scholarly journals Preservation of Modern and MIS 5.5 Erosional Landforms and Biological Structures as Sea Level Markers: A Matter of Luck?

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2127
Author(s):  
Stefano Furlani ◽  
Valeria Vaccher ◽  
Fabrizio Antonioli ◽  
Mauro Agate ◽  
Sara Biolchi ◽  
...  
Keyword(s):  
Sea Level ◽  
Last Interglacial ◽  
Central Mediterranean ◽  
Sea Levels ◽  
Change Models ◽  
Erosion Processes ◽  
Significant Difference ◽  
The Mediterranean ◽  
Shore Platforms ◽  
Mis 5.5

The Mediterranean Basin is characterized by a significant variability in tectonic behaviour, ranging from subsidence to uplifting. However, those coastal areas considered to be tectonically stable show coastal landforms at elevations consistent with eustatic and isostatic sea level change models. In particular, geomorphological indicators—such as tidal notches or shore platforms—are often used to define the tectonic stability of the Mediterranean coasts. We present the results of swim surveys in nine rocky coastal sectors in the central Mediterranean Sea using the Geoswim approach. The entire route was covered in 22 days for a total distance of 158.5 km. All surveyed sites are considered to have been tectonically stable since the last interglacial (Marine Isotope Stage 5.5 [MIS 5.5]), because related sea level markers fit well with sea level rise models. The analysis of visual observations and punctual measurements highlighted that, with respect to the total length of surveyed coast, the occurrence of tidal notches, shore platforms, and other indicators accounts for 85% of the modern coastline, and only 1% of the MIS 5.5 equivalent. Therefore, only 1% of the surveyed coast showed the presence of fossil markers of paleo sea levels above the datum. This significant difference is mainly attributable to erosion processes that did not allow the preservation of the geomorphic evidence of past sea level stands. In the end, our research method showed that the feasibility of applying such markers to define long-term tectonic behaviour is much higher in areas where pre-modern indicators have not been erased, such as at sites with hard bedrock previously covered by post-MIS 5.5 continental deposits, e.g., Sardinia, the Egadi Islands, Ansedonia, Gaeta, and Circeo. In general, the chances of finding such preserved indicators are very low.

Erosional landforms and biological structures in tectonically stable areas in the Mediterranean basin

2021 ◽  
Author(s):  
Valeria Vaccher ◽  
Stefano Furlani ◽  
Sara Biolchi ◽  
Chiara Boccali ◽  
Alice Busetti ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Sea Level ◽  
Mediterranean Basin ◽  
Vertical Position ◽  
Structural Constraints ◽  
Last Interglacial ◽  
Central Mediterranean ◽  
Biological Structures ◽  
The Mediterranean ◽  
The Mediterranean Basin

<p>The Mediterranean basin displays a variety of neotectonics scenarios leading to positive or negative vertical displacement, which change the vertical position of former coastlines. As a result, the best locations to evaluate former sea levels and validate sea-level models are tectonically stable areas. There are a number of coastal areas considered to be stable based on the elevation of paleo sea-level markers, the absence of historical seismicity, and by their position far from major Mediterranean faults. We report here the results of swim surveys carried out at such locations following the Geoswim approach described by Furlani (2020) in nine coastal sectors of the central Mediterranean Sea (Egadi Island - Marettimo, Favignana, Levanzo, Gaeta Promontory, Circeo Promontory, North Sardinia - Razzoli, Budelli, Santa Maria, NW Sardinia – Capocaccia, Maddalena Archipelago, Tavolara Island, East of Malta - Ahrax Point, Bugibba-Qawra, Delimara, Addura, Palermo, Ansedonia Promontory). All the sites are considered to be tectonically stable, as validated by the elevation of sea-level indicators. In fact, modern and MIS5.5 (last interglacial) m.s.l. altitudes fit well with accepted figures based upon field data and model projections. Starting from precise morphometric parameters such as the size of tidal notches and indicative landforms and biological structures, we have developed a procedure that integrates multiple geomorphological and biological descriptors applicable to the vast spectrum of locally diverse coastal situations occurring in the Mediterranean Sea. We took detailed measurements of features such as modern and MIS5.5 tidal notches at 146 sites in all the areas, the absence of modern tidal notch at Circeo promontory, shore platforms, and MIS5.5 marine terraces at Egadi islands, Malta, and Palermo. Biological structures were also measured. In particular, vermetid platforms at Egadi, Palermo and Malta. The morphometric characteristics of these indicators depend on 1) local geological and structural constraints, 2) local geomorphotypes, 3) climate, sea, and weather conditions that affect geomorphic and biological processes, and 4) the sea level change history.</p>

