Tsunamis are large
water waves created by seismic activity, land slides,
volcanic activity or by any vertical disturbance of water.
Historically, tsunamis have killed tens of thousands of people and
have caused significant damage to coastal areas of the world. The
word "tsunami" comes from the Japanese and means "harbor wave".
from regular wind-generated waves in that wind-generated waves have shorter period and wavelength. A tsunami can have a wavelength in excess of 100 km
over a period of hours.
Tsunamis can travel
at hundred of miles per hour for great distances. As
tsunamis get closer to shore and water depth becomes shallower, a
tsunami slows down. As a tsunami slows, its height increases.
Once ashore, tsunami height may reach up to 30 meters. A tsunami
continues inland until it loses its energy. While
proceeding inland, it causes flooding, death and destruction.
bottom pressure recorder uses a Digiquartz® Pressure
Transducer manufactured by
Paroscientific, Inc. Digiquartz® Instruments were selected
for this application due to their high accuracy, excellent
resolution and long-term stability. Digiquartz® Technology
provides a resolution of 0.0001% of full scale, enabling NOAA PMEL
to measure very small waves (1 cm) on the surface from 6000 meters
(21,000 ft) depth. Pressure readings from the bottom
pressure recorder are acoustically transmitted to the surface
buoy. The data are then relayed via a GOES satellite link to
ground stations, which demodulate the signals for immediate
NOAA's Tsunami Warning Centers and PMEL.
Digiquartz® Pressure Products make the detection of a
tsunami possible from great ocean depths with the highest
resolution, lowest noise, and most accurate instruments available
today. The transducers are based on the inherently digital, highly
stable, vibrating quartz crystal technology developed by
Paroscientific over the last three decades. They are designed and
tested to deliver outstanding performance even under difficult
Although many applications require both high resolution and
accuracy, short-term measurements generally benefit more from our
high pressure sensitivity, while longer term measurements need our
accuracy, stability, and insensitivity to environmental errors.
With a sensor of inadequate resolution, real signals can be
obscured by noise, or sensor noise can be misinterpreted as real
signals. Paroscientific transducer mechanisms, oscillator
circuits, and digital interfaces are carefully designed for high
resolution. Typical delivered resolution of our transducers is
better than one part per million, and under stabilized laboratory
conditions, resolution can approach 1 part per billion.
information on this application and Digiquartz® Products,
contact our applications