The Aleutian Islands (possibly from Chukchi aliat, "island") are a chain of more than 300 small volcanic islands forming a volcanic arc in the Northern Pacific Ocean, occupying an area of 6,821 sq mi (17,666 km²) and extending about 1,200 mi (1,900 km) westward from the Alaska Peninsula toward the Kamchatka Peninsula. Crossing longitude 180°, they are the westernmost part of the United States (and technically also the easternmost; see Extreme points of the United States). Nearly all the archipelago is part of Alaska and usually considered as being in the "Alaskan Bush", but at the extreme western end the small, geologically-related, and remote Commander Islands are in Russia. The islands, with their 57 volcanoes, are in the northern part of the Pacific Ring of Fire. The Alaska Marine Highway passes through the islands.
Physiographically, they are a distinct section of the larger Pacific Border province, which in turn is part of the larger Pacific Mountain System physiographic division.
The islands, known before 1867 as the Catherine Archipelago, comprise five groups (east to west): the Fox, Islands of Four Mountains, Andreanof, Rat, and Near island groups (with Buldir Island halfway between Rat and Near Islands, but part of neither group). They are all located between 52° and 55° N latitude and 172° E and 163° W longitude.
The axis of the archipelago near the mainland of Alaska has a southwest trend, but near the 179th meridian its direction changes to the northwest. This change of direction corresponds to a curve in the line of volcanic fissures that have contributed their products to the building of the islands. Such curved chains are repeated about the Pacific Ocean in the Kuril Islands, the Japanese chain, and in the Philippines. All these island arcs are at the edge of the Pacific Plate and experience a lot of seismic activity, but are still habitable; the Aleutians lie between the Pacific and North American tectonic plates. The general elevation is greatest in the eastern islands and least in the western. The island chain is a western continuation of the Aleutian Range on the mainland.
The great majority of the islands bear evident marks of volcanic origin, and there are numerous volcanic cones on the north side of the chain, some of them active; many of the islands, however, are not wholly volcanic, but contain crystalline or sedimentary rocks, and also amber and beds of lignite. The coasts are rocky and surf-worn, and the approaches are exceedingly dangerous, the land rising immediately from the coasts to steep, bold mountains.
Makushin Volcano (5691 ft/1,735 m) located on Unalaska Island, is not quite visible from within the town of Unalaska, though the steam rising from its cone is visible on a (rare) clear day. denizens of Unalaska need only to climb one of the smaller hills in the area, such as Pyramid Peak or Mt. Newhall, to get a good look at the snow-covered cone. The volcanic Bogoslof and Fire Islands, which rose from the sea in 1796 and 1883 respectively, lie about 30 miles (48 km) west of Unalaska Bay.
The climate of the islands is oceanic, with moderate and fairly uniform temperatures and heavy rainfall. Fogs are almost constant. Summer weather is much cooler than Southeast Alaska (Sitka), but the winter temperature of the islands and of the Alaska Panhandle is very nearly the same. The mean annual temperature for Unalaska, the most populated island of the group, is about 38 °F (3.4 °C), being about 30 °F (−1.1 °C) in January and about 52 °F (11.1 °C) in August. The highest and lowest temperatures recorded on the islands are 78 °F (26 °C) and 5 °F (−15 °C) respectively. The average annual rainfall is about 80 in (2,030 mm), and Unalaska, with about 250 rainy days per year, is said to be one of the rainiest places within the United States.
In 1741 the Russian government sent Vitus Bering, a Dane in the service of Russia, and Aleksei Chirikov, a Russian, in the ships Saint Peter and Saint Paul on a voyage of discovery in the Northern Pacific. After the ships were separated by a storm, Chirikov discovered several eastern islands of the Aleutian group, and Bering discovered several of the western islands, finally being wrecked and losing his life on the island of the Komandorskis (Commander Islands) that now bears his name (Bering Island). The survivors of Bering's party reached the Kamchatka Peninsula in a boat constructed from the wreckage of their ship, and reported that the islands were rich in fur-bearing animals.
Siberian fur hunters flocked to the Commander Islands and gradually moved eastward across the Aleutian Islands to the mainland. In this manner, Russia gained a foothold on the northwestern coast of North America. The Aleutian Islands consequently belonged to Russia, until that country transferred all its possessions in North America to the United States in 1867.
The Russians were ruthless in their expansion, using technology and cruelty to enslave the Aleuts, especially for sea otter hunting. The Russians captured otter pelts from the Aleutian Islands, through the Gulf of Alaska, along the Alaska Panhandle, and south, even to California. Some Aleuts were moved to the Pribilof Islands so that fur seals could be captured there as well.
By 1760, the Russian merchant Andrian Tolstykh had made a detailed census in the vicinity of Adak and extended Russian citizenship to the Aleuts.
Despite some attempts to eliminate slavery and reduce cruel treatment in the 1790s, the Shelikhov company depended on the labor of Aleut hunters to collect sea otter pelts.
During his third and last voyage, in 1778, Captain James Cook surveyed the eastern portion of the Aleutian archipelago, accurately determined the position of some of the more important islands, and corrected many errors of former navigators.
Another early Christian missionary of the Russian Orthodox Church was Father Veniaminov who arrived in Unalaska in 1824. He was named Bishop Innokentii in 1840 and moved to Sitka. He is now known in the Orthodox Church as Saint Innocent of Alaska.
The principal settlements were on Unalaska Island. The oldest was Iliuliuk (also called Unalaska), settled in 1760-1775, with a customs house and an Orthodox church.
The U.S. Congress extended American citizenship to all Natives (and this law has been held to include the indigenous peoples of Alaska) in 1924.
A hospital was built in Unalaska in 1933 by the U.S. Bureau of Indian Affairs.
During World War II, small parts of the Aleutian islands were occupied by Japanese forces, when Attu and Kiska were invaded in order to divert American forces away from the main Japanese attack at Midway Atoll. The U.S. Navy, having broken the Japanese naval radio codes, knew that this was just a diversion, and it did not expend large amounts of effort in defending the islands. A few Americans were taken to Japan as prisoners of war. Most of the civilian population of the Aleutians were interned by the United States in camps in the Alaska Panhandle. During the Aleutian Islands Campaign, American forces invaded Japanese-held Attu and defeated the Japanese, and subsequently regained control of all the islands. The islands were also a stopping point for hundreds of aircraft sent from California to Russia as part of the war effort.
Monday, June 3, 2002 was celebrated as Dutch Harbor Remembrance Day. The governor of Alaska ordered state flags lowered to half-staff to honor the 78 soldiers who died during the two-day Japanese air attack in 1942. The Aleutian World War II National Historic Area Visitors Center opened in June 2002.
In 1906 a new volcanic cone rose between the islets of Bogoslof and Grewingk, near Unalaska, followed by another in 1907. These cones were nearly demolished by an explosive eruption on September 1, 1907.
The Aleutian Islands are an important part of the National missile defense system proposed to defend the United States from small ballistic missile attacks.
The last shot of the Civil War was fired from the CSS Shenandoah in the Aleutian Islands.
Total area of from Encyclopædia Britannica Online