Description of the attraction
The Kronstadt tide gauge was installed in Kronstadt on the abutment of the Blue Bridge in order to measure the level of the Baltic Sea. From zero, it is the Kronstadt footstock that measures the heights and depths, and the orbits of spacecraft throughout the vast territory of the former USSR. The Kronstadt tide gauge is one of the oldest in the world network of level posts.
The need to measure sea level has existed for a long time. The sea level was taken as zero compared to the land level for a certain observation period. Depths and heights in Western Europe are determined by the Amsterdam footstaff, the level of the Mediterranean Sea by the Marseilles.
The foot service in Russia was organized by Peter I in 1707 on the island of Kotlin. The first tide stock appeared in 1703 in St. Petersburg. Sea level measurements were of great importance for the young Russian fleet, since the passage of ships along the Gulf of Finland and the mouth of the Neva, the construction of defensive structures on the island depended on sea level.
In 1825-1839 the Russian hydrographer M. F. Reinecke calculated mean sea levels for several locations in the Gulf of Finland. The hydrographer noticed that at these points the footstock zeros were above average. Then he proposed to combine the zeros of the footstocks and the mean sea level. In 1840, a horizontal mark was made on the granite abutment of the Blue Bridge across the Obvodny Canal in Kronstadt, which corresponded to the average water level in the Gulf of Finland according to observations for 1825-1839. Such an innovation made it possible to observe the sea level from a certain zero mark.
To control the position of the tide rod zero, special benchmarks are used, which are marks on land. The main benchmark of the Kronstadt footstock is the horizontal line of the letter "P" on the monument to P. K. Pakhtusov in the word "Benefit". According to measurements for many years, the excess of the benchmark over the zero of the Kronstadt tide stock confirmed the stability of the 1840 mark.
In Oranienbaum there is a mark 173. It is located on the building of the Oranienbaum railway station, leveling is also periodically carried out with it. The results of these levelings, which have been conducted since 1880, demonstrate the relative invariability of the zero position of the tide rod in Kronstadt.
In 1871-1904, astronomer V. E. Foos performed a leveling connection of the zero, taken at the Kronstadt foot-rod, with marks on the mainland.
In 1886, surveyor and astronomer F. F. Vitram, at the zero point, mounted a copper plate with a horizontal line in the stone, representing the zero of the Kronstadt footstaff.
In 1898, a tide gauge was installed in a wooden booth. This is a device that continuously records the water level in the well relative to the zero of the tide rod. Somewhat later, the tide gauge was moved to a small pavilion with a deep well. Mareograph records any fluctuations in the sea, including floods and low tides.
In 1913 H. F. Tonberg, head of the instrumental chamber in the port of Kronstadt, installed a new plate with a horizontal mark, which is used to this day as the starting point for the entire leveling network of the Russian Federation.
Measurements of all depths and heights are made from the zero of the Kronstadt tide rod. Geographic maps and space orbits are equal to the Kronstadt reference point.
Description added:
nivel 2014-07-08
The problem of the Kronstadt footstock is that the transfer of its mark to the mainland for more than a century was a technical and technological problem for surveyors in obtaining a sufficiently small RMS.(root mean square error) measurements. Determination of the excess between "zero"
Kronstadt foot stock
Show full text The problem of the Kronstadt footstock is that the transfer of its mark to the mainland for more than a century was a technical and technological problem for surveyors in obtaining a sufficiently small RMS. (root mean square error) measurements. Determination of the excess between "zero"
The Kronstadt foot stock and the mark in Oranienbaum were made exactly ten times over the course of a century, but it always turned out "rough" - s.o. more than 20 mm.
In 1969, specialists of the Institute of Physics of the Earth and Astronomy of the Academy of Sciences of the Estonian SSR, using the method of hydrostatic leveling, with high accuracy (r.m.s. = 0.7 mm) determined the height of the mark on the mainland relative to the tide rod. It was this value of the mark's height (slightly more than 5 meters above "sea level") that was used as the initial value in all mathematical calculations of the basis of the leveling network of the USSR.
After that, no other measurements were taken as unnecessary.
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