How long before tsunami after earthquake happens?

Question

An earthquake struck in Japan and a tsunami is expected. What is the length of time between the earthquake and the tsunami?

Answer 1

The tsunami starts immediately, as it is caused by the movement of the bottom of the sea. How long it will take before it hits a specific point depends on how far that point is from the epicenter of the quake, and how many obstacles there are (it is not distance as the crow flies, it is distance as the wave moves).
The wave propagates at the speed of a jet airliner across an ocean.

Answer 2

The quake movement is what initiates the tsunami, so they start simultaneously. However the movenment travels through rock at a very high speed so that the quake can be detected at seismographs first. once 3 seismographs record the first arrival, the epicenter can be plotted and if under the ocean, a tsunami alert can be issued. where the quake is close to land as in Japan, the warning may only be a couple of minutes. The seismograph does not measure tsunami, only gives a warning that one could happen.

to get more accurate tsunami information, sensors measuring sea surface movement have been placed at strategic locations. these verify a disturbance was generated and provide better arrival predictions at long distances from the quake as a tsunami can travel 1000s of miles and arrive many hours after the quake occured.

Answer 3

Well, water will first contract back into the sea, leaving fish exposed. Around five to ten minutes later, a tsunami MAY strike. The 2004 boxing day tsunami lasted 1 1/2 hours, with a few waves hitting. AND till the next day, small waves still continue to strike.

Answer 4

The experts can't answer your question. In Japan, yesterday, they gave the tsunami warnings and had to sit and wait. Sometimes they don't occur or their effect is minimal. But all you can do is sit and wait...

Answer 5

because of fact human beings are blind to geography. that's much extra unhappy because of fact, whilst the media actual is unlikely out of their thank you to coach that issues are particularly everyday in places like Kyoto and Osaka, they DO regularly coach maps indicating the place issues are happening and all of the activities are indicated as happening north of Tokyo. human beings purely have not any concept in any respect of ways huge Japan is or the place issues are. I keep in mind the 1st time i grew to become into there and there grew to become into an poor earthquake someplace interior the northern area of Japan (i think of it is going to have been the Chuuetsu Offshore Earthquake of 2007 based on the date) or maybe in spite of the indisputable fact that i grew to become into in Aichi -- i.e. nowhere close to the quake area -- my entire kinfolk grew to become into confident I had died. human beings are ignorant and barely flow out of their thank you to stunning their very own lack of understanding with self reliant analyze.