Energy flux as a tool in locating tsunami secondary sources

Kowalik Zygmunt
2008 Science of Tsunami Hazards   unpublished
The sea levels recorded in the wake of Indian Ocean Tsunami of December 2004 and of the Kuril Island Tsunami of November 2006 show strong tsunami signal enhancement of the late arriving secondary waves. Using these tsunami events we demonstrate that sudden changes caused by higher energy pulses in the intermittent tsunami wave trains can be assessed by energy fluxes. Therefore, to delineate the regions of tsunami wave amplification and travel time we propose to use energy flux. A series of
more » ... x. A series of numerical experiments defined in explicit way the bathymetric features which scatter tsunami signal towards ports, like Crescent City. Identification of the distant bathymetric features was achievable since the energy flux vector delineated the energy pathways that coupled distant bathymetric features to ports located thousands of kilometers apart. Calculations of the energy flux vector involves simple formulas based on two components of velocity and sea level. The maximum of the energy flux (which has no directional properties) can be evaluated from the sea level amplitude, hence both observed and computed sea level can be used for this purpose. The main task of this paper is to suggest that tsunami warning and prediction services should use numerical-hydrodynamical models with wider scope of physical processes by incorporating the energy balance equation into presently used tools.