Technical Reports and Recent Events

CGS Special Report 241

Download SR 241
California's experience during 2010 Chile and 2011 Japan tsunamis has 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.  Harbors 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.

Science Application for Risk Reduction (SAFFR)

Download Report
Tsunami scenario describing impact on California from a magnitude 9 earthquake off Alaska.

CGS Special Report 236

Download SR 236
To provide more detailed information for secondary evacuation zones, 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.

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 zone (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.

March 11, 2011 Tohoku-oki Earthquake and Tsunami

Summary of effects on California.

Posters of California's Recent Tsunamis (2009, 2010, 2011):

Other Documents

CGS and CalEMA guidance document for assessing secondary hazards after a large local earthquake that could inhibit safe evacuation from tsunami hazard areas.

Community exposure to tsunami hazards in California, Wood, N., Ratliff, J., and Peters, J., 2013, U.S. Geological Survey Scientific Investigations Report 2012-5222, 49 p.

Poster describing the methodology for how the California Inundation maps were created.