scholarly journals Last interglacial sea-level proxies in East Africa and the Western Indian Ocean

2021 ◽  
Vol 13 (4) ◽  
pp. 1633-1651
Author(s):  
Patrick Boyden ◽  
Jennifer Weil-Accardo ◽  
Pierre Deschamps ◽  
Davide Oppo ◽  
Alessio Rovere

Abstract. In this paper, we describe a sea-level database compiled using published last interglacial, Marine Isotopic Stage 5 (MIS 5), geological sea-level proxies within East Africa and the Western Indian Ocean (EAWIO). Encompassing vast tropical coastlines and coralline islands, this region has many occurrences of well-preserved last interglacial stratigraphies. Most notably, islands almost entirely composed of Pleistocene reefs (such as Aldabra, the Seychelles) have provided reliable paleo relative sea-level indicators and well-preserved samples for U-series chronology. Other sea-level proxies include uplifted marine terraces in the north of Somalia and Pleistocene eolian deposits notched by the MIS 5 sea level in Mozambique to tidal notches in luminescence-limited eolian deposits in Mozambique. Our database has been compiled using the World Atlas of Last Interglacial Shorelines (WALIS) interface and contains 58 sea-level indicators and 2 terrestrial-limiting data points. The open-access database is available at https://doi.org/10.5281/zenodo.4302244 (Version 1.03; Boyden et al., 2020).

2020 ◽  
Author(s):  
Patrick Boyden ◽  
Jennifer Weil-Accardo ◽  
Pierre Deschamps ◽  
Davide Oppo ◽  
Alessio Rovere

Abstract. In this paper, we describe a sea-level database compiled using published Last Interglacial, Marine Isotopic Stage 5 (MIS 5), geological sea-level proxies within Eastern Africa and the Western Indian Ocean (EAWIO). Encompassing vast tropical coastlines and coralline islands, this region has many occurrences of well preserved last interglacial stratigraphies. Most notably, islands almost entirely composed by Pleistocene reefs (such as Aldabra, the Seychelles) have provided reliable paleo relative sea-level indicators and well-preserved samples for U-series chronology. Other sea-level proxies include uplifted marine terraces in the north of Somalia and tidal notches in luminescence limited aeolian deposits in Mozambique. Our database has been compiled using the World Atlas of Last Interglacial Shorelines (WALIS) interface and contains 57 sea-level indicators and 2 terrestrial limiting data points. The database is available open access at https://doi.org/10.5281/zenodo.4043366 (Version 1.02) (Boyden et al., 2020).


2020 ◽  
Author(s):  
Deirdre D. Ryan ◽  
Alastair J. H. Clement ◽  
Nathan R. Jankowski ◽  
Paolo Stocchi

Abstract. This paper presents the current state-of-knowledge of the New Zealand (Aotearoa) last interglacial (MIS 5 sensu lato) sea-level record compiled within the framework of the World Atlas of Last Interglacial Shorelines (WALIS) database. Seventy-seven total relative sea-level (RSL) indicators (direct, marine-, and terrestrial-limiting points), commonly in association with marine terraces, were identified from over 120 studies reviewed. Extensive coastal deformation around New Zealand has resulted in a significant range of elevation measurements on both the North Island (276.8 to −94.2 msl) and South Island (173.1 to −70.0 msl) and prompted the use of RSL indicators to estimate rates of vertical land movement; however, indicators lack adequate description and age constraint. Identified RSL indicators are correlated with MIS 5, MIS 5e, MIS 5c, and MIS 5a and indicate the potential for the New Zealand sea-level record to inform sea-level fluctuation and climatic change within MIS 5 (sensu lato). The Northland (North Island) and Otago (South Island) regions, historically considered stable, have the potential to provide a regional sea-level curve in a remote location of the South Pacific across broad degrees of latitude. Future work requires modern analogue information, heights above a defined sea-level datum, better stratigraphic descriptions, and use of improved geochronological methods. The database presented in this study is available open-access at this link: http://doi.org/10.5281/zenodo.4056376 (Ryan et al., 2020a).


2021 ◽  
Vol 13 (7) ◽  
pp. 3467-3490
Author(s):  
Schmitty B. Thompson ◽  
Jessica R. Creveling

Abstract. In this review we compile and document the elevation, indicative meaning, and chronology of marine isotope substage 5a and 5c sea level indicators for 39 sites within three geographic regions: the North American Pacific coast, the North American Atlantic coast and the Caribbean, and the remaining globe. These relative sea level indicators, comprised of geomorphic indicators such as marine and coral reef terraces, eolianites, and sedimentary marine- and terrestrial-limiting facies, facilitate future investigation into marine isotope substage 5a and 5c interstadial paleo-sea level reconstruction, glacial isostatic adjustment, and Quaternary tectonic deformation. The open-access database, presented in the format of the World Atlas of Last Interglacial Shorelines (WALIS) database, can be found at https://doi.org/10.5281/zenodo.5021306 (Thompson and Creveling, 2021).


