Agrihan
Encyclopedia
Agrihan is a stratovolcano
which forms an island in the Northern Mariana Islands
in the Pacific Ocean
. The entire island is a massive volcano which rises over 4000 metres (13,123.4 ft) from the ocean floor, and is the fifth largest in the Marianas volcanic arc
. At 965 m (3,166 ft), its summit is the highest point in Micronesia
. The volcano is topped by a large caldera, 1 x 2 km (0.6 x 1.2 mi) in size and about 500 m (1,640.4 ft) deep.
The island was evacuated in 1990 due to the threat of volcanic activity, although in the end no eruption occurred. A settlement has since been reestablished in one of the four original villages, and as of September 2005 there were nine inhabitants. Five years earlier, in the 2000 census
no population was reported. The island has a total land area of 43.51 km² (16.80 sq mi). Politically it is part of the Northern Islands Municipality
.
Stratovolcano
A stratovolcano, also known as a composite volcano, is a tall, conical volcano built up by many layers of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile and periodic, explosive eruptions...
which forms an island in the Northern Mariana Islands
Northern Mariana Islands
The Northern Mariana Islands, officially the Commonwealth of the Northern Mariana Islands , is a commonwealth in political union with the United States, occupying a strategic region of the western Pacific Ocean. It consists of 15 islands about three-quarters of the way from Hawaii to the Philippines...
in the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
. The entire island is a massive volcano which rises over 4000 metres (13,123.4 ft) from the ocean floor, and is the fifth largest in the Marianas volcanic arc
Volcanic arc
A volcanic arc is a chain of volcanoes positioned in an arc shape as seen from above. Offshore volcanoes form islands, resulting in a volcanic island arc. Generally they result from the subduction of an oceanic tectonic plate under another tectonic plate, and often parallel an oceanic trench...
. At 965 m (3,166 ft), its summit is the highest point in Micronesia
Micronesia
Micronesia is a subregion of Oceania, comprising thousands of small islands in the western Pacific Ocean. It is distinct from Melanesia to the south, and Polynesia to the east. The Philippines lie to the west, and Indonesia to the southwest....
. The volcano is topped by a large caldera, 1 x 2 km (0.6 x 1.2 mi) in size and about 500 m (1,640.4 ft) deep.
The island was evacuated in 1990 due to the threat of volcanic activity, although in the end no eruption occurred. A settlement has since been reestablished in one of the four original villages, and as of September 2005 there were nine inhabitants. Five years earlier, in the 2000 census
United States Census, 2000
The Twenty-second United States Census, known as Census 2000 and conducted by the Census Bureau, determined the resident population of the United States on April 1, 2000, to be 281,421,906, an increase of 13.2% over the 248,709,873 persons enumerated during the 1990 Census...
no population was reported. The island has a total land area of 43.51 km² (16.80 sq mi). Politically it is part of the Northern Islands Municipality
Northern Islands Municipality
Northern Islands Municipality is one of the four main political divisions of the Commonwealth of the Northern Mariana Islands. It consists of a long string of the northernmost islands of the Northern Marianas, including Farallon de Pajaros, the Maug Islands, Asuncion, Agrihan, Pagan, Alamagan,...
.