Master Project 2: Geological history of reef islands in the Spermonde Archipelago, South Sulawesi, Indonesia The aim of this project is to elucidate the geological history of low-lying reef island / coral cays on reef flats of the Spermonde Archipelago, Indonesia. The Archipelago is a barrier reef and lagoon complex on a submerged shelf along the west coast of South Sulawesi. The whole shelf was dry during the last glacial maximum, and it is assumed that hills (“paleotopographic heights”, possibly fossil reefs, grown during previous inundations) on the shelf platform became the bases for today’s reef complexes. Most of the islands in the archipelago are sand cays (also referred to as reef islands in the literature), composed of accumulations of biogenic sediments from the surrounding reef platforms. Low-lying reef islands are perceived as particularly vulnerable to sea level rise, and their stability is a major concern wherever those islands provide the only habitable land. In spite of that, little directed research has been conducted on the morphological adjustment of reef islands in response to changing boundary conditions until recently. A rising sea level will likely exert a pressure on coral reefs to grow upwards, and more material might be retained in the reef framework instead of being available as loose sediment to contribute to island growth. Seagrass meadows are an important component of the reef flat habitat since they interfere with the transport of sediment. They also fulfill an important function as sinks for carbon. Practical work: In order to predict the future of the low-lying reef islands it is necessary to understand their history. On representative islands along a cross shelf transect, sediment cores will be taken with a push drill rig. Samples will be analyzed for their composition (coral, mollusk shell, foraminiferan etc.) to identify the patterns of sediment supply to the islands. Selected components may be aged using C14. We aim to understand the accumulation history of the islands. An analysis of the Foraminiferan and mollusc community can indicate past seagrass cover. In addition, the organic component of sediments will be quantified to determine whether the seagrass systems on the studied reef flats are long-term carbon sinks. Basic facilities are available in Indonesia but more complex analysis (stable isotopes etc.) will have to be carried out in Germany. We offer professional supervision during field work in Indonesia (ca. 6 months) and excellent research facilities and professional supervision upon return to Germany at the Wadden Sea Station of the Alfred Wegener Institute for Polar and Marine Research (AWI). Expenses for travelling and material will be covered. Upon the delivery of a dedicated work, authorship on a publication in a journal will be aspired. We are looking for a highly motivated student with an interest in carbonate sedimentology. The applicant should have experience in geological work and be able to work independently. Proficiency in written and spoken English is essential. We invite you to apply for this project and take the opportunity to set a foot in the exciting fields of tropical marine ecology and geology. Application deadline: June 30, 2014 or as soon as a suitable candidate has been found. To apply, please send a motivation letter and CV to the contact address below. Contact: Dr. Dominik Kneer, Alfred-Wegener-Institute for Polar and Marine Research; [email protected], +49 4651 956-4220
