Mr. Amit Kumar Prajapati
Mr. Rajveer Marwal
Seminar Coordinators (Sec B)
4th Year, 8th Sem.
DEPARTMENT OF ELECTRONICS & COMMUNICATION ENGINEERING
POORNIMA COLLEGE OF ENGINEERING, JAIPUR
Tsunami Warning System
Digiquartz Broadband Depth Sensor
DART I & II System
Advantages & Disadvantages
It is a series of wave with long wavelength and long wave
Apart from seismic activity, there are many other factors
responsible for Tsunami.
These gigantic waves are probably one of the most
powerful and destructive forces of nature.
TSUNAMI WARNING SYSTEM
TWS is a system which detects tsunami and issue a
warning to prevent loss of life and property.
This system consist of two main parts:
WORKING OF TWS
Network of seismic monitoring station at sea floor
detects presence of earthquake.
Seismic monitoring station determines location and
depth of earthquake having potential to cause tsunami.
Any resulting tsunami are verified by sea level
monitoring station such as DART buoys, tidal gauge.
TYPES OF TWS
There are two distinct types of TWS:
INTERNATIONAL WARNING SYSTEM
This system uses both data like seismic and water level
data from coastal buoys.
Tsunami travel at 500-1000 km/hr, while seismic wave
travel at 14,400 km/hr.
This give sufficient time for tsunami forecast to be
It is commonly used in Pacific ocean and Indian ocean.
NATIONAL WARNING SYSTEM
This system use seismic data about nearby recent
This system is unable to predict which earthquake will
produce significant tsunami.
Watch is issued based on seismic information.
Watch is issued without confirmation that destructive
tsunami is underway.
Tsunami watch is issued to officials which may later
impact the watch area.
Tsunami warning is issued when potential tsunami is
It alert officials to take action for entire tsunami hazard
Warning is issued automatically if an earthquake
powerful enough to create tsunami occur nearby.
Three types of technologies are used for detecting
• COAST TIDAL GAUGES
• DART BUOYS
Information available about source of tsunami is based
on seismic information.
Earthquake are measured based on its magnitude
recorded by its seismograph.
DRAWBACK OF SEISMOMETERS
Data are indirect and interpretation is difficult.
It involve poor understanding of seismic coupling.
Measure sea level near coastal area.
Continuously monitors and confirms tsunami waves
following an earthquake.
If tsunami occurred other than earthquake we depend
solely on data of tidal gauge.
DRAWBACK OF TIDAL GAUGE
May not survive impact of tsunami.
Cannot provide data that are especially important to
operational hazard assessment directly.
Report to tsunami warning centre, when tsunami occur.
Information are processed to produce a new and more
refined estimate of tsunami source.
Result is an accurate forecast of tsunami.
ADVANTAGE OF DART BUOYS
Seismometer do not measure tsunami.
Tidal gauge do not provide direct measurement of deep
ocean tsunami energy propagating.
DART overcomes drawback of both.
WORKING OF DART BUOYS
DART BUOY consist of two main component:
• Bottom Pressure Recorder (BPR)
• Surface Buoy
BPR consisting of a modem to transmit data to surface
Surface buoy transmit data to warning centre via satellite
BOTTOM PRESSURE RECORDER:
Digiquartz Broadband depth Sensor is the main sensing
This sensor continuously monitors pressure and if
pressure exceeds threshold value, it automatically report
to warning centre.
Surface buoys makes satellite communication to
warning centers that evaluate the threat and issue a
DIGIQUARTZ BROADBAND DEPTH
This depth sensor provide accurate & stable data.
Superior performance of digiquartz instruments is
achieved through use of quartz crystal.
Pressure transducer employs bellows tube as pressure to
Change in frequency of quartz crystal oscillator is a
measure of the applied pressure.
A electrical device that converts sound wave into
Hydrophone is used in this case.
When electrical plates are exposed to sound vibration
electrical energy is produced.
Electrical energy is sent to amplifier and then to final
Acoustic communication is a technique of sending and
receiving signals under water.
It is done by help of acoustic modem.
Modem operates at frequency of 10Hz – 1MHz.
It provides an accurate and efficient method to send and
receive data underwater.
NOAA AND DART STATIONS
(NATIONAL OCEANIC & ATMOSPHERIC ADMINISTRATION)
• Responsible for providing tsunami warning to the
(DEEP OCEAN ASSESSMENT & REPORTING OF TSUNAMI)
• Station that detects tsunami.
MODES OF OPERATION
DART buoy has two modes of operation:
System generally operates in standard mode.
DART transmits data every six hours with recording
period of 15 minutes.
When tsunami wave occur standard mode trigger to
Transmit data every15 minutes at an average of 1 minute
for three hours.
SERIES OF DART SYSTEM
There are two series of DART buoy system:
DART I SYSTEM
One way communication ability.
Relied solely on software’s ability to detect a tsunami
and trigger to event mode.
To avoid false alarm, a threshold value is set such that
tsunami with low amplitude could fail to trigger the
DART II SYSTEM
It is a two way communication
Measure seal level change of less than a millimeter in
the deep ocean.
Two way communication allows for trouble shooting of
System can be switched to event mode by concerned
authority for research purpose.
Deep water pressure produce low false reading.
Multiple sensor can detect wave propagation.
Good advance warning system.
Use of GPS to detect tsunami.
Developed by NASA.
GPS detects ground motion preceding tsunami.
It estimate tsunami destructive potential within minutes.
Estimates energy that undersea earthquake transfer to
With help of these data, ocean floor displacement
caused by earthquake can be inferred.