In regions where it is known from geologic evidence that tsunamis have occurred, yet none have been witnessed in modern history, the ability of engineers and scientists to plan for and mitigate the possible tsunami hazard is severely degraded. However, field surveys of tsunamis in the past decades have shown that as a tsunami inundates and floods the land, it leaves behind a calling card in the form of widespread sediment deposits. If the skill to look back into geologic history to estimate tsunami intensity and extreme event recurrence from deposits existed, the implications for efficient hazard planning are tremendous.
There are a number of research gaps that must be addressed before this skill is attained, as detailed by the NSF-Sponsored Tsunami Deposits Workshop in June, 2005 at the University of Washington. First, it must be determined what hydrodynamic information can be extracted from modern deposits created by observed and well constrained tsunamis. Next, it must be understood how a deposit might transform after being buried for centuries or millennia. With these two pieces of information, the widespread study of paleo-deposits would provide an abundance of invaluable information on paleo-tsunamis. The significance of this work will reveal itself when it is possible for tsunami researchers to take a record of deposits, and state with some confidence the intensity of previous, unobserved tsunamis.
Major Topical Areas:
- Hurricane/storm beach erosion
- Soil Failure / Scour around structures
- Extreme event sediment deposit inversion
What we hope to see posted on this WG discussion group:
The goal of this WG forum is to broaden researchers understanding of the wide variety of fluid and sediment modeling approaches, and to create discussion regarding the drawbacks, limitations, and appropriateness of these models for tsunami inundation simulation. Topics of discussion include
- Hydrodynamics of nearshore tsunamis
- Modes of sediment transport
- Sediment transport formulations
- Field records of tsunami hydrodynamics and deposits
- Forward modeling vs inverse modeling
- Limitations/uncertainties related to hydrodynamic and transport modeling