Not exact matches
While there are management solutions to stabilizing the landscape, those solutions are not without challenges, Goodbred said, but the study notes that systematically breaching embankment sections to allow for delivery
of sediment to the
coastal sea might at least partially reduce problems.
The team's research, supported by the National Science Foundation and a NASA graduate fellowship, began with a study
of coastal lake
sediments in Japan to establish long - term records
of tsunami flooding.
Since the first project
of its kind in the U.S. at Coney Island, N.Y., in 1922,
coastal managers have used beach nourishment — essentially importing sand to replace
sediment lost through storms or erosion — to restore damaged beaches, but it is laborious and expensive.
To further refine the probability estimates, they took into account past (prior to recorded history) tsunamis — evidence
of which is preserved in geological layers in
coastal sediments, volcanic tephras, and archeological sites.
The biggest known bacterial cells, belonging to the
coastal sediment bacterium Thiomargarita namibiensis, are 7,500 times the size
of ultramicrobacteria.
Pushed by the natural motion
of wind and ocean currents — often over long distances — the litter is present in oceans worldwide, as well as in sea floor
sediment and
coastal sands.
COAWST combines models
of ocean, atmosphere, waves and
sediment transport for analysis
of coastal change.
The flume will also provide new insights into natural processes such as
sediment transport along shorelines and the mechanical properties
of coastal soils, López Lara says.
The combination
of powerful storms and the
sediment shortfall produced what U.S. Geological Survey
coastal scientist Patrick Barnard called a «worst - case scenario» that «may be an indication
of what's to come.»
And the conundrum for
coastal engineers is that
sediment can only come in large quantities from the processes
of erosion — especially from fast - eroding cliff faces.
In
coastal protection, it can mean, for instance, artificially building beaches that absorb the power
of storm waves, or encouraging the natural forces that raise and extend a coastline, including salt marsh, by ensuring a supply
of sediment.
«This research underscores the necessity for future
coastal developments to consider the adverse effects
of sediment on fish and reef ecosystems,» adds Dr Wenger.
Sediment is the key to managed retreat and all forms
of soft
coastal defence.
Marshes and other natural
coastal bulwarks can grow taller as seas rise, protecting against floods, but most
of them need
sediment - rich waters to do so.
«Once the oil, because
of high tides or high winds, gets into the
coastal wetland, it gets trapped in the
sediment,» notes Héctor M. Guzmán
of the Smithsonian Tropical Research Institute in Panama, who studied the effects
of the 1986 spill off Panama.
One is geomorphological: erosion provides the
sediment that builds up the natural
coastal defences
of other areas
of coastline, by forming marshes or beaches, shingle bars or mud flats.
Warming and the seas — both on the rise Those ancient samples
of sediment from 10
coastal wetlands in North Carolina provide some
of the best evidence that sea - level rise closely follows warmer temperatures, Rahmstorf says.
The northern third
of the delta is lowering at the rate
of about 4 to 8 mm per year due to compaction
of strata underlying the plain, seismic motion, and the lack
of sufficient new
sediment to re-nourish the delta margin being eroded by Mediterranean
coastal currents.
Large uncertainties were caused by the GMSLR scenario and
sediment size; however, the minimum projected rate
of beach loss was 18 % in the near future, and this rate
of loss is expected to have significant implications for
coastal management.
Prior to the industrial age, decomposing plant materials in
coastal waters and
sediments likely led to the release
of carbon dioxide.
Professor Pierre Friedlingstein from the University
of Exeter said: «Carbon storage in
sediments in these rivers and
coastal regions could present a more secure environment than carbon stored in soil on land.
Fellow Melissa Garren from the Scripps Institution
of Oceanography at the University
of California - San Diego collects
sediment samples beneath
coastal milkfish (Chanos chanos) farms in Bolinao, Republic
of the Philippines.
Scott has recently taken up an adjunct research position at the Centre for Tropical Water and Aquatic Ecosystem Research, James Cook University where he is currently: (i) investigating the importance
of enhanced larval survival and strong «local» reef interconnectedness as a triggering agent for primary outbreaks
of crown ‐
of ‐ thorns starfish on the central GBR, and (ii) assessing potential improvements in the health
of coastal seagrass and dependent dugong populations due to targeted reductions in fine
sediment loads from the GBR catchment.
