T S U N A M I
water waves generated by wind
crinkling the surface of oceans
have a wave length l of up to 150 m, up to 3 m high,
with a speed of up to 30 kilometers/h [20 miles/h].
Tsunami is produced by an undersea earthquake,
an underwater landslide or volcanic eruption.
Tsunami's wave involves deep water [as tides do]
reaching just the ocean bottom.
In deep water the l of tsunami's wave
may be up to 500 kilometer [300 miles] or greater
and of an height of 50 cm [~ 20 inches].
Tsunami's wave may be as wide as the Pacific ocean.
The speed of tsunami may reach up to 700 Km/h [434 miles/h]
Tsunami is not dangerous in deep water.
Single waves are less than few meters high.
In shallow water, near the coasts,
the l of tsunamis wave
may be of 1.5 - 3 km [1 - 2 miles],
with an height of up to 30 m [100 feet] or more.
Tsunami waves loses energy at a rate inversely related to l.
The Speed, S, of tsunamis water waves
is obtained from:
S = [g * d] 0.5
where 'g' equals the acceleration of gravity [ = 9.8 m / s2 ]
and d = water depth in meters [m].
Accordingly, the relationship between water depth and the tsunami's waves speed equals:
|d, m|| S
m / sec
km / h