Tsunami on the Volga is a natural catastrophe which, according to the research of Professor Pelinovsky, has threatened Nizhny Novgorod from the most ancient times to the present day.
The nature of the phenomenon
— Tsunamis can happen not only in seas and oceans, — says Professor Yefim Pelinovsky, chief researcher at the laboratory of nonlinear geophysical processes of the Nizhny Novgorod Institute of Applied Physics of the Russian Academy of Sciences. — On the Volga, it has happened too, more than once. A tsunami can be triggered by anything, from a landslide to an earthquake.
Background
A recognized expert in the physics of tsunamis, Professor Pelinovsky has devoted his whole life to studying this destructive natural phenomenon. According to him, the main sources of tsunamis are earthquakes (about 85% of cases), as happened in Japan. But in fact, for a wave to strike a coastline or a city, seismic activity is not even necessary.
— 15% of tsunami cases are caused by other, no less grand causes, — the scientist adds. — Waves can be "raised" by landslides, underwater volcanic eruptions, and meteorites. In the 20th century, humans were added to this list of causes.
In 1958, a landslide came down in Lituya Bay (Alaska), causing a tsunami wave of about 21 meters, but on the opposite side of the bay the water rose to 524 meters. In sporting terms, this is still the world record for tsunamis.
The first artificial tsunami occurred in the port of Halifax (Canada) in 1917, during the First World War, when two ships loaded with explosives collided. The tsunami waves reached 10 meters. Meteorite impacts into water caused "raging" tsunamis in prehistoric times (one — near Kaluga, when there was water where land is now). The probability of such events is not negligible even today — neither in an ocean, nor in a lake, nor in a river.
— Speaking of tsunamis in Russia, the first thing that comes to mind is the Far East, where the phenomenon is relatively frequent, and a warning service operates there, — says Professor Pelinovsky. — But tsunamis have also occurred in the Black Sea and the Caspian Sea.
After the Indonesian tsunami of 2004, which claimed more than 240,000 lives, the Russian government commissioned a special study into the possibility of such a catastrophic event happening in Russia.
— The forecast of Russian scientists was brilliantly confirmed in November 2006, when a tsunami with a height of 30 meters arose near Simushir Island (Kuril Islands), — says Yefim Naumovich. — Fortunately, no one lives there, but these waves caused great damage to people on the opposite side of the ocean, in the USA.
According to research by Nizhny Novgorod scientists, about 20 tsunami cases have been recorded at a popular Russian resort — the Black Sea. The most recent one, 3-4 meters high, occurred off the coast of Bulgaria in 2008. Tsunamis also occur in inland bodies of water (lakes and rivers) and in reservoirs, including in our region.
The largest Nizhny Novgorod tsunami
— The largest Nizhny Novgorod tsunami is dated to 1597, — says Professor Pelinovsky. — It was caused by a landslide that destroyed the Pechersky Monastery. A giant mass of soil, 300 by 200 meters, slid into the Volga.
The tsunami is mentioned in the Nizhny Novgorod chronicle. It describes unusual waves on the surface of the water that threw boats onto the shore almost 50 meters. Based on the facts set out in the chronicle, the event was modeled on a computer. It turned out that the wave near the monastery could have reached 25-30 meters (the height of a ten-story building).
Another tsunami, caused by a weak earthquake (intensity 6), occurred in the early 19th century near the town of Kozmodemyansk (Chuvashia). On the Volga, tsunamis have also occurred near Yelabuga (Tatarstan) and the Soksky Cliffs (Samara Region).
Fragile earth
Today, about a tsunami — which has been seriously studied for about 100 years — almost everything is known within 10-20 minutes of its onset. Countries that could be affected by it receive a relatively reliable forecast.
— The wave goes around our "little globe" in about 1.5 days, so I don't have to lose sleep over it, — Yefim Naumovich admits.
— Unfortunately, the epicenter of an earthquake often lies under land (as is currently the case in Japan). Then the tsunami begins there instantly, and nothing can be done anymore.
Asked why tsunamis caused by earthquakes still cannot be predicted, the scientist answers this way:
— A chair stands in front of you, and it seems quite sound. And suddenly it breaks. You'd say it was flimsy. Well, the earth is flimsy too. Plates collide inside it, and it is constantly shaking. Of course, some tsunamis can already be anticipated, but not with 100% certainty, since they occur in different places, with different frequency and their own particular features.
According to the scientist, one of the best laboratories of the international tsunami service is located precisely in the city of Sendai, and it has been destroyed. Russian experts, including "Pelinovsky's team," will soon fly to Japan.
— It's clear that in Nizhny Novgorod Region the danger of a tsunami occurring is relatively small, — says Yefim Pelinovsky. — Since we live in a zone that is not currently seismic, any tsunamis caused by landslides will be very localized. But this needs to be studied. And in order to say anything about possible tsunamis, a full map of landslide hazard along the Volga's banks needs to be compiled.