Tsunami Generation by Combined Fault Rupture and Landsliding

Tsunami generation and propagation mechanisms should be clearly understood in order to inform predictive models and improve coastal community preparedness. Experimental results, supported by mathematical models, could potentially provide valuable input data for standard predictive models of tsunami generation and propagation. A unique set-up has been developed to reproduce a dual-source tsunami generation mechanism. The test-rig replicates a two-dimensional underwater fault rupture followed by a submarine landslide. The set-up was placed in a 20m flume of the COAST laboratory at Plymouth University. The aim of the experiments is to provide quality data for developing a parametrization of the initial conditions for tsunami generation processes which are triggered by a dual-source. The free surface elevation changes are investigated in relation to the fault rupture and landslide motions. During the test programme, the water depth and the landslide density were varied. The position of the landslide model was tracked and the free surface elevation of the water body was measured. Hence tsunami characteristics of wave height, wavelength and propagation speed were determined. This paper provides a detailed description of the test rig and presents some preliminary results which highlight the performance of the test rig in terms of repeatability

Parametric study of tsunamis generated by earthquakes and landslides

Tsunami generation and propagation mechanisms need to be clearly understood in order to inform predictive models and improve coastal community preparedness. Physical experiments, supported by mathematical models, can potentially provide valuable input data for standard predictive models of tsunami generation and propagation. A unique experimental set-up has been developed to reproduce a coupled-source tsunami generation mechanism: a two-dimensional underwater fault rupture followed by a submarine landslide. The test rig was located in a 20 m flume in the COAST laboratory at the University of Plymouth. The aim of the experiments is to provide quality data for developing a parametrisation of the initial conditions for tsunami generation processes which are triggered by a dual-source. During the test programme, the water depth and the landslide density were varied. The position of the landslide model was tracked and the free surface elevation of the water body was measured. Hence the generated wave characteristics were determined. For a coupled-source scenario, the generated wave is crest led, followed by a trough of smaller amplitude decreasing steadily as it propagates along the flume. The crest amplitude was shown to be influenced by the fault rupture displacement scale, whereas the trough was influenced by the landslide’s relative density