DATE:

Friday, December 1, 2023

TIME:

3:30 PM

LOCATION:

GMCS 314

SPEAKER:

Ignacio Sepulveda, Civil, Construction and Environmental Engineering, San Diego State University

ABSTRACT:

Catastrophic tsunamis of the last 2 decades have been responsible of 10% of the total economic losses due to natural disasters. Equally concerning is the evidence that tsunami genesis and coastal responses are more complex than previously thought, putting tsunami modeling and risk prediction tools under scrutiny. New tsunami research is needed which shall integrate multiple disciplines. Two pressing research questions investigated by our group are the influence of compounding processes increasing tsunami hazard and the understanding of non-conventional geophysical processes cascading into tsunamis.

Tides and climate driven sea level rise (SLR) contribute significantly to water level changes in the short and long term, respectively. In terms of magnitude, they could be comparable to tsunamis of interest at certain regions such as the California coast. New non-stationary probabilistic tsunami hazard assessment (nPTHA) methods are developed to incorporate the mean sea level changes due to a warming climate and the uncertainty of the tidal phase at the moment of tsunami occurrence. A surrogate model is used in the nPTHA method to render the calculation feasible and efficient. As an illustration, these methods are applied for assessing the tsunami hazard in the South China Sea and the California coast.

Recent tsunamis have also evidenced the relevance of non-conventional tsunamigenic. The 2022 Tonga Volcano eruption, in particular, triggered a tsunami which was recorded globally. While the highest tsunami crest-to-trough heights, up to 3 meters, were only observed within the Pacific coastlines, heights up to 1 meter were also observed in remote locations, such as Portugal. These far-field tsunamis were generated by a Lamb pressure wave, generated by the explosive eruption and that travels within the atmosphere. We are investigating the signature of the 2022 Tonga and 1883 Krakatoa far-field volcanic tsunamis by means of new mathematical and numerical models developed in our lab. This research aims to improve volcanic tsunami hazard assessments around the world.

Bio: Ignacio Sepulveda is Tenure-Track Assistant Professor in Coastal Engineering at the Department of Civil, Construction and Environmental Engineering, San Diego State University. He earned a PhD Degree in Civil and Environmental Engineering at Cornell University. He was also a John Miles Fellow at Scripps Institution of Oceanography, UCSD. Professor Sepulveda’s expertise is Coastal Hazards. He has developed new methods for probabilistic tsunami hazard assessments and Uncertainty Quantification, combining top-notch stochastic and geophysical fluid mechanics models. His recent research addresses the development of new atmospheric-induced tsunami models, the study of new remote sensing techniques for coastal observation and the assessment of climate change impacts.

Ph.D. Institution: School of Civil and Environmental Engineering, Cornell University.

Postdoc position: John Miles Fellow at Scripps Institution of Oceanography, University of California San Diego.

Areas of Specialization: Coastal Engineering, Coastal Hazards, Coastal Remote Sensing, Probabilistic Hazard Assessments, Uncertainty Quantification, Geophysical Fluid Mechanics, Stochastic Processes.

HOST:

Pablo Machuca

VIDEO: