Document created: 11 August 05
Air University Review, September-October 1966

Drifting Ice Stations

First Lieutenant Charles L. Smith

The Arctic Ocean is one of the largest remaining unexplored areas in the world, comprising one twenty-third of the total area of all the oceans. Connected to the Pacific Ocean by the shallow and narrow Bering Strait and linked with the Atlantic Ocean by the Norwegian and Greenland seas, it is bounded by over one million miles of shoreline in small, ill-defined seas. Many rivers of the Eurasian land mass enter this ocean, but few flow into it from North America.

Throughout the year, approximately 75 percent of the Arctic Ocean's surface is covered by pack ice, composed mainly of ice floes. These floes average from 6 to 9 feet thick during the summer and 9 to 12 feet during the winter. Their surface is uneven because of pressure ridges and rafting or overriding of the floes. The other form of ice in the Arctic Ocean comes from a large ice shelf along the northern coast of Ellesmere Island. Pieces of this shelf break free in the form of large tabular icebergs up to 200 feet thick. They are called ice islands.

 As recently as the early twentieth century, exploration of the arctic has been inhibited by the lack of proper vehicles to traverse the vast areas of ice and water. This technological deficiency affected not only the travels of explorers themselves but also the transport of food, supplies, and equipment necessary to sustain life in the harsh, inhospitable environment. In 1925 a breakthrough was made when an airplane made a successful landing on pack ice. This event ushered in one of the most interesting eras in the history of exploration. The airplane provided the means for the establishment and maintenance of scientific stations on the drifting ice. 

Much of the early information about the Arctic Ocean was acquired from ships frozen into the ice and drifting with the pack. One such ship was the Fram, which left Norway in 1893 for the Arctic Ocean. The captain of the Fram, Fridtjof Nansen, had her built to withstand the pressure of the ice pack and hoped to prove his theory that the currents of the ocean passed close to the North Pole. Depth soundings taken from the Fram revealed that the Arctic Ocean was deeper than had previously been thought, and the course of drift indicated that the currents in the region where the drift began do not pass close to the North Pole.

The first recorded drifting ice station was established in 1918 by Storker Storkerson when his party occupied a section of ice about 190 miles north of Alaska. It is now believed that the 7-by-15-mile piece of drifting ice may have been an ice island. The station was in operation for 6 months and drifted about 440 miles. It was evacuated in late 1918 when Storkerson became ill.

Soviet ice stations

In 1934 an event occurred which was to have an important bearing upon the development of drifting ice stations. The Soviet passenger ship Chelyuskin was trapped in the pack ice north of the Soviet Union in late 1933. On 13 February 1934 the ship was crushed by ice pressure and sank. The 103 passengers and crew members, including women and children, were able to establish a camp on the surrounding ice floes. The last survivor of the Chelyuskin was evacuated from the ice by aircraft two months later. This first mass airlift in the arctic was significant for transportation techniques later used in support of arctic research.

The fate of the Chelyuskin made the Soviets realize the need for additional data regarding the ice, meteorology, and hydrology of the Arctic Ocean, in order to operate the Northern Sea Route successfully. In May 1937 they established a drifting ice station called Severny Polyus or North Pole, to collect the necessary information. Because of World War II the second Soviet drifting ice station, North Pole-2, was not placed in operation until 1950. They have established a total of 14 stations, each with the name North Pole and a numerical suffix. Since 1954 the Soviets have maintained or tried to maintain two stations in operation at the same time. Only one of the 14 stations was on an ice island, North Pole-6. This station lasted longer than any other Soviet station, 1243 days, and drifted farther.

Because it was on more stable ice, North Pole-6 did not encounter some of the problems experienced at the other stations. Ice pressure proved to be one of the most common problems at the stations. It caused many of the ice floes to fracture and split and was one of the primary reasons for abandoning the stations. North Pole-8 was reported to have fractured 22 times in one year, and North Pole-5 fractured 111 times in a period of 536 days. Fracturing also forced some crews to relocate their camp sites and hindered the evacuation of two stations. One problem common to all the stations was that the melting ice during the summer made the surface slushy and difficult to walk upon. On numerous occasions the camps had to be moved because the tents and huts protected a portion of the ice floe and created pillar-like structures under the buildings. The radio antenna at station North Pole-2 fell down because the supporting wires would not stay anchored in the melting ice.

