scholarly journals Holocene and Common Era sea level changes in the Makassar Strait, Indonesia

2019 ◽  
Author(s):  
Maren Bender ◽  
Thomas Mann ◽  
Paolo Stocchi ◽  
Dominik Kneer ◽  
Tilo Schöne ◽  
...  
Keyword(s):  
Sea Level ◽  
Published Data ◽  
Glacial Isostatic Adjustment ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Isostatic Adjustment ◽  
Thousand Islands ◽  
The Common ◽  
Common Era ◽  
Spermonde Archipelago

Abstract. Indonesia is a country composed of several thousand islands, many of them small, low-lying and densely inhabited. These are, in particular, subject to high risk of inundation due to future relative sea level changes. The Spermonde Archipelago, off the coast of Southwest Sulawesi, consists of more than 100 small islands. This study presents a dataset of 24 sea-level index points from fossil microatolls, surveyed on five islands in the Spermonde Archipelago and compares these new results with published data from the same region and with relative sea level predictions from different Glacial Isostatic Adjustment (GIA) models. The newly surveyed fossil microatolls are located around the islands of Tambakulu, Suranti (both ~ 60 km offshore of Makassar city), Bone Batang and Kodingareng Keke (both located in the center of the Archipelago) and Sanrobengi (located ~ 20 km south-southwest of Makassar). Results from the near- and mid-shelf islands indicate that relative sea level between 4 to 6 ka BP was less than one meter above present sea level. The only exception to this pattern is the heavily populated island of Barrang Lompo, where we record a significant subsidence when compared to the other islands. These new results support the conclusions from a previous dataset and are relevant to constrain late Holocene ice melting scenarios. Samples from the two outer islands (Tambakulu and Suranti) yielded ages spanning the Common Era that represent, to our knowledge, the first reported for the entire Southeast Asian region.

scholarly journals Late Holocene (0–6 ka) sea-level changes in the Makassar Strait, Indonesia

2020 ◽  
Vol 16 (4) ◽  
pp. 1187-1205 ◽  
Author(s):  
Maren Bender ◽  
Thomas Mann ◽  
Paolo Stocchi ◽  
Dominik Kneer ◽  
Tilo Schöne ◽  
...  
Keyword(s):  
Sea Level ◽  
Late Holocene ◽  
Glacial Isostatic Adjustment ◽  
Mantle Structure ◽  
Ice Melting ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
The Past ◽  
Isostatic Adjustment ◽  
Spermonde Archipelago

Abstract. The Spermonde Archipelago, off the coast of southwest Sulawesi, consists of more than 100 small islands and hundreds of shallow-water reef areas. Most of the islands are bordered by coral reefs that grew in the past in response to paleo relative sea-level changes. Remnants of these reefs are preserved today in the form of fossil microatolls. In this study, we report the elevation, age, and paleo relative sea-level estimates derived from fossil microatolls surveyed in five islands of the Spermonde Archipelago. We describe 24 new sea-level index points, and we compare our dataset with both previously published proxies and with relative sea-level predictions from a set of 54 glacial isostatic adjustment (GIA) models, using different assumptions on both ice melting histories and mantle structure and viscosity. We use our new data and models to discuss Late Holocene (0–6 ka) relative sea-level changes in our study area and their implications in terms of modern relative sea-level estimates in the broader South and Southeast Asia region.

Late Holocene sea-level changes and isostasy in western Denmark

2006 ◽  
Vol 66 (2) ◽  
pp. 288-302 ◽  
Author(s):  
W. Roland Gehrels ◽  
Katie Szkornik ◽  
Jesper Bartholdy ◽  
Jason R. Kirby ◽  
Sarah L. Bradley ◽  
...  
Keyword(s):  
Salt Marsh ◽  
Sea Level ◽  
Salt Marshes ◽  
Late Holocene ◽  
Glacial Isostatic Adjustment ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Isostatic Adjustment ◽  
Tidal Embayment ◽  
Made In

