A tsunami, (Japanese: 津波 “harbor wave”) is a series of 10 or more waves up to one hour apart normally caused by underwater earthquakes, and less commonly caused by landslides, volcanic eruptions, meteors or man-made explosions. Tsunamis travel extremely fast in the deep ocean, but they slow down and can grow quickly in height in shallow water. Waves can reach heights of 50 feet and taller and can have devastating impact on coastal areas. Not all tsunamis are life-threatening but they commonly cause damage in harbors. The first wave may not be the biggest and inundation can extend inland over 1,000 feet, flooding coastal areas for several hours.
In the past 100 years approximately 85 tsunamis have been reported in Hawaii including 15 that caused significant damage or death. Only four originated near Hawaii — most came from the northwest Pacific and near South American coasts. Hilo has seen the most devastating impacts in 1946 and 1960.
A local earthquake can cause a local tsunami; leaving little time to react or judge the situation. If you experience an earthquake your first reaction should be to drop, cover and hold until the initial earthquake is over. After your group is safe, immediately move to high ground and away from low-lying coastal areas – DO NOT wait for an official warning. Do not return to the area, and wait for the ‘all clear’ from local emergency officials.
Tsunami waves can travel thousands of miles. The Pacific Tsunami Warning Center was created in 1949 to track and warn the public of potential tsunamis. The Emergency Alert System is uses the Outdoor Siren Warning System, Wireless Emergency Alerts, and local emergency notification systems to notify the public of approaching hazards. If you are alerted about a tsunami, turn on the nearest radio or TV. Foreign language emergency broadcasts are on AM stations.
Hurricane season in Hawaii is from June 1st until November 30th. The terms hurricane and typhoon are regionally specific names for a strong tropical cyclone. A tropical cyclone is the generic term for a non-frontal synoptic scale low-pressure storm system over tropical or sub-tropical waters with organized convection and high winds. In addition to strong winds and rain, tropical cyclones are capable of generating high waves, damaging storm surge, and tornadoes. The last category 4 hurricane to hit Hawaii was Hurricane Iniki in 1992.
Being prepared for a natural disaster is all about planning. Have a family plan including family communications, identifying responsibilities, meeting places and escape routes. Several apps are available to help families plan and react to emergencies. Plan for special needs people including elderly, handicap, pets, children, infants, homeowners, boat owners, schools, visitors, language barriers, and those lacking transportation. Research tsunami warnings, watches, evacuation zones, hazard zones, shelters, refuge areas and evacuation scenarios.
Every home should have an emergency kit. This includes food, water and other supplies to last for at least 3-7 days. Other supplies include a whistle, matches, can opener, battery operated radio, flashlight, medication, medical supplies, first aid kit, bedding, bleach, pens, pencils, small tools, clock, knife, maps, tape, paper, games, cash in small bills, personal protection, personal documents, hygiene supplies, plastic bags and small storage containers.
Unlike a tsunami, you should have several days to prepare for an approaching hurricane. Follow the weather reports and tracking as local expert try to predict the hurricane’s path and speed. Stock up on water and non-perishable food and follow the advice of the experts.
For more information and to better prepare yourself, family, friends and community for disasters please contact NOAA, the Pacific Tsunami Warning Center, American Red Cross or the Hawaii Emergency Management Agency at 808-733-4300. More information can be found in the following publications: