Is the Kremlin sinking?

In August 1989 a cave-in created a two and a half meter wide, three-and-a-half meter deep crater in the Kremlin, near the former Senate building. This was just the most recent in a long series of “sinkings” on Kremlin grounds, all of which testify to this historical structure’s geological instability.

The Poteshny Palace (near the Armoury) started sinking as early as in the seventeenth century. During the reign of Tsar Alexei Mikhailovich (1629-1676), the building sank one meter into the earth.

The Arsenal building has long been threatened with flooding. It stands in the northern corner of the Kremlin triangle, where numerous springs emptied into the Neglinka River before they were dammed in the nineteenth century by the foundations of the buildings.

A drainage ditch dug in the twentieth century to save the Arsenal building did not keep the water from breaking through. Since the soil under the building is constantly wet, the foundation is weaker than it should be. Besides, the Arsenal stands much higher than the adjacent Alexandrovsky Gardens and is therefore sliding downward and slowly being deformed.

Ironically, the famous architect Vasili Bazhennov contributed to the weakening of the Kremlin’s stability in the eighteenth century. In an attempt to improve the Kremlin’s panorama as viewed from the Moskva River, he ordered that the wall that supported the slope of Kremlin Hill be demolished. Empress Catherine the Great, upon learning that the Archangel Cathedral had “moved" toward the slope as a result of the wall’s destruction, ordered that that activity be stopped immediately. The wall was hastily reconstructed, but not in its former place. It is uneven along the embankment, and buttresses had to be installed near the cathedral.

In modern times a tunnel, stretching from the Spasskaya Tower to the Rossiya Hotel, caused a certain unevenness in Red Square. The tunnel, three meters in diameter and six meters deep, changed the flow of subsoil waters. Fine soil particles were washed out, and pavement stones sank. The same process affected St. Basil's Cathedral; its left portal was fractured, and the Whole building was left slightly lopsided.

After the 1989 cave-in near the former Senate building, a geophysical study of the earth mass under the Kremlin was was subsequently filled with rubbish and planted with trees.

Endless operations by subsoil waters, with their unpredictable character, played a negative part as well. As a result, water is dripping into the underground chambers of cathedrals and towers.

The general conclusion is that human activity has changed the rock strata beyond recognition over a geologically negligible period of time, and the possible consequences of this may be truly catastrophic if proper measures are not duly taken. A useful admonition given the current rise in “human activity.” Massive excavation and construction are now underway in Manezh square, neighboring the Kremlin. The square is to be the site of a huge underground shopping mall and parking garage, to be completed prior to the 350th anniversary of Moscow, in 1997.

A final footnote. Geological researchers recently demonstrated that the rock mass under the Kremlin has a different gravitational force in various parts of the fortress territory. This is because the Kremlin, and indeed the entire center of Moscow, stand over a deep, narrow geological cleft, almost two and a half kilometers deep. The contours of this unusual depression cause changes in gravitational force on the surface above it .