Maui Nui is a modern geologists' name given to a prehistoric Hawaiian island and the corresponding modern

biogeographic Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, ...

region. Maui Nui is composed of four modern islands:

Maui Maui (; Hawaiian language, Hawaiian: ) is the second largest island in the Hawaiian archipelago, at 727.2 square miles (1,883 km2). It is the List of islands of the United States by area, 17th-largest in the United States. Maui is one of ...

, Molokaʻi,

Lānaʻi Lānai is the sixth-largest of the Hawaiian Islands and the smallest publicly accessible inhabited island in the chain. It is colloquially known as the Pineapple Island because of its past as an island-wide pineapple plantation. The island's o ...

, and

Kahoʻolawe Kahoolawe (Hawaiian: ), anglicized as Kahoolawe ( ), is the smallest of the eight main volcanic islands of the Hawaiian Islands. Unpopulated, it lies about southwest of Maui. The island is long by wide, with a total land area of . Its highes ...

. Administratively, the four modern islands comprise

Maui County Maui County (), officially the County of Maui, is a county in the U.S. state of Hawaii. It consists of the islands of Maui, Lānai, Molokai (except for a portion of Molokai that comprises Kalawao County), Kahoolawe, and Molokini. The latter ...

(and a tiny part of Molokaʻi called

Kalawao County Kalawao () is a location on the eastern side of the Kalaupapa Peninsula of the island of Molokai, in Hawaii, which was the site of Hawaii's leper colony between 1866 and the early 20th century. Thousands of people in total came to the island to ...

). Long after the breakup of Maui Nui, the four modern islands retained plant and animal life similar to each other. Thus, Maui Nui is not only a prehistoric island but also a modern

region.

Geology

Maui Nui formed and broke up during the

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

Epoch, which lasted from about 2.58 million to 11,700 years ago. Maui Nui is built from seven

shield volcanoes A shield volcano is a type of volcano named for its low profile, resembling a shield lying on the ground. It is formed by the eruption of highly fluid (low viscosity) lava, which travels farther and forms thinner flows than the more viscous lava ...

. The three oldest are Penguin Bank, West Molokaʻi, and East Molokaʻi, which probably range from slightly over to slightly less than 2 million years old. The four younger volcanoes are Lāna‘i, West Maui, Kaho‘olawe, and

Haleakalā Haleakalā (; Hawaiian: ), or the East Maui Volcano, is a massive, active shield volcano that forms more than 75% of the Hawaiian Islands, Hawaiian Island of Maui. The western 25% of the island is formed by another volcano, Mauna Kahalawai, als ...

, which probably formed between 1.5 and 2 million years ago. At its prime 1.2 million years ago, Maui Nui was , 50% larger than today's Hawaiʻi Island. The island of Maui Nui included four modern islands (

, Molokaʻi,

, and

) and landmass west of Molokaʻi called Penguin Bank, which is now completely submerged. Maui Nui broke up as rising sea levels flooded the connections between the volcanoes. The breakup was complex because global sea levels rose and fell intermittently during the

Quaternary glaciation The Quaternary glaciation, also known as the Pleistocene glaciation, is an alternating series of glacial period, glacial and interglacial, interglacial periods during the Quaternary period that began 2.58 Year#SI prefix multipliers, Ma (million ...

. About 600,000 years ago, the connection between Molokaʻi and the island of Lāna‘i/Maui/Kahoʻolawe became intermittent. About 400,000 years ago, the connection between Lāna‘i and Maui/Kahoʻolawe also became intermittent. The connection between Maui and Kahoʻolawe was permanently broken between 200,000 and 150,000 years ago. Maui, Lāna‘i, and Molokaʻi were connected intermittently thereafter, most recently about 18,000 years ago during the

Last Glacial Maximum The Last Glacial Maximum (LGM), also referred to as the Last Glacial Coldest Period, was the most recent time during the Last Glacial Period where ice sheets were at their greatest extent between 26,000 and 20,000 years ago. Ice sheets covered m ...

. Today, the sea floor between these four islands is relatively shallow, about deep. At the outer edges of former Maui Nui, as with the edges of all

Hawaiian Islands The Hawaiian Islands () are an archipelago of eight major volcanic islands, several atolls, and numerous smaller islets in the Pacific Ocean, North Pacific Ocean, extending some from the Hawaii (island), island of Hawaii in the south to nort ...

