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The Hawaiian Islands form an archipelago that extends over a vast area of the North Pacific Ocean. The archipelago is made up of 132 islands, atolls, reefs, shallow banks, shoals, and seamounts stretching 1,523 miles (2,451 km) from the island of Hawai’i in the southeast to Kure Atoll in the northwest. The archipelago lies across the Tropic of Cancer between 154o 40' to 178o 25' W longitude, and 18o 54' to 28o 15' N latitude. It has a total land area of approximately 6,425 square miles (16,642 km2) (Ref 1). The archipelago represents the exposed peaks of an undersea mountain range, formed by volcanic activity over a hotspot in the Earth's mantle.
Northwestern Islands and Banks of the Hawaiian Archipelago
The inhabited eight Main Hawaiian Islands (MHI) are separated from the southernmost of the mostly uninhabited Northwestern Hawaiian Islands (NWHI) by approximately 155 miles (250 km) of open ocean. This is the distance between Kaua'i in the south and Nihoa Island in the north.