Sentences with phrase «on ocean sediment»

What effect do breakers have on ocean sediments?

On the contrary, independent data on both ocean sediments in the Sargasso Sea and dendrology favor repeated strong temperature oscillations with comparably large gradients in historic times.

I recall also seeing work on ocean sediments indicating that during the dusty - dry climates when lots of windblown dust is in the air, plankton did not bloom in the oceans in proportion to the added minerals.

Not exact matches

Dr. Shivji tells of sharks that use this extrasensory ability to hunt stingrays that hide beneath sediment on the ocean floor.

Carried within the water column, accumulating on the ocean bottom or becoming entrained in marine sediments — a spill of Alberta bitumen might prove impossible to contain.

A 9.0 - magnitude earthquake off the coast of the Aleutian Islands triggered the mighty wave, which left behind up to nine shipping containers worth of ocean sediment in a sinkhole on the island of Kauai.

When the weather warms and no ice sits upon the seas, the sediment on the ocean floor is mainly organic: remains of plankton and diatoms.

And so a team of marine sediment experts has set up shop on the Nathaniel B. Palmer, hoping to sink great hollow cores deep into the ocean off Antarctica.

Comparing layers in the ice - core samples and ocean sediments has allowed researchers to deduce e.g. how the average temperature on Earth has changed over time, and also how great the variability was.

Working in remote conditions, researchers in the winter of 2012 ran a drill through 450 meters of ice and 500 meters of ocean to collect seafloor sediments on either side of this lost bulwark.

This newest threat follows on the heels of overfishing, sediment deposition, nitrate pollution in some areas, coral bleaching caused by global warming, and increasing ocean acidity caused by carbon emissions.

According to Dohm, this is a likely indication that the elements were leached out of the soil by runoff water and concentrated in sediment on the muddy floor of a standing ocean.

That may in turn have caused the planet to heat up enough to melt deposits of methane frozen in sediments on the ocean floor (something, incidentally, that could happen again), discharging even more potent greenhouse gases into the atmosphere and further heating the planet in an escalating feedback loop.

This past June scientists at NASA's Stennis Space Center in Mississippi reported that the eyewall's extreme conditions can stir up ocean currents 300 feet below the surface, disrupting sediment and organisms on the seafloor for as long as a week after the storm subsides.

Scientists» understanding of the climate during the Pliocene has largely been pieced together from fossil records preserved in sediments deposited beneath lakes and on the ocean floor.

Dr. Hoffmann: «The isotope Hafnium 176 in contrast to its counterpart Neodymium 143 was transported by means of weathering into the oceans and became part of iron - rich sediments on the sea floor 2,700 million years ago.»

Last year, her research team delivered the coup de grâce: evidence of an impact crater off the northwest coast of Australia, hidden beneath two miles of sediment on the ocean floor.

A multinational team on board the research vessel Joides Resolution, a «floating laboratory», is about to collect sediment samples from 1.5 kilometres beneath the ocean floor.

Before, during and after the PETM, these sediments were laid down on the sea floor at the edge of the Atlantic Ocean, at depths of ~ 1000m, on the boundary between the continents and the open oOcean, at depths of ~ 1000m, on the boundary between the continents and the open oceanocean.

To untangle the impacts that these three climate stressors will have on seafloor diversity in the future, the researchers examined existing published data and collected new data on organisms living in deep - sea sediments in upwelling regions along continental margins, where the ocean and continental crusts meet along the seafloor.

The study focuses on one such removal process, burial of phosphorus in the organic matter in ocean sediments.

The increased wave action reaches down and stirs up sediments on shallow continental shelves, releasing radium and other chemicals that are carried up to the surface and swept away into the open ocean by currents such as the Transpolar Drift.

The new findings on Arctic Ocean salinity conditions in the Eocene were calculated in part by comparing ratios of oxygen isotopes locked in ancient shark teeth found in sediments on Banks Island in the Arctic Circle and incorporating the data into a salinity model.

