Haleakalā

Haleakalā (; Hawaiian: Hawaiian pronunciation: [ˈhɐlɛˈjɐkəˈlaː]), or the East Maui Volcano, is a massive, active shield volcano that forms more than 75% of the Hawaiian Island of Maui. The western 25% of the island is formed by another volcano, Mauna Kahalawai, also referred to as the West Maui Mountains. The tallest peak of Haleakalā ("house of the sun"), at 10,023 feet (3,055 m), is Puʻu ʻUlaʻula (Red Hill). From the summit one looks down into a massive depression some 11.25 mi (18.11 km) across, 3.2 mi (5.1 km) wide, and nearly 800 m (2,600 ft) deep. The surrounding walls are steep and the interior mostly barren-looking with a scattering of volcanic cones.

History Early Hawaiians applied the name Haleakalā ("house of the sun") to the general mountain. Haleakalā is also the name of a peak on the southwestern edge of Kaupō Gap. In Hawaiian folklore, the depression (crater) at the summit of Haleakalā was home to the grandmother of the demigod Māui. According to the legend, Māui's grandmother helped him capture the sun and force it to slow its journey across the sky in order to lengthen the day.

Geology Haleakalā started forming 2 million years ago and built a massive shield volcano along 3 rift zones that was once broken by a central caldera. Haleakalā is currently in the Rejuvenated Stage of Volcanism and has produced numerous eruptions in the last 30,000 years, including ten eruptions in the past 1,000 years and at least one in the last 400–600 years, making it the only active volcano on the island of Maui. This volcanic activity has been along two rift zones: the southwest and east. These two rift zones together form an arc that extends from La Perouse Bay on the southwest, through the Haleakalā Crater, and to Hāna to the east. The east rift zone continues under the ocean beyond the east coast of Maui as Haleakalā Ridge, making the combined rift zones one of the longest in the Hawaiian Islands chain. In its prime, Haleakalā may have reached a height of 12,000 feet (3,700 m) before water and wind erosion, and possibly glaciers, began to carve two large river valleys out of the rim. Eventually, these valleys formed gaps that merged at the volcano summit to create a crater-like basin. A third rift zone exists on a North/Northwest trend that hasn't seen any recent volcanic activity. Haleakalā, also known as East Maui Volcano, was previously thought to have last erupted around 1790, based largely on comparisons of maps made during the voyages of La Perouse and George Vancouver. In 1999, the U.S. Geological Survey published in a column that radiocarbon dating indicated that the last eruption was more likely to have taken place sometime between 1480 and 1600. These last flows from the southwest rift zone of Haleakalā make up the large lava deposits of the Ahihi Kina`u/La Perouse Bay area of South Maui. The Haleakalā crater is not volcanic in origin, as it formed when the headwalls of two large erosional valleys merged at the summit of the volcano. These valleys formed the two large gaps — Koʻolau on the north side and Kaupō on the south — on either side of the depression. Macdonald, Abbott, & Peterson state it this way:

Haleakalā is far smaller than many volcanic craters (calderas); there is an excellent chance that it is not extinct, but only dormant; and strictly speaking, it is not of volcanic origin, beyond the fact that it exists in a volcanic mountain.

Volcanic hazard

On the island of Hawaiʻi, lava-flow hazards are rated on a scale of one through nine with one being the zone of highest hazard and nine being the zone of lowest hazard. For example, the summits and rift zones of Kilauea and Mauna Loa volcanoes are rated Hazard Zone 1. Using this same scale, preliminary estimates of lava-flow hazard zones on Maui made in 1983 by the U.S. Geological Survey rated the summit and southwest rift zone of Haleakalā as Hazard Zone 3. The steep, downslope areas of the Kanaio and Kahikinui ahupuaʻa and the area north of Hana are rated as Hazard Zone 4. Other areas of Haleakalā are rated comparable to the lava-flow hazards of Mauna Kea and Kohala (Hazard Zones 7 through 9). These high hazard estimates for Haleakalā are based on the frequency of its eruptions. Haleakalā has erupted three times in approximately the last 900 years. By way of comparison, both Mauna Loa and Kilauea have erupted more than a dozen times each in the last 90 years. Hualalai has an eruption rate comparable to Haleakalā. All of Hualalai is rated as Hazard Zone 4. However, the frequency of eruption of a volcano is only one of the criteria on which hazards are based. The other important criterion is the lava flow coverage rate. Using the preliminary dates for Haleakalā flows, only 8.7 square miles (23 km2) of lava flows have been emplaced in the last 900 years. In comparison, approximately 43 square miles (110 km2) of Hualalai are covered with flows 900 years old or younger and approximately 104 square miles (270 km2) on Kilauea and 85 square miles (220 km2) on Mauna Loa are covered by lavas less than 200 years old. Thus, Haleakalā is a distant fourth in coverage rates. According to the United States Geological Survey Volcano Warning Scheme for the United States, the Volcano Alert Level for Haleakalā as of 3 June 2021 was "normal". A "Normal" status is used to designate typical volcanic activity in a background, non-eruptive phase.

Endangered species

Nēnē The nēnē bird is on the endangered species list. The bird was once on all the islands of Hawaii, but now it is only on the Island of Hawai’i, Maui, Moloka’i, and Kaua’i. Habitat loss, hunting, and the introduction of mammals caused the bird population to dwindle. Since 2010, only 2,000 birds were left. These birds were then kept in captivity to increase the population.

Silversword

Haleakalā silversword is a quintessential plant of Haleakalā since it grows nowhere else on Earth. Climate change has been threatening the population of this plant due to hotter temperatures and lower rainfall. The park service has erected fences to prevent damage from local herbivores and from visitors taking the plants as souvenirs.

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