How are tsunami waves different from normal ocean waves?
Both normal ocean waves and tsunami waves can be described by their period (time between two waves), wavelength (horizontal distance between waves), amplitude (wave height), and speed. Normal ocean waves are caused by the wind, weather, tides, and currents. They have periods of 5-20 seconds, wavelengths of 100-200 meters (300-600 feet), and travel at speeds of 8-100 km per hour (5-60 miles per hour). Tsunami waves have much longer periods of 10 minutes to 2 hours, wavelengths of 100-500 km (60-300 miles), and travel at speeds of 800-1000 km per hour (500-600 miles per hour). The amplitude of normal waves and tsunami waves are similar in deep ocean water, but near shore, tsunami waves can be much larger with heights of 10 meters (32 feet) or more. Furthermore, normal ocean waves only involve motion of the uppermost layer of the water, but tsunami waves involve movement of the entire water column from surface to seafloor. This means a normal wave is like a small ripple on top of the ocea