«The data of the model simulation was so close to the deep ocean sediment data, that we knew immediately, we were on the right track,» said co-author Dr Laurie Menviel from the University of New South Wales, Australia, who conducted the model simulation.

Alongside tales of grim winters in Ithaca, New York, and spilling acid on himself, he covers argon's role in dating ocean sediments and the discovery that xenon is a splendid...

For this, scientists rely on proxies — traces of climate's imprint contained in sediment collected from ocean beds or from the shells of creatures that lived back then.

In 2014, they embarked on an ocean voyage to the central equatorial Pacific Ocean, where they drilled into the sediment bed and collected six cocean voyage to the central equatorial Pacific Ocean, where they drilled into the sediment bed and collected six cOcean, where they drilled into the sediment bed and collected six cores.

The researchers came up with a simple ratio to predict a delta's shape, based on a river's sediment flux, or the flow rate of sediment through a river, and the strength of ocean waves, determined by a wave's height, frequency, and angle of approach.

Bacteria, however, have remained Earth's most successful form of life — found miles deep below as well as within and on surface rock, within and beneath the oceans and polar ice, floating in the air, and within as well as on Homo sapiens sapiens; and some Arctic thermophiles apparently even have life - cycle hibernation periods of up to a 100 million years while waiting for warmer conditions underneath increasing layers of sea sediments (Lewis Dartnell, New Scientist, September 20, 2010; and Hubert et al, 2010).

In environments like Antarctica that seldom preserve foraminifera — tiny organisms whose shells are the gold standard for dating ocean sediments — researchers have relied on dating bulk organic matter.

The dates on two other ocean sediment cores (Stott et al 2004 — # 14 and # 15) are on the correct scale thankfully, but are still marginal in terms of resolution (29 and 44 years respectively, but effectively longer still due to bioturbation of the sediments).

In 2012, Mars Express spotted a possible ancient ocean on Mars: sediments on the planet's northern plains appeared to resemble what is seen on an ocean on Earth.

Ancient sediments that once resided on a lake bed and the ocean floor show sulfur isotope ratios unlike those found in other samples from the same time, calling into question accepted ideas about when the Earth's atmosphere began to contain oxygen, according to researchers from the U.S., Canada and Japan.

On glacial - interglacial time scales, atmospheric CO2 is mainly governed by the interplay between ocean circulation, marine biological activity, ocean - sediment interactions, seawater carbonate chemistry and air - sea exchange.

Wallace S. Broecker: Preface 1: Jean - Pierre Gattuso and Lina Hansson: Ocean Acidification: Background and History 2: Richard E. Zeebe and Andy Ridgwell: Past Changes of Ocean Carbonate Chemistry 3: James C. Orr: Recent and Future Changes in Ocean Carbonate Chemistry 4: Andrew H. Knoll and Woodward W. Fischer: Skeletons and Ocean Chemistry: The Long View 5: Markus G. Weinbauer, Xavier Mari, and Jean - Pierre Gattuso: Effect of Ocean Acidification on the Diversity and Activity of Heterotrophic Marine Microorganisms 6: Ulf Riebesell and Philippe D. Tortell: Effects of Ocean Acidification on Pelagic Organisms and Ecosystems 7: Andreas J. Andersson, Fred T. Mackenzie, and Jean - Pierre Gattuso: Effects of Ocean Acidification on Benthic Processes, Organisms, and Ecosystems 8: Hans - Otto Pörtner, Magda Gutowska, Atsushi Ishimatsu, Magnus Lucassen, Frank Melzner, and Brad Seibel: Effects of Ocean Acidification on Nektonic Organisms 9: Stephen Widdicombe, John I. Spicer, and Vassilis Kitidis: Effects of Ocean Acidification on Sediment Fauna 10: James P. Barry, Stephen Widdicombe, and Jason M. Hall - Spencer: Effects of Ocean Acidification on Marine Biodiversity and Ecosystem Function 11: Frances Hopkins, Philip Nightingale, and Peter Liss: Effects of Ocean Acidification on the Marine Source of Atmospherically - Active Trace Gases 12: Marion Gehlen, Nicolas Gruber, Reidun Gangstø, Laurent Bopp, and Andreas Oschlies: Biogeochemical Consequences of Ocean Acidification and Feedback to the Earth System 13: Carol Turley and Kelvin Boot: The Ocean Acidification Challenges Facing Science and Society 14: Fortunat Joos, Thomas L. Frölicher, Marco Steinacher, and Gian - Kasper Plattner: Impact of Climate Change Mitigation on Ocean Acidification Projections 15: Jean - Pierre Gattuso, Jelle Bijma, Marion Gehlen, Ulf Riebesell, and Carol Turley: Ocean Acidification: Knowns, Unknowns, and Perspectives Index

