Can strike-slip (horizontal motion) earthquakes trigger tsunamis?Yes, approximately 10-15% of damaging tsunamis are triggered by strike-slip earthquakes.
As tsunamis propagate into shallow water, the wave height can increase by over 10 times. The waves can be amplified by shoreline and sea floor features.
A large tsunami can flood low-lying coastal land over a mile from the coast.
Tsunamis are also triggered by landslides into or under the water surface, and can be generated by volcanic activity and meteorite impacts. On the average, two tsunamis occur per year throughout the world which inflict damage near the source.
Approximately every 15 years a destructive, ocean-wide tsunami occurs.
Tsunamis generated by strike-slip earthquakes normally affect regions near the source only. Tsunami (soo-NAH-mee) is a Japanese word meaning harbor wave. Tsunami velocity depends on the depth of water through which it travels.
Velocity equals the square root of the product of the water depth times the acceleration of gravity.Did you know…A tsunami travels from the central Aleutian Islands to Hawaii in about 5 hours and to California in about 6 hours, or from the Portugal coast to North Carolina in about 8.5 hours. Tsunamis range in size from inches to over a hundred feet.In deep water (greater than 600 feet), tsunamis are rarely over 3 feet and are not normally noticed by ships due to their long period or time between crests.There are a few signs like hard ground shaking for 20 seconds near the coast or a sudden sea level withdrawal. Once an earthquake has occurred, the arrival time of a tsunami, if generated, can be determined accurately.Tsunamis may be accompanied by loud, booming noises. There is not normally enough time to accurately predict tsunami heights near the source. A tsunami is a large ocean wave usually caused by an underwater earthquake or a volcanic explosion. Tidal waves are caused by the forces of the moon, sun, and planets upon the tides, as well as the wind as it moves over the water. Tsunamis are generated by any large, impulsive displacement of the sea level.With typical waves, water flows in circles, but with a tsunami, water flows straight. The most common cause of a tsunami is sea floor uplift associated with an earthquake.On September 28, a 7.5 earthquake in Central Sulawesi, Indonesia, triggered a localized tsunami which crashed up the long, narrow bay at the mouth of the Palu river.Palu, a city of more than 330,000, suffered horrific damage as a wave estimated to have risen to 5 meters (16.4 feet) smashed into the city.Wind-generated waves usually have periods or time between crests between 5 and 15 seconds.Tsunami periods normally range from 5 to 60 minutes.