If a Soviet drifting ice station survived the forces within the ice pack and appeared to be leaving the Arctic Ocean through the Greenland Sea, the decision was made to evacuate it. This happened with North Pole-1, 5, 6, and 7. North Pole-7 was abandoned north of Greenland in 1959 and was sighted in 1961 off the eastern coast of Baffin Island, a distance of 1200 miles from where it was abandoned. A team of Canadian scientists visited the station and observed that approximately 14 feet of ice had melted from the surface of the floe since its establishment in 1957. The scientists found a hut, food, and other supplies which the Soviets had left on the floe.

As the Soviets gained experience with drifting ice stations, they improved their arctic equipment. One example is the improvement in sleeping quarters. The crews of North Pole-l and 2 used fur-covered tents and sleeping bags. The crews of North Pole-3 and 4 had heated huts, which allowed them to sleep in beds without sleeping bags. North Pole-5 in 1955 marked the first use of collapsible huts mounted on skids. Other equipment used at the stations included jeeps, tractors, trucks, boats, and helicopters. The helicopters and later small airplanes served several purposes. They enabled the scientific parties to conduct research at points far from the camp. They were also used to transport supplies to the camp from the landing strip used by the large resupply aircraft. These landing sites were often 5 miles from the camp, and at North Pole-4 the distance between camp and landing strip was 17 miles.

 Only one of the Soviet stations was visited by Americans, although some of the Soviet and American stations maintained radio contact. A plane en route to an American station on 6 May 1962 flew over station North Pole-11. The pilot made a few low passes over the camp and then landed. The crew of the airplane was not taken into the main camp but was warmly received at the landing strip. After about fifteen minutes of smiles, handshakes, and photographing, the American plane took off and proceeded on its way to ARLIS II, the eighth American drifting ice station to be established in the Arctic Ocean.

American ice stations

The Americans have operated a total of eleven ice stations, although four of them have been on the same ice island, T-3. The first American station, the Polar Ice Pack Station established in 1951, lasted only 19 days and was destroyed by pressure within the ice pack. The United States has been fortunate enough to use two ice islands in its drifting ice station program. The ice island T-3, which has been occupied for eleven of the last fourteen years, was the site of the second American station in 1952. The station was abandoned in 1954 when it drifted close to the weather stations on Ellesmere Island. During the International Geophysical Year the United States decided to maintain two drifting ice stations, Alpha and Bravo. Station Alpha was established on an ice floe, and station Bravo was located on T-3. The ice floe on which Alpha was situated was subjected to a great deal of pressure and had to be evacuated after eighteen months. Bravo remained in operation for over four years and was finally abandoned after grounding in shallow water. The first five U.S. stations were operated and maintained by the Air Force; station Charlie, which lasted less than one year, was a joint Air Force and Navy project. The first Arctic Research Laboratory Ice Station, ARLIS I, was supported by the U.S. Office of Naval Research through the University of Alaska and the Arctic Research Laboratory, as all subsequent American drifting ice stations have been. ARLIS II was located on an ice island and remained in operation from 1961 until May 1965, when it entered the Denmark Strait between Greenland and Iceland. The two latest American stations, ARLIS III and IV, were of a temporary nature, being established on ice floes and lasting 96 and 80 days respectively. Ice island T-3 was occupied again by the Arctic Research Laboratory in 1962, and this station is still in operation.

Equipment utilized at American stations has undergone change just as Soviet equipment did. Early stations used Jamesway huts as quarters and required heavy equipment such as tractors and bulldozers to maintain runways on which C-124 resupply airplanes could land. Station Bravo was equipped with insulated commercial trailers that served as quarters. ARLIS I and the American drifting ice stations operated by the Arctic Research Laboratory marked a departure from the previous methods of operating the stations. Light aircraft, including the Cessna 180 and 195 and the R4D (C-47), were used to establish and maintain the station, and thus the requirement for heavy equipment and mechanics at the station was eliminated. Another innovation was the use of prefabricated huts that could be transported in an R4D. Also, the number of support personnel at the camp was greatly reduced, the scientists performing some of the camp chores themselves. 