Cursor movement keys or arrow keys are buttons on a computer keyboard that are either programmed or designated to move the cursor in a specified direction A cay forms when ocean currents transport loose sediment across the surface of a reef to a depositional node, where the current slows or converges with

******* Jan BackmanC, Martin Jakobssonb, Reidar Løvliec, Leonid Polyakd and L.A.Lawrence A. Febo Quaternary Science Reviews Volume 23, Issues 11 - 13, June 2004, Pages 1435 - 1454 «Numerous short sediment cores have been retrieved from the central Arctic Ocean, many of which have been assigned sedimentation rates on the order of mm / ka implying that the Arctic Basin was starved of sediments during Plio — Pleistocene times.»

Massive blooms of Azolla growing in a fresh / brackish surface layer on the Arctic ocean created laminated sediments alternating with marine siliceous sediments during the early Eocene, and sequestered large amounts of CO2.

Now the locations of avaialble proxy data (tree rings, ice cores, ocean sediment records, corals etc.) are not necessarily optimally spread out, but the spatial sampling error is actually quite easy to calculate, and goes into the error bars shown on most reconstructions.

CO2 not sole determinant of ocean pH. The pH of the ocean depends not only on atmospheric CO2 content, but also how much time that CO2 has had to spread through the ocean and interact with carbonate sediments, and how much carbonate and silicate rock weathering has occured on land.

The potential for confusion on any large science archive like this is always important to watch for — especially here where several different dating systems (tree rings, ice cores, lake sediments, ocean sediments) are being correlated.

Upwelling in the northwest Indian Ocean provides sufficient surface productivity to provide an excess of organic matter to sediments on the continental slope of the Arabian Peninsula where the oxygen minimum zone intersects the slope.

Climate reconstructions based on borehole and ocean sediments (Moburg) are lower over the past few hundred years than reconstructions based on surface proxys.

Rather, excess CO2 returns toward baseline at a multitude a different rates, with chemical equilibration in the ocean occurring over decades (depending on depth), ocean carbonate buffering through sediment dissolution requiring centuries to millennia, and eventual restoration of carbonate sediment levels by terrestrial weathering occurring over hundreds of thousands of years — a long «tail» that can account for as much as 20 to 40 percent of CO2 excess in the estimates described by David Archer et al in CO2 Atmospheric Lifetimes.

In this paper, the authors reconstruct North Atlantic water temperature over the last millennium using oxygen isotopes from ocean sediment cores on the Canadian east coast.

As sediments form on the floor of the ocean and snow piles up, trapping air bubble into ice, they store information concerning the climate of their day and the factors which affected it.

To reach further back, the team relied on natural stand - ins, or proxies, that include ice cores, ocean and lake sediments, mineralized «rings» from slices of stalactites or stalagmites in caves, coral growth rings, and tree rings.

This «new evidence» is based on a single analysis of «proxy» data (that is, data that do not come from thermometers but rather from sources like tree rings, ice cores, corals, and ocean and lake sediments) showing the twentieth century to be the warmest in the past thousand years.

Based on changes in tree line, pollen samples and ocean sediments, scientists estimate Arctic air temperatures during the mid Holocene averaged 2 to 7 °C higher than today.

The oceans are buffered by sediments and volcanic rocks on the sea floor and even in past times when atmospheric temperature and CO2 were far higher than at present, there were no acid oceans.