When Ultrasonic waves of
sufficient amplitude are indtroduced into a liquid, the
result is cavitations of the liquid at the "rarefaction"
or low pressure points of the sound waves, As waves pass
by a given point in the liquid, low pressure areas are
replaced by high pressure or "Compression" areas.
Cavitations bubbles produced under rarefaction implode
during compression, resulting in the production of
extremely small but highly intense shock waves radiating
from the point of implosion. It is these high intensity
shock waves that do most of the clearing job.