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Posts tagged Mount Recheshnoi

Shield and Strato-Volcanoes of Umnak Island, USA

53.1N 168.5W

December 9th, 2009 Category: Volcanoes

Alaska, USA - November 10th, 2009

Alaska, USA - November 10th, 2009

Volcanoes with distinctive shapes can be observed on Umnak Island, one of the Aleutian Islands that are part of the state of Alaska, USA, in this orthorectified image. The northern end of the island is mostly occupied by the circular volcanic caldera of Mount Okmok.

The southern end of the island is home to the steep symmetrical cone of Mount Vsevidof  and the heavily eroded Mount Recheshnoi (right of the former).

Both Mount Vsevidof and Mount Recheshnoi are stratovolcanoes, while Mount Okmok is a shield volcano. The summit of Mount Vsevidof is the highest point on Umnak Island at 7051 ft (2149 m), while its neighbor Mount Recheshnoi is lower, due in part to erosion, with a maximum elevation of 6,509 feet (1984 m). Returning to the north end of the island, Mount Okmok itself, near the caldera rim, is much lower than its southern-end counterparts, with a height of 3,520 feet (1073 m).

Volcanoes of Umnak Island, Alaska, USA

53.4N 168.1W

September 7th, 2009 Category: Volcanoes

Alaska, USA - July 28th, 2009

Alaska, USA - July 28th, 2009

Umnak Island, part of the Aleutian Islands in Alaska, USA, is visible here in its entirety, from Mount Okmok in the upper right quadrant to its thin southwestern tip towards the bottom edge of this orthorectified image.

The wide, circular caldera of the Mount Okmok volcano can be seen in great detail. Of note is an eroded segment of the rim on the northeast side, through which the lake that used to fill the cadera drained.

Southwest of Mount Okmok, on the southern lobe of the island, are Mount Recheshnoi  (right) and Mount Vsevido (left).

Vsevidof and Recheshnoi Volcanoes, Alaska, USA

53.1N 168.6W

August 21st, 2009 Category: Volcanoes

USA - July 1st, 2009

USA - July 1st, 2009

Umnak is one of the Fox Islands of the Aleutian Islands, part of Alaska, USA. With 686.01 square miles (1,776.76 km2) of land area, it is the third largest island in the Aleutian archipelago and the 19th largest island in the United States.

The island is home to several volcanoes: Mount Okmok (with a large volcanic caldera, right edge), Mount Vsevidof (white cone, center) and Mount Recheshnoi (right of the former).

Mount Vsevidof is a stratovolcano whose summit is the highest point on Umnak Island. Its symmetrical cone rises abruptly from its surroundings.

Mount Recheshnoi, on the other hand, is a heavily eroded stratovolcano. It is notable for its northeast flank, which has one of the hottest and most extensive thermal areas in Alaska.

This image has been orthorectified. Please click here to see other such images.

The Circular Cadera of Mount Okmok, Alaska, USA

53.4N 168.1W

July 18th, 2009 Category: Volcanoes

Alaska, USA - July 9th, 2009

Alaska, USA - July 9th, 2009

Mount Okmok is the highest point on the rim of Okmok Caldera on the northeastern part of Umnak Island, in the eastern Aleutian Islands of Alaska, USA. Two other volcanoes, Mount Recheshnoi  and Mount Vsevido, are visible on the southwestern part of the island in this orthorectified image.

Mount Okmok’s 5.8 mile (9.3 km) wide circular caldera truncates the top of a large shield volcano. A crater lake once filled much of the caldera to a depth of over 500 ft, but the lake ultimately drained through a notch eroded in the northeast rim. Only a small remnant lake about 1000 ft across exists in a depression in the western area of the largely flat caldera floor.

The last major eruptions of Okmok—with an estimated VEI strength of 6—occurred 8,300 and 2,400 years Before Present. The volcano is currently rated by the Alaska Volcano Observatory as Aviation Alert Level Yellow and Volcanic-alert Level Advisory.