Aleutians Theater with major U.S. Installations as of 1 August 1942
Insets: Attu and Kiska islands
Until the end of the Pacific War no one can make a conclusive statement of the objectives of the Japanese attack on the Aleutian Islands in June 1942. The enemy may have been planning the subsequent conquest of all the islands in order to obtain access to Canada and our northwestern states. He may even have aimed at an immediate invasion of Alaska, only to be deterred by our victory at Midway. It is well known that the Japanese had long coveted Alaska and the Aleutians, and that many of their military leaders considered these poorly defended outposts the logical route for an invasion of North America.
The enemy's intentions may have been less ambitious, however, He may merely have planned to protect his northern flank, to divide our forces, and to complicate our defense of Hawaii and the West Coast after the expected capture of Midway.
Whatever his primary motives, the crushing blow administered by our forces in the mid-Pacific drastically revised the strategic situation. The reasons why Japan clung thereafter to her footholds in the western Aleutians are obscure. But it is probable that Attu and Kiska were either to provide jumping-off places for a future invasion, or to constitute advanced observation posts and defenses for the Empire. Perhaps both ends were envisaged. At all events, it was immediately clear that the occupation provided a continuing threat to our security. Even if this threat did not develop, any plans for seizing the offensive in the Central Pacific would be difficult to execute while the enemy maintained his flanking positions in the north. Furthermore, considering the war as a whole, every day
that hostile troops remained on American soil was as beneficial to Japanese morale as it was deleterious to that of our own people.
The situation was grave. Because of our commitments elsewhere, the means of quickly resolving it were far from adequate. As a result, the Japanese were ejected from the Aleutians only after 15 months of arduous operations which were hampered by shortages afloat, ashore, and in the air, as well as by almost insuperable obstacles of weather and terrain.
The Geographical Factor
One cannot form an accurate picture of the Aleutians Campaign without a thorough understanding of the geographical and meteorological peculiarities of the area. Practically every offensive or defensive move by either side was conditioned as much by terrain and weather as by the efforts of the enemy.
Approximately 120 islands comprise the Aleutian chain, which stretches from the tip of the Alaskan peninsula to within 90 miles of Kamchatka. The easternmost island, Unimak, is also the largest, measuring 65 by 22 miles. To the southwest is Unalaska, on the north coast of which Dutch Harbor is located. Unalaska is about 2,000 miles from both San Francisco and Honolulu. Westward, in order, lie Umnak, Atka, and Adak. Kiska is 610 miles west of Dutch Harbor, while Attu, the westernmost American island, is nearly 1,000 miles from the Alaskan mainland and 750 miles northeast of the northernmost of the Japanese Kurile Islands. Attu is about 20 by 35 miles in size.
All the Aleutians are volcanic in origin. They are uniformly rocky and barren, with precipitous mountains and scant vegetation. The mountains are conical in shape and covered with volcanic ash and resembling cinders. There are no trees on the islands, except a few stunted spruces at Dutch Harbor, and no brush, which complicates the building and heating problems. The lowlands are blanketed with tundra or muskeg as much as three feet thick. This growth forms a spongy carpet which makes walking most difficult. Below the tundra is volcanic ash which has been finely ground and watersoaked until it has the consistency of slime. In many places water is trapped in ponds under the tundra. Frequently men have fallen into these bogs and been lost.
Throughout the Aleutians, jagged shorelines and submerged rock formations
render navigation hazardous. Conditions are least unfavorable in the eastern islands. Unalaska has two comparatively good anchorages, Dutch Harbor and Captain's Bay, while Umnak has three, of which Nikolski Bay on the west coast is the most important. Farther west, protected anchorages are scarce. Atka has two fair harbors. Adak has three small bays on the west coast. Amchitka offers one small bay on the east coast. Neither Kiska nor Attu possesses a harbor which is entirely suitable for larger vessels. Kiska is the better endowed, having a broad, moderately deep indentation on the eastern shore which is protected by Little Kiska Island, lying across its mouth. Attu has four less adequately guarded bays--Holtz, Chichagof, and Sarana on the northeast side, and Massacre Bay on the southeast.1 Of these Chichagof is the best.
Meteorological conditions become progressively worse as the western end of the island chain is approached. On Attu five or six days a week are likely to be rainy, and there are hardly more than eight or ten clear days a year. The rest of the time, even if rain is not falling, fog of varying density is the rule rather than the exception. Weather is highly localized, however, and areas of high visibility will often be found within 20 miles of fog concentration.
Throughout the islands annual rainfall averages 40 to 50 inches, spread over most of the year. Precipitation is rarely heavy, but reaches a peak in fall and early winter.
A special hazard to sea and air navigation is provided by sudden squalls known as "williwaws," which sweep down from the mountainous area with great force, sometimes reaching gale proportions within half an hour. The mountains are concentrated on the north sides of the islands, and the williwaws cause strong off-shore winds which make it difficult to find a lee along the north coasts. The columns of spray and mist resulting from the williwaws frequently resemble huge waterfalls.
Winds generally are gusty because of the deflection of air currents by the steep mountain slopes. The greatest velocities occur in March. In the Aleutians, curiously enough, winds and fogs may persist together many days at a time. Humidity is always high. Temperatures are moderate and not subject to much variation. In this connection it should be remembered
that, contrary to popular conception, the Aleutians are not arctic territory. In places they are only 02º north of the border between Canada and the United States proper. Kiska lies in the latitude of London and the longitude of New Zealand.
While Aleutian weather was a constant impediment to he military operations of the United States and Japan alike, the enemy enjoyed one advantage. Weather in this theater moves from west to east, with the result that the Japanese always knew in advance the conditions which were likely to prevail in the islands.
See chart opposite p. 1.
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