Climate, sea-level and coastal changes

2019 ◽  
pp. 206-234 ◽  
Author(s):  
Michael J. Tooley
Keyword(s):  
Sea Level ◽  
Coastal Changes

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.

Holocene relative sea levels and coastal changes in the lower Cree valley and estuary, SW Scotland, U.K.

2002 ◽  
Vol 93 (4) ◽  
pp. 301-331 ◽  
Author(s):  
D. E. Smith ◽  
J. M. Wells ◽  
T. M. Mighall ◽  
R. A. Cullingford ◽  
L. K. Holloway ◽  
...  
Keyword(s):  
Sea Level ◽  
Early Holocene ◽  
Coastal Geomorphology ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Sea Levels ◽  
Coastal Changes

ABSTRACTChanges in Holocene (Flandrian) relative sea levels and coastal geomorphology in the lower Cree valley and estuary, SW Scotland, are inferred from detailed morphological and stratigraphical investigations. A graph of relative sea level changes is proposed for the area. Rising relative sea levels during the early Holocene were interrupted at c. 8300–8600 14C years B.P.(c. 9400–9900 calibrated years B.P.), when an extensive estuarine surface was reached at c. −1 m O.D., after which a fluctuating rise culminated at c. 6100–6500 14C B.P. (c. 7000–7500 calibrated years B.P.) in a prominent shoreline and associated estuarine surface measured at 7·7–10·3 m O.D. A subsequent fall in relative sea level was followed by a rise to a shoreline at 7·8–10·1 m O.D., exceeding or reoccupying the earlier shoreline over much of the area after c. 5000 14C B.P. (c. 5,800 calibrated years B.P.), before relative sea level fell to a later shoreline, reached after c. 2900 14C B.P. (c. 3100 calibrated years B.P.) at 5·5–8·0 m O.D., following which relative sea levels fell, ultimately reaching present levels. During these changes, a particular feature of the coastline was the development of a number of barrier systems. The relative sea level changes identified are compared with changes elsewhere in SW Scotland and their wider context is briefly considered.

scholarly journals Archaeological and Natural Indicators of Sea-Level and Coastal Changes: The Case Study of the Caesarea Roman Harbor

Geosciences ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 306
Author(s):  
Ehud Galili ◽  
Amos Salamon ◽  
Gil Gambash ◽  
Dov Zviely
Keyword(s):  
Sea Level ◽  
Active Fault ◽  
Supporting Evidence ◽  
Western Basin ◽  
Winter Storms ◽  
Sea Levels ◽  
Natural Processes ◽  
Sediment Deposits ◽  
Unconsolidated Sand ◽  
Coastal Changes

Archaeological and geomorphological features, as well as traces left by tsunamis, earthquakes, and vertical earth-crust displacements, are used to identify sea-level and coastal changes. Such features may be displaced, submerged or eroded by natural processes and human activities. Thus, identifying ancient sea levels and coastal changes associated with such processes may be controversial and often leads to misinterpretations. We exemplify the use of sediment deposits and sea-level and coastline indicators by discussing the enigmatic demise of the Roman harbor of Caesarea, one of the greatest marine constructions built in antiquity, which is still debated and not fully understood. It was suggested that the harbor destruction was mainly the result of either tectonic subsidence associated with a local, active fault line, or as a result of an earthquake/tsunami that struck the harbor. Here we examine and reassess the deterioration of the harbor in light of historical records, and geological, geomorphological and archaeological studies of natural and man-made features associated with the harbor. We show that the alleged evidence of an earthquakes or tsunami-driven damage to the outer breakwaters is equivocal. There is no supporting evidence for the assumed tectonic, active fault, nor is there a reliable historic account of such a catastrophic destruction. It is suggested that geo-technic failure of the breakwater’s foundations caused by a series of annual winter storms was the main reason for the destruction and ultimate collapse of the western basin of the harbor. The breakwaters were constructed on unconsolidated sand that was later washed away by storm waves and sea currents that frequently hit the Israeli coast and undercut the breakwaters. The pounding effect of the waves could have contributed to the destruction by scouring and liquefying the sandy seabed underlying the foundations. Tsunamis that may have hit Caesarea could have added to the deterioration of the breakwaters, but did not constitute the main cause of its destruction.

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.

Sea-level, sediment supply and coastal changes: Examples from the coast of Ireland

1987 ◽  
Vol 18 (1-4) ◽  
pp. 79-101 ◽  
Author(s):  
R.W.G. Carter ◽  
T.W. Johnston ◽  
J. McKenna ◽  
J.D. Orford
Keyword(s):  
Sea Level ◽  
Sediment Supply ◽  
Coastal Changes

AMS-dated mollusks in beach ridges and berms document Holocene sea-level and coastal changes in northeastern Kuwait Bay

2015 ◽  
Vol 84 (2) ◽  
pp. 200-213 ◽  
Author(s):  
Linda M. Reinink-Smith
Keyword(s):  
Sea Level ◽  
Age Progression ◽  
Beach Ridges ◽  
Oxygen Isotope Stage ◽  
Holocene Transgression ◽  
Mollusk Fauna ◽  
Before And After ◽  
Coastal Changes ◽  
Level 2 ◽  
Ams Dates

In northeastern Kuwait, ancient beach ridges and associated berms are separated from the present shoreline by a 4–6 km-wide sabkha. A diverse mollusk fauna in the beach ridges attests to a former open marine environment. A total of 21 AMS dates were obtained in this study. Thirteen mollusk samples from beach ridges yielded AMS dates ranging from ~ 6990 cal yr BP in the southeast to ~ 3370 cal yr BP in the northwest, suggesting a southeast to northwest age progression during the Holocene transgression. In contrast, four samples from berms throughout the study area yielded AMS dates of 5195–3350 cal yr BP showing no age progression; these berms consist largely ofConomurex persicusgastropods that aggregated by storms during a highstand at ~ 5000–3500 cal yr BP. The berms are presently at ~ + 6 m above sea level, 2–3 m above the beach ridges. Human settlements were common on the ridge crests before and after the highstand. Regression to present-day sea level commenced after the highstand, which is when the sabkha began forming. A landward, marine-built terrace, which yielded AMS dates > 43,50014C yr BP, probably formed during Marine Oxygen Isotope Stage 5e and hence is not genetically related to the beach ridges.

Note on Selection of Coordinate Systems for Geodynamics

1975 ◽  
Vol 26 ◽  
pp. 395-407
Author(s):  
S. Henriksen
Keyword(s):  
Sea Level ◽  
The Other ◽  
Coordinate Systems ◽  
Mean Sea Level ◽  
The Earth ◽  
The One ◽  
Static Systems ◽  
Selection Of

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.

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