The Hawaiian – Emperor seamount chain is a series of volcanoes and seamounts extending across the Pacific Ocean. The chain has been produced by the movement of the ocean crust over the Hawaiʻi hotspot, an upwelling of hot rock from the Earth's mantle. As the oceanic crust moves the volcanoes farther away from their source of magma, their eruptions become less frequent and less powerful until they eventually cease to erupt altogether. At that point erosion of the volcano and subsidence of the seafloor cause the volcano to gradually diminish. As the volcano sinks and erodes, it first becomes an atoll island and then an atoll. Further subsidence causes the volcano to sink below the sea surface, becoming a seamount and/or a guyot.[1] This list documents the most significant volcanoes in the chain, ordered by distance from the hotspot; however, there are many others that have yet to be properly studied.
The chain can be divided into three subsections. The first, the Hawaiian archipelago (also known as the Windward isles), consists of the islands comprising the U.S. state of Hawaiʻi (not to be confused with the island of Hawaiʻi). As it is the closest to the hotspot, this volcanically active region is the youngest part of the chain, with ages ranging from 400,000 years[2] to 5.1 million years.[3] The island of Hawaiʻi is comprised by five volcanoes, of which two (Kilauea and Mauna Loa) are still active. Lōʻihi Seamount continues to grow offshore, and is the only known volcano in the chain in the submarine pre-shield stage.[1]
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 in age.[3] Erosion has long since overtaken volcanic activity at these islands, and most of them are atolls, atoll islands, and extinct islands. They contain many of the most northerly atolls in the world; one of them, Kure Atoll, is the northern-most atoll in the world.[4] On June 15, 2006, U.S. President George W. Bush issued a proclamation creating Papahānaumokuākea Marine National Monument under the Antiquities Act of 1906. The national monument, meant to protect the biodiversity of the Hawaiian isles,[n 1] encompasses all of the northern isles, and is one of the largest such protected areas in the world. The proclamation limits tourism to the area, and calls for a phase-out of fishing by 2011.[5]
The oldest and most heavily eroded part of the chain are the Emperor seamounts, which are 39[6] to 85 million years in age.[7] The Emperor and Hawaiian chains are separated by a large L-shaped bend that causes the orientations of the chains to differ by about 60°. This bend was long attributed to a relatively sudden change in the direction of plate motion, but research conducted in 2003 suggests that it was the movement of the hotspot itself that caused the bend.[8] The issue is still currently under debate.[9] All of the volcanoes in this part of the chain have long since subsided below sea level, becoming seamounts and guyots (see also the seamount and guyot stages of Hawaiian volcanism). Many of the volcanoes are named after former emperors of Japan. The seamount chain extends to the West Pacific, and terminates at the Kuril–Kamchatka Trench, a subduction zone at the border of Russia.[10]
Contents |
| Name | Island | Last eruption | Coordinates | Age (years) | Notes |
|---|---|---|---|---|---|
| Lōʻihi Seamount | Big Island | 1996 (active)[2] | 400,000[2] | The seamount is a submarine volcano approximately 35 km (22 mi) southeast of Hawaiʻi. It will eventually breach sea level and become the newest Hawaiian island.[2] | |
| Kīlauea | Big Island | Erupting[11] | 300,000–600,000[11] | Kīlauea is considered one of the most active volcanoes on Earth.[12]
Puʻu ʻŌʻō, a cinder cone of Kīlauea, has been erupting continuously since January 3, 1983, making it the longest-lived rift-zone eruption of the last six centuries.[13] |
|
| Mauna Loa | Big Island | 1984 (active)[14] | 700,000–1 million[15] | Largest volcano on Earth[14] | |
| Hualālai | Big Island | 1801 (active)[16] | > 300,000[16] | Lies on the western edge of the Big Island[16] | |
| Mauna Kea | Big Island | 4460 BP (dormant) | ~1 million[17] | World's tallest mountain if below-sea elevation is counted[18] | |
| Kohala | Big Island | 120,000 BP (extinct)[19] | ~ 120,000–1 million[19] | Oldest volcano that remains part of the island of Hawaiʻi[19] | |
| Māhukona | Big Island |
—
|
K-Ar 298,000±25,000 and 310,000±31,000[20][n 2] | Submerged, having long since disappeared into the sea[21] | |
| Haleakalā | Maui | between A.D. 1480 and 1600[22] | ~ 2 million[22] | Forms more than 75% of Maui[22] | |
| West Maui | Maui |
—
|
K-Ar 1.32±0.04 million[3] | Very eroded shield volcano that makes up the western quarter of Maui | |
| Kahoʻolawe | Kahoʻolawe |
—
|
