June 17-18 2004
Wrigley Marine Science Center
Catalina Island, California

Background / Benchmark Problems / Contact Information (organizing committee)
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The first workshop was held in the Wrigley Marine Science Center of the University of Southern California at Catalina Island, CA, on August 15-17, 1990. In this workshop state-of-the-art reviews on long-wave runup were presented. Tsunami run-up and flooding and tsunami run-up hazard mitigation were the main topics discussed in the workshop. The workshop brought together researchers from Japan, Russia, England, and the United States and evidently revitalized research efforts on long-wave runup, spawning several major research programs on long-wave runup had commenced in the United States as well as overseas. The workshop has also facilitated further international research collaborations. Liu, et al. (1991) reported the proceedings of the workshop.

From 1992 to 1994 several major tsunamis occurred, including Nicaraguan tsunami on September 2, 1992; Flores tsunami on December 12, 1992; Hokkaido tsunami on July 12, 1993. All three tsunamis caused devastating property damages and many deaths. Moreover, in 1994 alone four additional tsunamis, including the East Java (Indonesia), the Shikotan Island (Russia/Japan), the Mindoro (Philippines), and the Skagway (Alaska, USA) tsunamis, occurred around the world. The runup heights along affected coastlines were surveyed and documented by various research teams. Different research groups have performed numerical simulations of all these events with different numerical models. The community felt the strong need to gather researchers together to discuss similarities and dissimilarities among these models and to discuss the difficulties in modeling coastal effects of tsunami.

Consequently, the Second International Workshop on Long-Wave Runup Models was held at Friday Harbor, San Juan Island, Washington, on September 12 - 16, 1995. Total of 55 scientists and students participated in the workshop; it is emphasized that student participation was encouraged and in fact 21 of the 55 participants were students. Unlike the first workshop, the format of the second workshop was designed to focus more on discussions than on formal presentations. To accomplish this goal, four benchmark problems were selected before the workshop so that numerical models can be compared, both qualitatively and quantitatively, evaluated and discussed among the participants during the workshop. All of the benchmark-problem descriptions and necessary data were provided to the participants nine months prior to the workshop. Based on the benchmark problems, each participant was asked to submit his/her written discussion 50 days prior to the workshop, and the written discussions were distributed to each participant 30 days prior to the workshop. The actual laboratory or physical measurements were only presented during the workshop in the same format, allowing the comparisons of predictions with measurements. The four-benchmark problems were the following:

  • 1) The prediction of an edge-wave packet propagation along a uniformly sloping beach,
  • 2) The interaction and runup of incident solitary waves with a conical island,
  • 3) The runup of solitary waves on a vertical wall, and
  • 4) The tsunami runup around Okushiri Island, Japan.
  • During the workshop, seven discussion themes were organized as follows: laboratory, analytical, finite-difference, finite-element, vertical-plane models, boundary-integral-element models, and marker-and-cell models. All the presentations and discussions were edited and published in a book entitled "Long-wave runup models" (Yeh, et al. 1996); some of the general observations are discussed below.

    There was no doubt that the benchmark-problem exercises used in the second workshop proved extremely useful in identifying absolute and comparative modeling capabilities. Overall, in terms of tsunami runup modeling, significant advances had been made between two workshops, due to the advancement of computational capabilities, and because of the generation of a large 2-D and 3-D laboratory data set and the fortuitous field measurements in 1992-1995, all of which have contributed to model calibrations. The tsunami modeling efforts had become more directed towards their implementation for real tsunami predictions and hind-castings than ever before. At the time of the first workshop in 1990, large differences between computed runup results and field measurements might have been attributed to both errors in the seismic estimates of the source motion and to the hydrodynamic calculations, during the second workshop researchers were much more confident in the hydrodynamic calculations, at least for non-breaking waves. It was equally clear that reduction and even elimination of numerical dispersion and numerical dissipation effects would -if not already- soon become reality. At the same time, the workshop participants recognized additional and important problems arising from modeling improvements, such as determination of highly accurate initial wave conditions, modeling the three-dimensional flow effects, and turbulence. There is no question that actual tsunami runup motions are turbulent; the runup flow patterns, impacts, scouring effects, and sediment transport are all affected by turbulence in the runup motions.

    Since the second workshop in 1995, there have been four additional large tsunamis resulting in catastrophic loss of life and property. They are the Peru tsunami in 1996, the Papua New Guinea tsunami in 1998, the Turkey tsunami in 2000 and the Peru tsunami in 2001. Among these four tsunamis, the Turkey tsunami was definitely caused by land subsidence and slides associated with earthquakes. On the other hand, the source of the Papua New Guinea tsunami, which killed more than 2000 people and destroyed completely three villages, remains controversial and has been postulated as due either to seafloor dislocation or sediment slump. Because of the occurrence of these two tsunamis, research interest and efforts on the modeling of landslide generated tsunamis have been intensified in recent years.

    THE THIRD INTERNATIONAL WORKSHOP ON LONG-WAVE RUNUP MODELS will take place June 11-12, 2004 in Catalina Island, California. The conference venue is the Wrigley Marine Science Center of the University of Southern California Center. The National Science Foundation sponsors the workshop.


    Liu, P. L.-F., Synolakis, C., and Yeh, H. 1991 "A report on the international workshop on long wave runup", J. Fluid Mech., 229, 678-88.

    Yeh, H. Liu, P., and Synolakis, C. (ed.), 1996 Long-wave runup models. World Scientific.

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