Utku Kanoglu

Runup of solitary waves on a circular island

This is a study of the interactions of solitary waves climbing up a circular island. A series of large-scale laboratory experiments with waves of different incident height-to-depth ratios and different crest lengths is described. Detailed two-dimensional run-up height measurements and time histories of surface elevations around the island are presented. A numerical model based on the two-dimensional shallow-water wave equations including runup calculations was developed. Numerical model predictions agreed very well with the laboratory data and the model was used to study wave trapping and the effect of slope. Under certain conditions, enhanced runup and wave trapping on the lee side of the island were observed, suggesting a possible explanation for the devastation reported by field surveys in Babi Island off Flores, Indonesia, and in Okushiri Island, Japan.

Nonlinear evolution and runup–rundown of long waves over a sloping beach

The initial value problem of the nonlinear evolution, shoreline motion and flow velocities of long waves climbing sloping beaches is solved analytically for different initial waveforms. A major difficulty in earlier work utilizing hodograph-type transformation when solving either boundary value or initial value problems has been the specification of equivalent boundary or initial condition in the transformed space. Here, in solving the initial value problem, the transformation is linearized in space at

Producing Tsunami Inundation Maps: The California Experience

t{=}0

LONG WAVE RUNUP ON COASTAL STRUCTURES

, then the full nonlinear transformation is used to solve the initial value problem of the nonlinear shallow-water wave equations. A solution method is presented to describe the most physically realistic initial waveforms and simplified equations for the runup–rundown motions and shoreline velocities. This linearization of the initial condition does not appear to affect the subsequent nonlinear evolution, as shown through comparisons with earlier studies. Comparisons with runup results from solutions of the boundary value problem suggest the same variation with the runup laws. The methodology presented here appears simpler than earlier work as it does not involve the numerical calculation of singular elliptic integrals.

Vanuatu earthquake and tsunami cause much damage, few casualties

More than 20 tsunami events have impacted the State of California in the past two centuries. While some earlier 19th century reports are subject to interpretation, there is little question that offshore seismic sources exist, and could trigger tsunamis directly or through coseismic submarine offshore landslides or slumps. Given the intense coastal land use, and recreational activities along the coast of California, even a small hazard may pose high risk. California presents nontrivial challenges for assessing tsunami hazards, including a short historic record and the possibility of nearshore events with less than 20min propagation times to the target coastlines. Here we present a brief history of earlier reports to assess tsunami hazards in the State, and our methodology for developing the first generation inundation maps. Our results are based on worst case scenario events, and suggest inundation heights up to 13m. These maps are only to be used for emergency preparedness, and evacuation planning.

Field surveys and modeling of the 1999 Izmit tsunami

A study of alternatives including a shoreline evolution numerical modelization has been carried out in order to both diagnose the erosion problem at the beaches located between Cambrils Harbour and Pixerota delta (Tarragona, Spain) and select nourishment alternatives.