K-Ar > 1.03±0.18 million[3][23] | Smallest of the 8 principal Hawaiian islands;[19] uninhabited[24] | |
| Lānaʻi | Lānaʻi |
—
|
K-Ar date of 1.28±0.04 million[3] | Sixth-largest island[25] The only town is Lānaʻi City, a small settlement. | |
| East Molokaʻi | Molokaʻi |
—
|
K-Ar 1.76±0.04 million[3] | The northern half of this volcano suffered a large collapse 1.5 million years ago.[26] Only the southern half remains above the sea today.[19] | |
| West Molokaʻi | Molokaʻi |
—
|
K-Ar date of 1.9±0.06 million[3] | ||
| Penguin Bank | Molokaʻi |
—
|
|||
| Koʻolau Range | Oʻahu |
—
|
2.7 million[27] | A fragmented remnant of the eastern or windward shield volcano, which also suffered a large collapse sometime before the Molokaʻi collapse[26] | |
| Waiʻanae Range | Oʻahu | ~1.7 MYA[28] | ~1.7–3.9 million; K-Ar 3.7±0.1 million[3][27][28] | The eroded remains of a shield volcano that comprised the western half of the island[28] | |
| Kaʻula | Kaʻula |
—
|
K-Ar 4.0±0.2 million[3] | Tiny crescent-shaped barren island; uninhabited except for divers and fishermen[29] | |
| Niʻihau | Niʻihau |
—
|
K-Ar 4.89±0.11 million[3][30] | Smallest inhabited island;[31] | |
| Kauaʻi | Kauaʻi |
—
|
K-Ar 5.1±0.2 million[3][32] | Oldest and fourth largest of the main islands, and home to Mount Waialeale, one of the wettest areas on Earth in terms of precipitation[33] |
| Name | Type | Coordinates | Age[34] | Notes |
|---|---|---|---|---|
| Nihoa | Extinct Island | K-Ar 7.2±0.3 million[3] | Small rocky island which supported a small population around 1000 CE; features over 80 cultural sites, including religious places, agricultural terraces, and burial caves[35] | |
| Necker Island | Extinct Island | K-Ar 10.3±0.4 million[3] | Small deserted island with Hawaiian religious shrines and artifacts[36] | |
| French Frigate Shoals | Atoll | 12 million[37] | Largest atoll in the northwestern Hawaiian islands[38] | |
| Gardner Pinnacles | Atoll Island | K-Ar 12.3±1.0 million[3] | Two barren rock outcrops surrounded by a reef[39] | |
| Maro Reef | Atoll | 12.3 to 19.9 million[n 3] | Largest coral reef of the northwestern Hawaiian islands[40] | |
| Laysan | Atoll Island | K-Ar 19.9±0.3 million[3] | Originally named "Kauō" meaning egg, referring to its shape, and home to one of only five natural lakes in all of Hawaiʻi[41] | |
| Lisianski Island | Atoll Island | 19.9 to 20.6 million[n 3] | A small island surrounded by a huge coral reef nearly the size of Oahu;[42] named after a captain in the Russian navy whose ship ran aground there in 1805[43] | |
| Pearl and Hermes Atoll | Atoll Island | K-Ar 20.6±2.7 million[3] | A collection of small, sandy islands, with a lagoon and coral reef; named after two whaling ships which were wrecked on the reef in 1822[44] | |
| Midway Atoll | Atoll Island | K-Ar 27.7±0.6 million[3] | Consists of a ring-shaped barrier reef and two large islets; named "Midway" because of its strategic location in the center of the Pacific Ocean, and was the site of a key battle during World War II[45] | |
| Kure Atoll | Atoll | 27.7 to 38.7 million[n 3] | Northernmost coral atoll in the world[4] |
| Name | Type | Coordinates[46] | Age | Notes |
|---|---|---|---|---|
| Hancock | Seamount | 27.7 to 38.7 million[n 3] |
—
|
|
| Colahan | Seamount | K-Ar 38.7±0.2 million[6] |
—
|
|
| Abbott | Seamount | K-Ar 41.5±0.3 million[6] |
—
|
|
| Daikakuji | Guyot | K-Ar 42.4±2.3[3] and 46.7±0.1 million[6] | Also the name of a Japanese temple | |
| Kammu | Guyot | 42.4 to 43.4 million[n 3] | Named after Emperor Kammu, former ruler of Japan | |
| Yuryaku | Guyot | K-Ar 43.4±1.6 million[3] | Named after Emperor Yūryaku, former ruler of Japan | |
| Kimmei | Seamount | K-Ar 39.9±1.2[3] and 47.9±0.2 million[6] | Named after Emperor Kimmei, former ruler of Japan | |
| Koko | Guyot | K-Ar 48.1±0.8,[3] 50.4±0.1 (south side),[6] and 52.6±0.8 (north side) million[6] | Named after Emperor Kōkō, former ruler of Japan | |
| Ojin | Guyot | K-Ar 55.2±0.7 million[3] | Named after Emperor Ōjin, former ruler of Japan | |
| Jingu | Guyot | K-Ar 55.4±0.9 million[47] | Named after Empress Jingū, former ruler of Japan | |
| Nintoku | Guyot | K-Ar 56.2±0.6 million[3] | Named after Emperor Nintoku, former ruler of Japan | |
| Yomei | Guyot | 56.2 to 59.6 million[n 3] | Named after Emperor Yōmei, former ruler of Japan | |
| Suiko | Guyot | K-Ar 59.6±0.6 (southern),[3][48] 64.7±1.1 (central),[3][48] and 60.9±0.3[6] million | Named after Empress Suiko, former ruler of Japan | |
| Detroit | Seamount | ~ 81 million[7] | Well-documented seamount, second-oldest | |
| Meiji | Seamount | 85 million[7] | Named after Emperor Meiji, former ruler of Japan; oldest known seamount in the chain |
This abstract contains preliminary data for several of the seamount dates; these dates are revised in the subsequent paper (as reported here).