Search results
Results from the WOW.Com Content Network
The second part of the chain is composed of the Northwestern Hawaiian Islands, collectively referred to as the Leeward isles, the constituents of which are between 7.2 and 27.7 million years old. [3] Erosion has long since overtaken volcanic activity at these islands, and most of them are atolls, atoll islands, and extinct islands.
Kohala is the oldest of five volcanoes that make up the island of Hawaii.Kohala is an estimated one million years old—so old that it experienced, and recorded, the reversal of Earth's magnetic field 780,000 years ago.
The volcanoes are progressively younger to the southeast; the oldest dated volcano, located at the northern end, is 81 million years old. The break between the two subchains is 43 million years; in comparison, the oldest of the principal islands, Kauaʻi, is little more than 5 million years. [1]
Kīlauea is one of five subaerial (originating under water) volcanoes that make up the island of Hawaii, originated from the Hawaiian hotspot. [16] The oldest volcano on the island, Kohala, is more than a million years old, [17] while Kīlauea, the youngest, is between 300,000 and 600,000 years of age. [16]
The main shield-building stage of volcanism ended about 470,000 years ago. The summit of the shield volcano was once 800 feet (250 m) above sea level, but subsided below sea level between 435,000 and 365,000 years ago. [1] Māhukona is the oldest volcano to build Hawaiʻi island, older than Kohala and Mauna Kea. [2]
Kaʻena Ridge was the oldest of the three volcanoes to form Oʻahu and it was also the shortest when it grew out of sea level. It was about 3,000 ft. [1] Activity from Kaʻena began roughly 5 million years ago. [2] [3] Despite being Oʻahu's oldest volcano, it broke sea level 400,000 years after the Waiʻanae did. [2]
According to Wilson's theory, the Hawaiian volcanoes should be progressively older and increasingly eroded the further they are from the hotspot, and this is easily observable; the oldest rock in the main Hawaiian islands, that of Kauaʻi, is about 5.5 million years old and deeply eroded, while the rock on Hawaiʻi Island is a comparatively ...
Mauna Kea (/ ˌ m ɔː n ə ˈ k eɪ ə, ˌ m aʊ n ə-/, [6] Hawaiian: [ˈmɐwnə ˈkɛjə]; abbreviation for Mauna a Wākea) [7] is a dormant shield volcano on the island of Hawaiʻi. [8] Its peak is 4,207.3 m (13,803 ft) above sea level, making it the highest point in Hawaii and the island with the second highest high point, behind New Guinea, the world's largest tropical island with ...