When one first takes a look at this lake-sea, whether
from the cliff shore near the source of the Angara, or from the flat banks at the mouth
of the Selenga overgrown with small bushes and reeds, the human imagination is
overwhelmed by the unembraceability of this watery mass, and automatically thoughts
spring up about the great bulk of water plunging down into the depths. These very
thoughts are clearly felt in the first Russian documents on Baikal.
In 1675, the Russian ambassador to China, Nikolai Milesku-Spafarii, crossed
over Baikal in a wooden boat. The ambassador described his journey in a brief diary account. Passing by the Irkutsk stockade, not yet a town, he acquainted
himself with works on the geography of the region. In his description Spafarii
included information on the rivers Lena and Vitim, where, in fact, he never went.
And he made a place in his diary for a special chapter - "A description of the
Baikal sea all around...". This description was not compiled by Spafarii, all the
more since he never journeyed around the lake by land or sea.
In the "Description..." it is said that "...its [Baikal's - S.G] size in length, breadth
and depth is very great indeed...". An explanation follows: "Its depth is great, as
many a time a hundred and more fathoms have been measured and the bottom not
reached...". This explanation indicates that the first to try to measure the depth of
Baikal were Russian explorers. Even then, in the XVII century, it became clear
that the deepest part of the lake was near the island of Olkhon. In the
"Description..." it is recorded: "...from the island of Olkhon to the Svyatoi Nos
peninsular, where people cross over, the depth is very great, it can take a day and a
half to cross with difficulty, and in those places many vessels perish". In the same
place the idea of a connection between the depth of the lake and the height of the
surrounding mountains is put forward: "Its depth is enormous... which is governed
by the fact that all around Baikal there are extremely high mountains..."
It was only in 1797 that the depth of the lake in South Baikal, in a line from
the source of the Angara towards the mouth of the Selenga, was measured by
workers of the Kolyvano-Voskresensky factories in the Altai, Smetanin and
Kopylov. They determined that the greatest depth was 1238 metres. Later, in
1821, a bathymetric profile of South Baikal was compiled and published according
to the findings of investigators.
In 1876 a bathymetric map of South Baikal was published that had been
compiled by the Polish exiles and outstanding researchers of Baikal, Benedict
Dybovsky and Victor Godlevsky. Here the deepest part of Baikal was 1373
metres.
From 1876 till 1902 a hydrographic expedition under the direction of
F.K.Drizhenko carried out work at Baikal and a navigational chart of the lake was
compiled. Measurements of the depths were taken mainly near the shores and only
rarely over the whole lake. It was established that the greatest depths were in
Central Baikal, these being 1450 and 1552 metres.
In the 1920s and 30s investigations into the depth of the lake were carried out
by the Limnological Station (now the Limnological Institute) under the direction of
Gleb Y.Vereshagin. In South Baikal a depth of 1419 was found, and, in the Central
region, large areas with depths of over 1500 metres. A maximum depth of 1741
metres was established near Olkhon, off Cape Ukhan.
In the '50s and '60s bathymetric work was undertaken not with ropes and
lines, as had been the case up till then, but using echometers that register the
passage of sound waves through water. In these years Central Baikal was
measured most thoroughly. In these investigations a depth of 1741 was not found.
The results here were limited to a maximum depth of 1620 metres, which is
officially accepted to this day.
There were also annoying mistakes made in this period. At one time in the
newspapers there appeared a sensational statement made by a scientist of the
Limnological station, Vassily V. Lamakin about the discovery in Central Baikal of
a depth of 1900 metres. However, it was soon discovered that this was a mistake.
In one of the soundings on a vessel in almost stormy weather the echo sounder gave a
series of false readings. The scientist made his apologies, but then only in a
scientific journal.
In 1992 a bathymetric map of the whole of Baikal was published, having been
compiled by the Head Office of Navigation and Oceanography of the USSR
Ministry of Defence. Echo soundings for a definite grid gave the following
results: the maximum sounded depth of the Southern Basin is 1461 m. (to the south-west
of the mouth of the Selenga), of the Central Basin 1642 m. (off Cape Izhimei), and of the
Northern Basin - 904 m. (off Cape Zavorotny).
The lake's depth has been measured at each submersion of "Pisces". According
to the reports of observers going down in this craft, the deepest part in Central
Baikal, off the island of Olkhon, is a little more than 1620 m. and reaches 1637 m.
Will a depth of over 1642 metres ever be established, I wonder?
Baikal is the deepest lake on the planet (1642 m.) In second place is Lake
Tanganyika (Africa) at 1470m., following which is the Caspian Sea at 945 m.,
and Lake Nyasa (Africa) with a depth of 706 metres.
The greatest depths are in the central part of Baikal, equidistant from its south
and north ends. In respect to this it is impossible not to recollect the empirical rule
on determining places of greatest depth in lakes, set down by the American
naturalist and writer Henry D.Thoreau, and the rule so-called by him of two
diameters. It says: the greatest depth of a lake lies at the intersection of its length
with its greatest width. That is just what it is in the case of Baikal: it is widest at
the latitude of Olkhon, and it is no accident that its greatest depths lie off this
island. |
Depth