scholarly journals Environmental impact on Greenland glaciers

1995 ◽  
Vol 165 ◽  
pp. 79-87
Author(s):  
O.B Olesen ◽  
A Weidick ◽  
N Reeh ◽  
H.H Thomsen ◽  
R.J Braithwaite
Keyword(s):  
Global Change ◽  
Environmental Impact ◽  
Sea Level ◽  
Climate Changes ◽  
Ice Cover ◽  
Climate Oscillations ◽  
Environmental Consequences ◽  
Main Emphasis ◽  
Melt Water ◽  
Coastal Changes

The main emphasis of present investigations of Greenland glaciers concerns former climate oscillations and the variations in glacier cover related to these changes. The data acquired on climate and glacier variations provide a basis for prediction of future environmental consequences of climate changes. These include local change of ice cover and related coastal changes caused by variations in glacier load on the earth's crust in Greenland as well as global change of sea level in the oceans caused by the storage or release of melt water and calf ice from the Greenland ice cover.

Consequences of sea level and climate changes on the morphodynamics of a tropical coastal lagoon during Holocene: An evolutionary model

2014 ◽  
Vol 333 ◽  
pp. 156-172 ◽  
Author(s):  
D. Padmalal ◽  
K.P.N. Kumaran ◽  
K.M. Nair ◽  
Ruta B. Limaye ◽  
S. Vishnu Mohan ◽  
...  
Keyword(s):  
Sea Level ◽  
Coastal Lagoon ◽  
Climate Changes ◽  
Evolutionary Model ◽  
Tropical Coastal Lagoon

Middle to late-Holocene decreased fluvial aggradation and widespread peat initiation in the Ishikari lowland (northern Japan)

The Holocene ◽  
2016 ◽  
Vol 26 (12) ◽  
pp. 1924-1938 ◽  
Author(s):  
Yuji Ishii ◽  
Kazuaki Hori ◽  
Arata Momohara ◽  
Toshimichi Nakanishi ◽  
Wan Hong
Keyword(s):  
Sea Level ◽  
Late Holocene ◽  
Climate Changes ◽  
Asian Summer Monsoon ◽  
Sedimentary Environment ◽  
New Approach ◽  
Sea Level Fluctuations ◽  
Asian Summer ◽  
Fluvial Sedimentation ◽  
Northern Japan

This study investigated the influence of sea-level and climate changes on the decreased fluvial aggradation and subsequent widespread peat initiation in the middle to late-Holocene in the Ishikari lowland, which is a coastal floodplain formed in response to the postglacial sea-level change. By introducing a new approach to separately evaluate the rates of organic and clastic sediment input, we demonstrated that the peat began to form when the fluvial sedimentation rate was significantly decreased (less than 0.6 mm/yr), while plant macrofossil analysis suggested that lowering of water level is also important to the peat initiation. Such changes in sedimentary environment may be associated with the abrupt abandonment of crevasse splays. The concentrated ages of the peat initiation around 5600–5000, 4600–4300, and 4100–3600 cal. BP suggest that an allogenic control promoted the abandonment of crevasse splays, and different onset ages can be explained by different fluvial responses of the Ishikari River and its tributaries. The abandonment of crevasse splays could result from sea-level fall or decreased precipitation. While submillennial sea-level fluctuations coincident with the peat initiation have not been reported in coastal lowlands of Japan, the close comparison of the onset ages and decreased precipitation recorded in a stalagmite from China, which represents the strength of the East Asian summer monsoon (EASM), suggests that decrease in precipitation led to the abandonment of crevasse splays. Our results may indicate that similar fluvial responses might be common in other coastal floodplains affected by the EASM.

scholarly journals Geomorphic response to sea level and climate changes during Late Quaternary in a humid tropical coastline: Terrain evolution model from Southwest India

PLoS ONE ◽  
2017 ◽  
Vol 12 (5) ◽  
pp. e0176775 ◽  
Author(s):  
Maya K. ◽  
Vishnu Mohan S. ◽  
Ruta B. Limaye ◽  
Damodaran Padmalal ◽  
Navnith K. P. Kumaran
Keyword(s):  
Sea Level ◽  
Climate Changes ◽  
Late Quaternary ◽  
Evolution Model ◽  
Geomorphic Response ◽  
Southwest India

scholarly journals Ancient Coastal Changes Due to Ground Movements and Human Interventions in the Roman Portus Julius (Pozzuoli Gulf, Italy): Results from Photogrammetric and Direct Surveys

