Marie Byrd Land in West Antarctica.
Doug Wiens, professor of earth and planetary science at Washington University, and his team wanted to weigh the ice sheet to help create a picture of Antarctica’s climate history.
Like a giant CT machine, the seismograph array used disturbances created by distant earthquakes to make images of the ice and rock deep within the region.
The technology found two bursts of seismic events between January 2010 and March 2011, which Wiens’ PhD student Amanda Lough believed were caused by a previously unseen volcano buried over half a mile (1 kilometre) beneath the ice sheet.
‘I started seeing events that kept occurring at the same location, which was odd,’ Lough said.
‘Then I realised they were close to some mountains – but not right on top of them.
‘My first thought was, “Okay, maybe it’s just coincidence.” But then I looked more closely and realised that the mountains were actually volcanoes and there was an age progression to the range.
‘The volcanoes closest to the seismic events were the youngest ones.’
The tremors were weak and very low frequency, which Lough said suggested they weren’t caused by movements in tectonic plates, associated with earthquakes.
The tremors beneath Marie Byrd Land, pictured, were low frequency suggesting they weren’t caused tectonic plates moving. Low-magnitude tectonic tremors typically have frequencies of 10 to 20 cycles per second. The shaking discovered by Lough was 2 to 4 cycles per second making it more like volcanic activity
For example, low-magnitude seismic tremors caused by tectonic movement typically have frequencies of 10 to 20 cycles per second, continued Lough.
The shaking she discovered was in frequencies of 2 to 4 cycles per second.
Lough then used a global computer model of seismic speeds to find exactly where the seismic events were taking place.
Published on Nov 6, 2013
Dr. Annalee Newitz is an editor of i09, was a lecturer at UC Berkeley, a policy analyst at the Electronic Frontier Foundation, a journalist at Wired, and author of ‘Scatter, Adapt, and Remember’.
Plant production could decline as climate change affects soil nutrients
The cliff face of Cedar Mesa, in southeast Utah, overlooks one of many sites sampled in the world’s drylands.
by Staff Writers
Flagstaff AZ (SPX) Nov 04, 2013
As drylands of the world become even drier, water will not be the only resource in short supply. Levels of nutrients in the soil will likely be affected, and their imbalance could affect the lives of one-fifth of the world’s population.
That includes people living in Arizona, who may be in for a dustier future.
The findings are presented in a study published in Nature that details how soil changes may occur and discusses the implications. Co-author Matthew Bowker, assistant professor of forest soils and ecosystem ecology at Northern Arizona University, was involved with the project since 2009.
Bowker explained that most of the 17 nutrients that plants need to grow to their potential are soil resources, such as nitrogen and phosphorus. The statistical model he helped develop for the study suggests that as the climate becomes more arid, nitrogen will decrease and phosphorus will increase.
“Both are essential for plant growth, and both are typical components of fertilizer, but both need to be around in the right quantities for plant growth to proceed most efficiently,” Bowker said.
Warm winters let trees sleep longer
For their experiments, TUM researchers used twigs around 30 centimeters long from 36 different trees and shrubs, which they exposed to different temperature and light conditions in climate chambers. Each climate chamber experiment lasted six weeks. The twigs came from the “Weltwald” or “World Forest” near Freising, Germany, in which Bavarian state foresters have planted stands of trees from different climate regions. Credit: Photo by Julia Laube Copyright TU Muenchen.
by Staff Writers
Munich, Germany (SPX) Nov 04, 2013
In the temperate zones, vegetation follows the change of the seasons. After a winter pause, plants put out new growth in spring. Research has now brought a new correlation to light: The colder the winter, the earlier native plants begin to grow again.
Since warmer winters can be expected as the climate changes, the spring development phase for typical forest trees might start later and later – giving an advantage to shrubs and invasive trees that don’t depend on the cold.
In a recently published study, researchers at the Technische Universitaet Muenchen (TUM) investigated 36 tree and shrub species.
Their work delivered a surprising result, as lead author Julia Laube explains: “Contrary to previous assumptions, the increasing length of the day in spring plays no big role in the timing of budding. An ample ‘cold sleep’ is what plants need in order to wake up on time in the spring.”
This applies above all to native tree species such as beech and oak, because they rely on resting in the cold to protect themselves from freezing by late spring frosts.
A different behavior is observed among pioneer species – including shrubs such as hazel bushes and primary settlers such as birch trees – and among species like locust and walnut that have moved in from warmer climate zones.
“These trees take the risk of starting earlier in the spring, because they are less strongly dependent on the cold periods,” Laube says, “and in addition they sprout more quickly as temperatures rise.”
CREDIT: Shutterstock: Katarish
California is known for its massive water infrastructure in which northern reservoirs, which fill up from the Sierra Nevada snowpack, supply the populous southern and coastal regions of the state. However going into a third year of dry winter conditions, many of these northern man-made oases are at precariously low levels, hovering between one-third and one-half capacity, far less than the average for October.
More than 20 million Californians and many farmers in the state’s crop-intensive Central Valley depend on northern reservoirs for their water.
“Both the State Water Project and federal Central Valley Project heavily depend on the Sierra Nevada snowpack,” Mark Cowin, director of the state Department of Water Resources, told The Fresno Bee. “We are now facing real trouble if 2014 is dry.”
