气候变化领域集成服务门户(CCPortal): Pūhāhonu: Earth's biggest and hottest shield volcano

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DOI	10.1016/j.epsl.2020.116296
	Pūhāhonu: Earth's biggest and hottest shield volcano
	Garcia M.O.; Tree J.P.; Wessel P.; Smith J.R.
发表日期	2020
ISSN	0012821X
卷号	542
英文摘要	New bathymetric and gravity mapping, refined volume calculations and petrologic analyses show that the Hawaiian volcano Pūhāhonu is the largest and hottest shield volcano on Earth. This ∼12.5-14.1 Ma volcano in the northwest Hawaiian Ridge (NWHR) is twice the size of Mauna Loa volcano (148 ± 29 vs. 74.0×103km3), which was assumed to be not only the largest Hawaiian volcano but also the largest known shield volcano. We considered four testable mechanisms to increase magma production, including 1) thinner lithosphere, 2) slower propagation rate, 3) more fertile source, and 4) hotter mantle. The first three of these have been ruled out. The lithosphere was old (∼88 Myrs) when Pūhāhonu was formed, and thus, too thick and cold to allow for greater extents of partial melting. The propagation rate was relatively fast when it erupted (87 km/Myr), so this is another unlikely reason. Source fertility was Kea-like and no more fertile than for other much smaller NWHR volcanoes. A hotter mantle remains the best mechanism to produce the large magma volumes and is consistent with the high forsteritic olivine phenocryst compositions (up to 91.8%) and the calculated high percent of melting (24%). Thus, the gargantuan size of Pūhāhonu reflects its high melting temperature, the highest reported for any Cenozoic basalt. A solitary wave within the Hawaiian plume is the probable cause of Pūhāhonu's higher melting temperature and the resulting increased volume flux given the absence of a more fertile source for Pūhāhonu basalts, as found for many basalts from the Hawaiian Islands. © 2020 Elsevier B.V.
关键词	gravity Hawaii magma temperature olivine solitary wave volume
英文关键词	Basalt; Melting point; Silicate minerals; Solitons; Cenozoic; Hawaiian Islands; Mauna Loa; Olivine phenocryst; Partial melting; Propagation rate; Volume calculation; Volume flux; Volcanoes; basalt; high temperature; mantle source; partial melting; petrogenesis; petrology; volcanic eruption; volcanism; volcanology; Hawaii [(ISL) Hawaiian Islands]; Hawaii [United States]; Hawaiian Islands; Hawaiian Ridge; Mauna Loa; Pacific Ocean
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202596
作者单位	Department of Earth Sciences, University of Hawai‘i at Mānoa, Honolulu, HI 96822, United States; Department of Oceanography, University of Hawai‘i at Mānoa, Honolulu, HI 96822, United States
推荐引用方式 GB/T 7714	Garcia M.O.,Tree J.P.,Wessel P.,et al. Pūhāhonu: Earth's biggest and hottest shield volcano[J],2020,542.
APA	Garcia M.O.,Tree J.P.,Wessel P.,&Smith J.R..(2020).Pūhāhonu: Earth's biggest and hottest shield volcano.Earth and Planetary Science Letters,542.
MLA	Garcia M.O.,et al."Pūhāhonu: Earth's biggest and hottest shield volcano".Earth and Planetary Science Letters 542(2020).