SeanPaul La Selle
Science and Products
Science Seminar Series
Welcome to the Pacific Coastal Marine Science Center Seminar Series! Upcoming public seminars will be broadcast virtually via Microsoft Teams.
Science Seminar Series Archives
Our past science seminars at the Pacific Coastal and Marine Science Center in Santa Cruz, California.
Tsunami Hazards, Modeling, and the Sedimentary Record
Basic research to develop the geologic record of paleotsunamis and improve the ability to interpret that record is needed to mitigate tsunami risk in the U.S.
Selective sediment transport during Hurricane Sandy on Fire Island (New York, USA): Inferences from heavy-mineral assemblages
In October 2012, Hurricane Sandy caused severe erosion on beaches and dunes of Fire Island (New York, USA). Major shoreline changes occurred with erosional dominance in the upper shoreline and aggradation in the lowermost section of the beach due to the deposition of eroded upper beach and dune sediment. Sand laminations with a high concentration...
Cascalho, João; Costa, Pedro; Gelfenbaum, Guy R.; La Selle, Seanpaul; Jaffe, Bruce E. Sedimentary evidence of prehistoric distant-source tsunamis in the Hawaiian Islands
Over the past 200 years of written records, the Hawaiian Islands have experienced tens of tsunamis generated by earthquakes in the subduction zones of the Pacific "Ring of Fire" (e.g., Alaska-Aleutian, Kuril-Kamchatka, Chile, and Japan). Mapping and dating anomalous beds of sand and silt deposited by tsunamis in low-lying areas along Pacific...
La Selle, Seanpaul; Richmond, Bruce M.; Jaffe, Bruce E.; Nelson, Alan; Griswold, Frances; Arcos, Maria E.M.; Chague, Catherine; Bishop, James M.; Bellanova, Piero; Kane, Haunani H.; Lunghino, Brent D.; Gelfenbaum, Guy R. Organic geochemical investigation of far‐field tsunami deposits of the Kahana Valley, O'ahu, Hawai'i
Far‐field tsunami deposits observed in the Kahana Valley, O'ahu, Hawai'i (USA), were investigated for their organic‐geochemical content. During short high‐energy events, (tsunamis and storms) organic and chemical components are transported with sediment from marine to terrestrial areas. This study investigates the use of anthropogenic based...
Bellanova, Piero; Frenken, Mike; Richmond, Bruce M.; Schwarzbauer, Jan; La Selle, Seanpaul; Griswold, Frances; Jaffe, Bruce E.; Nelson, Alan R.; Reicherter, Klaus The roles of flow acceleration and deceleration in sediment suspension in the surf zone
Prediction of sediment suspension in the surf zone remains elusive. We explore how suspended sediment concentration at 19 cm above the bed in the mid-surf zone during a storm is influenced by flow acceleration and deceleration. There is a tendency for higher suspended sediment concentrations during onshore flow, with decelerating onshore flows...
Jaffe, Bruce E.; La Selle, Seanpaul Evidence for frequent, large tsunamis spanning locked and creeping parts of the Aleutian megathrust
At the eastern end of the 1957 Andreanof Islands magnitude-8.6 earthquake rupture, Driftwood Bay (Umnak Island) and Stardust Bay (Sedanka Island) lie along presently locked and creeping parts of the Aleutian megathrust, respectively, based on satellite geodesy onshore. Both bays, located 200-km apart, face the Aleutian trench and harbor coastal...
Witter, Robert C.; Briggs, Richard W.; Engelhart, Simon E.; Gelfenbaum, Guy R.; Koehler, Richard D; Nelson, Alan R.; La Selle, Seanpaul; Corbett, Reide; Wallace, Kristi L. The application of microtextural and heavy mineral analysis to discriminate between storm and tsunami deposits
Recent work has applied microtextural and heavy mineral analyses to sandy storm and tsunami deposits from Portugal, Scotland, Indonesia and the USA. We looked at the interpretation of microtextural imagery (scanning electron microscopy) of quartz grains and heavy mineral compositions. We consider inundation events of different chronologies and...
Costa, Pedro J.M.; Gelfenbaum, Guy R.; Dawson, Sue; La Selle, Seanpaul; Milne, F; Cascalho, J.; Ponte Lira, C.; Andrade, C.; Freitas, M. C.; Jaffe, Bruce E.
New evidence for a roughly 600-year-old tsunami impacting the Hawaiian Islands
In a comprehensive survey of Hawaiian tsunami deposits, USGS scientists from the USGS Pacific Coastal and Marine Science Center and collaborators found evidence for a widespread tsunami striking the islands between 1250 and 1450 CE.