Sentences with phrase «of the sediment column»

My hunch for what it's worth is that drilling holes are probably not a huge addition to the complexity of the real heat transport of the sediment column.

Variant to the right assumes lateral variation in the deformability of the sediment column, leading to irregular lateral compression.

Bottom waters at depths of 50 or 100 m might warm relatively quickly with a collapse in sea ice cover, but it would take centuries for that heat to diffuse through the 100 - 150 m of sediment column to the hydrate stability zone.

When this model ``... neglects many of the mechanisms that could come into play in transporting methane quickly to the atmosphere, such as faults, channels, and blowouts of the sediment column» then one must ask what bearing or predictive - value it has for abrupt methane release.

Not exact matches

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.

The team analysed the chemical composition of tiny shells built by organisms (foraminifera) that had lived in the water column and at the sea bottom before their shells became embedded in the seafloor sediments.

His team bored several three - meter - long columns of sediment from parts of the seafloor that were covered by Larsen B until its collapse.

The researchers found the chironomids burrowed into the sediment, moving water and oxygen into the sediment and increased the levels of nutrients released into the sediment porewater and water column.

This «purification» function is carried out by the microorganisms present in their water column and sediments and, with it, they improve the general quality of the water and reduce the nitrogen load by promoting denitrification.»

In 97 - million - year - old freshwater sediments in eastern Morocco, researchers discovered new Spinosaurus fossils, including parts of the skull, vertebral column, pelvis, and limb bones.

The bacteria living in these sediments were respiring the oxygen but at a slower rate than the supply of organic material dropping out of the water column, allowing these ancient deep marine sediments to remain oxygenated.

Carozza et al (2011) find that natural global warming occurred in 2 stages: First, global warming of 3 ° to 9 ° C accompanied by a large bolus of organic carbon released to the atmosphere through the burning of terrestrial biomass (Kurtz et al, 2003) over approximately a 50 - year period; second, a catastrophic release of methane hydrate from sediment, followed by the oxidation of a part of this methane gas in the water column and the escape of the remaining CH4 to the atmosphere over a 50 - year period.

So it's not too much of a stretch of the imagination to think that those sediments would still contain microorganisms that essentially don't care if a big column of sea - water, or ice, is above them.»

During such periods, a wave surge scours the sandy bottom and suspends clouds of sediment in the water column.

Strong variations in the geochemical and paleo - ecological composition and genetic signature of the sediments in the Black Sea provide testimony that the conditions in the water column have been far from constant over the past ∼ 7.5 kyr.

This will induce massive dissolution of CaCO3 in the water column as well as the sediment,... we project detectable dissolution - driven changes only by the year 2070 in the surface ocean and after 2230 and 2500 in the deep Atlantic and Pacific respectively.

But these experiments spanned 100 hours, while the sediment column has been warming for thousands of years, so the experiments do not really address the question.

The real sediment column has faults and explosions (there are lots of things in the ocean that look like this thing in Siberia, they are called «pockmarks»).

[Response: As a modeler of the deep sediment column, I go to talks about observations of the real world (geology, in other words), and am struck by how simplistic the models are.

Damming of the river has resulted in the build - up of highly methanogenic sediments under a shallow water column, facilitating the transformation of fixed CO2 to atmospheric CH4.

Note that the sediments can still remain unfrozen because of the salt contamination», page 7, right column, first paragraph.

Some of this is lost to sediments and some dissolved as it sinks to maintain water column chemistry.

First through reductions in calcium carbonate polymorph super-saturation and then by dissolution of water column and sediment sources.

«Pelagic sediment or pelagite is a fine - grained sediment that has accumulated by the settling of particles through the water column to the ocean floor beneath the open ocean far from land.

Carozza et al (2011) find that natural global warming occurred in 2 stages: First, global warming of 3 ° to 9 ° C accompanied by a large bolus of organic carbon released to the atmosphere through the burning of terrestrial biomass (Kurtz et al, 2003) over approximately a 50 - year period; second, a catastrophic release of methane hydrate from sediment, followed by the oxidation of a part of this methane gas in the water column and the escape of the remaining CH4 to the atmosphere over a 50 - year period.

Large amounts of methane are stored in seafloor sediments as gas hydrate, and as these melt the gas is released into the water column.

Even on the Siberian continental margin, where water temperatures are colder than the global average, and where the sediment column retains the cold imprint from its exposure to the atmosphere during the last glacial time 20,000 years ago, any methane hydrate must be buried under at least 200 m of water or sediment.

Another approach is to «grow» the sediment column through geologic time to obtain an initial condition for a climate change perturbation scenario (Archer et al., 2012), but uncertainties in various model parameters, such as the methane production rate and the fate of bubbles in the sediment column, prevent a well - constrained model forecast of the methane hydrate response to climate warming.

Episodic and explosive escapes of gaseous methane from the sediment column have been documented by kilometer - scale «wipeout zones» in seismic images (Riedel et al., 2002), and pockmarks on the sea floor, called eruption craters (Hill et al., 2004).

Warming bottom waters in deeper parts of the ocean, where surface sediment is much colder than freezing and the hydrate stability zone is relatively thick, would not thaw hydrates near the sediment surface, but downward heat diffusion into the sediment column would thin the stability zone from below, causing basal hydrates to decompose, releasing gaseous methane.

The time scale for this mechanism of hydrate thawing is on the order of centuries to millennia, limited by the rate of anthropogenic heat diffusion into the deep ocean and sediment column.

Coupled atmosphere - ocean climate models can be used to simulate the thermal response of the ocean water column to climate change with a moderate degree of uncertainty and the subsequent penetration of heat into the sediment column.

Organic matter in the uppermost few centimetres of sediments is first attacked by aerobic bacteria, generating CO2, which escapes from the sediments into the water column.

By understanding the relationship between the size, composition and distribution of particles found on the bottom with the motion of the water column above, scientists who study long cores of ocean sediment can tell how currents have changed or moved over time.

The idea is that the bubbles might lift the grains off of each other, destabilizing the sediment column.

As part of the Dead Sea Deep Drill Core Project, Goldstein and other colleagues drilled deep below the lakebed of the Dead Sea in 2010 and 2011 to pull up more than 1,300 feet (400 meters) of sediment in a long column — a record of sediment deposits spanning 200,000 years.