Reconstruction of the MIS 5.5, 5.3 and 5.1 coastal terraces in Latium (central Italy): A re-evaluation of the sea-level history in the Mediterranean Sea during the last interglacial

2019 ◽  
Vol 525 ◽  
pp. 54-77 ◽  
Author(s):  
Fabrizio Marra ◽  
Jean-Jacques Bahain ◽  
Brian R. Jicha ◽  
Sebastien Nomade ◽  
Danilo M. Palladino ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Sea Level ◽  
Central Italy ◽  
Last Interglacial ◽  
The Mediterranean ◽  
Mis 5.5

scholarly journals Sea level 400 000 years ago (MIS 11): analogue for present and future sea-level

2009 ◽  
Vol 5 (4) ◽  
pp. 1853-1882 ◽  
Author(s):  
D. Q. Bowen
Keyword(s):  
Sea Level ◽  
Present Level ◽  
Last Interglacial ◽  
Sea Levels ◽  
Correction Formula ◽  
West Antarctic ◽  
Uplift Rates ◽  
Mis 5.5

Abstract. Comparison of sea-levels today and 400 000 years ago (MIS 11), when the Earth's orbital characteristics were similar, may provide indications of future sea-level during the present interglacial. Evidence for former sea-levels occur on uplifting coastlines where shorelines are preserved. The sea-level term and the uplift term may be separated with an "uplift uplift correction" formula. This discovers the original sea-level at which the uplifted shoreline was fashioned. Estimates are based on average uplift rates of the "last interglacial" sea-level (MIS 5.5) using a range estimates for sea-level and age at that time and at different locations. These, with varying secular tectonic regimes in different ocean basins, provide a band of estimates for MIS 11. They show the MIS 11 sea-level was close to its present level and Greenland and West Antarctic ice volumes were similar to present.

scholarly journals Submerged Speleothems and Sea Level Reconstructions: A Global Overview and New Results from the Mediterranean Sea

Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1663
Author(s):  
Fabrizio Antonioli ◽  
Stefano Furlani ◽  
Paolo Montagna ◽  
Paolo Stocchi ◽  
Lucio Calcagnile ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Sea Level ◽  
Late Quaternary ◽  
Sea Level Changes ◽  
Central Mediterranean ◽  
Sea Levels ◽  
Cave Deposits ◽  
Regional Sea Level ◽  
Sea Level Variations ◽  
The Mediterranean

This study presents a global overview of the submerged speleothems used to reconstruct paleo sea levels and reports new results from two stalactites collected in the Mediterranean Sea. Coastal cave deposits significantly contributed to the understanding of global and regional sea-level variations during the Middle and Late Quaternary. The studied speleothems cover the last 1.4 Myr and focused mainly on Marine Isotope Stages (MIS) 1, 2, 3, 5.1, 5.3, 5.5, 7.1, 7.2, 7.3 and 7.5. The results indicate that submerged speleothems represent extraordinary archives that can provide detailed information on former sea-level changes. The two stalactites collected in the central Mediterranean Sea, at Favignana and Ustica islands (Sicily, Italy), are both characterized by continental, phreatic or marine layers. The U-Th and 14C ages of the new speleothems provide results of great interest for relative sea-level changes over the last 1000 years.

scholarly journals Relict inland mangrove ecosystem reveals Last Interglacial sea levels

2021 ◽  
Vol 118 (41) ◽  
pp. e2024518118
Author(s):  
Octavio Aburto-Oropeza ◽  
Carlos Manuel Burelo-Ramos ◽  
Exequiel Ezcurra ◽  
Paula Ezcurra ◽  
Claudia L. Henriquez ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Sea Level ◽  
Environmental Changes ◽  
Terrestrial Ecosystems ◽  
Mangrove Ecosystem ◽  
Last Interglacial ◽  
Sea Levels ◽  
Climatic Oscillations ◽  
Floristic Data ◽  
The Impact

Climatic oscillations during the Pleistocene played a major role in shaping the spatial distribution and demographic dynamics of Earth's biota, including our own species. The Last Interglacial (LIG) or Eemian Period (ca. 130 to 115 thousand years B.P.) was particularly influential because this period of peak warmth led to the retreat of all ice sheets with concomitant changes in global sea level. The impact of these strong environmental changes on the spatial distribution of marine and terrestrial ecosystems was severe as revealed by fossil data and paleogeographic modeling. Here, we report the occurrence of an extant, inland mangrove ecosystem and demonstrate that it is a relict of the LIG. This ecosystem is currently confined to the banks of the freshwater San Pedro Mártir River in the interior of the Mexico–Guatemala El Petén rainforests, 170 km away from the nearest ocean coast but showing the plant composition and physiognomy typical of a coastal lagoon ecosystem. Integrating genomic, geologic, and floristic data with sea level modeling, we present evidence that this inland ecosystem reached its current location during the LIG and has persisted there in isolation ever since the oceans receded during the Wisconsin glaciation. Our study provides a snapshot of the Pleistocene peak warmth and reveals biotic evidence that sea levels substantially influenced landscapes and species ranges in the tropics during this period.

