EGU22-9107, updated on 10 Jan 2023
https://doi.org/10.5194/egusphere-egu22-9107
EGU General Assembly 2022
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

From rapid growth to intense area loss within one century: The moving past and present of an inhabited reef island in Indonesia

Yannis Kappelmann1,2, Hildegard Westphal2,3, Dominik Kneer1, and Thomas Mann4
Yannis Kappelmann et al.
  • 1Leibniz Centre for Tropical Marine Research (ZMT), Department of Biogeochemistry & Geology, Bremen, Germany (yannis.kappelmann@leibniz-zmt.de)
  • 2University of Bremen, Bremen, Germany
  • 3King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
  • 4Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Hannover, Germany

Reef islands in monsoonal regions undergo constant erosion and accumulation, making seasonally shifting morphologies part of their nature. Additionally, sea-level rise alongside climate change is thought to be incisive and challenge coastal communities. With multiple pressures acting on sediment-generating coral reef ecosystems, changes in sediment supply may force further response of these dynamic landforms. Here we present new sedimentological data from a larger reef island in the Spermonde Archipelago, Indonesia. By evaluating the subsurface data in the context of the island’s morphological behavior, we reconstruct its agile past and present. Based on remote sensing data complemented by reports of local citizens, we find the inhabited island to have tripled its surface area in the past century, however also losing more than 10% of surface area in the recent decades. The deeper sediments of the island are dominated by coral fragments, the youngest and uppermost sediments indicate the green algae Halimeda as dominating material contributor. Our study thereby (1) underlines the highly and far-reaching dynamics of reef islands and (2) suggests their adaptive potential to altering material budgets.

How to cite: Kappelmann, Y., Westphal, H., Kneer, D., and Mann, T.: From rapid growth to intense area loss within one century: The moving past and present of an inhabited reef island in Indonesia, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9107, https://doi.org/10.5194/egusphere-egu22-9107, 2022.