2021 ◽  
Vol 13 (7) ◽  
pp. 3399-3437
Author(s):  
Deirdre D. Ryan ◽  
Alastair J. H. Clement ◽  
Nathan R. Jankowski ◽  
Paolo Stocchi

Abstract. This paper presents the current state of knowledge of the Aotearoa New Zealand last interglacial (marine isotope stage 5, MIS 5, sensu lato) sea-level record compiled within the framework of the World Atlas of Last Interglacial Shorelines (WALIS) database. A total of 77 relative sea-level (RSL) indicators (direct, marine-limiting, and terrestrial-limiting points), commonly in association with marine terraces, were identified from over 120 studies reviewed. Extensive coastal deformation around New Zealand has prompted research focused on active tectonics, the scale of which overprints the sea-level record in most regions. The ranges of last interglacial palaeo-shoreline elevations are significant on both the North Island (276.8 ± 10.0 to −94.2 ± 10.6 ma.m.s.l., above mean sea level) and South Island (165.8 ± 2.0 to −70.0 ± 10.3 ma.m.s.l.) and have been used to estimate rates of vertical land movement; however, in many instances there is a lack of adequate description and age constraint for high-quality RSL indicators. Identified RSL indicators are correlated with MIS 5, MIS 5e, MIS 5c, and MIS 5a and indicate the potential for the New Zealand sea-level record to inform sea-level fluctuation and climatic change within MIS 5. The Northland Region of the North Island and southeastern South Island, historically considered stable, have the potential to provide a regional sea-level curve, minimally impacted by glacio- and hydro-isostatic adjustment (GIA) and reflecting near-eustatic fluctuations in a remote location of the South Pacific, across broad degrees of latitude; however, additional records from these regions are needed. Future work requires modern analogue information, heights above a defined sea-level datum, better stratigraphic descriptions, and use of improved geochronological methods. The database presented in this study is available open access at this link: https://doi.org/10.5281/zenodo.4590188 (Ryan et al., 2020a).


2021 ◽  
Author(s):  
Ciro Cerrone ◽  
Matteo Vacchi ◽  
Alessandro Fontana ◽  
Alessio Rovere

<p>An open access database containing raw data of Last Interglacial sea-level proxies for the Western Mediterranean has been compiled by reviewing hundreds of original published papers in accordance with the WALIS template (https://warmcoasts.eu/world-atlas.html). WALIS allows collecting both the relative sea-level (RSL) indicators and ages data in a standardized format. Ca. 360 sea-level index points for the coasts of Spain, France, Italy, Albania, Algeria and Morocco have been included in the database. The sea-level index points of the database are related to ca. 350 samples dated by a wide range of dating techniques, e.g., U-series, Amino Acid Racemization, Luminescence (Tl/OSL) and Electron Spin Resonance methods or chronostratigraphically correlated to marine deposits bearing P. latus and “Senegalese fauna”. In fact, for some areas of the Mediterranean Sea, the “Senegalese fauna” is indicative of the MIS 5e.</p><p>Among the eleven types of sea-level indicators of our database, the majority of them are represented by marine terraces, beach deposits (or beachrocks), and tidal notches. Whenever the relationship between the RSL indicators and the former sea-level could not be quantified, such indicators have been considered as marine or terrestrial limiting points. An indirect age of the tidal notches has been provided by correlation with the nearby dated deposit. In the case no precise elevation information has been reported by the Authors, the elevation error of RSL datapoints has been reassessed in the 20 % of the elevation value, more a 5% if the sea-level datum was lacking in the scientific papers we have reviewed.  Overall, the quality of each RSL datapoints and the associated age have been ranked in a 0 to 5 scale score according to Rovere et al., (2020).</p><p> </p><p><strong>References</strong></p><p>Rovere, A., Ryan, D., Murray-Wallace, C., Simms, A., Vacchi, M., Dutton, A., Gowan, E., 2020. Descriptions of database fields for the World Atlas of Last Interglacial Shorelines (WALIS) (Version 1,0). Zenodo. https://doi.org/http://doi.org/10.5281/zenodo.3961544</p>


2020 ◽  
Author(s):  
Patrick Boyden ◽  
Jennifer Weil Accardo ◽  
Pierre Deschamps ◽  
Alessio Rovere

<p>With global average temperatures 2°C higher than pre-industrial and eustatic sea-level ranging between 5 and 9 m above present, the Last Interglacial is often regarded as a good process-analogue for a future warmer climate.  Large uncertainties are associated with Last Interglacial eustatic sea-level estimations. To quantify these uncertainties through standardization of sea-level metadata, the World Atlas of Last Interglacial Shorelines (WALIS) provides a community-wide standard for documenting the geological context of sea-level indicators and their chronology. By applying this standard, WALIS allows for the quantitative cross-comparison between previous studies, often times separated by decades.</p><p> </p><p>We use WALIS to review published sea-level indicators for the Last Interglacial within the Western Indian Ocean basin. Located in the far field with respect to past glaciations, the Western Indian Ocean has the potential to provide precisely measured and dated sea level proxies, enabling a reliable estimation of maximum eustatic sea level for the Last Interglacial. This, in turn, would allow to better constrain upper boundaries of melting within ice-sheet models. Furthermore, this review highlights localities that should be revisited based on the presence of geological facies indicative of former highstands where not enough detail has been reported or where advanced dating and geodetic techniques can increase the accuracy of metadata.</p>


2021 ◽  
Author(s):  
Schmitty B. Thompson ◽  
Jessica R. Creveling

Abstract. In this review we compile and detail the elevation, indicative meaning, and chronology of Marine Isotope Stage 5a and 5c sea level indicators for 39 sites within three geographic regions: the Pacific coast of North America, the Atlantic coast of North America and the Caribbean, and the remaining globe. These relative sea level indicators, comprised of geomorphic indicators such as marine and coral reef terraces, eolianites, and sedimentary marine and terrestrial limiting facies, facilitate future investigation into Marine Isotope Stage 5a and 5c interstadial paleo-sea level reconstruction, glacial isostatic adjustment, and Quaternary tectonic deformation. The open access database, presented in the format of the World Atlas of Last Interglacial Shorelines (WALIS) database, can be found at https://doi.org/10.5281/zenodo.4426206 (Thompson and Creveling, 2021).


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