scholarly journals Allometry, condition factor and growth of the swimming blue crab Portunus segnis in the Gulf of Gabes, Southeastern Tunisia (Central Mediterranean)

2019 ◽  
Vol 20 (3) ◽  
pp. 566
Author(s):  
OLFA BEN ABDALLAH-BEN HADJ HAMIDA ◽  
NADER BEN HADJ HAMIDA ◽  
HOUDA CHAOUCH ◽  
HECHMI MISSAOUI
Keyword(s):  
Carapace Length ◽  
Condition Factor ◽  
Growth Parameters ◽  
Carapace Width ◽  
Central Mediterranean ◽  
Gulf Of Gabes ◽  
Gulf Of Gabès ◽  
Significant Difference ◽  
The Mediterranean ◽  
Portunus Segnis

The blue swimming crab Portunus segnis (Forskål, 1775) is one of the earliest Lessepsian invaders of the Mediterranean Sea, and is recorded since decades in various areas of the Mediterranean. Its presence in the southeastern Tunisian coasts (Gulf of Gabes) is, however, very recent. Allometry, condition factor and growth of P. segnis were studied along the Gulf of Gabes coasts. Sampling was performed by artisanal fishing gears as well as trawl net during a one-year period (October 2015 to September 2016) as processed 4971 crabs were collected. The crab carapace width (CW) ranged from 45 to 168 mm for males and 50 to 159 mm for females. The crab carapace length (CL) was 22.02-89.20 mm and 38.70-85.28 mm, respectively for males and females. The carapace width-carapace length, carapace width- front, carapace width-carapace height and carapace width-weight relationships were studied in separate sexes of crab. The covariance analysis indicates a significant difference between the two sexes with respect to the carapace width-carapace length and the carapace width-weight relationships. The condition factor ranged between 0.0042 and 0.0118 with a mean of 0.0078. The condition factor decreased with increasing crab size. The Von Bertalanffy growth parameters CW∞, K and t0 were estimated on the basis of Length-frequency modal progression analysis methods. The mean values of L∞ (mm), K (year-1) and t0 would be, respectively, 206.48 mm, 1.34 and -0.130 for males; 183.89 mm, 1.42 and -0.127 for females and, 190.60 mm, 1.02 and -0.177 for combined sexes.

The influence of changes in sea level on coastal cliff instability in Devon

1991 ◽  
Vol 7 (1) ◽  
pp. 361-367 ◽  
Author(s):  
P. G. Kalaugher ◽  
P. Grainger
Keyword(s):  
Sea Level ◽  
Climatic Changes ◽  
Future Trends ◽  
Quaternary Deposits ◽  
Climatic Fluctuations ◽  
Sea Levels ◽  
Landslide Hazards ◽  
Coastal Cliff ◽  
Shore Platforms

AbstractMajor variations in sea level have resulted from climatic changes during the Quaternary. In addition, beyond the maximum limit of glaciation, periglacial climates in southern Britain have produced Quaternary deposits which can affect the nature of coastal slopes and their response to marine erosion. Examples are given of cliffs in head (solifluction) deposits which overlie raised shore platforms in Devon. The present styles and distribution of coastal landslide hazards, recorded in recent surveys, are directly related to past Quaternary sea levels and climatic fluctuations. Future trends in relative sea level are a significant factor in the determination of the hazards in the longer term, as there could be changes in the level at which marine erosion is effective. Rankings of the hazards, which should in any case be updated routinely by repeated monitoring of the landslide activity, ought to reflect expected changes in sea level.

scholarly journals Morphology of the Raised Shore Platforms along the Coastline between Daghmar and Dhabab, Sultanate of Oman

2017 ◽  
Vol 8 (2) ◽  
pp. 13 ◽  
Author(s):  
Salim Mubarak Al Hatrushi
Keyword(s):  
Sea Level ◽  
Late Quaternary ◽  
Aerial Photographs ◽  
Tectonic Activity ◽  
Present Level ◽  
Sea Level Changes ◽  
Last Interglacial ◽  
Southeastern Part ◽  
Relative Level ◽  
Shore Platforms