American stations are, of course, subject to the same destructive forces within the ice pack as the Soviet stations. Ice pressure reduced the area of many stations; for example, Charlie, when abandoned, was one-fourth its original size. The pressure destroyed the Polar Ice Pack Station and caused the evacuation of Alpha. The ice islands used by the Americans were not without their problems. T-3 was reduced in size while grounded and is now only 6 by 3 miles in size as compared to its original measurements of 10.36 by 5 miles. The ARLIS II ice island fractured shortly after the station was established, and its width was reduced from 3 miles to 1.  An unusual incident occurred at ARLIS II when a large melt-water lake began to empty through holes in the bottom. Investigation revealed that the pool had formed above a dome in the bottom of the ice island which had been covered by only twelve feet of ice.

A comparison of the length of occupation of Soviet and American drifting ice stations, as of 1 September 1965, shows that the Soviet stations were occupied for a total of 8794 days and the American stations for 5999 days. The Soviet stations were occupied for an average of 627 days while the American average length of occupancy was 545 days, based on a separate counting of each period of occupation of T-3. ARLIS II was in continuous operation longer than any other American or Soviet station, 1499 days; however, T-3 was in operation for a total of 3432 days, although not continuously. North Pole-6 was the longest-lasting Soviet station, being occupied 1246 days.

Soviet findings

Many of the later Soviet findings on drifting ice islands have not been translated into English. The Soviet scientists have obtained a great deal of information concerning the physical geography of the arctic basin. They found that the Lomonosov Ridge extends from near the New Siberian Islands across the floor of the ocean to the continental shelf near Ellesmere Island. North Pole-6 recorded one peak of this ridge only 2472 feet below the surface of the ocean. North Pole-4 discovered another ridge west of the Lomonosov Ridge. It is called the Mendeleyev Ridge (Alpha Rise by Americans) and stretches 932 miles from the vicinity of Wrangel Island toward Ellesmere Island, reaching within 4592 feet of the surface. Depth soundings taken on North Pole-2 revealed the existence of a large feature north of the Bering Strait, named Chukchi Cap. One of the most interesting findings of North Pole-3 was that the station had passed over a submarine volcanic eruption on 24 November 1954. As the station approached the area of the eruption (near the Lomonosov Ridge), the ice floe felt a series of strong shocks and cracked. Sulfuric gases were responsible for the death of one crew member. Soviet stations have located at least seventeen sites of volcanic deposits and three sites of volcanic glass that has been dated as less than 5000 years old. These sites lie in a great-circle arc, which the Soviets believe marks a fault line extending in part along the western side of the Lomonosov Ridge for about 300 miles.

Investigations conducted at North Pole-1 led Soviet scientists to the conclusion that a second magnetic north pole was located near 80 N and 178 W, with magnetic medians extending across the Arctic Ocean to the other magnetic north pole. Later observations disproved the existence of a second magnetic north pole, and a large magnetic anomaly was shown to extend across the arctic basin. This magnetic anomaly led one Soviet scientist to the conclusion, before discovery of the Lomonosov Ridge, that a large ridge of folded rock existed under the Arctic Ocean.

The Soviet drifting ice stations made many observations regarding the currents and drifts of the Arctic Ocean and found that water from the East Siberian and Laptev seas moved westward toward the Greenland Sea. There were two smaller currents formed from this large current, one in the Laptev Sea and another near Franz Josef Land. Another Current begins in the Chukchi Sea and Bering Strait and flows toward the Greenland Sea, passing over the North Pole. This has shown that Nansen had the right idea about the existence of currents but that he began the drift of the Fram in the wrong area. When the two large currents enter the Greenland Sea, they join. The currents in the Beaufort Sea, north of Alaska, generally form a closed circle, moving in a clockwise direction. This closed circulation, cal1ed Pacific Gyral, is caused by wind and atmospheric pressure factors and is centered at approximately 82 N and 120 W.

