Magma transfer at Campi Flegrei caldera (Italy) before the 1538 AD eruption.
Magma transfer at Campi Flegrei caldera (Italy) before the 1538 AD eruption.
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DOI：
10.1038/srep32245
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发表时间：
2016-08-25
影响因子：
4.6
通讯作者：
Terrasi F
中科院分区：
文献类型：
--
作者：
Di Vito MA;Acocella V;Aiello G;Barra D;Battaglia M;Carandente A;Del Gaudio C;de Vita S;Ricciardi GP;Ricco C;Scandone R;Terrasi F
火山口是与岩浆储层排空有关的崩塌结构，通常与长期存在的岩浆系统的大喷发有关。了解岩浆是如何在喷发前从岩浆库转移到地表的是一项重大挑战。本文利用Campi Flegrei火山口的历史、考古和地质记录，估计了Nuovo火山喷发前的地表变形，并研究了浅层岩浆转移。我们的数据表明，从1251年到1536年，岩浆在火山口中心下方4.6±0.9 km深的岩浆源中逐渐聚集，并在1536年至1538年之间转移到火山口中心西北约4 km深的岩浆源中，在Monte Nuovo下方；这个外围源通过一个深度为0.4±0.3公里的较浅源喷发。这是Campi Flegrei火山爆发前岩浆转移的首次重建，并证实了火山口中心下方一个静止的扁形源的存在，该源在过去约5 ka内一直为横向喷发提供补给。结果表明：1)岩浆通过火山口中心以下的侵入体反复侵位；2)偶尔的岩浆横向转移为火山口内的非中心喷发提供了补给。与世界范围内火山口的历史动荡相比，这种行为很常见。
Calderas are collapse structures related to the emptying of magmatic reservoirs, often associated with large eruptions from long-lived magmatic systems. Understanding how magma is transferred from a magma reservoir to the surface before eruptions is a major challenge. Here we exploit the historical, archaeological and geological record of Campi Flegrei caldera to estimate the surface deformation preceding the Monte Nuovo eruption and investigate the shallow magma transfer. Our data suggest a progressive magma accumulation from ~1251 to 1536 in a 4.6 ± 0.9 km deep source below the caldera centre, and its transfer, between 1536 and 1538, to a 3.8 ± 0.6 km deep magmatic source ~4 km NW of the caldera centre, below Monte Nuovo; this peripheral source fed the eruption through a shallower source, 0.4 ± 0.3 km deep. This is the first reconstruction of pre-eruptive magma transfer at Campi Flegrei and corroborates the existence of a stationary oblate source, below the caldera centre, that has been feeding lateral eruptions for the last ~5 ka. Our results suggest: 1) repeated emplacement of magma through intrusions below the caldera centre; 2) occasional lateral transfer of magma feeding non-central eruptions within the caldera. Comparison with historical unrest at calderas worldwide suggests that this behavior is common.