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WITHDRAWN The Role of Climate-Change Sea Level Rise Exacerbating California's Tsunami Hazards

Description: 

WITHDRAWN A new era of engineering is arising in which coastal risk assessments are carried out in a more holistic manner. One key improvement is the incorporation of compounding processes. New tsunami hazard evaluations, for example, shall integrate the influence of tides and climate-driven sea level changes. In terms of magnitude, they could be comparable to tsunamis of interest at certain regions, such as those threatening the Southern 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. Results show that sea level rise shifts hazard curves towards greater values, while tides cause a diffusion making the tails of hazard distributions heavier.

As an illustration, the developed nPTHA is employed for assessing tsunami hazards in San Francisco, Long Beach and San Diego due to earthquakes in the Alaska-Aleutian and Cascadia subduction zones. The nPTHA is carried out by generating synthetic random earthquakes, by simulating tsunami scenarios in the framework of a stochastic reduced order model (SROM) and by employing a surrogate model that simulates the effects of tides and sea level rise. When analyzing the Maximum Considered Tsunami (MCT) results, defined as the sea level exceeded with a probability of 2% in 50 years in building codes, we observe significant exacerbation of the hazard at the assessed regions. MCT maps in Long Beach Port, for example, exhibit an increase beyond 60% when considering the NOAA's moderate-high sea level rise projection. These results suggest that critical coastal infrastructure, projected to serve several decades in the California coast, shall incorporate a nPTHA in the design process.

Session: Six Decades of Tsunami Science: From the Source of the 1964 Tsunami to Modern Community Preparedness [Poster Session]

Type: Poster

Date: 5/2/2024

Presentation Time: 08:00 AM (local time)

Presenting Author: Ignacio

Student Presenter: No

Invited Presentation: 

Authors