, the sea floor plummets to the

abyssal plain An abyssal plain is an underwater plain on the deep ocean floor, usually found at depths between . Lying generally between the foot of a continental rise and a mid-ocean ridge, abyssal plains cover more than 50% of the Earth's surface. They ...

of the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

Biogeography

The term Maui Nui is also used as a modern

region of Hawaii. Long after the breakup of Maui Nui, the four modern islands retained similar plant and animal life. Many plant and animal species occur across multiple islands of former Maui Nui but are found nowhere else in Hawaii. Many of Hawaii's

native species In biogeography, a native species is indigenous to a given region or ecosystem if its presence in that region is the result of only local natural evolution (though often popularised as "with no human intervention") during history. The term is equi ...

declined or became extinct after Polynesian arrival or in the

modern era The modern era or the modern period is considered the current historical period of human history. It was originally applied to the history of Europe and Western history for events that came after the Middle Ages, often from around the year 1500 ...

, making the study of Hawaiian

biogeography Biogeography is the study of the species distribution, distribution of species and ecosystems in geography, geographic space and through evolutionary history of life, geological time. Organisms and biological community (ecology), communities o ...

more complicated. Among Hawaii's native birds, the ʻākohekohe (''Palmeria dolei'') only survives on

, but it also occurred on Molokaʻi until 1907. The black mamo (''Drepanis funerea'') was historically documented only on Molokaʻi until its extinction in 1907, but

fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

are also known from Maui. The Maui Nui icterid-like gaper (''Aidemedia lutetiae'') was never documented historically, but fossils are known from Maui and Molokaʻi. Among Hawaii's native plants, the maui hala pepe ('' Dracaena rockii'') is known from Maui and Molokaʻi, and survives on both islands. Pua ʻala ('' Brighamia rockii'') survives only on Molokaʻi, but was historically documented on Maui and Lāna‘i. Additional examples of plants and animals

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the Maui Nui region appear in

List of Hawaiian animals extinct in the Holocene This is a list of Hawaiian animal species extinct in the Holocene that covers extinctions from the Holocene epoch, a Geologic time scale, geologic epoch that began about 11,650 years Before Present, before present (about 9700 Common Era, BCE) ...

and

Endemism in the Hawaiian Islands Located about 2,300 miles (3,680 km) from the nearest continental shore, the Hawaiian Islands are the most isolated group of islands on the planet. The plant and animal life of the Hawaiian archipelago is the result of early, very infrequen ...

. Conversely, the ʻelepaio (genus ''Chasiempis'') have a

disjunct distribution In biology, a taxon with a disjunct distribution is one that has two or more groups that are related but considerably separated from each other geographically. The causes are varied and might demonstrate either the expansion or contraction of a s ...

. These birds occur on Hawaiʻi Island,

Oʻahu Oahu (, , sometimes written Oahu) is the third-largest and most populated island of the Hawaiian Islands and of the U.S. state of Hawaii. The state capital, Honolulu, is on Oahu's southeast coast. The island of Oahu and the uninhabited Northwe ...

, and

Kauaʻi Kauai (), anglicized as Kauai ( or ), is one of the main Hawaiian Islands. It has an area of 562.3 square miles (1,456.4 km2), making it the fourth-largest of the islands and the 21st-largest island in the United States. Kauai lies 73 mi ...

, but are curiously absent from the islands of former Maui Nui (both currently and in the

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

record). Some bird species use the term "Maui Nui" in their

common names In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contras ...

, such as the

Maui Nui large-billed moa-nalo The Maui Nui large-billed moa-nalo (''Thambetochen chauliodous''), also known as the Maui Nui moa-nalo, is one of two species of moa-nalo in the genus ''Thambetochen''. Moa-nalo are a group of extinct, flightless, large goose-like ducks, which ev ...

(''Thambetochen chauliodous''), Maui Nui icterid-like gaper (''Aidemedia lutetiae''),

Maui Nui ʻakialoa The Maui Nui ʻakialoa or Lānaʻi ʻakialoa (''Akialoa lanaiensis'') is an extinct species of Hawaiian honeycreeper in the subfamily Carduelinae of the family Fringillidae. It inhabited the islands of Maui, Lānaʻi, and Molokaʻi in Hawaii. ...

(''Akialoa lanaiensis''), Maui Nui ʻalauahio (''Paroreomyza montana''), and Maui Nui finch (''Telespiza ypsilon''). All of these species survived for thousands of years after the breakup of Maui Nui, and the Maui population of the Maui Nui ʻalauahio survives to the present. Thus, Maui Nui is not just a prehistoric island but also a modern

region.

References

{{authority control Geology of Hawaii Islands of Hawaii Former islands of the United States Physical oceanography Volcanism of Hawaii Geography of Hawaii Geography of Maui County, Hawaii Cenozoic Hawaii

Geology

Biogeography

See also

References