Boyden et al., “Last Interglacial sea-level proxies in East Africa and the Western Indian Ocean”

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).

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Review of Borden et al "Last Interglacial sea-level proxies in East Africa and the Western Indian Ocean"

10.5194/essd-2020-349-rc2 ◽

2021 ◽

Author(s):

Anonymous

Keyword(s):

Indian Ocean ◽

East Africa ◽

Sea Level ◽

Western Indian Ocean ◽

Last Interglacial

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Last Interglacial changes in sea level on Aldabra, western Indian Ocean

Sedimentology ◽

10.1111/sed.12738 ◽

2020 ◽

Vol 67 (6) ◽

pp. 3236-3258

Author(s):

Colin J. R. Braithwaite

Keyword(s):

Indian Ocean ◽

Sea Level ◽

Western Indian Ocean ◽

Last Interglacial

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Last Interglacial Sea-Level Indicators in the Western Indian Ocean

10.5194/egusphere-egu2020-18309 ◽

2020 ◽

Author(s):

Patrick Boyden ◽

Jennifer Weil Accardo ◽

Pierre Deschamps ◽

Alessio Rovere

Keyword(s):

Indian Ocean ◽

Sea Level ◽

Ice Sheet ◽

Western Indian Ocean ◽

Ocean Basin ◽

Far Field ◽

Last Interglacial ◽

Global Average ◽

The World ◽

Geological Facies

With global average temperatures 2&#176;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.&#160; 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.&#160;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.

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Last Interglacial sea-level proxies in East Africa and the Western Indian Ocean

10.5194/essd-2020-349 ◽

2020 ◽

Author(s):

Patrick Boyden ◽

Jennifer Weil-Accardo ◽

Pierre Deschamps ◽

Davide Oppo ◽

Alessio Rovere

Keyword(s):

Indian Ocean ◽

Sea Level ◽

Western Indian Ocean ◽

Eastern Africa ◽

Last Interglacial ◽

Marine Isotopic Stage ◽

The North ◽

Aeolian Deposits ◽

Marine Terraces ◽

Data Points

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).

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Morphology and distribution of the acorn barnacle Tetraclita reni nom. nov. (Crustacea: Cirripedia) in Madagascar and adjacent waters

Zootaxa ◽

10.11646/zootaxa.2019.1.4 ◽

2009 ◽

Vol 2019 (1) ◽

pp. 57-68 ◽

Cited By ~ 8

Author(s):

BENNY KWOK KAN CHAN ◽

CHIH-HSIUNG HSU ◽

PEI-CHEN TSAI

Keyword(s):

South Africa ◽

Indian Ocean ◽

Light Microscopy ◽

East Africa ◽

Western Indian Ocean ◽

Type Locality ◽

Museum Specimens ◽

The South ◽

Acorn Barnacle ◽

Distribution Record

In Madagascan waters, both Tetraclita rufotincta Pilsbry 1916 and T. africana Ren 1989 have been reported. Tetraclita rufotincta is more widely distributed than T. africana, extending to the western Indian Ocean and east Africa. Tetraclita africana is reported from Madagascar and no further distribution record has been made apart from its type locality. Both species have pink parietes and are similar in size, which could lead to identification confusion. In this study, we revealed that T. africana differed from T. rufotincta in having multicuspidate setae on cirrus III, a feature that can be observed with both light microscopy and SEM. Additionally, the tergum of T. africana has a rounded spur and a larger basi-scutal angle than that of T. rufotincta. However, since the name Tetraclita africana has been pre-occupied under the name Tesseropora (Tetraclita) wireni africana Nilsson-Cantell, 1932, we, therefore, propose herein a replacement name, Tetraclita reni nom. nov. Based on museum specimens examined, Tetraclita reni nom. nov. is present in northeastern and southern Madagascar and Mauritius but absent from Yemen, Kenya, South Africa, Aldabra and northwestern Madagascar, suggesting the distribution of T. reni nom. nov. could be confined to the south and northeast of Madagascar and adjacent waters.

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A 17-My-old whale constrains onset of uplift and climate change in east Africa

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1421502112 ◽

2015 ◽

Vol 112 (13) ◽

pp. 3910-3915 ◽

Cited By ~ 34

Author(s):

Henry Wichura ◽

Louis L. Jacobs ◽

Andrew Lin ◽

Michael J. Polcyn ◽

Fredrick K. Manthi ◽

...

Keyword(s):

Indian Ocean ◽

East Africa ◽

Sea Level ◽

Drainage System ◽

Beaked Whale ◽

East African ◽

Surface Uplift ◽

The Indian Ocean ◽

Mantle Processes ◽

The Impact

Timing and magnitude of surface uplift are key to understanding the impact of crustal deformation and topographic growth on atmospheric circulation, environmental conditions, and surface processes. Uplift of the East African Plateau is linked to mantle processes, but paleoaltimetry data are too scarce to constrain plateau evolution and subsequent vertical motions associated with rifting. Here, we assess the paleotopographic implications of a beaked whale fossil (Ziphiidae) from the Turkana region of Kenya found 740 km inland from the present-day coastline of the Indian Ocean at an elevation of 620 m. The specimen is ∼17 My old and represents the oldest derived beaked whale known, consistent with molecular estimates of the emergence of modern strap-toothed whales (Mesoplodon). The whale traveled from the Indian Ocean inland along an eastward-directed drainage system controlled by the Cretaceous Anza Graben and was stranded slightly above sea level. Surface uplift from near sea level coincides with paleoclimatic change from a humid environment to highly variable and much drier conditions, which altered biotic communities and drove evolution in east Africa, including that of primates.

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Timing of the Last-Interglacial High Sea Level on the Seychelles Islands, Indian Ocean

Quaternary Research ◽

10.1006/qres.1998.2030 ◽

1999 ◽

Vol 51 (3) ◽

pp. 306-316 ◽

Cited By ~ 36

Author(s):

Carsten Israelson ◽

Barbara Wohlfarth

Keyword(s):

Indian Ocean ◽

Sea Level ◽

Coralline Algae ◽

Rock Surface ◽

Last Interglacial ◽

Mean Sea Level ◽

Field Evidence ◽

Seychelles Islands

AbstractCorals from the Seychelles Islands, Indian Ocean, occur mainly as small coralline algae–vermetid remnants found in cavities adhering to the rock surface, and they rarely attain more than 2 m2 in area. Samples of Goniastrea and Porites from elevations between 1.7 and 6 m above present mean sea level were dated by TIMS 238U–234U–230Th techniques. The ages from well-preserved corals lie between 131,000 and 122,000 yr B.P., in agreement with most other observations of the last-interglacial sea level. Field evidence and dating from high marine limestones from two sections at La Digue Island indicate a period of coral buildup until 131,000 yr B.P., followed by a drop in sea level between 131,000 and 122,000 yr B.P.

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