JUST IN: New Maps Chart Mantle Plumes Melting Greenland Glaciers

Many large glaciers in Greenland are at greater risk of melting from below than previously thought, according to new maps of the seafloor around Greenland created by an international research team. Like other recent research findings, the maps highlight the critical importance of studying the seascape under Greenland’s coastal waters to better understand and predict global sea level rise.

Uummannaq fjord

Researchers from the University of California, Irvine; NASA’s Jet Propulsion Laboratory, Pasadena, California; and other research institutions combined all observations their various groups had made during shipboard surveys of the seafloors in the Uummannaq and Vaigat fjords in west Greenland between 2007 and 2014 with related data from NASA’s Operation Icebridge and the NASA/U.S. Geological Survey Landsat satellites. They used the combined data to generate comprehensive maps of the ocean floor around 14 Greenland glaciers. Their findings show that previous estimates of ocean depth in this area were as much as several thousand feet too shallow.

Why does this matter? Because glaciers that flow into the ocean melt not only from above, as they are warmed by Sun and air, but from below, as they are warmed by water.

Iceland - Greenland Mid-Atlantic Ridge3

In most of the world, a deeper seafloor would not make much difference in the rate of melting, because typically ocean water is warmer near the surface and colder below. But Greenland is exactly the opposite. Surface water down to a depth of almost a thousand feet (300 meters) comes mostly from Arctic river runoff. This thick layer of frigid, fresher water is only 33 to 34 degrees Fahrenheit (1 degree Celsius). Below it is a saltier layer of warmer ocean water. This layer is currently more than 5 degrees F (3 degrees C) warmer than the surface layer, and climate models predict its temperature could increase another 3.6 degrees F (2 degrees C) by the end of this century.

About 90 percent of Greenland’s glaciers flow into the ocean, including the newly mapped ones. In generating estimates of how fast these glaciers are likely to melt, researchers have relied on older maps of seafloor depth that show the glaciers flowing into shallow, cold seas. The new study shows that the older maps were wrong.

“While we expected to find deeper fjords than previous maps showed, the differences are huge,” said Eric Rignot of UCI and JPL, lead author of a paper on the research. “They are measured in hundreds of meters, even one kilometer [3,300 feet] in one place.” The difference means that the glaciers actually reach deeper, warmer waters, making them more vulnerable to faster melting as the oceans warm.

Co-author Ian Fenty of JPL noted that earlier maps were based on sparse measurements mostly collected several miles offshore. Mapmakers assumed that the ocean floor sloped upward as it got nearer the coast. That’s a reasonable supposition, but it’s proving to be incorrect around Greenland.

Rignot and Fenty are co-investigators in NASA’s five-year Oceans Melting Greenland (OMG) field campaign, which is creating similar charts of the seafloor for the entire Greenland coastline. Fenty said that OMG’s first mapping cruise last summer found similar results. “Almost every glacier that we visited was in waters that were far, far deeper than the maps showed.”

The researchers also found that besides being deeper overall, the seafloor depth is highly variable. For example, the new map revealed one pair of side-by-side glaciers whose bottom depths vary by about 1,500 feet (500 meters). “These data help us better interpret why some glaciers have reacted to ocean warming while others have not,” Rignot said.

The lack of detailed maps has hampered climate modelers like Fenty who are attempting to predict the melting of the glaciers and their contribution to global sea level rise. “The first time I looked at this area and saw how few data were available, I just threw my hands up,” Fenty said. “If you don’t know the seafloor depth, you can’t do a meaningful simulation of the ocean circulation.”

BREAKING NEWS: Volcanoes Responsible for Climate Change Through Much of Earth’s History

A new study in the April 22 edition of the journal ‘Science’, reveals that volcanic activity associated with the plate-tectonic movement of continents may be responsible for climatic shifts from hot to cold throughout much of Earth’s history. The study, led by researchers at The University of Texas at Austin Jackson School of Geosciences, addresses why Earth has fluctuated from periods when the planet was covered in ice to times when polar regions were ice-free.

volcanic arc

Lead researcher Ryan McKenzie said the team found that periods when volcanoes along continental arcs were more active coincided with warmer trends over the past 720 million years. Conversely, periods when continental arc volcanoes were less active coincided with colder, or cooling trends.

