Numerical study of withdrawal and return of water following a volcanic eruption at sea

A speculation is presented to explain in physical terms the biblical story in which the withdrawal and return of the sea saved the Hebrews but drowned the army of Pharaoh. The explosion of the volcano on the island of Thira (Santorini) is speculated to be connected with this biblical story. To support our proposition concerning depression and flooding waves, we have made a numerical calculation with a highly accurate computer code and provided an outline of the PLIM method (piecewise linear interpolation method) used. This calculation is numerically very challenging because the volcano is located far from the shore and hence detailed discretization is not practical. In addition, we show that if a less accurate numerical method is used, the whole phenomenon is lost because of numerical errors. Our simple approach provides a withdrawal and return of the water to the shore that is sufficiently large, but the duration of this occurrence is only a few minutes. The opportunity for a much longer duration as a consequence of other phenomena has not been excluded, however.