sensors thet r used for detection of tsunami

[pankaj kumar]

plese kindly message me the relevant information to my emil id

pankaj22121984@yahoo.co.im

 

[williB]

i believe that they use ( or could use) GPS , global positioning ...
the way it would work is, they would (or could) use an average wave height to sort of filter out the smaller wave peaks..
as i understand it the tsunami waves have a very long period , from the videos i saw the peaks lasted at least five minutes ,depending on how close or far away they were from the epicenter..

 

[jbeng]

I didn't see the video (I don't watch tv), but if I recall, the water will oftentimes drain from a bay or greatly recede from the shoreline prior to the tsunami's arrival. In Sri Lanka, I heard a lot of people walked a good distance offshore and then were caught with nowhere to go when the tsunami came in. Seems you could monitor waterline height similar to what williB suggested and have several minutes to sound an alarm to give warning.
JB

 

[Russlk]

A tsunami is caused by an undersea earthquake. The vibrations in the earth travel a lot faster than the sea wave, so a seismograph can give early warning. The problem was that there was no warning system in place.

 

[Dialtone]

What I saw indicated that the measurment was done by a submerged water pressure sensor. The sensor is calibrated to a known depth and signals a surface transceiver linked by sat to monitor station. Whenever a wave passes over, the depth of the water column above the sensor changes and is resistered by the changing pressure.
Dialtone

 

[checkmate]

I'm not sure what the sensor was used, but according to news reports they are pressure sensors placed on the sea-bed, which are linked by cable to a floating buoy with GPS capabilities. Since pressure depends on the height of the column of water above it, and normal sea waves can be metres high while tsunami waves are merely inches or at most feets high in the open seas, the signal would probably be noisy. But if you have a large network of it, the signals could probably be processed to identify a wavefront.

 

[pankaj kumar]

thank u

A tsunami is caused by an undersea earthquake. The vibrations in the earth travel a lot faster than the sea wave, so a seismograph can give early warning. The problem was that there was no warning system in place.

 

[Oznog]

I'm not sure what the sensor was used, but according to news reports they are pressure sensors placed on the sea-bed, which are linked by cable to a floating buoy with GPS capabilities. Since pressure depends on the height of the column of water above it, and normal sea waves can be metres high while tsunami waves are merely inches or at most feets high in the open seas, the signal would probably be noisy. But if you have a large network of it, the signals could probably be processed to identify a wavefront.

From what I heard, the pressure sensor was more reliable than the seismometer because it was difficult to predict if the earthquake was going to cause a tsunami merely by the intensity of the quake; there were more subtle questions of how much the ocean's bottom had subsided that had to be answered to know if a strong quake was going to create a tsunami or a false alarm.