In the tsunami of 1946, the people of Hawaii were not warned ahead of time because the U.S. Coast and Geodetic Survey thought that it was a false alarm. Their seismographs (earthquake detecting system) had detected it. Why was there no warning? The answer from the U.S. Coast and Geodetic survey was that the seismograph always detects earthquakes but that does not always mean it is being accompanied by a tsunami. If they send out a warning everytime there is an earthquake and there is no tsunami people will begin to not believe them. What are they going to do about it? Then an idea was struck. In 1948 they approved the plans for the Seismic Sea Wave Warning System or what they call TWS. Alot of laboratories where set up along shores of the pacific ocean. The machine had to take alot of steps before it could send the siren out. The first thing they had to do was locate where the tsunami's are generated then they put watches out in the laboratories along the shores to watch for a tsunami. Next the watches look for waves that rise above normal sea level and thats how they know a siren about to hit. Then they try to figure out when the tsunami will hit. To do this the personel watching looks at the the depth of the ocean and by doing this they can figure out how long it will take. Next