For this study, researchers looked at the uranium-lead crystallization ages of the mineral zircon, which is largely created during continental volcanic arc activity. They looked at data for roughly 120,000 zircon grains from thousands of samples across the globe.

zircon and mantle

Zircon is often associated with mantle plumes. If the zircon Hf model age is very close to its formation age (zircon U–Pb) – the magma could be subsequent of a depleted mantle plume. On the other hand, if the zircon Hf model age is older than its formation age, it can be concluded that the magma was derived from enriched mantle sources or was contaminated by crustal materials.

“We’re looking at changes in zircon production on various continents throughout Earth’s history and seeing how the changes correspond with the various cooling and warming trends,” McKenzie said. “Ultimately, we find that during intervals of high zircon production we have warming trends, and as zircon production diminishes, we see a shift into our cooling trends.”

equation-mantle plumes

New Equation:
Increase Charged Particles → Decreased Magnetic Field → Increase Outer Core Convection → Increase of Mantle Plumes → Increase in Earthquake and Volcanoes → Cools Mantle and Outer Core → Return of Outer Core Convection (Mitch Battros – July 2012)

One question unanswered in recent climate change debates, is what caused the fluctuations in CO2 observed in the geologic record. Other theories have suggested that geological forces such as mountain building have, at different times in the planet’s history, introduced large amounts of new material to the Earth’s surface, and weathering of that material has drawn CO2 out of the atmosphere.

warming-cooling-trends4

Using nearly 200 published studies and their own fieldwork and data, researchers created a global database to reconstruct the volcanic history of continental margins over the past 720 million years.

“We studied sedimentary basins next to former volcanic arcs, which were eroded away over hundreds of millions of years,” said co-author Brian Horton, a professor in the Jackson School’s Department of Geological Sciences. “The distinguishing part of our study is that we looked at a very long geologic record – 720 million years – through multiple warming and cooling trends.”

The cooling periods tended to correlate with the assembly of Earth’s supercontinents, which was a time of diminished continental volcanism, Horton said. The warming periods correlated with continental breakup, a time of enhanced continental volcanism.

NASA Missions Measure Solar Flare Electromagnetic Phenomenon

Solar flares are intense bursts of light from the Sun. They are created when complicated magnetic fields suddenly and explosively rearrange themselves, converting magnetic energy into light through a process called magnetic reconnection – at least, that’s the theory, because the signatures of this process are hard to detect. But during a December 2013 solar flare, three solar observatories captured the most comprehensive observations of an electromagnetic phenomenon called a current sheet, strengthening the evidence that this understanding of solar flares is correct.

eclectromagnetic sheet

These eruptions on the Sun eject radiation in all directions. The strongest solar flares can impact the ionized part of Earth’s atmosphere – the ionosphere – and interfere with our communications systems, like radio and GPS, and also disrupt onboard satellite electronics. Additionally, high-energy particles – including electrons, protons and heavier ions – are accelerated by solar flares.

Unlike other space weather events, solar flares travel at the speed of light, meaning we get no warning that they’re coming. So scientists want to pin down the processes that create solar flares – and even some day predict them before our communications can be interrupted.

Image converted using ifftoany

“The existence of a current sheet is crucial in all our models of solar flares,” said James McAteer, an astrophysicist at New Mexico State University in Las Cruces and an author of a study on the December 2013 event, published on April 19, 2016, in the Astrophysical Journal Letters. “So these observations make us much more comfortable that our models are good.”

And better models lead to better forecasting, said Michael Kirk, a space scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who was not involved in the study. “These complementary observations allowed unprecedented measurements of magnetic reconnection in three dimensions,” Kirk said. “This will help refine how we model and predict the evolution of solar flares.”

A current sheet is a very fast, very flat flow of electrically-charged material, defined in part by its extreme thinness compared to its length and width. Current sheets form when two oppositely-aligned magnetic fields come in close contact, creating very high magnetic pressure. Electric current flowing through this high-pressure area is squeezed, compressing it down to a very fast and thin sheet. It’s a bit like putting your thumb over the opening of a water hose – the water, or, in this case, the electrical current, is forced out of a tiny opening much, much faster. This configuration of magnetic fields is unstable, meaning that
the same conditions that create current sheets are also ripe for magnetic reconnection.