Jorgenson, M.T., and J. Brown, 2005: Classification
of the Alaskan Beaufort Sea Coast and estimation
of carbon and
sediment inputs from
coastal erosion.
Linking RPO results from riverine and
coastal marine
sediments will enhance our understanding
of what material survives transport from the terrestrial environment to the ocean.
In addition, stronger storms may also lead to greater coral damage due to increased flooding events, associated terrestrial runoff
of freshwater and dissolved nutrients from
coastal watersheds, and changes in
sediment transport (leading to smothering
of corals).
Magnetite production and transformation in the methanogenic consortia from
coastal riverine
sediments — Shiling Zheng — Journal
of Microbiology
(2012) OSL dating
of mixed
coastal sediment (Sylt, German Bight, North Sea).
The term feeder bluff has been applied to certain
coastal cliffs or headlands that provide
sediment to down - current beaches as the result
of wave action on the bluff.
The assessment considered the impacts
of several key drivers
of climate change: sea level change; alterations in precipitation patterns and subsequent delivery
of freshwater, nutrients, and
sediment; increased ocean temperature; alterations in circulation patterns; changes in frequency and intensity
of coastal storms; and increased levels
of atmospheric CO2.
In their study
of sediments from the Black Sea, Eckert et al. (2013, p. 431 in this issue
of Geology), make this step by providing, for the first time, a basin - wide reconstruction
of the evolution
of the chemocline in this silled
coastal basin over the Holocene.
David, I havent been keeping up with all the PETM research, but I do recall that individual plankton recovered from Bass River, New Jersey show a single step CIE. Due to the high sedimentation rate
of coastal fluvial systems, Bass River
sediments are consistent with a much shorter duration
of organic carbon release during the PETM (estimated as less than 500 years).
The tertiary source
of CaCo3 is
sediments themselves — in both
coastal areas and open water — as fined grained
sediment, shell and coral.
New Zealand
coastal geomorphologist Paul Kench,
of the University
of Auckland's School
of Environment, and colleagues in Australia and Fiji,... found that reef islands change shape and move around in response to shifting
sediments, and that many
of them are growing in size, not shrinking, as sea level inches upward.
Mappings
of the geochemistry and magnetic susceptibility
of detrital sources in the watershed
of the lagoon and from the
coastal barriers were undertaken in order to track the terrestrial or
coastal / marine origin
of sediments deposited into the lagoon.
Detailed impacts, however, will vary strongly from region to region and coast to coast and therefore can not be easily generalized, as changing mean and extreme
coastal water levels depend on a combination
of near shore and offshore processes, related to climatic but also non-climatic anthropogenic factors, such as natural land movement arising from tectonics, volcanism or compaction; land subsidence due to anthropogenic extraction
of underground resources; and changes in
coastal morphology resulting from
sediment transport induced by natural and / or anthropogenic factors.
Barrier islands like the one's that stretch along the coast
of Georgia are formed from deposition
of sediments coming from Georgia's rivers, and sand being deposited along the
coastal side
of the island by the longshore drift.
report that ocean
sediment cores containing an «undisturbed history
of the past» have been analyzed for variations in PP over timescales that include the Little Ice Age... they determined that during the LIA the ocean off Peru had «low PP, diatoms and fish,» but that «at the end
of the LIA, this condition changed abruptly to the low subsurface oxygen, eutrophic upwelling ecosystem that today produces more fish than any region
of the world's oceans... write that «in
coastal environments, PP, diatoms and fish and their associated predators are predicted to decrease and the microbial food web to increase under global warming scenarios,» citing Ito et al..
A fraction
of this carbon is released as CO2 by rivers and lakes to the atmosphere, a fraction is buried in freshwater organic
sediments and the remaining amount (~ 0.9 PgC / year) is delivered by rivers to the
coastal ocean.
What kind
of emphasis should be put on trying to re-naturalize river systems and
coastal areas, i.e. building wetlands, removing dams that prevent
sediment from reaching barrier islands etc., and could this practice actually be better for
coastal areas as opposed to hard infrastructure?
Seasonal distribution
of nitrifying bacteria and rates
of nitrification in
coastal marine
sediments
Organic matter diagenesis at the oxic / anoxic interface in
coastal marine
sediments, with emphasis on the role
of burrowing animals
Bioturbating shrimp alter the structure and diversity
of bacterial communities in
coastal marine
sediments