Cowin said that dwindling reservoirs should be a wake-up call to Californians, and indicate that it’s time to prepare for additional water-conservation measures.
Pete Lucero of the U.S. Bureau of Reclamation, owner of the Central Valley Project, told the Fresno Bee that January through May 2013 were California’s driest in about 90 years of recordkeeping.
Currently the San Luis Reservoir, which gets water from the Sacramento-San Joaquin River Delta, is only 22 percent of its historical average for this time of year.
At a recent workshop that brought together leaders to hear about California’s water challenges, Cowin said that decades of disagreement among environmentalists, farmers, water agencies, and other interests in various parts of California has “resulted in gridlock.” And that with “environmental laws, climate change, and population growth intensifying the conflict, there’s simply no time to waste.”
It turns out that it doesn’t take much to turn our planet’s ocean waters into something that’s toxic to life. Scientists have taken a closer look at a massive extinction event that occurred 93.9 million years ago and have found that it didn’t take as much sulfide as previously thought in the ocean waters to cause this major climatic perturbation.
In order to examine this particular extinction, the scientists examined the chemistry of rocks deposited during that time period. This revealed that oxygen-free and hydrogen sulfide-rich waters extended across roughly five percent of the global ocean. That’s far more than today modern ocean’s at .1 percent, but far less than previously thought.
“These conditions must have impacted nutrient availability in the ocean and ultimately the spatial and temporal distribution of marine life,” said Jeremy Owens, one of the researchers, in a news release. “Under low-oxygen environments, many biologically important metals and other nutrients are removed from seawater and deposited in the sediments on the seafloor, making them less available for life to flourish.”
“Today, we are facing rising carbon dioxide contents in the atmosphere through human activities, and the amount of oxygen in the ocean may drop correspondingly in the face of rising seawater temperatures,” said said Timothy W. Lyons, a professor of biogeochemistry at University of California (Riverside). “Oxygen is less soluble in warmer water, and there are already suggestions of such decreases. In the face of these concerns, our findings from the warm, oxygen-poor ancient ocean may be a warning shot about yet another possible perturbation to marine ecology in the future.”
Oxygen in the atmosphere and ocean rose dramatically about 600 million years ago, coinciding with the first proliferation of animal life. Since then, numerous short-lived biotic events — typically marked by significant climatic perturbations — took place when oxygen concentrations in the ocean dipped episodically.
The most studied and extensive of these events occurred 93.9 million years ago. By looking at the chemistry of rocks deposited during that time period, specifically coupled carbon and sulfur isotope data, a research team led by UCR biogeochemists reports that oxygen-free and hydrogen sulfide-rich waters extended across roughly five percent of the global ocean during this major climatic perturbation — far more than the modern ocean’s 0.1 percent but much less than previous estimates for this event.
The research suggests that previous estimates of oxygen-free and hydrogen sulfide-rich conditions, or “euxinia,” were too high. Nevertheless, the limited and localized euxinia were still sufficiently widespread to have dramatic effect on the entire ocean’s chemistry and thus biological activity.
Yellowstone has the world’s largest collection of geysers, and it has the underground plumbing to prove it. Scientists have announced that the volcanic activity beneath the National Park’s surface may be far bigger and better connected than once thought.
The National Park is home to hot springs, mudpots, fumaroles and geysers, so it’s not surprising that it has quite a bit of volcanic activity under the ground. Known as a hotspot, a massive volume of molten magma is located beneath Yellowstone. This plume of superheated rock rises from Earth’s mantle, punching through the continent’s crust as North America has slowly drifted over it. The phenomenon has left a trail of calderas created by massive volcanic eruptions in its wake; the most recent occurred about 640,000 years ago.
Yellowstone is infamous for its potential for a “super eruption.” When the Huckleberry Ridge eruption in Yellowstone occurred about 2 million years ago, it darkened the skies with ash from southern California to the Mississippi River. It was one of the largest eruptions to have occurred on our planet. Understanding the volcanic activity of this location is therefore crucial for predicting future eruptions.
Large magma reservoir gets bigger
But earthquakes, not eruptions, are Yellowstone’s most serious geological risk.
The reservoir of molten rock underneath Yellowstone National Park in the United States is at least two and a half times larger than previously thought. Despite this, the scientists who came up with this latest estimate say that the highest risk in the iconic park is not a volcanic eruption but a huge earthquake.
Yellowstone is famous for having a ‘hot spot’ of molten rock that rises from deep within the planet, fuelling the park’s geysers and hot springs1. Most of the magma resides in a partially molten blob a few kilometres beneath Earth’s surface.
New pictures of this plumbing system show that the reservoir is about 80 kilometres long and 20 kilometres wide, says Robert Smith, a geophysicist at the University of Utah in Salt Lake City. “I don’t know of any other magma body that’s been imaged that’s that big,” he says.
Smith reported the finding on 27 October at the annual meeting of the Geological Society of America in Denver, Colorado.
Yellowstone lies in the western United States, where the mountain states of Wyoming, Montana and Idaho converge. The heart of the park is a caldera — a giant collapsed pit left behind by the last of three huge volcanic eruptions in the past 2.1 million years.