This award is an outcome of the NSF 09-524 program solicitation "George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) Research (NEESR)" competition and includes the Georgia Institute of Technology (lead institution), the University of Alaska, Fairbanks (subaward), and Texas A&M University, Galveston (subaward). This project will utilize the NEES tsunami wave basin at Oregon State University.
Tsunamis are commonly associated with submarine earthquakes, such as the 2004 Indian Ocean tsunami, which are limited in wave height by seafloor displacement. In contrast, landslide and volcanic eruption generated tsunamis are typically regionally confined but account for all known localized heights exceeding 100 meters. Some of the most catastrophic tsunamis are produced by volcanic eruptions and landslides. The two deadliest non-tectonic tsunamis in the past 300 years were due to gravitational or eruptive volcanic island collapses at Mount Unzen and Krakatoa. For some earthquakes, such as the 2006 South Java tsunami with 600 fatalities, it has been proposed that the large tsunamis were triggered by failure of the sea floor in the form of giant submarine landslides.
Intellectual Merit: This project's long-term goal is to transform assessment and mitigation of the landslide tsunami hazard through hybrid modeling of landslide tsunami evolution in real world scenarios, where the generation, propagation, and runup stages overlap. Rare field measurements are mostly limited to landslide scarp, deposit, tsunami runup, and eyewitness accounts, while critically important data related to the landslide motion and tsunami evolution is lacking. The goal of the research is to compensate for missing data by combined physical and numerical modeling of fully three-dimensional landslide tsunami scenarios. The proposed work builds upon the developed, NSF-supported (NEESR-SG award CMMI-0421090), deformable landslide tsunami generator, which enables full control of the dynamic landslide parameters. Towards this goal, the following significant objectives will be achieved in this project: (1) analysis of landslide tsunami generation and source runup scenarios - the characteristics of historical landslides and tsunamis will be used to generate linked laboratory and numerical models of landslide tsunamis; (2) experimental program at tsunami wave basin - a joint numerical modeling and experimental program will be designed based on well-constrained, real-world landslide generated tsunami and near-source runup scenarios. Particular focus is on the source with backward runup for conical island scenarios and the multiple runup in confined fjord-like bays; and (3) validation of landslide generated tsunami models - the measured landslide and tsunami characteristics will be compared to existing real world observations providing a validation for physical, analytical and numerical models used in this research. This research enhances knowledge, understanding and modeling of landslide generated tsunamis towards mitigation of the deadliest, non-tectonic tsunami hazard. Originality of the proposed work is based on its interdisciplinary nature combining experimental and numerical modeling with geology, volcanology, and geophysics.
Broader Impacts: Transitioning landslide tsunami modeling from experiments to natural scale applications has broad implications not only to engineering but also to saving lives. It will both transform assessment and mitigation of tsunami and landslide hazards. The deployed landslide tsunami generator will complement existing NEES tsunami facilities and provide payload opportunities. Instrumentation funds provided from this award will upgrade the particle imagery velocimetry (PIV) system at the NEES tsunami wave basin to full three-dimensional capabilities for the entire community. The results of this research will be incorporated into both undergraduate and graduate courses. The research results will be disseminated to a broad scientific and engineering audience through journal publications and via presentations at national and international meetings. K-12 students will be reached by popular lectures emphasizing the important role of engineering professions in mitigation of natural hazards. The project team will coordinate education and outreach activities with the NEES tsunami wave basin site. Collaboration with the West Coast/Alaska Tsunami Warning Center (WC/ATWC) will enable implementation of research results into tsunami warning practice and reach potential users. Data from this project will be archived and made available to the public through the NEES data repository.
