The approximate height of the tsunami at the entrance to the bay is 5 m. In the Avachinskaya Bay with a diameter of 15 km (small water volume) with a strait width of 4 km and a depth of 15 m (a wide and deep strait), according to the data of minute-by-minute sea level measurements, no tsunami waves were recorded (the graph of the level is given in my discussion on the topic "Nuclear submarines of the Russian Pacific fleet are immobilized after the tsunami and are easy prey for the United States. What do experts think?"). In the same discussion is a graph of the ocean level near the epicenter of the earthquake. The destruction of the moorings of the base of nuclear submarines in the bay is obvious, but the wave of 5 m height, which reached the shore in 15 minutes, was not recorded in the bay. Submarines were damaged and "tied" to the piers (usually during a tsunami danger, ships are taken out into the open sea, and these cannot go out to sea). All publications claim that the infrastructure of the military base was destroyed by a tsunami that did not occur.
I propose to discuss what hydrodynamic processes occur in closed bays during the arrival of a tsunami.
Let's calculate a theoretical estimate of the sea level rise in Avacha Bay due to a tsunami 5 m high.
Input data:
Diameter of the bay: 20 km.
Depth of the bay: 7 m.
Width of the strait: 4 km.
Depth of the strait: 15 m.
Time of water inflow from the ocean: 5 minutes
Calculation results: the maximum level in the bay will increase by only 56 cm.
I have attached a graph of time changes in the water level in Avacha Bay during the tsunami (approximately 23:45), shown by the arrow. The source of the information is contained in the graph. The tsunami occurred in conditions of outflow of water from the bay under the influence of the ebb tide (within 6 hours the level decreased by 60 cm).
What is the conclusion?
The tsunami, even with a height of 5 m, did not generate fluctuations in the water level in the bay. that is, is the bay safe in theory and practice?
The conclusion is wrong. The naval base for nuclear submarines has been destroyed, and the submarines that were standing around the concrete piers are now unable to leave Avacha Bay on their own.
Please join the discussion. It's simple...
I propose to obtain a theoretical assessment of the destructive impact of tsunamigenic standing waves (seisha) in the bay of Rybachy Island (Avachinskaya Bay) due to the tsunami. I have attached maps and photos of the military base.
Let's calculate a single-node seisha (standing wave) in the VMS Bay (Conventional name of the Krasheninnikov Bay) with a length of 5.3 km, a width of 2.5 km, and a depth of 10 m.
According to the calculations, in the VMS Bay, a single-node seisha will have a period of 18 minutes. Given a water flow height in the corner of the bay of 1 m
the horizontal current velocity at the node of the standing wave will be 1.1 m/s. (If the seiche height was 2 m, then the current speed at the node of the standing wave reached: 2.2 m/s.)
The location of the node of the single-node seiche in the VMS Bay (Avachinskaya Bay) coincided with the place of the break-off of the floating berth (pontoon) from its anchors. Photo added (source of information in the photo).
Conclusion. under the conditions of the bay in the bay during the tsunami, the level in the bay did not change significantly, but a seiche arose in the closed corner of the VMS Bay. If the seiche height was even 1 m (there is evidence of flooding of the port infrastructure), then in the area of the destroyed berth for 9 minutes a current of 1.1 m/s was formed in one direction, and the next 9 minutes in the other direction.
Submarines moored at the entrance to the Navy Bay were in the antipodes of the standing wave, where vertical water movements occur. I will present a number of photos of the "floating" oscillations of the submarine in the Navy Bay, which indicate the likelihood of destructive impacts of the boat on the bottom and destruction of the hull and propeller, which is confirmed in the source https://focus.ua/world/717048-zemletryasenie-na-kamchatke-atomnaya-baza-rf-pod-ugrozoy
Dear Borys Kapochkin, thanks for this interesting question. We are looking into a similar question for a little while. How does the tsunami magnitude change when entering a converging or diverging water body geometry (bay, fjord, etc.). The geometry can easily modify the tsunami magnitude by an order of magnitude, particularly for landslide-tsunamis. Here are some more recent papers about this topic:
Ruffini, G., Heller, V., Briganti, R. (2019). Numerical modelling of landslide-tsunami propagation in a wide range of idealised water body geometries. Coastal Engineering 153:103518 (https://doi.org/10.1016/j.coastaleng.2019.103518).
Chen, Z., Heller, V., Briganti, R. (2024). Numerical modelling of tsunami propagation in idealised converging water body geometries. Coastal Engineering 189:104482 (https://doi.org/10.1016/j.coastaleng.2024.104482).
Chen, Z., Heller, V., Briganti, R. (2025). Asymmetrical interaction of solitary waves in idealised converging water bodies. Physics of Fluids 37:077180 (https://doi.org/10.1063/5.0277482).
My whole family specializes in ocean physics. We proposed our own theory of tsunami origin. The latest edition in the monograph is chapter 7 and what interests you, chapter 6 https://www.researchgate.net/publication/361514437_Volume_3_Previously_unknown_aspects_of_the_formation_of_climate_weather_including_natural_hazards
In our opinion, a tsunami is not a movement of the bottom in water that does not change volume under pressure, but a hydraulic shock in water that compresses by 1%. This is a fundamentally different theory of tsunamis.
A magnitude 8.8 earthquake, such as the one that struck Russia’s Kamchatka Peninsula on July 29, 2025, can indeed generate significant tsunami waves. These waves can travel vast distances across the Pacific Ocean, impacting coastal regions far from the epicenter.
Video tsunami 29.07.25 M=8.8 Seaside Kamchatka H=20 m.
https://www.tiktok.com/@jaimebce1/video/7534717695502093582