Study of tides and sea levels at Deception and Livingston islands, Antarctica

2011 ◽  
Vol 24 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Juan Vidal ◽  
Manuel Berrocoso ◽  
Alberto Fernández-Ros
Keyword(s):  
Harmonic Analysis ◽  
Sea Level ◽  
Seawater Temperature ◽  
Pressure Sensors ◽  
Geodetic Network ◽  
South Shetland Islands ◽  
Bottom Pressure ◽  
Sea Levels ◽  
Phase Lags ◽  
Tidal Characteristics

AbstractDuring the 2007–08 Spanish Antarctic campaign, two moorings of bottom pressure sensors were carried out over a ten week period. This paper presents the results of the tidal analysis from sea level records obtained at Deception and Livingston islands (South Shetland Islands, Antarctica). The main objective of this paper is to present a detailed study of the tidal characteristics at these two islands, for which statistical and harmonic analysis techniques are applied to the tidal records. A geodetic network was used to reference the pressure sensors. Geometric levelling, with an accuracy of 1 mm, allowed us to link the tidal marks with geodetic vertices located on Livingston and Deception islands. The amplitudes and phase lags obtained by harmonic analysis are compared to the harmonic constants of several coastal stations and co-tidal and co-range charts. Results show an evident influence of tides in the sea level signal, with a clear mixed semi-diurnal behaviour and a daily inequality between high and low waters. Measurements of salinity and temperature were made using electronic sensors. Results from this study showed that salinity and temperature were strongly influenced by tides. Seawater temperature varied in a manner that was consistent with the time series of residual bottom pressure.

Seasonal variability of the M2 tide in the Bohai Bay: development and application of modified enhanced harmonic analysis

2020 ◽  
Author(s):  
Daosheng Wang ◽  
Haidong Pan ◽  
Lin Mu
Keyword(s):  
Harmonic Analysis ◽  
Sea Level ◽  
Seasonal Variability ◽  
The Other ◽  
Major Influence ◽  
Bohai Bay ◽  
Phase Lag ◽  
Phase Lags ◽  
Ocean Environment ◽  
One Year

<p>The seasonal variability of the M<sub>2</sub> tide exerts a major influence on the coastal ocean environment. In this study, a novel method, namely modified enhanced harmonic analysis (MEHA), is developed to synchronously extract the temporally varying amplitudes and phase lags of significant tides and the constant values of the other constituents. The seasonal variability of the M<sub>2</sub> tide in the Bohai Bay, China, is investigated by analyzing one-year sea level observations at two stations with MEHA.</p><p>In ideal twin experiments, the artificial sea level observations were analyzed. Both the estimated temporally varying amplitude and phase lag of the M<sub>2</sub> tide and constant values of the S<sub>2</sub>, K<sub>1</sub> and O<sub>1</sub> tides using MEHA were much closer to the prescribed values than those obtained using the other methods, indicating the capability and efficacy of MEHA. When the real sea level observations were analyzed using MEHA, the estimated M<sub>2</sub> tidal amplitude has significant seasonal variability, with large values in summer and small values in winter, which is robust and not affected by experimental settings. The results of numerical experiments indicate that the seasonality of vertical eddy viscosity induces seasonal variations of the M<sub>2</sub> tide in the Bohai Bay.</p>

scholarly journals Economic damages from Hurricane Sandy attributable to sea level rise caused by anthropogenic climate change

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Benjamin H. Strauss ◽  
Philip M. Orton ◽  
Klaus Bittermann ◽  
Maya K. Buchanan ◽  
Daniel M. Gilford ◽  
...  
Keyword(s):  
Climate Change ◽  
Sea Level Rise ◽  
Sea Level ◽  
East Coast ◽  
The United States ◽  
Hurricane Sandy ◽  
Water Levels ◽  
Anthropogenic Climate Change ◽  
Economic Damage ◽  
Sea Levels

AbstractIn 2012, Hurricane Sandy hit the East Coast of the United States, creating widespread coastal flooding and over $60 billion in reported economic damage. The potential influence of climate change on the storm itself has been debated, but sea level rise driven by anthropogenic climate change more clearly contributed to damages. To quantify this effect, here we simulate water levels and damage both as they occurred and as they would have occurred across a range of lower sea levels corresponding to different estimates of attributable sea level rise. We find that approximately $8.1B ($4.7B–$14.0B, 5th–95th percentiles) of Sandy’s damages are attributable to climate-mediated anthropogenic sea level rise, as is extension of the flood area to affect 71 (40–131) thousand additional people. The same general approach demonstrated here may be applied to impact assessments for other past and future coastal storms.