“Magnetic reconnection happens at the interface of oppositely-aligned magnetic fields,” said Chunming Zhu, a space scientist at New Mexico State University and lead author on the study. “The magnetic fields break and reconnect, leading to a transformation of the magnetic energy into heat and light, producing a solar flare.”

Because current sheets are so closely associated with magnetic reconnection, observing a current sheet in such detail backs up the idea that magnetic reconnection is the force behind solar flares.

“You have to be watching at the right time, at the right angle, with the right instruments to see a current sheet,” said McAteer. “It’s hard to get all those ducks in a row.”

This isn’t the first time scientists have observed a current sheet during a solar flare, but this study is unique in that several measurements of the current sheet – such as speed, temperature, density and size – were observed from more than one angle or derived from more than method.

This multi-faceted view of the December 2013 flare was made possible by the wealth of instruments aboard three solar-watching missions: NASA’s Solar Dynamics Observatory, or SDO, NASA’s Solar and Terrestrial Relations Observatory, or STEREO – which has a unique viewing angle on the far side of the Sun – and Hinode, which is a collaboration between the space agencies of Japan, the United States, the United Kingdom and Europe led by the Japan Aerospace Exploration Agency.

Even when scientists think they’ve spotted something that might be a current sheet in solar data, they can’t be certain without ticking off a long list of attributes. Since this current sheet was so well-observed, the team was able to confirm that its temperature, density, and size over the course of the event were consistent with a current sheet.

As scientists work up a better picture of how current sheets and magnetic reconnection lead to solar eruptions, they’ll be able to produce better models of the complex physics happening there – providing us with ever more insight on how our closest star affects space all around us.

This research was funded by a CAREER grant from the National Science Foundation awarded to James McAteer.

The Causes of Heating and Cooling of Earth’s Core and Climate Change

Ongoing studies supported by the NSF (National Science Foundation) indicate a connection between submarine troughs (rifts), Earth’s mantle, and Earth’s outer core. Furthermore, new research indicates the shifting of magnetic flux via Earth’s magnetic field, has a direct and symbiotic relationship to Earth’s outer core, mantle, lithosphere, and crust.

_new_equation-2012

As a living entity, Earth fights for its survival. If internal or external events begin to throw Earth out of balance i.e. orbital, tilt, or magnetic alignment – it begins to correct itself. When oceanic tectonic subductions occur, it cools the mantle and outer core. To balance this shift in temperatures, the Earth’s core increases heat and as a result releases what is known as “mantle plumes”. These plumes filled with super-heated liquid rock float up to the ocean bottom surface.

This action both cools the outer core and heats the oceans. As a result of heated oceans, we get tropical storms and various forms of extreme weather. When troughs, subduction zones, and rifts shift, as a result of convection, earthquakes, tsunamis, and volcanoes occur.

What makes this all work is the Earth’s magnetic field. Right now the magnetic field is weakening significantly. This will continue until it reaches zero point, at which time there will be a full magnetic reversal. Until this time, we will witness magnetic north bouncing in the northern hemisphere. Closer to the moments of a full reversal, we will see magnetic north drop down to/then below the equator.

As a result of a weakened magnetic field, larger amounts of radiation via charged particles such as solar flares, coronal mass ejections, gamma rays, and galactic cosmic rays – are more abundantly reaching Earth’s atmosphere and having a heightened reaction with Earth’s core layers. This is what causes looped reaction. Radiation heats the core layers, the outer core reacts by producing ‘mantle plumes’, which causes crustal fracturing, which then causes earthquakes, volcanoes, heated oceans – all of which cools the outer core.

This seemingly repeating loop will continue until the Earth will once again find its balance. Until then, we can expect naturally occurring earth changing events which will produce the loss of mass in some parts of the world, and emergence of mass in other parts. Maybe this is the time to change the things we can (attitude, environment, community, self, surroundings), one would be a fool not to apply themselves within their means – but then there is the time to loosen up a bit, know what is happening is just part of a process.

Just as the Earth, we humans can just keep on trucking, and maybe, just maybe, some will simply ‘enjoy-the-ride’.