We studied the basic principles of the global early warning system that a tsunami wave was generated by an earthquake and there is a need to evacuate the population from coastal areas. Look at the chart. We calculated with what speed the first wave arrives at DART by bottom buoy stations. It is this wave that the system identifies as an ocean tsunami wave. This is mistake. The first wave that hits the DART station is not a tsunami. The arrival speed of the first wave is 1.1-3.9 km/s. Now the main thing. The maximum speed of a tsunami is 0.25 km/s. The first wave that hits the DART station is not a tsunami. Most likely these are vertical movements of the seabed. A real tsunami wave comes or does not come later, when the automatic system has already given a warning on a false sign. See the discussion "What type of wave does the Deep-ocean Assessment and Reporting of Tsunamis (DART®) mistake for a tsunami?" for details.

Look at the map of the Global Tsunami Early Warning System after a major earthquake in 2012. The red star is the epicenter of the earthquake. The yellow diamonds are the buoys that gave the tsunami warning. Pay attention to the buoys in the Pacific Ocean. The evacuation was carried out in 28 countries of the Indian Ocean. The earthquake did not generate a tsunami.

Very big problems with the identification of the tsunami after the explosion of the volcano on 01/16/2022 (attached the picture). The blue circle is where the volcano exploded. According to the actual data of the DART buoys, there was no tsunami (attached the picture), but in fact there was. The map shows a buoy near the explosion site of the volcano. The graph shows that, apart from the tides, the buoy showed nothing. He did not record the tsunami. But we've all seen this tsunami on the internet.

Maps from open resources on the Internet.

To further demonstrate the current state of understanding of the physical nature of tsunamis and the success of its forecasting, let's consider in more detail the tsunami that occurred during a strong earthquake near the island. Sumatra (Indian Ocean) December 26, 2004. The paper [www.noaanews.noaa.gov/stories2005/s2365.htm] shows the results of a comparison of model calculations of tsunami movement with the results of sea level measurements along the satellite track. The maps show the results of such a comparison 2 hours after the earthquake. Consider the reliability of the tsunami simulation 2 hours after the earthquake. The main criterion for model verification is the accuracy of determining the number of tsunami waves, because people die both from the first wave and as a result of the possible return to the site of the disaster of the unexpected second and third waves.

According to the results of the calculation.

In the direction of the satellite's track from the epicenter to the southwest, one tsunami wave with a height of 60 cm was predicted.

To the northeast of the epicenter - waves with a height of more than 20 cm were not predicted.

Actually.

In the direction of the satellite's track from the epicenter to the southwest, two tsunami waves with a height of 70-80 cm moved. According to calculations, it was not possible to predict the first wave. The second wave is calculated quite correctly, both in terms of amplitude and phase.

In the direction of the satellite's track from the epicenter to the northeast, one tsunami wave with a height of 50 cm actually moved, which could not be predicted by calculations.

Conclusion.

Of the three tsunami waves that have catastrophic consequences, one wave is predicted by the results of mathematical modeling. The most dangerous first wave came unexpectedly.

If there is interest in this discussion, you can make an excursion on the theory of tsunami waves.

Read article: Ocean Gravity Wave Split from the Meteotsunami at the Japan Trench Following the 2022 Tonga Volcanic Eruption Is a discussion necessary?

Short theses on the physics of the tsunami generation process. Wrong hypothesis. Water doesn't compress. With a sharp rise in the bottom, the level of the ocean also rises and a wave forms around the epicenter as if from a stone thrown into the water. Signs of a false hypothesis:

With earthquakes of the same strength, the height of the tsunami wave is proportional to the thickness of the water layer above the epicenter. Earthquakes in oceanic trenches with depths greater than 7 km generate tsunamis of maximum height.

Our theory of tsunami generation:

Water is compressed by 1%. In the ocean at a depth of 7 km, it is compressed by 70 meters. At a depth of 1 km, water is compressed by 10 meters. This is a rough estimate. During a water hammer during an earthquake, the pressure of the water column decreases and the water expands by 1%. The ocean level above the epicenter of the earthquake rises and this is a tsunami. This happens several times. The number of tsunami waves is greater than one.

Dear Borys Kapochkin ,

Your explanation is great!

Can you explain what causes the water column pressure to drop?

Regards,

Laszlo

Dear László Horvath, Watch the video of the underwater explosion after 31 minutes. https://www.youtube.com/watch?v=G5Hs0BzeGzY&t=718s In the water you will see the extension of the stretch zone. she is white. The elongation zone in water is manifested by degassing under conditions of pressure reduction. There are other videos that show that a dark blue ring is moving in front of the white zone from the explosion. This is the expansion of the compression zone in which gases in the form of bubbles go into a dissolved state. Sincerely, Boris.

Dear László Horvath, I made a screenshot from this video.

Sincerely, Boris.