Records of sea-level highstand over the Meghalayan age/late Holocene from uranium-series ages of beachrock in Weizhou Island, northern South China Sea

The Holocene ◽  
2021 ◽  
pp. 095968362110332
Author(s):  
Tingli Yan ◽  
Kefu Yu ◽  
Rui Wang ◽  
Wenhui Liu ◽  
Leilei Jiang
Keyword(s):  
South China Sea ◽  
Sea Level ◽  
South China ◽  
Intertidal Zone ◽  
Meteoric Water ◽  
Northern South China Sea ◽  
Water Environment ◽  
Sea Levels ◽  
China Sea ◽  
Micro Structures

Beachrock is considered a good archive for past sea-levels because of its unique formation position (intertidal zone). To evaluate sea-level history in the northern South China Sea, three well-preserved beachrock outcrops (Beigang, Gongshanbei, and Hengling) at Weizhou Island, northern South China Sea were selected to examine their relative elevation, sedimentological, mineralogical, and geochemical characteristics. Acropora branches with well-preserved surface micro-structures were selected from the beachrocks and used to determine the ages of these beachrocks via U-series dating. The results show that the beachrocks are composed of coral reef sediments, terrigenous clastics, volcanic clastics, and various calcite cements. These sediments accumulated in the intertidal zone of Weizhou Island were then cemented in a meteoric water environment. The U-series ages of beachrocks from Beigang, Gongshanbei, and Hengling are 1712–768 ca. BP, 1766–1070 ca. BP, and 1493–604 ca. BP (before 1950 AD) respectively. Their elevations are 0.91–1.16 m, 0.95–1.24 m, and 0.82–1.17 m higher than the modern homologous sedimentary zones, respectively. Therefore, we concluded that the sea-level in the Meghalayan age (1766–604 ca. BP) was 0.82–1.24 m higher than the present, and that the sea-level over this period showed a declining trend.

scholarly journals Flooding Conditions at Aveiro Port (Portugal) within the Framework of Projected Climate Change

2021 ◽  
Vol 9 (6) ◽  
pp. 595
Author(s):  
Américo Soares Ribeiro ◽  
Carina Lurdes Lopes ◽  
Magda Catarina Sousa ◽  
Moncho Gomez-Gesteira ◽  
João Miguel Dias
Keyword(s):  
Climate Change ◽  
Sea Level ◽  
Climate Change Impacts ◽  
Storm Surges ◽  
Historical Period ◽  
Return Periods ◽  
Wave Regime ◽  
Mean Sea Level ◽  
Sea Levels ◽  
Far Future

Ports constitute a significant influence in the economic activity in coastal areas through operations and infrastructures to facilitate land and maritime transport of cargo. Ports are located in a multi-dimensional environment facing ocean and river hazards. Higher warming scenarios indicate Europe’s ports will be exposed to higher risk due to the increase in extreme sea levels (ESL), a combination of the mean sea level, tide, and storm surge. Located on the west Iberia Peninsula, the Aveiro Port is located in a coastal lagoon exposed to ocean and river flows, contributing to higher flood risk. This study aims to assess the flood extent for Aveiro Port for historical (1979–2005), near future (2026–2045), and far future (2081–2099) periods scenarios considering different return periods (10, 25, and 100-year) for the flood drivers, through numerical simulations of the ESL, wave regime, and riverine flows simultaneously. Spatial maps considering the flood extent and calculated area show that most of the port infrastructures' resilience to flooding is found under the historical period, with some marginal floods. Under climate change impacts, the port flood extent gradually increases for higher return periods, where most of the terminals are at high risk of being flooded for the far-future period, whose contribution is primarily due to mean sea-level rise and storm surges.

scholarly journals Twenty-first century response of Petermann Glacier, northwest Greenland to ice shelf loss

2020 ◽  
pp. 1-11
Author(s):  
Emily A. Hill ◽  
G. Hilmar Gudmundsson ◽  
J. Rachel Carr ◽  
Chris R. Stokes ◽  
Helen M. King
Keyword(s):  
Sea Level ◽  
First Century ◽  
Ice Shelf ◽  
Ice Shelves ◽  
Sea Levels ◽  
Grounding Line ◽  
Global Mean Sea Level ◽  
Near Future ◽  
Global Mean ◽  
Large Sections

