Far-Field Tsunami Hazard Assessment Along the Pacific Coast of Mexico by Historical Records and Numerical Simulation. Part II: Tsunami-Induced Currents in the Port of Ensenada, Baja California

Abstract

The time evolution of the velocity field in and around the Port of Ensenada, induced by large distant tsunamis as produced by Mw 9.3 hypothetical earthquakes around the Pacific Ocean, is analyzed through the numerical modeling of distant tsunamis. The results indicate that tsunami-induced currents are 4–6 knots (~ 2 to 3 m/s) at the harbor entrance and 2–4 knots (~ 1 to 2 m/s) inside and outside the harbor. Low amplitude tsunamis, as well as the reverberance or coda of large distant tsunamis, may produce currents of 2 knots (~ 1 m/s) along the harbor channel induced by the interaction of coastal and harbor seiches. Visual scrutiny of the resulting velocity field at time steps of 1 min, as well as the mathematical concept of residual velocity, reveal transient eddies fed by flood and ebb currents that produce transversal currents by the harbor entrance. Currents induced by large distant tsunamis are practically negligible at depths greater than 120 m (15 km offshore from the harbor).