Raised shore platforms, are rocky surfaces formed by wave action and subaerial weathering during global high sea level stands. The present height of the raised shore platforms is attributed to several factors, mainly to eustatic sea level changes, isostatic changes in the relative level of land and sea, and vertical tectonic activities. The aim of this study is to investigate the detailed morphology of the raised shore platform along the rocky coastline between Daghmar and Dhabab, in the southeastern part of Muscat Governorate. The study also intends to establish a tentative chronology of the raised shore platforms development. The methodology is based on field observation and documentation, along with satellite and aerial photographs analysis. The results have shown that the study area has a sequence of five successive, well developed raised shore platforms and well preserved, except the platform at 10m altitude which is only found in isolated fragments. The formation of the raised shore platforms has been affected by a number of constructive factors including tectonic activity, and destructive factors such as fluvial action and subaerial weathering. No absolute dating has been reported or can be obtained from the study area, due to its erosional nature. However, dating from the shorelines adjacent to the study area, ranging in heights from 3 to 15m above sea level, revealed a narrow range of 26,400 to 29,600 years. This period coincides with the last glaciations when the sea level was at about 75m below the present level, and thus did not match with the altitudes of the platforms. This suggests that the platforms could be belong to the last interglacial high sea level, when the sea level stood at about 6m above the present level. Based on this scenario, the study concludes that the coastline of the study area has not experienced any significant uplift during the Late Quaternary. 

scholarly journals Last interglacial sea-level proxies in the Korean Peninsula

2021 ◽  
Author(s):  
Woo Hun Ryang ◽  
Alexander R. Simms ◽  
Hyun Ho Yoon ◽  
Seung Soo Chun ◽  
Gee Soo Kong
Keyword(s):  
Sea Level ◽  
West Coast ◽  
Korean Peninsula ◽  
East Coast ◽  
Vertical Movement ◽  
Last Interglacial ◽  
The West ◽  
Sea Levels ◽  
Marine Terraces ◽  
Data Points

Abstract. Like most of the world’s coastlines, the Korean Peninsula experienced higher-than-present sea levels during the Last Interglacial (LIG) otherwise known as Marine Isotope Stage (MIS) 5e. However, the expression of that highstand in sea levels differs across the eastern and western Korean Peninsula. The active east coast of the Korean Peninsula is characterized by broad uplifted marine terraces, while the stable west coast is characterized by tidal flats and rias. In this study, we used a standardized database template to review and extract the existing constraints on LIG sea levels along both the east and west coasts of the Korean Peninsula. A total of 62 LIG constraining data points were compiled including 34 sea-level indicators, 22 marine limiting records, and 6 terrestrial limiting records. The ages from these data points are based on 61 optically stimulated luminescence (OSL) measurements and 1 paleomagnetic-based age. Along the uplifted east coast, LIG sea-level indicators based on marine terraces are at elevations ranging from +9 to +32 m. The uplifted marine terraces are cut or otherwise deformed by faults developed under a compressional regime due to backarc closing of the East Sea since the early Pliocene. As a result, tectonic uplift likely contaminates the elevation of the east coast LIG shorelines. On the contrary, LIG sea-level constraints on the west coast of the Korean Peninsula are found at heights of between +2 and +5 m and include marine and terrestrial limiting records as well as true sea-level indicators. The LIG sea-level constraints along the west coast of the Korean Peninsula are likely uncontaminated by vertical movement or experienced minor subsidence during the Quaternary.

Taphonomic problems in reconstructing sea-level history from the late Quaternary marine terraces of Barbados

2017 ◽  
Vol 88 (3) ◽  
pp. 409-429 ◽  
Author(s):  
Daniel R. Muhs ◽  
Kathleen R. Simmons
Keyword(s):  
Sea Level ◽  
Late Quaternary ◽  
Case Analysis ◽  
Interglacial Period ◽  
Last Interglacial ◽  
Marine Terraces ◽  
Fossil Corals ◽  
Last Interglacial Period ◽  
Storm Deposit ◽  
Mis 5.5

AbstractAlthough uranium series (U-series) ages of growth-position fossil corals are important to Quaternary sea-level history, coral clast reworking from storms can yield ages on a terrace dating to more than one high-sea stand, confounding interpretations of sea-level history. On northern Barbados, U-series ages corals from a thick storm deposit are not always younger with successively higher stratigraphic positions, but all date to the last interglacial period (~127 ka to ~112 ka), Marine Isotope Substage (MIS) 5.5. The storm deposit ages are consistent with the ages of growth-position corals found at the base of the section and at landward localities on this terrace. Thus, in this case, analysis of only a few corals would not have led to an error in interpreting sea-level history. In contrast, a notch cut into older Pleistocene limestone below the MIS 5.5 terrace contains corals that date to both MIS 5.5 (~125 ka) and MIS 5.3 (~108 ka). We infer that the notch formed during MIS 5.3 and the MIS 5.5 corals are reworked. Similar multiple ages of corals on terraces have been reported elsewhere on Barbados. Thus, care must be taken in interpreting U-series ages of corals that are reported without consideration of taphonomy.

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