CGS Special Report 241 - Maritime Tsunami Response Playbooks: Background Information and Guidance for Response and Hazard Mitigation Use (2016)
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California's experience during 2010 Chile and 2011 Japan tsunamis brought to light the desire by harbor/port authorities to obtain more detailed information on the estimated hazard and impact of tsunamis well ahead of their first wave surge arrival time. To address the needs of the maritime communities, the California Tsunami Program is providing: 1) harbor-specific maps and other products about in-harbor tsunami hazards (currents and wave heights) and damage potential; 2) the minimum offshore safe depth for vessels to evacuate beyond during a tsunami; and 3) guidance for each harbor which can be tailored to future tsunamis of different size and damage potential. This information was incorporated into maritime tsunami response "Playbook" plans to help harbors/ports respond to tsunamis of different sizes and distances from the California coast. "Playbooks" provide harbor officials with tsunami-specific maps and guidance about in-harbor hazards (strong currents, eddies, damage potential, potential for docks overtopping piles) and offshore safe areas for boats. Using a sports analogy, the Playbook approach provides the best defensive response "play" (or plan) against a tsunami of a particular size and source origin location. Ultimately, each maritime community is responsible for determining and implementing tsunami evacuations and response activities. Harbor officials can refer to their Playbook document to find the applicable response map and associated set of instructions for the recommended Playbook Plan.
In addition to using Playbooks for tsunami response, the California Tsunami Program, FEMA, and its partners encourage maritime communities to utilize these products and plans to pre-identify real-time response mitigation measures, determine where infrastructure enhancements should be initiated, and provide a mechanism for focused, pre-disaster hazard mitigation funding through additions to their Local Hazard Mitigation Plans. Although these products, plans, and related mitigation efforts will not eliminate all casualties and damages from future tsunamis, they will provide a basis for greatly reducing future tsunami impacts on life-safety, infrastructure, and recovery in California maritime communities.
CGS Special Report 236 - Tsunami Emergency Response Playbooks and FASTER Tsunami Height Calculation: Background Information and Guidance for Use (2014)
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To provide more detailed information for secondary evacuation areas, CGS and the California Office of Emergency Services (CalOES) are developing tsunami evacuation “playbooks” to plan for tsunami scenarios of various sizes and source locations. CGS Special Report 236 includes a summary of how these products are being developed as well as guidance on how communities should implement them during an emergency.
FASTER is an acronym representing an approach developed by the state tsunami program to calculate tsunami flood conditions (Wilson et al., 2014). FASTER includes the following variables for calculating the most conservative, yet accurate run-up and flood elevation that a tsunami could reach at a particular location:
- FA = Forecasted Amplitude (wave heights) calculated and provided by the National Tsunami Warning Center during the first hours after a tsunami is generated;
- S = Storm surge or existing ocean conditions, predicted by the regional NOAA Weather Forecast Offices;
- T = Maximum Tidal height in the first 5 hours of a tsunami, obtained from NOAA tidal forecast data;
- E = Forecast modeling Error potential, which has been calculated to be 30% of the forecast amplitude based on analysis of past events (Wilson et al., 2012); and,
- R = Site-specific amplified Run-up potential, calculated from existing state tsunami modeling.
Background: California’s experience during 2010 Chile and 2011 Japan tsunamis has brought to light the desire by coastal emergency managers and decision makers to obtain more detailed information on the estimated impact and hazard of the tsunami well ahead of its arrival time. The main issue is that existing tsunami evacuation plans call for evacuation of the predetermined “worst-case” tsunami evacuation area (typically at a 30- to 50-foot elevation) during a “Warning” level event; the alternative is to not call an evacuation at all.
Please note that evacuation planning and emergency response for future tsunamis is the responsibility of each community, and these playbook products are intended as internal emergency response planning tools for community emergency managers.
SAFRR: Science Application for Risk Reduction
The Science Application for Risk Reduction (SAFRR) tsunami scenario depicts a hypothetical but plausible tsunami created by an earthquake offshore from the Alaska Peninsula and its impacts on the California coast. The tsunami scenario is a collaboration between the U.S. Geological Survey (USGS), the California Geological Survey (CGS), the California Governor’s Office of Emergency Services (Cal OES), the National Oceanic and Atmospheric Administration (NOAA), other Federal, State, County, and local agencies, private companies, and academic and other institutions.
The SAFRR scenario was developed to better understand tsunami impacts to California coastal communities. The project includes evaluations of tsunami science such as tsunami source mechanics and tsunami deposits, as well as estimates of potential damage and the socio-economic and environmental impacts from such a scenario. For example, it is estimated that at least 1/3 of all boats in coastal harbors and ports will experience damage or sink during this scenario. Overall damage costs to coastal harbors and buildings could be $8-billion statewide.
Web page by:
California Seismic Hazards Program