STUDYING HIGH-ENERGY AND RAPID LARGE-SCALE GEODYNAMIC PROCESSES WITH THE HYDROCODES iSALE AND SOVA

The hydrocodes iSALE and SOVA have been developed to simulate the formation of impact craters, including the propagation of shock/rarefaction waves, the expansion/collapse of an ejecta plume (a mixture of fragments and vaporized material interacting with an atmosphere), and the generation of tsunami waves after oceanic impacts. They are well validated against other codes and laboratory experiments and have been used to study a large number of terrestrial and extraterrestrial impact craters.

These codes, dealing with compressible flows in a wide range of densities and temperatures, require sophisticated models of mechanical and thermodynamic response of the involved materials (rocks, ice, water, atmosphere). In many cases (extremely high pressure, strain or strain rate), material properties are only vaguely known and cannot be extracted from laboratory measurements or from the theory. Hence, the same impact scenario has to be repeated many times to reproduce observational data (crater shape, melt distribution, ejecta deposits). To enable parametric studies the simulation of a single scenario needs to be computable in a reasonable timeframe. Another problem of any model is the level of simplification – how detailed should be a description of a natural system which, on the one hand, allows to reproduce (or to predict) the consequences of natural events with high reliability, and on the other hand, does not demand years of modeling.

In this study we review whether the impact codes (after minor modification) are applicable to simulate other geohazards: landslides and avalanches, explosive volcanic eruptions and propagation of volcanic density currents, tsunamis and earthquakes.