1.5 – 2ft

How is Wave Height measured? Wave height is the vertical distance between the crest (peak) and the trough of a wave. Some other definitions: Still-Water Line is the level of the lake surface if it were perfectly calm and flat.

The highest part of the wave is called the crest. The lowest part is called the trough. The wave height is the overall vertical change in height between the crest and the trough and distance between two successive crests (or troughs) is the length of the wave or wavelength.

Amplitude, in physics, the maximum displacement or distance moved by a point on a vibrating body or wave measured from its equilibrium position. It is equal to one-half the length of the vibration path.

The wave height is the vertical difference between a wave crest and a wave trough. The wave velocity (celerity) equals the wave length divided by the wave period. Sea reports give the significant wave height. This is calculated from the height of all the waves during a 20 minute period.

For it to be considered big wave surfing, a surfer must tackle a wave of at least 20 feet (6.2 metres) high.

Thus, a “3-foot” wave is roughly six feet high (in actuality an Hm0 of ~1.8 m), i.e., head-high to a 6-foot (~180 cm) person; a “2-foot” wave is roughly four feet high (Hm0 of ~1.2 m), i.e., chest-high to such a person; and a “6- to 8-foot” wave would be 2 to approaching 3 times head-high to such a person (Hm0 of ~3.5 …

If the wave length is 7 times or less than the wave’s height, then you should take precautions. For example, using the minimum 30 percent wave height to boat length, if your boat is 40 feet long, then the wave-height danger zone starts at waves 12 feet high (40 x 30).

1958 Lituya Bay earthquake and megatsunami

1720 feet

Most tsunamis cause the sea to rise no more than 10 feet (3 meters). The Indian Ocean tsunami caused waves as high as 30 feet (9 meters) in some places, according to news reports. In other places witnesses described a rapid surging of the ocean. Flooding can extend inland by a thousand feet (300 meters) or more.

500 mph

10 miles

“A person will be just swept up in it and carried along as debris; there’s no swimming out of a tsunami,” Garrison-Laney says. “There’s so much debris in the water that you’ll probably get crushed.” Eventually, the wave will pull back, dragging cars, trees, and buildings with it.

2. The ocean could be affected by high tsunami and/or pressure waves in the case of a large asteroid or comet impact. Most current submarines can survive at a depth of 400 m, so they might survive long pressure spikes created by the waves above them as high as 200–400 m, but not kilometer size waves.

Pacific Ocean

The reality of a tsunami hitting NYC is pretty slim, mostly because (for reasons you can read about here) the Atlantic is not prone to earthquakes. Short version: If there is a tsunami coming get on a tall roof somewhere, presuming whatever earthquake initiated the tsunami didn’t flatten New York first.

300 ft