Early Soviet research indicated the presence of four distinct layers of water in the Arctic Ocean. Additional studies have provided the Soviets with sufficient data for a clearer picture of these ocean layers. The upper water from the surface to about 164 feet deep on the Atlantic side of the ocean and to depths of 328 feet on the Pacific side is a layer of arctic surface water. This water has a salinity of only 30 parts per million compared to a salinity in other oceans of 35 parts per million. Below this there is an intermediate layer to depths of 656 or 850 feet with an average salinity of 34 parts per mi11ion. A layer of Atlantic water moves north and eastward at depths from 984 to 2626 feet and has a salinity between 34.7 and 34.9 parts per million. Cold waters form a layer at depths below 2626 feet. North Pole-3 observed that the deep water on the Atlantic side of the Lomonosov Ridge was colder and less saline than water at the same depth on the Pacific side. Observations of a layer of Pacific water at a depth between 164 and 328 feet of the surface, made by the Soviet scientists, showed that this water has the higher temperatures and higher salinity and extends from the Chukchi Sea to the North Pole.

Soviet meteorologists have been very active at drifting ice stations. By January 1959 a total of over 15,000 meteorological observations had been taken. Meteorological data obtained at North Pole-l invalidated the older theory of a permanent high-pressure cell over the Arctic Ocean. A relatively stable high-pressure cell is situated over the central Arctic Ocean in the winter, but during the summer a low-pressure cell of an unstable nature hovers over the area, causing a large number of intense cyclonic storms to pass through the region. Unstable weather, overcast skies, precipitation, and fog are often associated with these storms. In the spring these storms are often accompanied by strong winds, snow or other precipitation, and blizzards, and they seem to intensify over the central Arctic Ocean. During the winter the high-pressure cell tends to keep cyclonic storms out of the Arctic Ocean, and visibility is generally good. The dominant high-pressure cell of the winter is associated with cold temperatures. This cold, high-pressure air mass was found to be similar to the cold air mass situated over Siberia at the same time of the year; however, temperatures in the arctic are approximately 25 degrees higher than those over Siberia. The Soviet drifting ice stations observed that July is the warmest month in the Arctic Ocean, but temperatures seldom rise above 32. North Pole-3 recorded a high temperature on 1 June 1955 of -14 even though there were 24 hours of sunshine.  The lowest temperature reported by a Soviet station was -46.8 at North Pole-1.

Another field of Soviet investigation on drifting ice stations was the stratification of the atmosphere. The lowest stratum of air is strongly cooled by the ice of the ocean and has a maximum thickness of about 120 feet in the fall. Temperatures in this layer are frequently inverted. North Pole-3 reported that temperatures at the top of this layer were from 27 to 36 degrees higher than those at the surface. The tropopause, or zone between the troposphere and stratosphere, was reported by North Pole-4 to occur at a height of 7 miles in January. In September the tropopause was observed only 2.6 miles above the surface of the Arctic Ocean. Temperatures in the stratosphere were found either to be constant or to rise with increased height.

The large number of zooplankton and phytoplankton collected by Soviet marine biologists destroyed the old idea that the Arctic Ocean was barren. These biologists also discovered new species of zooplankton in the Pacific side of the Arctic Ocean, probably the result of blockage of deep-water exchange by the Lomonosov Ridge. Abundant organic life was found where the water from the Pacific Ocean enters the Arctic Ocean and in the vicinity of the Lomonosov Ridge.

American findings

Because only one of the eleven American drifting ice stations, ARLIS II, has drifted west of 180, American studies in the Arctic Ocean have generally been restricted to the area north of the Chukchi Sea, Beaufort Sea, and Canadian Archipelago. The Alpha Rise was first observed by American scientists when station Alpha drifted across the rise twice and then drifted along its lineal direction. They found the Lomonosov Ridge to be 1118 miles long and from 37 to 124 miles wide. The minimum depth of water over the rise was found to be 3739 feet. A profile of the Alpha Rise obtained by station Alpha suggested that it is an area of fault-block mountains.

One submarine feature studied by four American drifting ice stations was the Chukchi Cap, which was found to have a greatly dissected surface at an average depth of 925 feet. Although the Chukchi Cap rises to within 807 feet of the ocean surface, the ocean floor on the northwestern side of it reaches a depth of 9955 feet. T-3 discovered another ridge on the floor of the Arctic Ocean during its early drift. It has been named the Marvin Ridge and is not as extensive as the Lomonosov Ridge or the Alpha Rise. These three ridges join to form a broad submarine shelf north of Ellesmere Island. ARLIS II reported that the Markarov Deep, which is enclosed by the three ridges, is an abyssal plain averaging 9187 feet below the surface of the ocean. ARLIS I discovered another submarine feature to the southeast of the Chukchi Cap, the Northwind Seahigh, which is smaller in size but has surface relief and elevations similar to the Chukchi Cap.

