Geohazard assessment of the north-eastern Sicily continental margin (SW Mediterranean): coastal erosion, sea-level rise and retrogressive canyon head dynamics

2022 ◽  
Vol 43 (1) ◽  
Author(s):  
Valeria Lo Presti ◽  
Fabrizio Antonioli ◽  
Daniele Casalbore ◽  
Francesco Latino Chiocci ◽  
Stefania Lanza ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Continental Margin ◽  
Coastal Erosion ◽  
The North ◽  
North Eastern ◽  
Geohazard Assessment

scholarly journals Transboundary geophysical mapping of geological elements and salinity distribution critical for the assessment of future sea water intrusion in response to sea level rise

2012 ◽  
Vol 16 (7) ◽  
pp. 1845-1862 ◽  
Author(s):  
F. Jørgensen ◽  
W. Scheer ◽  
S. Thomsen ◽  
T. O. Sonnenborg ◽  
K. Hinsby ◽  
...  
Keyword(s):  
Groundwater Flow ◽  
Sea Level Rise ◽  
Sea Level ◽  
Preferential Flow ◽  
Sea Water ◽  
Saline Water ◽  
Seismic Survey ◽  
Salinity Distribution ◽  
Geological Structures ◽  
The North

Abstract. Geophysical techniques are increasingly being used as tools for characterising the subsurface, and they are generally required to develop subsurface models that properly delineate the distribution of aquifers and aquitards, salt/freshwater interfaces, and geological structures that affect groundwater flow. In a study area covering 730 km2 across the border between Germany and Denmark, a combination of an airborne electromagnetic survey (performed with the SkyTEM system), a high-resolution seismic survey and borehole logging has been used in an integrated mapping of important geological, physical and chemical features of the subsurface. The spacing between flight lines is 200–250 m which gives a total of about 3200 line km. About 38 km of seismic lines have been collected. Faults bordering a graben structure, buried tunnel valleys, glaciotectonic thrust complexes, marine clay units, and sand aquifers are all examples of geological structures mapped by the geophysical data that control groundwater flow and to some extent hydrochemistry. Additionally, the data provide an excellent picture of the salinity distribution in the area and thus provide important information on the salt/freshwater boundary and the chemical status of groundwater. Although the westernmost part of the study area along the North Sea coast is saturated with saline water and the TEM data therefore are strongly influenced by the increased electrical conductivity there, buried valleys and other geological elements are still revealed. The mapped salinity distribution indicates preferential flow paths through and along specific geological structures within the area. The effects of a future sea level rise on the groundwater system and groundwater chemistry are discussed with special emphasis on the importance of knowing the existence, distribution and geometry of the mapped geological elements, and their control on the groundwater salinity distribution is assessed.

Subsidence and sea-level rise in the Thames Estuary

1972 ◽  
Vol 272 (1221) ◽  
pp. 121-130 ◽  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Average Rate ◽  
Thames Estuary ◽  
The North ◽  
Storm Waves ◽  
Late Cretaceous Period ◽  
The North Sea ◽  
Sea Area ◽  
Cretaceous Period

The development of the area, of the Thames Estuary is briefly traced since the late Cretaceous period, with its present outline being due to a combination of factors. The overall subsidence of the North Sea area, the ‘Alpine5 fold movements, and the transgression of the sea since the retreat of the Weichselian icesheets have all contributed. The positions of the shore-line during the critical phase, 9600 b.p. to 8000 b.p., of this last transgression of the sea are shown. Subsequent to this main transgressive phase, erosion of the shoreline has been rapid due to storm-waves and tidal current action. An estimation of the average rate of subsidence and/or sea-level rise is given based on the concept of sedimentary equilibrium in which a figure of 12.7 cm (5 in) per century is arrived at.

scholarly journals Supplemental Material: Detrital signals of coastal erosion and fluvial sediment supply during glacio-eustatic sea-level rise, Southern California, USA

2021 ◽  
Author(s):  
Glenn Sharman ◽  
et al.
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Coastal Erosion ◽  
Southern California ◽  
Mixture Modeling ◽  
Sediment Supply ◽  
Analytical Methodology ◽  
Fluvial Sediment ◽  
Icp Ms ◽  
Data Tables

Sample summary, LA-ICP-MS data tables, sources of Cretaceous-Paleogene forearc data, Peninsular Ranges batholith zircon U-Pb ages, mixture modeling results, and U-Pb analytical methodology.<br>

scholarly journals Supplemental Material: Detrital signals of coastal erosion and fluvial sediment supply during glacio-eustatic sea-level rise, Southern California, USA

2021 ◽  
Author(s):  
Glenn Sharman ◽  
et al.
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Coastal Erosion ◽  
Southern California ◽  
Mixture Modeling ◽  
Sediment Supply ◽  
Analytical Methodology ◽  
Fluvial Sediment ◽  
Icp Ms ◽  
Data Tables

Sample summary, LA-ICP-MS data tables, sources of Cretaceous-Paleogene forearc data, Peninsular Ranges batholith zircon U-Pb ages, mixture modeling results, and U-Pb analytical methodology.<br>

scholarly journals Carbon isotope (δ<sup>13</sup>C) excursions suggest times of major methane release during the last 14 kyr in Fram Strait, the deep-water gateway to the Arctic

