Past wave climate reconstruction through paleo shoreline analysis and implications under future climate scenarios

Strandplain formations along the world’s coastlines provide a unique record of paleo sea level and wave climate. Here, sequentially formed beach deposits preserve the direction of dominant wave energy flux over decadal to centennial scales. This is especially true in sheltered embayments that minimize factors such as longshore transport, extreme waves, and eolian reworking. Beach profile and planform reflect the prevailing local wave conditions and numerical models provide the link between nearshore waves and their deep-water genesis, allowing the description of regional wave climate and its interpretation in the context of global atmospheric patterns. Still, opportunities exist to extend the range of past wave climate studies in order to disentangle the signal of climatic forcing from that of other processes such as changes in sediment budget, Glacial Isostatic Adjustment, and tombolo evolution. We focus on the understudied South Atlantic Ocean due its unique wave climate and atmospheric circulation patterns with relevance to global teleconnections. Specifically, sites along the Brazilian coast evidence past changes in sediment supply and shifts in estuarine inlets or fluvial deltas. Meanwhile, sites along the coast of Argentina reflect onshore reworking of sediments and tombolo evolution. Both scenarios lend themselves to the study of climatic versus non-climatic forcing and we seek to determine if past wave climate reconstruction is possible from paleo shorelines along South Atlantic coasts.

This presentation is a contribution to the WARMCOASTS project, which has received funding from the European Research Council under the European Union's Horizon 2020 research and innovation programme (grant agreement n. 802414)