Tsunami Impacts Near The Origin And At A Distant Shore

Tsunami waves are basically mechanical waves, and thus move through the phenomenon of compression and rarefaction. Their energy and momentum is defined by mass (volume), wavelength, frequency, and amplitude. Near their origin tsunami waves have very large wavelengths and thus smaller frequencies and amplitudes. This makes them less threatening when offshore and also its difficult to detect and experience tsunami waves offshore. Tsunami waves reach onshore areas in the form of a series of successive crests and troughs, which have a time period of about 10 to 45 minutes. Tsunami waves have lower speeds in shallow water and vice versa, which implies that tsunami waves traveling at greater depths reach onshore regions in lesser time. So the tsunami waves traveling ahead in shallow waters are continually pushed towards the shore by faster tsunami waves generated through the origin. This causes compression of the slower tsunami waves, which decreases their wavelength and increases their amplitude. This increases the height of these tsunami waves from 1 meter in deep sea to 30-35 meters near shore. These gigantic tsunami waves onshore are highly destructive with their great smashing force, and thus pose a serious threat to life and property.