2015 ◽  
Vol 11 (4) ◽  
pp. 669-685 ◽  
Author(s):  
C. Consolaro ◽  
T. L. Rasmussen ◽  
G. Panieri ◽  
J. Mienert ◽  
S. Bünz ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Carbon Isotope ◽  
Deep Water ◽  
Planktonic Foraminifera ◽  
Sediment Supply ◽  
The Arctic ◽  
Fram Strait ◽  
The North ◽  
Carbon Isotope Excursion

Abstract. We present results from a sediment core collected from a pockmark field on the Vestnesa Ridge (~ 80° N) in the eastern Fram Strait. This is the only deep-water gateway to the Arctic, and one of the northernmost marine gas hydrate provinces in the world. Eight 14C AMS dates reveal a detailed chronology for the last 14 ka BP. The δ 13C record measured on the benthonic foraminiferal species Cassidulina neoteretis shows two distinct intervals with negative values termed carbon isotope excursion (CIE I and CIE II, respectively). The values were as low as −4.37‰ in CIE I, correlating with the Bølling–Allerød interstadials, and as low as −3.41‰ in CIE II, correlating with the early Holocene. In the Bølling–Allerød interstadials, the planktonic foraminifera also show negative values, probably indicating secondary methane-derived authigenic precipitation affecting the foraminiferal shells. After a cleaning procedure designed to remove authigenic carbonate coatings on benthonic foraminiferal tests from this event, the 13C values are still negative (as low as −2.75‰). The CIE I and CIE II occurred during periods of ocean warming, sea-level rise and increased concentrations of methane (CH4) in the atmosphere. CIEs with similar timing have been reported from other areas in the North Atlantic, suggesting a regional event. The trigger mechanisms for such regional events remain to be determined. We speculate that sea-level rise and seabed loading due to high sediment supply in combination with increased seismic activity as a result of rapid deglaciation may have triggered the escape of significant amounts of methane to the seafloor and the water column above.

scholarly journals Variations in Persistence and Regenerative Zones in Coastal Forests Triggered by Sea Level Rise and Storms

2019 ◽  
Vol 11 (17) ◽  
pp. 2019 ◽  
Author(s):  
Sergio Fagherazzi ◽  
Giovanna Nordio ◽  
Keila Munz ◽  
Daniele Catucci ◽  
William S. Kearney
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Forest Disturbance ◽  
Remote Sensing Data ◽  
Storm Events ◽  
Coastal Forests ◽  
The North ◽  
Significant Difference

Retreat of coastal forests in relation to sea level rise has been widely documented. Recent work indicates that coastal forests on the Delmarva Peninsula, United States, can be differentiated into persistence and regenerative zones as a function of sea-level rise and storm events. In the lower persistence zone trees cannot regenerate because of frequent flooding and high soil salinity. This study aims to verify the existence of these zones using spectral remote sensing data, and determine whether the effect of large storm events that cause damage to these forests can be detected from satellite images. Spectral analysis confirms a significant difference in average Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI) values in the proposed persistence and regenerative zones. Both NDVI and NDWI indexes decrease after storms triggering a surge above 1.3 m with respect to the North American Vertical Datum of 1988 (NAVD88). NDWI values decrease more, suggesting that this index is better suited to detect the effect of hurricanes on coastal forests. In the regenerative zone, both NDVI and NDWI values recover three years after a storm, while in the persistence zone the NDVI and NDWI values keep decreasing, possibly due to sea level rise causing vegetation stress. As a result, the forest resilience to storms in the persistence zone is lower than in the regenerative zone. Our findings corroborate the ecological ratchet model of coastal forest disturbance.

scholarly journals Comment [on “Sea level rise shown to drive coastal erosion”]

Eos ◽  
2000 ◽  
Vol 81 (38) ◽  
pp. 436 ◽  
Author(s):  
Orrin H. Pilkey ◽  
Robert S. Young ◽  
David M. Bush
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Coastal Erosion

scholarly journals The impact of sea-level rise on tidal characteristics around Australia

Ocean Science ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 147-159 ◽  
Author(s):  
Alexander Harker ◽  
J. A. Mattias Green ◽  
Michael Schindelegger ◽  
Sophie-Berenice Wilmes
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Open Boundary ◽  
Open Boundary Conditions ◽  
Tidal Dissipation ◽  
North West ◽  
The North ◽  
Tidal Changes ◽  
Tidal Characteristics ◽  
The Impact

Abstract. An established tidal model, validated for present-day conditions, is used to investigate the effect of large levels of sea-level rise (SLR) on tidal characteristics around Australasia. SLR is implemented through a uniform depth increase across the model domain, with a comparison between the implementation of coastal defences or allowing low-lying land to flood. The complex spatial response of the semi-diurnal M2 constituent does not appear to be linear with the imposed SLR. The most predominant features of this response are the generation of new amphidromic systems within the Gulf of Carpentaria and large-amplitude changes in the Arafura Sea, to the north of Australia, and within embayments along Australia's north-west coast. Dissipation from M2 notably decreases along north-west Australia but is enhanced around New Zealand and the island chains to the north. The diurnal constituent, K1, is found to decrease in amplitude in the Gulf of Carpentaria when flooding is allowed. Coastal flooding has a profound impact on the response of tidal amplitudes to SLR by creating local regions of increased tidal dissipation and altering the coastal topography. Our results also highlight the necessity for regional models to use correct open boundary conditions reflecting the global tidal changes in response to SLR.

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