The Thorium-230 isotope in the marine sediment is used for paleo researchers to calibrate and normalize particle fluxes of past times. The isotope is present both in the water column and in the ocean sediments, the latter being the item for marine paleo geologists to examine.
Using marine sediment cores containing isotopes of aluminum and beryllium, a group of international researchers has discovered that East Greenland experienced deep, ongoing glacial erosion over the past 7.5 million years.The research reconstructs ice sheet erosion dynamics in that region during the past 7.5 million years and has potential implications for how much the ice sheet will respond to future interglacial warming.The team, made up of researchers from Lawrence Livermore National Laboratory, University of Vermont, Boston College and Imperial College London, analyzed sediments eroded from the continent and deposited in the ocean off the coast, which are like a time capsule preserving records of glacial processes. The research appears in the Dec. 8 edition of the journal, Nature.
A key glacier in Antarctica is breaking apart from the inside out, suggesting that the ocean is weakening ice on the edges of the continent.The Pine Island Glacier, part of the ice shelf that bounds the West Antarctic Ice Sheet, is one of two glaciers that researchers believe are most likely to undergo rapid retreat, bringing more ice from the interior of the ice sheet to the ocean, where its melting would flood coastlines around the world.A nearly 225-square-mile iceberg broke off from the glacier in 2015, but it wasn’t until Ohio State University researchers were testing some new image-processing software that they noticed something strange in satellite images taken before the event.
Marine ecosystems are responsible for about half of global annual primary production and more than one billion people rely on fish as their primary protein source. Latest studies show that enormous warm water bubbles in the ocean are having a noticeable impact on ecosystems. How should we interpret these changes?
Methane is stored under the sea floor, concentrated in form of hydrates, crystalline ice structures that stay stable under high pressure and in low temperatures. Several studies suggest that as the ocean warms, the hydrates might melt and potentially release methane into the ocean waters and atmosphere.Several studies suggest that as the ocean warms, the hydrates might melt and potentially release methane into the ocean waters and atmosphere. This potent climate gas is profusely leaking from the seafloor in an area offshore western Svalbard, which is close to the gas hydrate stability zone.There, scientists have discovered over 250 methane flares in water depths from 90 to 240 meters.“Previous studies indicate that these seeps could be linked to gas hydrate dissociations. We suspected that dissociation of gas hydrate is not the primary control on seafloor methane seepage. We suggest that there is a strong lithological control on methane seepage.” says Dr. Giuliana Panieri, scientist at CAGE.
BUILDING IN RHODE Island isn’t easy. Hurricanes and tropical storms barrel through its quaint coastline towns, interrupting perfect summer weekends. Freezing winters bring blizzards that can shut down the entire state. And every season features corrosive salty winds, biting at the coast as if sent by a Britain still seething at the first American colony to declare independence.But one company sees the state’s incessant wind as a utility. Deepwater Wind has partnered with General Electric Renewable Energy to build the first offshore wind farm in the United States, off the coast of Block Island. Hooked up to the grid by the end of 2016, the system could supply 90 percent of the tourist destination’s power within the next few years. But it hasn’t been easy. Designing and building spinning fans hundreds of feet tall that stay sutured to the ocean floor in the face of currents and wicked winds has taken almost three years of work.
In case you thought wildlife in New York was pretty much limited to the squirrels and pigeons of Central Park, Howard Rosenbaum has news for you.“In less distance out to sea than the average New Yorker’s commute home, there is likely a whale singing at this very moment,” says Rosenbaum, director of the Ocean Giants program at the New York Aquarium in Coney Island, Brooklyn.7 Species Of Whales Spotted In New York WatersHumpback whales (seen above) are regularly seen in the waters off the Big Apple, while fin whales inhabit the waters around the eastern tip of Long Island. Five other species, the critically endangered North Atlantic right whale and minke and sperm whales, as well as sei whales and the blue whale, the largest animal that has ever lived (seen below) have also been seen or heard in New York waters.
There was a period during the last ice age when temperatures in the Northern Hemisphere went on a rollercoaster ride, plummeting and then rising again every 1,500 years or so. Those abrupt climate changes wreaked havoc on ecosystems, but their cause has been something of a mystery. New evidence published this week in the leading journal Science shows for the first time that the ocean's overturning circulation slowed during every one of those temperature plunges – at times almost stopping.”People have long supposed this link between overturning circulation and these abrupt climate events. This evidence implicates the ocean,” said L. Gene Henry, the lead author of the study and a graduate student at Columbia University's Lamont-Doherty Earth Observatory.
As climatologists closely monitor the impact of human activity on the world's oceans, researchers at the Georgia Institute of Technology have found yet another worrying trend impacting the health of the Pacific Ocean.A new modeling study conducted by researchers in Georgia Tech's School of Earth and Atmospheric Sciences shows that for decades, air pollution drifting from East Asia out over the world's largest ocean has kicked off a chain reaction that contributed to oxygen levels falling in tropical waters thousands of miles away.”There's a growing awareness that oxygen levels in the ocean may be changing over time,” said Taka Ito, an associate professor at Georgia Tech. “One reason for that is the warming environment — warm water holds less gas. But in the tropical Pacific, the oxygen level has been falling at a much faster rate than the temperature change can explain.”The study, which was published May 16 in Nature Geoscience, was sponsored by the National Science Foundation, a Georgia Power Faculty Scholar Chair and a Cullen-Peck Faculty Fellowship.In the report, the researchers describe how air pollution from industrial activities had raised levels of iron and nitrogen — key nutrients for marine life — in the ocean off the coast of East Asia. Ocean currents then carried the nutrients to tropical regions, where they were consumed by photosynthesizing phytoplankton.
Each spring, powerful dust storms in the deserts of Mongolia and northern China send thick clouds of particles into the atmosphere. Eastward winds sweep these particles as far as the Pacific, where dust ultimately settles in the open ocean. This desert dust contains, among other minerals, iron — an essential nutrient for hundreds of species of phytoplankton that make up the ocean’s food base.