Interdisciplinary Seminar: Saulo Mendes

An interdisciplinary seminar presented by UNC-CH Department of Marine Sciences graduate student, Saulo Mendes.

Seminar Title: Potential connections among climate change, tropical cyclones and tsunamis

Abstract: Tsunamis present a constant danger to coastal areas in part for behaving as shallow water waves, making early detection difficult. Normally, the physical characteristics of the waves are not known until their arrival at the coast, prompting a necessary but not accurate warning system. Due to hydrodynamical processes and interaction with beach geometry, it is very common for early warnings to either underpredict or overpredict them. Therefore, it is paramount to acquire historic time series to provide a reliable risk assessment. In the absence of a historical record, the analysis of tsunami deposits becomes the most reliable procedure, that on average, show a clear signature of the tsunami track. However, complications arise from storm deposits over the same area. Particularly, tsunami deposits may or may not be similar to the storm deposition. This uncertainty undermines the understanding of the tsunami intensity. Although storms have a negative impact on the tsunami sedimentology, they can be very helpful after all: storms have been associated with triggering earthquakes, potentially inducing tsunami. This effect is a feature of particular regions with high seismic activity as well as storm activity. Fulfilling this geophysical setting, several earthquakes in Taiwan appear to be triggered by typhoons, caused by rainfall as well as a drop in atmospheric pressure. Hence, as climate change affects storms, there is a secondary connection between climate and natural hazard chain reactions. A complete understanding of tsunami deposits and tsunamigenic storms have the potential to enhance current climate change models.