American scientists were able to add to Soviet information regarding ice drift. Studies at T-3 indicated that the pack ice usually drifted at angles between 30 and 50 to the right of the surface wind direction. The rate of ice drift varies from one-fortieth to one-eightieth of the speed of the surface winds, with an average rate of one-fiftieth. Since all American drifting ice stations have drifted in the area of closed clockwise circulation north of the North American continent, the Pacific Gyral, this region has been studied in detail. The water level near the center of this area is slightly higher than surrounding areas. Water flows out of this height anomaly to lower levels and is turned to the right. The observed drift of T-3 from 1952 to 1962 showed that it takes approximately ten years to make one revolution in the outer portion of the Pacific Gyral.

Research on American drifting ice stations has revealed considerable information regarding water stratification. In the Canadian Deep the water to a depth of about 500 feet has low salinity and a temperature near freezing. From 500 feet to 3000 feet there is a layer of water with a salinity between 34 and 35 parts per million. This is a layer of Atlantic water that enters the Arctic Ocean near Spitsbergen. The bottom layer of waters in the Arctic Ocean has a salinity just under 35 parts per million. This water is also Atlantic in origin, being formed in the Norwegian Sea and sinking below the arctic waters. Water entering the Arctic Ocean from the Pacific Ocean mixes with water from the Chukchi Sea and becomes part of the water in the Pacific Gyral.

Scientists at both T-3 and ARLIS II studied the formation and structure of ice islands. The age of the ice at these stations varied from 450 to 5800 years. Core holes drilled in T-3 revealed pockets of fresh water in the ice. At one location, eight feet of ice layover eight feet of fresh water. ARLIS II was discovered to be a section of glacial ice from the Ellesmere Island ice shelf which was bordered by sea ice. At the point of contact between the gray glacial ice and the blue sea ice, there were numerous enlongate, narrow areas of fresh-water ice and mud concentrations.

American meteorological findings showed temperatures remaining below zero degrees for five consecutive months during the early drift of T-3. The daily range of temperatures during the summer was small--in July 1952, only 2 degrees. A daily range of 14 degrees occurred in the fall and winter. The highest temperature reported by an American drifting ice station was 43 at T-3 during June. The lowest temperature noted by an American station was -72.5 recorded by T-3 on 30 and 31 January 1964. The temperature had to be estimated, as the only available thermometers would not record temperatures below -70. Prior to 30 January 1964 the temperatures at T-3 had been lower than -60 for three days. ARLIS II, which was also in operation at this time, recorded a temperature of almost -55. Studies at T-3 from 1952 to 1955 indicated that surface temperature inversion was evident 82 percent of the time from November to April. From June to August this type of inversion occurred about 11 percent of the time and averaged 56 percent on a yearly basis. The greatest difference of temperatures in this inversion was almost 55 degrees.

Contrary to the old theory that the Arctic Ocean was devoid of plant life, research on American drifting ice stations has produced considerable evidence that planktons are relatively common but much less numerous than in other oceans. Station Alpha observed that large diatom colonies which were attached to the underside of the ice floes formed the beginning of a food cycle. Crustaceans fed on the diatoms, fish ate the crustaceans, the fish provided the principal food of seals in the ocean, and finally the polar bear, ruler of the arctic region, fed on the seals. Polar bears were a hazard at the ice stations, and American crew members usually kept their rifles near for protection.

the programs compared

The Soviet government has always sent only scientists with the highest qualifications to serve on their drifting ice stations. American crews have often included members with less training and experience, although the leaders were men who ranked with the Soviet scientists. Once a Soviet or American had served at one drifting ice station, he was likely to serve at another. Many of the Soviet scientists who served on these stations have become leaders in the Northern Sea Route Administration, the Hydrometeorological Service, and other agencies. Similarly, American scientists have moved on to head institutions and agencies that can benefit from their knowledge and experience. 

