ICE ON THE NORTHERN SEA ROUTE IN
RELATION TO THE USE OF PHOTOGRAMMETRY
by Terence Armstrong
Scott Polar Research Institute,
Cambridge, England
ABSTRACT
The ice of the Northern Se& Route is described, and
the Soviet programme of observation and research is
outlined. The synoptic ice charts, which are compiled
at frequent intervals as part of that programme, are
found to be based on visual observations rather than
photogrammetry; the latter is used for subsidiary pur-
poses. Possible future applications of photogrammetry
are considered.
On decrit la banquise dans le secteur de la Route
Maritime du Nord ainsi que le programme Sovietique
d'observations et de recherches. Dans ce domaine des
cartes synoptiques des glaces sont produites à inter-
valles rapproches & partir d'observations visuelles
plutot que par photogrammétrie; cette derniére tech-
nique n'est employée qu'en second lieu, On envisage
enfin les futures possibilités d'emploi de la photo-
grammétrie.
The Northern Sea Route comprises the system of
shipping lanes running along the north coast of the
Soviet Union, between the Barents Sea in the west and
Bering Strait in the east. Its operation demands the
overcoming of many difficulties, of which the principal
is floating ice. For eight months of the year it is
continuously present over the whole length of the
route; for the remaining four, its presence is not con-
tinuous everywhere, but it is still frequently en -
countered.
The seas through which the Northern Sea Route runs -
the Kara, Laptev, East Siberian and Chukchi Seas - are
all quite open on the northern side to the Arctic Ocean,
of which they form bays. There is therefore nothing to
prevent the old and heavy floes from the central polar
basin drifting into the shipping lanes. This is parti-
cularly noticeable in the East Siberian and Chukchi
Seas, where heavy ice is often met comparatively close
inshore. Such ice is the most serious impediment to
Shipping. Most of the remaining ice is not more than
one year old - called winter ice - which forms, grows
and decays within the confines of a single sea. There
are also Intermediate types, making the total ice
gituation more complicated and thus more difficult to
recognise and classify, such as winter ice which has
failed to melt in the summer and survives to grow for
another winter. Icebergs, the floating fragments of
glacier ice which stand higher out of the water (and
extend much deeper into it) than the vastly commoner
sea ice, or frozen surface of the sea, are not fre-
quently found on the shipping lanes, due to the loca-
tion of the comparatively few glaciers from which they
calve. Almost all this floating ice, it is to be remem-
bered, is continuously moving under the influence of
wind or current. The exception is the ice which is at-
tached to the shore or to shoals, called fast ice. This
forms a fringe along parts of the coast, and in places,
such as off the Taymyr peninsula or the mouth of the
Yana river, may reach of width of 250 miles. The fast
ice tends to form late in the season and melt early, so
that it is not of particular direct significance to
shipping. On the other hand its extent and distribution
is likely to have an effect on the general pattern of
ice behaviour during the winter, which in turn affects
the pattern during the navigation season.
In order to arrive at an understanding of the laws
controlling the behaviour of the ice in this extensive
area, it is clearly necessary to undertake a large pro-
gramme of study. In the Soviet Union the existence of
25
Archives 6
the sea route has stimulated such an undertaking. To
the earlier methods of recording the ice seen from ships
and shore stations has been added the very much more ef-
fective use of air reconnaissance. In recent years some
25 aircraft have been engaged wholly on this work each
summer, flying between five and six thousand hours. The
reports obtained in this way are collated cartographic-
ally, so that a map of the ice conditions over the whole
area 1s made up every week or ten days during the ship-
ping season. Unfortunately none of these are published.
In addition, since 1948 special attention has been
paid to the movement of ice in the central polar basin.
There has been a series of remarkable expeditions in
which parties have been landed from the air at a great
many points on the drifting ice, and have remained there
either a few hours (if ‘the object was to make one set of
glaciological and oceanographical observations), or
several years (if the object was to record the annual
cycle of various geophysical phenomena, the drift of the
ice being one). The information collected by these ex-
peditions has very greatly increased knowledge of how
the mass of old ice in the central region circulates.
This bears directly on the Northern Sea Route, as we
have seen, and also of course on the ice problems in
waters the other side of the North Pole.
This synoptic information on the distribution and
character of the ice, together with the results of
studies of the influence of wind, current, temperature
and other factors on a given floe, is available to the
forecasters, who produce both long-range and short-
range forecasts. The long-range forecasts (looking
several months ahead) depend to a large extent on study
of the ice clusters (ledyanyye massivy), or concentra-
tions of sea ice covering hundreds of square miles,
which are found in the same region every summer. The
Russians distinguish eleven of these, and have found
that their size and exact location at particular times
is a good indicator of subsequent ice behaviour in the
area. The short-range forecasts are more closely de-
pendent on weather forecasts. (See Fig. 1).
In order to make this whole programme of ice studies
effective, it has been necessary to train a large number
of people, both to work on the theory of ice behaviour
and to record the ice seen during reconnaissance flights
and compile synoptic charts. This has been a very con-
siderable job. An aerial ice observer (or hydrologist,
in the Russian terminology) goes through a six-month
course of training, but only after about two years is he
fully trained and able to distinguish, for instance,
differences in age from the air.
An outline has been given of the problem which faces
the Russians and of some ways in which they have tried
to solve it. The object of giving this outline is to
see what present applications and future potentialities
there are for photogrammetry.
Something over 95 percent of the observations which
go to make up the synoptic ice charts come from air
reconnaissance, yet it is & fact thst photography plays
only & minor part in this. The Russians have found that
it is more satisfactory to train & men to plot carto-
graphically the ice he sees (using a highly developed
system of conventional signs), rather than to photograph
it and interpret the photographs. It would seem that
they are justified in this for several reasons. One is
that the map is wanted as quickly as possible after the
flight for synoptic purposes - and sometimes a copy has
even to be dropped from the aircraft to a ship in diffi-
culties. Another is that in some areas color film would
be essential to show up certain details, while in others
no photographs at all would be necessary because there
was no significant change in the ice situation. Expen-
