- Some tsunami impacts can be mitigated through warning and evacuation.
- If people can be evacuated outside of the hazard zone it would greatly reduce the likelihood of death and injuries.
- If equipment and materials can be shut down, moved or secured, some impacts may be reduced. For example, the rapid evacuation of toxic or flammable materials, evacuation of ships, shutdown of nuclear power plants.
- The project must adhere to workforce health and safety regulations. Often, this places constraints on the design, construction, and operation of the project, and may require protocols to be developed to maintain staff safety during a tsunami. In cases of high hazard, there may be an obligation to develop or gain access to early warnings of impending tsunami arrival and to have evacuation plans in place to satisfy health and safety obligations.
- Early warning is possible for most tsunami, but be aware that substantial and sustained investment is needed for early warnings to be effective, timely and reliable.
- Regional warning agencies are noted in the Links section.
- Plans should be made including evacuation routes, safe locations and capacity/welfare/communication at those locations for evacuation in response to all warnings.
- Regular exercises are essential to test plans (at least annually, or more frequent to match staff turnover cycles) exercises are essential to test plans. Exercises also act as some of the most effective education, causing staff to rapidly learn the plan ahead of the exercise, and reinforce it with action.
- If shaking from an earthquake continues for longer than a minute or if people find it hard to stand up (not necessarily both) evacuate immediately. D and do not wait for any official warning – it is unlikely to come in time.
- For tsunami coming from further away, particularly the other side of the Pacific or Indian Oceans, there may be many hours of warning via the respective Tsunami Warning Systems.
- Both the Pacific Tsunami Warning Centre (PTWC) and Indian Ocean systems connect to formal government warning agencies, and the country’s government should be consulted for a link to receive warnings. The Pacific and Indian Ocean Tsunami Warning Systems are independent of one-another.
- As a fall-back, informal monitoring of the PTWC website can provide non-secure, non-guaranteed, delivery of warnings which may provide a basis for response.
- In areas where the travel time to high ground is prohibitive compared to the tsunami arrival time, consider planning for vertical evacuation to levels above tsunami flow depths in reinforced concrete buildings with deep foundations (those with reinforcing and foundations typical of Japan/California/New Zealand earthquake building codes).
Pacific Tsunami Warning Centre: http://ptwc.weather.gov/
Indian Ocean Tsunami Warning and Mitigation System (ICG/IOTWMS), more information at http://www.ioc-tsunami.org/index.php?option=com_content&view=article&id=8&Itemid=58&lang=en
North-Eastern Atlantic, Mediterranean, and connected seas: Tsunami Information Centre. http://neamtic.ioc-unesco.org/
Tsunami evacuation: lessons from the Great East Japan earthquake and tsunami of March 11th, 2011
Guidelines for Design of Structures for Vertical Evacuation from Tsunamis
Designing for tsunamis (including vertical evacuation buildings) http://www.preventionweb.net/files/1505_DesigningforTsunamis.pdf