Repost: Hawaiian Volcanoes: Maui’s Haleakala



Haleakala is the sixth volcano monitored by the Hawaiian Volcano Observatory–the other five are on the Big Island.

Haleakala is sometimes called the East Maui Volcano, because it is East Maui, i.e., most of the island.

Screenshot_2018-05-27-13-10-44
West Maui, on the other side of a peninsula formed out of Haleakala lava flows, is volcanic but it hasn’t been active in over 300,000 years. Haleakala’s last eruption, somewhere between 1480 and 1600 AD, happened in the southwest rift zone. (Image source: NASA)

That beautiful crater is, as they said in the video, an erosional feature, not a true volcanic vent. It formed during the Pleistocene epoch as the Keanae and Kaupo valleys cut back into the volcano (some parts of eastern Maui get over 550 inches–1400 cm–of rain each year).

The exposed rimrock is about 145,000 years old, while the youngest lava found in Haleakala Crater erupted about 870 years ago from a fissure system on the north wall just below Hanakauhi Peak.

At 10,023 feet (3,055 meters) above sea level, Haleakala’s summit sits above the tropical inversion in our atmosphere and therefore is a good place for an observatory, just like Mauna Kea on the Big Island.

Also, like Mauna Kea, when measured from the sea floor, this massive volcano forming all of East Maui is taller than Mount Everest.

Will it erupt? Probably. But now that Haleakala is 124 miles (200 km) from the hot spot, it’s not active very often. The reason why volcanologists are monitoring it now, according to the Hawaiian Volcano Observatory website, is this:

Although another 500 years or more may pass before Haleakalā becomes restless, it’s also possible that new eruptions will begin in our lifetimes. We can better understand the precursory phenomena if we track the pattern of the volcano in repose. For these reasons, the U.S. Geological Survey maintains a sparse seismic network on Haleakalā volcano. Also we conduct surveys periodically, using GPS receivers that gather data about the volcano’s surface deformation or lack thereof.

So they’ve got an eye on it, and its aviation code is Green/Normal at present. Next time you’re in Maui, bundle up before dawn and head up there to watch a spectacular sunrise up above the clouds.

Aloha!

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Featured image: dronepicr, CC BY 2.0.



Sources:
Hawaiian Volcano Observatory. 2018. Haleakalā Geology and History. https://volcanoes.usgs.gov/volcanoes/haleakala/geo_hist_summary.html Last accessed May 27, 2018.

Sherrod, D. R.; Hagstrum, J. T.; McGeehin, J. P.; Champion, D. E.; and Trusdell, F. A. 2006. Distribution, 14C chronology, and paleomagnetism of latest Pleistocene and Holocene lava flows at Haleakalā volcano, Island of Maui, Hawai ‘i: a revision of lava flow hazard zones. Journal of Geophysical Research: Solid Earth, 111(B5).

Sinton, J. M. 1987. Geologic history of Maui. Field Trip Guide to Maui, Geological Society of America. 83rd Cordilleran Section Meeting, 1-12. PDF download here.

Wikipedia. 2018. Haleakalā. https://en.wikipedia.org/wiki/Haleakalā Last accessed May 27, 2018.

—. 2018. West Maui Mountains. https://en.m.wikipedia.org/wiki/West_Maui_Mountains Last accessed May 27, 2018.

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