Abstract Ice shelves restrain flow from the Greenland and Antarctic ice sheets. Climate-ocean warming could force thinning or collapse of floating ice shelves and subsequently accelerate flow, increase ice discharge and raise global mean sea levels. Petermann Glacier (PG), northwest Greenland, recently lost large sections of its ice shelf, but its response to total ice shelf loss in the future remains uncertain. Here, we use the ice flow model Úa to assess the sensitivity of PG to changes in ice shelf extent, and to estimate the resultant loss of grounded ice and contribution to sea level rise. Our results have shown that under several scenarios of ice shelf thinning and retreat, removal of the shelf will not contribute substantially to global mean sea level (<1 mm). We hypothesize that grounded ice loss was limited by the stabilization of the grounding line at a topographic high ~12 km inland of its current grounding line position. Further inland, the likelihood of a narrow fjord that slopes seawards suggests that PG is likely to remain insensitive to terminus changes in the near future.

Mean Sea Level as a Reference for Geodetic Leveling

1974 ◽  
Vol 28 (5) ◽  
pp. 524-530 ◽  
Author(s):  
G. W. Lennon
Keyword(s):  
Sea Level ◽  
World Ocean ◽  
Equipotential Surface ◽  
Scientific Discipline ◽  
Mean Sea Level ◽  
Sea Levels ◽  
Coastal Sea ◽  
Long Time ◽  
Marine System

The use of mean sea level as a surface of reference that might provide an independent control for geodetic leveling has been a long term goal arising from the classical analogy between the geoid as an equipotential surface and the surface assumed by a hypothetical undisturbed world ocean. The problems associated with this aim are now known to be vast, and are associated with the dynamics of the marine system, notably its response to meteorological forces, to variations in density and to the effects of basic circulation patterns. In consequence the mean sea level surface varies rapidly in both time and space. This identifies in fact a distinctive scientific discipline, coastal geodesy, in which contributions are required by both geodesists and oceanographers. It has come to be recognized that the coastal zone is a hazardous environment for all observational techniques concerned. On the one hand, the difficulties of measurement of coastal sea levels have only recently been understood; on the other hand, precise leveling procedures are now known to be influenced by the attraction of marine tides and by crustal deformation of tidal loading. Much of the data available for study are therefore inadequate and, moreover, it should be noted that long-time series are required. It is now possible to lay plans for both geodetic and oceanographic procedures to remedy these deficiencies in the long-term interests of the study.

scholarly journals Testing an “IoT” Tide Gauge Network for Coastal Monitoring

IoT ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 17-32
Author(s):  
Philip Knight ◽  
Cai Bird ◽  
Alex Sinclair ◽  
Jonathan Higham ◽  
Andy Plater
Keyword(s):  
Sea Level ◽  
Morphological Changes ◽  
Tide Gauge ◽  
Low Cost ◽  
Pressure Sensors ◽  
Wave Activity ◽  
Tide Gauges ◽  
Coastal Monitoring ◽  
Level Data ◽  
Operational Constraints

A low-cost “Internet of Things” (IoT) tide gauge network was developed to provide real-time and “delayed mode” sea-level data to support monitoring of spatial and temporal coastal morphological changes. It is based on the Arduino Sigfox MKR 1200 micro-controller platform with a Measurement Specialties pressure sensor (MS5837). Experiments at two sites colocated with established tide gauges show that these inexpensive pressure sensors can make accurate sea-level measurements. While these pressure sensors are capable of ~1 cm accuracy, as with other comparable gauges, the effect of significant wave activity can distort the overall sea-level measurements. Various off-the-shelf hardware and software configurations were tested to provide complementary data as part of a localized network and to overcome operational constraints, such as lack of suitable infrastructure for mounting the tide gauges and for exposed beach locations.