AbstractCores and exposed cliff sections in salt marshes around Ho Bugt, a tidal embayment in the northernmost part of the Danish Wadden Sea, were subjected to 14C dating and litho- and biostratigraphical analyses to reconstruct paleoenvironmental changes and to establish a late Holocene relative sea-level history. Four stages in the late Holocene development of Ho Bugt can be identified: (1) groundwater-table rise and growth of basal peat (from at least 2300 BC to AD 0); (2) salt-marsh formation (0 to AD 250); (3) a freshening phase (AD 250 to AD 1600?), culminating in the drying out of the marshes and producing a distinct black horizon followed by an aeolian phase with sand deposition; and (4) renewed salt-marsh deposition (AD 1600? to present). From 16 calibrated AMS radiocarbon ages on fossil plant fragments and 4 calibrated conventional radiocarbon ages on peat, we reconstructed a local relative sea-level history that shows a steady sea-level rise of 4 m since 4000 cal yr BP. Contrary to suggestions made in the literature, the relative sea-level record of Ho Bugt does not contain a late Holocene highstand. Relative sea-level changes at Ho Bugt are controlled by glacio-isostatic subsidence and can be duplicated by a glacial isostatic adjustment model in which no water is added to the world's oceans after ca. 5000 cal yr BP.

scholarly journals Comparing a thermo-mechanical Weichselian ice sheet reconstruction to GIA driven reconstructions: aspects of earth response and ice configuration

2013 ◽  
Vol 5 (2) ◽  
pp. 2345-2388 ◽  
Author(s):  
P. Schmidt ◽  
B. Lund ◽  
J-O. Näslund
Keyword(s):  
Sea Level ◽  
Ice Sheet ◽  
Younger Dryas ◽  
Slow Phase ◽  
Glacial Isostatic Adjustment ◽  
Relative Sea Level ◽  
Isostatic Adjustment ◽  
Earth Models ◽  
Uplift Rates ◽  
Best Fit

Abstract. In this study we compare a recent reconstruction of the Weichselian ice-sheet as simulated by the University of Main ice-sheet model (UMISM) to two reconstructions commonly used in glacial isostatic adjustment (GIA) modeling: ICE-5G and ANU (also known as RSES). The UMISM reconstruction is carried out on a regional scale based on thermo-mechanical modelling whereas ANU and ICE-5G are global models based on the sea-level equation. The Weichselian ice-sheet in the three models are compared directly in terms of ice volume, extent and thickness, as well as in terms of predicted glacial isostatic adjustment in Fennoscandia. The three reconstructions display significant differences. UMISM and ANU includes phases of pronounced advance and retreat prior to the last glacial maximum (LGM), whereas the thickness and areal extent of the ICE-5G ice-sheet is more or less constant up until LGM. The final retreat of the ice-sheet initiates at earliest time in ICE-5G and latest in UMISM, while ice free conditions are reached earliest in UMISM and latest in ICE-5G. The post-LGM deglaciation style also differs notably between the ice models. While the UMISM simulation includes two temporary halts in the deglaciation, the later during the Younger Dryas, ANU only includes a decreased deglaciation rate during Younger Dryas and ICE-5G retreats at a relatively constant pace after an initial slow phase. Moreover, ANU and ICE-5G melt relatively uniformly over the entire ice-sheet in contrast to UMISM which melts preferentially from the edges. We find that all three reconstructions fit the present day uplift rates over Fennoscandia and the observed relative sea-level curve along the Ångerman river equally well, albeit with different optimal earth model parameters. Given identical earth models, ICE-5G predicts the fastest present day uplift rates and ANU the slowest, ANU also prefers the thinnest lithosphere. Moreover, only for ANU can a unique best fit model be determined. For UMISM and ICE-5G there is a range of earth models that can reproduce the present day uplift rates equally well. This is understood from the higher present day uplift rates predicted by ICE-5G and UMISM, which results in a bifurcation in the best fit mantle viscosity. Comparison of the uplift histories predicted by the ice-sheets indicate that inclusion of relative sea-level data in the data fit can reduce the observed ambiguity. We study the areal distributions of present day residual surface velocities in Fennoscandia and show that all three reconstructions generally over-predict velocities in southwestern Fennoscandia and that there are large differences in the fit to the observational data in Finland and northernmost Sweden and Norway. These difference may provide input to further enhancements of the ice-sheet reconstructions.

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