Tropical beach ridge stratigraphy as a proxy for reconstructing late-Holocene regional sea-level histories in southeast Asia.

Sea-level histories spanning the Common Era are crucial for linking sea-level change to climate change, yet they have not been widely studied in Southeast Asia. This link is proxy dependant, and most proxies only provide decadal to centennial scale resolution of both sea level and climate. Here, we examine topographically corrected Ground Penetrating Radar (GPR) profiles along with Optically Stimulated Luminescence (OSL) ages for geochronology.  The efficiency of using this method to examine beach ridge stratigraphy as a proxy for reconstructing regional sea-level histories in the tropics has recently been demonstrated by Kumar et al., (2024).  This approach can be a highly efficient and effective means for reconstructing regional sea-level trends in beach ridges settings. Here, we present common er sea level histories from beach ridges in Indonesia and Thailand that were reconstructed by identifying downlap points that mark the boundary between the foreshore and shoreface and use this as a past low-tide marker. The datasets allow us to compare and contrast the Common Era sea level history of the two coasts and link the evolution to late Holocene sea level and climate variability.

Kumar, R., Switzer, A.D., Gouramanis, C., Bristow, C.S., Shaw, T.A., Jankaew, K., Li, T. and Brill, D., 2024. Late-Holocene sea-level markers preserved in a beach ridge system on Phra Thong Island, Thailand. Geomorphology, 465, p.109405.