Revising key parameters for long-term carbon cycle models

2021 ◽  
Author(s):  
Chloé M. Marcilly ◽  
Trond H. Torsvik ◽  
Mathew Domeier ◽  
Dana L. Royer
Keyword(s):  
Sea Level ◽  
Age Distribution ◽  
Silicate Weathering ◽  
Geological Time ◽  
Sea Levels ◽  
Climate Fluctuations ◽  
Climate Gradients ◽  
Sea Level Fluctuations ◽  
Temperature And Precipitation

&lt;p&gt;CO&lt;sub&gt;2&lt;/sub&gt; is the most important greenhouse gas in the Earth&amp;#8217;s atmosphere and has fluctuated considerably over geological time. However, proxies for past CO&lt;sub&gt;2 &lt;/sub&gt;concentrations have large uncertainties and are mostly limited to Devonian and younger times. Consequently, CO&lt;sub&gt;2&lt;/sub&gt; modelling plays a key role in reconstructing past climate fluctuations. Facing the limitations with the current CO&lt;sub&gt;2&lt;/sub&gt; models, we aim to refine two important forcings for CO&lt;sub&gt;2&lt;/sub&gt; levels over the Phanerozoic, namely carbon degassing and silicate weathering.&lt;/p&gt;&lt;p&gt;Silicate weathering and carbonate deposition is widely recognized as a primary sink of carbon on geological timescales and is largely influenced by changes in climate, which in turn is linked to changes in paleogeography. The role of paleogeography on silicate weathering fluxes has been the focus of several studies in recent years. Their aims were mostly to constrain climatic parameters such as temperature and precipitation affecting weathering rates through time. However, constraining the availability of exposed land is crucial in assessing the theoretical amount of weathering on geological time scales. Associated with changes in climatic zones, the fluctuation of sea-level is critical for defining the amount of land exposed to weathering. The current reconstructions used in&lt;sub&gt;&lt;/sub&gt;models tend to overestimate the amount of exposed land to weathering at periods with high sea levels. Through the construction of continental flooding maps, we constrain the effective land area undergoing silicate weathering for the past 520 million years. Our maps not only reflect sea-level fluctuations but also contain climate-sensitive indicators such as coal (since the Early Devonian) and evaporites to evaluate climate gradients and potential weatherablity through time. This is particularly important after the Pangea supercontinent formed but also for some time after its break-up.&lt;/p&gt;&lt;p&gt;Whilst silicate weathering is an important CO&lt;sub&gt;2&lt;/sub&gt; sink, volcanic carbon degassing is a major source but one of the least constrained climate forcing parameters. There is no clear consensus on the history of degassing through geological time as there are no direct proxies for reconstructing carbon degassing, but various proxy methods have been postulated. We propose new estimates of plate tectonic degassing for the Phanerozoic using both subduction flux from full-plate models and zircon age distribution from arcs (arc-activity) as proxies.&lt;/p&gt;&lt;p&gt;The effect of revised modelling parameters for weathering and degassing was tested in the well-known long-term models GEOCARBSULF and COPSE. They revealed the high influence of degassing on CO&lt;sub&gt;2&lt;/sub&gt; levels using those models, highlighting the need for enhanced research in this direction. The use of arc-activity as a proxy for carbon degassing leads to interesting responses in the Mesozoic and brings model estimates closer to CO&lt;sub&gt;2 &lt;/sub&gt;&amp;#160;proxy values. However, from simulations using simultaneously the revised input parameters (i.e weathering and degassing) large model-proxy discrepancies remain and notably for the Triassic and Jurassic.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

The Impact of Climate Change on States

2021 ◽  
Vol 23 (2-3) ◽  
pp. 115-132
Author(s):  
Łukasz Kułaga
Keyword(s):  
Climate Change ◽  
International Law ◽  
Sea Level Rise ◽  
Sea Level ◽  
The State ◽  
Fundamental Change ◽  
Sea Levels ◽  
Impact Of Climate Change ◽  
Potential Impact ◽  
The Impact

Abstract The increase in sea levels, as a result of climate change in territorial aspect will have a potential impact on two major issues – maritime zones and land territory. The latter goes into the heart of the theory of the state in international law as it requires us to confront the problem of complete and permanent disappearance of a State territory. When studying these processes, one should take into account the fundamental lack of appropriate precedents and analogies in international law, especially in the context of the extinction of the state, which could be used for guidance in this respect. The article analyses sea level rise impact on baselines and agreed maritime boundaries (in particular taking into account fundamental change of circumstances rule). Furthermore, the issue of submergence of the entire territory of a State is discussed taking into account the presumption of statehood, past examples of extinction of states and the importance of recognition in this respect.

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