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 658 ◽  
Author(s):  
Pietro P. C. Aucelli ◽  
Gaia Mattei ◽  
Claudia Caporizzo ◽  
Aldo Cinque ◽  
Salvatore Troisi ◽  
...  
Keyword(s):  
Sea Level ◽  
3D Model ◽  
First Century ◽  
Structural Elements ◽  
Sea Levels ◽  
Ground Movements ◽  
Vertical Ground ◽  
Coastal Changes ◽  
Fish Tank ◽  
The Military

This research aims to evaluate the amount of vertical ground movements during Roman times inside the archaeological area of Portus Julius (Gulf of Pozzuoli) using high-precision surveys on the most reliable archaeological sea-level markers. Measuring the submersion of ancient floors, structural elements belonging to a former fish tank, and several roman pilae, two different relative sea levels (RSLs), related to the beginning and the end of the first century BCE, respectively, −4.7/−5.20 m and −3.10 m MSL (mean sea level), were detected. A photogrammetric survey was carried out in order to produce a 3D model of the fish tank. The results in terms of the RSL variations have enabled us to reconstruct a morpho-evolution of the ancient coastal sector during the last 2.1 kyBP. At the beginning of the first century BCE, the area was characterized by a sheltered gulf with numerous maritime villae located along the coast. In 37 BCE, the construction of the military harbour of Portus Julius strongly modified the paleogeography of the sector, which was also affected by a prevailing subsidence at least until the end of the first century BCE (year 12 BCE), when the port was converted into a commercial hub.

scholarly journals Late Holocene relative sea level changes in SW Crete: evidence of an unusual earthquake cycle

1996 ◽  
Vol 39 (3) ◽  
Author(s):  
S. C. Stiros
Keyword(s):  
Sea Level ◽  
Late Holocene ◽  
Hanging Wall ◽  
Earthquake Cycle ◽  
Sea Level Changes ◽  
Land Uplift ◽  
Unusual Pattern ◽  
Wide Range ◽  
Coastal Changes ◽  
Seismic Deformation

Coastal challenges ill West Crete ill the last 4000 years can be described as a series of 11 relatively small (25 cm on the average) land subsidences alternating with short (150-250 year long) relatively still stands of the sea level. At 1500 B.P. an up to 9 m episodic relative land uplift and tilting of this part of the island occurred, but since then no significant coastal changes have been identified. There is strong evidence that these Late Holocene coastal changes are not a product of fluctuations of sea level, but reflect palaeoseismic events. The sequence of the latter is at variance with models of seismic deformation deduced from a wide range of observations in different tectonic environments, including coastal uplifts near major trenches: according to these models, strain buildup and release through earthquakes is described as a cyclic and rather uniform process, the earthquake cycle. In this process, the permanent seismic deformation accumulates after each earthquake to produce geological features, while the long-term deformation rate is approximately equal to the short term one. Obviously this is not the case with West Crete. The unusual pattern of seismic deformation in this island has been observed in other cases as well, but its explanation is not easy. The juxtaposition of different earthquake cycles, variations in the source and rate of stress or internal deformation of the uplifted hanging wall of a thrust in the pre-seismic period are some possible explanations for this unusual pattern of earthquake cycle in Greece.

scholarly journals Climate change in the recent geological past and the near future. Predicting its impacts: a Review

2019 ◽  
Vol 55 (1) ◽  
pp. 260
Author(s):  
Constantinos Perisoratis
Keyword(s):  
Climate Change ◽  
Sea Level Rise ◽  
Climatic Change ◽  
Sea Level ◽  
Scientific Community ◽  
Climate Changes ◽  
Late Quaternary ◽  
The Earth ◽  
Geological Past ◽  
Near Future

The climate changes are necessarily related to the increase of the Earth’s temperature, resulting in a sea level rise. Such continuous events, were taking place with minor and greater intensity, during the alternation of warm and cool periods in the Earth during the Late Quaternary and the Holocene periods. However, a particularly significant awareness has taken place in the scientific community, and consequently in the greater public, in the last decades: that a climatic change will take place soon, or it is on-going, and that therefore it is important to undertake drastic actions. However, such a climatic change has not been recorded yet, and hence the necessary actions are not required, for the time being.

scholarly journals Graptolite dynamics in Silurian and Devonian time

1987 ◽  
Vol 35 ◽  
pp. 149-159
Author(s):  
T. N. Koren'
Keyword(s):  
Environmental Factors ◽  
Sea Level ◽  
Comparative Studies ◽  
Climate Changes ◽  
Environmental Changes ◽  
Time Intervals ◽  
Early Devonian ◽  
Carbonate Sedimentation ◽  
Reference Sections ◽  
Devonian Age

