Geology Seminar Series - Dr Jessica E. Pilarczyk - Coastal sedimentary archives of tsunamis and storms

Wed., Feb. 16, 2022 4:00 p.m. - Wed., Feb. 16, 2022 5:00 p.m.

Location: https://uregina-ca.zoom.us/j/94220940658?pwd=TWltZ0hyTGdqSUlRQm9JczRzSDB5Zz09

Abstract: Coastal risk assessment and hazard mitigation require datasets on centennial and millennial timescales in order to capture the variability and multiple occurrences of the largest, but least frequent events. Coastal sediments from low-energy depositional environments archive geological evidence of storms and tsunamis, making it possible to assess patterns of intensity and recurrence over sufficiently long timescales. Many of the best reconstructions of these events are derived from stratigraphic, sedimentological, and paleoecological evidence (e.g., microfossils, mollusks). The use of microfossils as a proxy for marine inundation in coastal sequences is particularly effective because of their diverse ecological niches, which span the entire environmental gradient from marine to freshwater environments. The taphonomic (or surface) condition of individual microfossils (e.g., size and patterns of abrasion, corrosion, and fragmentation) can be used to further constrain the origin of sediment and, when applied to storm and tsunami deposits, can provide insight into depth of scour and size of an event. Using examples from Japan and Southeast Asia I will discuss the application of sedimentolgoical and paleoecological indicators to reconstruct long-term histories of storm and tsunami recurrence.