Умнак аралының тарихы мен географиясы

The earliest known settlement on Umnak Island is at Anangula and is 8,400 years old. Anangula was later abandoned and the Sandy Beach site became occupied, along with Idaliuk and Chaluka. Most of the early settlements on Umnak were located along the streams. A major geologic event was the cutting of strand flats during the Hypsithermal period, about 8250 to 3000 years ago, which led to a greater natural food supply on the island for the settlers. Umnak Island was first reached by independent Russian fur traders in the 1750s. Abuses by the Russians led to an alliance among Aleuts in the Fox Islands. During the winter of 1761–1762, the crews of four Russian ships were massacred. This included one entire crew on Umnak which was completely wiped out. Russian traders responded with a scorched earth campaign in 1764 that essentially ended the Aleuts' independence. The modern history of Umnak Island is linked to the military bases established by the United States during World War II. The purpose of the forward air bases in the Aleutian Islands was not only to defend the Dutch Harbor but also to launch attacks against the Japanese mainland. The island was separated in the last glacial period and now lies about from North American shores. It is an active volcanic island, with a land area of and with a coastline extending over The elevation of the island is The southern point of the island is known as Cape Sagak. The highest peak of the island, the Mount Vsevidof stratovolcano, is located in the southwestern part of the island. Its symmetrical cone rises abruptly from its surroundings and forms a crater at a height of To the east of Mount Vsevidof is the Russian Bay valley and another stratovolcano, Mount Recheshnoi which is also deeply dissected with a height of In the southwest is the settlement of Nikolski further south and a lake, Umnak Lake, to its southeast which is just over in length. The ancient settlement of Chaluka is located between this lake and Nikolski. This area is known as the Samalga Pass and was the center of ancient activity on the island and is located about 15 mile (24 km) off the southwestern tip of the island (Cape Sagak). The north northeastern part of the island contains tholeiitic basaltic rocks and is characterized by tension faulting, lava flows, and fragmental deposits of igneous rocks. The volcano of Mount Okmok, characterized by its 5.8 mile (9 km) wide circular caldera, it located in the northwestern part of the island. This generally flat central basin has an average elevation of 370 m above sea level, with the rim of the caldera reaching a height of A crater lake once filled much of the caldera to a depth of over 500 feet (152 m), but the lake ultimately drained through a notch eroded in the northeast rim. The prehistoric lake attained a maximum depth of about and the upper surface reached an elevation of about , at which point it overtopped the low point of the caldera rim. Small, shallow remnants of the lake remained north of Cone D at an altitude of about 1075 feet (328 m): a small shallow lake located between the caldera rim and Cone D; a smaller lake (named Cone B Lake) farther north near the caldera's gate. After the 2008 eruption, the hydrogeology of the caldera was greatly changed with five separate sizable lakes now emplaced. In addition to the caldera lakes, Cone A, Cone E, and Cone G and the new 2008 vent on Cone D contain small crater lakes. The volcano is currently rated by the Alaska Volcano Observatory as Aviation Alert Level Green and Volcanic alert Level Normal. To the north of Mount Recheshnoi, in the valley of Geyser Creek are located geothermal fields with geysers. In 1988 there were active 5 geysers up to 2 m high and 9 natural fountains up to 0.7 m high. Umnak has a subarctic climate (Köppen: Dfc), which borders on a subpolar oceanic climate (Köppen: Cfc) with short, mild to warm summers and long, cold, snowy winters.

On Saturday, July 12, 2008, Okmok Volcano on Mount Okmok, located on Umnak, erupted for several days, through a fresh vent sending wet, ash, and gas rich plume that reached an altitude of 50000 feet (15240 m) in the air and forcing the evacuation of Fort Glenn, a private cattle ranch located on the island. Ash fell not only on the eastern part of the island but also on a fishing village 65 mile (105 km) on the northeast. However, the Aleut village, Nikolski, on the opposite side of Umnak Island with a population of about 40 people to the west of Okmok Volcano escaped from the southeasterly path of the ash clouds. The ash plume also disrupted the operation of flights to the Dutch Harbor airport as it spread across many miles of the North Pacific. Okmok Caldera itself had been formed and reshaped in two major eruptions which occurred 12,000 and 2,000 years ago. Direct observations of later volcanic activity are known since 1805, with 16 eruptions recorded every 10 to 20 years. the island's population further declined to 39 persons. Its only remaining community, Nikolski, comprised the island's entire population. Fort Glenn, a former major military facility on the northeast shore of the island, played an instrumental role in the North Pacific Theater in World War II. As of the census of 2000, there were 15 households and 12 families residing on the island. The population density was There were 28 housing units at an average density of The racial makeup of was 30.77% White and 69.23% Native American. There were 15 households, out of which 40.0% had children under the age of 18 living with them, 53.3% were married couples living together, 20.0% had a female householder with no husband present, and 20.0% were non families. 20.0% of all households were made up of individuals, and none had someone living alone who was 65 years of age or older. The average household size was 2.60 and the average family size was 2.92. In 2000, the median age was 40 years, with 35.9% under the age of 18, 30.8% from 25 to 44, 23.1% from 45 to 64, and 10.3% who were 65 years of age or older. For every 100 females there were 105.3 males. For every 100 females of age 18 and over, there were 92.3 males. The median income for a household was $38,750, and the median income for a family was $40,250. Males had a median income of $26,250 versus $11,875 for females. The per capita income was $14,083. There were 23.5% of families and 20.7% of the population living below the poverty line, including 13.6% of under eighteens and 55.6% of those over 64.

The only school on the island was in Nikolski, part of the Aleutian Region Schools. The Nikolski School served grades K 12. The school had one teacher who lived in a small home adjacent to the school building. The home is owned by the school district and was purpose built for teachers and their families. The Nikolski School is in danger of extinction. Schools in rural Alaska must have at least 10 students to retain funding from the state. For the 2009–2010 school year, the Nikolski School had only nine students including a Samoan family who subsequently relocated, and was closed in 2010.

Umnak does not have a harbor. It does, however, have an airstrip, Nikolski Airport. Building an airport runway in the hilly terrain was a unique engineering achievement of the Army Engineers, commanded by Colonel Benjamin B. Talley. The construction work of the runway was proposed at Otter Point on the northeastern end of Umnak. Construction was started in the middle of January 1942 and was commissioned by April of the same year, being given the name Fort Glenn. of Marston Matting, a perforated steel plating (PSP), was assembled along with other steel plates and created a flat surface for aircraft to take off and land. The runway was completed on March 31, 1942, by the 807th Unit of the Army Engineers. It was 3000 feet (914 m) long with a width of 100 feet (30 m) sufficient for Capt. John S. Chennault's P 40 fighter aircraft in the 11th Fighter Squadron to land. After the war ended, Fort Glenn remained open as a refueling stop for transient aircraft in the Aleutians along with Military Air Transport Service flights using the Great Circle Route from Japan to the United States. The main runway was extended to 8,300 feet long to accommodate large, long range aircraft. By 1946, the base maintained only a skeleton staff due to the rapid demobilization of the Army Air Forces. The last AAF personnel were withdrawn by 30 September 1947, and the base was put on inactive status and was effectively abandoned. It was decommissioned in 1950 and the site was excessed between 1952–55 to the Bureau of Land Management. Many years later the airfield was added to the National Register of Historic Places as Cape Field at Fort Glenn. Some distance away, Nikolski is still served by a gravel airstrip.