Although the varied drifts of the Soviet drifting ice stations have enabled their scientists to conduct research in many sections of the Arctic Ocean where American stations have not visited, both groups of scientists have made significant discoveries regarding the topography of the ocean floor. One of the most important early findings was that the ocean floor was not as flat as had previously been thought. The findings of Soviet stations have provided data which make the interpretation of American findings much clearer. For instance, the Soviets discovered a rise in the Arctic Ocean, and later the American station Alpha drifted along the top of it; a better understanding of the true nature of this feature was gained from the findings of both nations. Although Soviet stations have found evidence of volcanic activity in the Arctic Ocean, American stations have not.

One problem in the use of depth soundings taken from early drifting ice stations was the difficulty in determining exact locations. Early Soviet bathographic charts did, however, provide valuable information regarding the entrance to the Arctic Ocean from the Bering Strait. This information was used by the U.S. nuclear submarines Nautilus and Skate when they first entered the Arctic Ocean in 1958. The USS Skate surfaced at station Alpha on 11 August 1958, proving that submarines could surface through the pack ice and operate in the Arctic Ocean. Submarines have demonstrated an ability to take depth soundings over a large area in a shorter time than drifting ice stations, but the stations can provide more data regarding bottom topography and ocean sediments. For this reason drifting ice stations remain one of the best modes for study of the Arctic Ocean.

Both Soviet and American scientists have investigated the subject of ice drift, and their findings are similar. The Soviet and American findings regarding water stratification contain a few minor differences, but in general they agree. It should be pointed out that the characteristics and depths of the water strata were often measured at different locations and at different times of the year. The same is true of the recording of different temperatures in the upper strata of water by American stations Alpha and Bravo (T-3).

Soviet and American scientists have been in general agreement in their meteorological findings, especially as to atmospheric pressures and temperatures. Whereas American station T-3 recorded both the highest and lowest temperature in the Arctic Ocean, both American and Soviet drifting ice stations reported and made records of frequent surface temperature inversions in the Arctic Ocean. In no area of investigation has a disagreement of major importance developed.

The prime purpose of Soviet drifting ice stations was to obtain meteorological and hydrological data. The information secured at these stations was very useful in the development of the Northern Sea Route. The success of the weather and ice forecasting, as well as the development of faster and stronger ships, was reflected in the discontinuation of the Northern Sea Route Administration in 1963. The Soviet government believed that the meteorological observations were still needed because of the effect of the weather of the Arctic Ocean on the climate of the Soviet Union. The first American drifting ice station was established along the flight lines of aircraft that were making meteorological observations over the Arctic Ocean. This station served primarily as a search and rescue station but also made meteorological observations.

Prior to the development of intercontinental ballistic missiles, both the Soviet Union and the United States realized the importance and need for information concerning the Arctic Ocean. The meteorological data obtained were necessary in the planning of possible military operations in arctic regions and were of significance in submarine operations. Also of major importance to arctic submarine operations was the information provided to the Office of Navy Research by ARLIS II when it drifted from the Arctic Ocean, passing through the Greenland Sea and Denmark Strait. Since this is the only deep-water entrance to the Arctic Ocean it was important to know its nature.

The final index to the value of drifting ice stations is the continuation of the programs by both the Soviet and American governments.

Arctic, Desert, Tropic Information Center (ASI)

CORRECTION: In the May-June issue of Air University Review, in the article entitled "Exercise Deep Furrow 65," the 322d Air Division was erroneously identified as a unit of United States Air Forces in Europe (USAFE). The 322d Air Division was a USAFE unit prior to 1 April 1964 but is now a unit of the Military Airlift Command (MAC).


First Lieutenant Charles L. Smith (M.S., University of Alabama) was with the Arctic, Desert, Tropic Information Center, Aerospace Studies Institute, Air University, prior to his recent assignment to attend the Air Intelligence Officer Course, 3415 Tech School, ATC, Lowry AFB, Colorado. After graduation from Kansas State University in 1960, he taught science in high school for a year before being called to active duty as an NCO with the 442d Troop Carrier Wing (H) (Reserve). Upon receiving his commission from Officer Training School in 1962, he was assigned to ADTIC, his areas of specialization being biology and South America. Lieutenant Smith attended the University of Alabama under Bootstrap in 1965-66, and the present article is adapted from his master's thesis.


The conclusions and opinions expressed in this document are those of the author cultivated in the freedom of expression, academic environment of Air University. They do not reflect the official position of the U.S. Government, Department of Defense, the United States Air Force or the Air University.

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