On the basis of biostratigraphic data known at present some preliminary attempts are made to evaluate graptolite dynamics, that is changes in graptolite diversity in time and space within pelagic fades of Si­lurian and Early Devonian age. For the comparative studies of diversity fluctuations versus some major environmental changes a standard graptolite zonation is used. Several critical and more or less well stu­died stratigraphical intervals are chosen; among them the Ordovician/Silurian, Sheinwoodian/Gorstian and Gorstian/Ludfordian boundary beds. For each level the most complete reference sections are analy­zed. Special attention is given to the graptolite extinction, specification and radiation events within these time intervals. They might have been partly connected with or influenced by the environmental factors as a result of eustatic sea-level and climate changes, alteration of anoxic conditions, migration of carbonate sedimentation in pelagic direction, and other globally detectable events. The graptolite evolution during the time of monograptid existence can be subdivided into three phases using the comparison of the ampli­tude of the extinction-origination events and repeatability of the synphasic cycles.

scholarly journals INFLUENCE OF THE PALEOCLIMATIC RECONSTRUCTIONS UNCERTAINTY ON THE SUBMARINE PERMAFROST DYNAMICS

2019 ◽  
Vol 4 (1) ◽  
pp. 99-105
Author(s):  
Valentina Malakhova ◽  
Alexey Eliseev
Keyword(s):  
Time Series ◽  
Sea Level ◽  
Air Temperature ◽  
Climate Changes ◽  
Arctic Shelf ◽  
The Arctic ◽  
Time Intervals ◽  
Ocean Level ◽  
Subsea Permafrost ◽  
Uncertainty Coefficient

The estimates of the subsea permafrost sensitivity to the uncertainty of paleoclimatic reconstructions of air temperature and ocean level have been obtained. This was done by using the model for thermophysical processes in the subsea sediments and the scenario for climate changes at the Arctic shelf for the last 400 kyr. This model was forced by four time series of temperature at the sediment top, by using different combinations of air temperature and sea level. The uncertainty coefficient of the response of the permafrost base depth is less than 0,3, with the exception of isolated time intervals and / or the deepest areas of the shelf.

scholarly journals Sea ice drift in the Southern Ocean: Regional patterns, variability, and trends

Elem Sci Anth ◽  
2017 ◽  
Vol 5 ◽  
Author(s):  
Ron Kwok ◽  
Shirley S. Pang ◽  
Sahra Kacimi
Keyword(s):  
Southern Ocean ◽  
Sea Ice ◽  
Sea Level ◽  
Ice Cover ◽  
The Arctic ◽  
Positive Trend ◽  
Amundsen Sea ◽  
Regional Patterns ◽  
Ice Drift ◽  
Sea Ice Drift

Understanding long-term changes in large-scale sea ice drift in the Southern Ocean is of considerable interest given its contribution to ice extent, to ice production in open waters, with associated dense water formation and heat flux to the atmosphere, and thus to the climate system. In this paper, we examine the trends and variability of this ice drift in a 34-year record (1982–2015) derived from satellite observations. Uncertainties in drift (~3 to 4 km day–1) were assessed with higher resolution observations. In a linear model, drift speeds were ~1.4% of the geostrophic wind from reanalyzed sea-level pressure, nearly 50% higher than that of the Arctic. This result suggests an ice cover in the Southern Ocean that is thinner, weaker, and less compact. Geostrophic winds explained all but ~40% of the variance in ice drift. Three spatially distinct drift patterns were shown to be controlled by the location and depth of atmospheric lows centered over the Amundsen, Riiser-Larsen, and Davis seas. Positively correlated changes in sea-level pressures at the three centers (up to 0.64) suggest correlated changes in the wind-driven drift patterns. Seasonal trends in ice edge are linked to trends in meridional winds and also to on-ice/off-ice trends in zonal winds, due to zonal asymmetry of the Antarctic ice cover. Sea ice area export at flux gates that parallel the 1000-m isobath were extended to cover the 34-year record. Interannual variability in ice export in the Ross and Weddell seas linked to the depth and location of the Amundsen Sea and Riiser-Larsen Sea lows to their east. Compared to shorter records, where there was a significant positive trend in Ross Sea ice area flux, the longer 34-year trends of outflow from both seas are now statistically insignificant.

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