Historical volcanism in the Canary Islands; part 1: A review of precursory and eruptive activity, eruption parameter estimates, and implications for hazard assessment
Historical volcanism in the Canary Islands; part 1: A review of precursory and eruptive activity, eruption parameter estimates, and implications for hazard assessment
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DOI：
10.1016/j.jvolgeores.2021.107363
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发表时间：
2021-08-16
影响因子：
2.9
通讯作者：
Felpeto, Alicia
中科院分区：
文献类型：
--
作者：
Longpre, Marc-Antoine;Felpeto, Alicia
尽管有十年至千年的休眠期，但加那利群岛的火山对当地社区和基础设施造成了重大的危害，尽管人们对这些危害知之甚少。自公元1500年以来，该群岛至少发生了13次火山喷发，形成了单成锥和熔岩流：六个在拉帕尔马岛（1585年、1646年、1677年至1678年、1712年、1949年和1971年），四个在特内里费岛两次在兰萨罗特岛（1730 - 1736年和1824年），一次在耶罗岛的潜艇侧翼（2011-2012年）。在本文中，我们综合了这些历史喷发的可用数据，侧重于其物理特性和时序发展，并提供了新的估计喷发参数，如熔岩流流出，面积和体积，通知火山灾害评估的群岛。虽然不完整和不精确，但历史记录表明，在火山爆发前几天到几年就开始了强烈的地震活动，这与2011-2012年火山爆发的三个月有据可查的动荡一致。除了1730-1736年的非典型事件，火山爆发持续了10天到不到5个月。最初的喷发阶段通常涉及多个喷口的开放沿着堤馈裂缝，与Strombolian爆炸活动形成单成锥。熔岩流排放一般很快，后来的喷发阶段通常是由喷涌行为为主。然而，有些喷发（1704-1705年、1824年和1949年）经历了复杂的演变，其间不时出现相隔几公里的不同喷口。喷口定义的裂缝总长度为0.2至14.0公里，最大熔岩流流出为2.7-9.4公里，75%的喷发延伸到海岸线。近源喷发沉积覆盖1.8-7.8 km（2）。已发表的估计陆上喷发量平均在11至66 × 10（6）m（3）之间。相比之下，一个新的经验关系的基础上约束熔岩流面积和体积数据在其他玄武岩火山产生的体积为10-76 × 10（6）米（3）加那利岛爆发。1730-1736年兰萨罗特岛上的Timanfaya火山爆发是加那利岛火山活动历史背景下的一个异常值，持续时间为2055天，总裂缝长度≥ 14.4公里，由至少10个主要排放中心定义，最大熔岩流长度为21.7公里，熔岩流场面积为146 km（2），体积至少为2.2-3.7 km（3）。历史上的喷发率很低，每年1.0-2.1 × 10（6）立方米或每年7.3-11.0 × 10（6）立方米，包括1730-1736年的喷发，这与基于地质数据的长期火山增长率一致。我们没有发现历史喷发序列的时间可预测或体积可预测行为的证据，其平均复发间隔为39 +/- 24年。我们的分析概述了一个有用的框架，预测的发病，发展和未来的火山喷发的风格在群岛。进一步的工作，特别是详细的基于现场的火山喷发沉积物和火山喷发运行过程的岩石学重建的研究，将有助于完善我们的历史火山作用和相关的危险在加那利群岛的理解。(C)2021爱思唯尔有限公司版权所有。
Despite decadal-millennial repose periods, volcanoes of the Canary Islands pose significant, though poorly understood hazards to local communities and infrastructure. At least 13 volcanic eruptions forming monogenetic cones and lava flows have occurred in the archipelago since 1500 CE: six on the island of La Palma (in 1585, 1646, 1677-1678, 1712, 1949 and 1971), four on Tenerife (1704-1705, 1706, 1798 and 1909), two on Lanzarote (1730-1736 and 1824) and one on the submarine flank of El Hierro (2011-2012). In this paper, we synthesize available data on these historical eruptions, focusing on their physical characteristics and chronological development, and provide new estimates of eruption parameters, such as lava flow runout, area and volume, to inform volcanic hazard assessment in the archipelago. While incomplete and imprecise, historical records indicate that precursory seismicity began days to years prior to eruption onset, consistent with the three months of well-documented unrest for the 2011-2012 eruption. Excluding the atypical 1730-1736 event, eruptions lasted from ten days to a little under five months. Initial eruptive phases usually involved the opening of multiple vents along dike-fed fissures, with Strombolian explosive activity forming monogenetic cones. Lava flow emission generally quickly followed, and later eruptive phases were typically dominated by effusive behavior. Some eruptions (1704-1705, 1824 and 1949), however, had a complex evolution punctuated by the sequential opening of distinct vents several kilometers apart. Total lengths of vent-defined fissures range from 0.2 to 14.0 km, and maximum lava flow runout is 2.7-9.4 km, extending to the coastline in 75% of eruptions. Proximal eruptive deposits cover 1.8-7.8 km(2). Published estimates of subaerial eruptive volumes average between 11 and 66 x 10(6) m(3). In comparison, a new empirical relationship based onwell-constrained lava flow area and volume data at other basaltic volcanoes yields volumes of 10-76 x 10(6) m(3) for Canary Island eruptions. The 1730-1736 Timanfaya eruption on Lanzarote represents an outlier in the context of historical Canary Island volcanism, with a duration of 2055 days, a total fissure length >= 14.4 km defined by at least ten main emission centers, a maximum lava flow length of 21.7 km, a lava flow field area of 146 km(2) and volume of at least 2.2-3.7 km(3). Historical eruptive rates are low, at 1.0-2.1 x 10(6) m(3)/year or 7.3-11.0 x 10(6) m(3)/year including the 1730-1736 eruption, in agreement with long-term volcano growth rates based on geologic data. We find no evidence for time-predictable or volume-predictable behavior of the historical eruptive sequence, which has a mean recurrence interval of 39 +/- 24 years. Our analysis outlines a useful framework for forecasting the onset, development and style of future eruptions in the archipelago. Further work, particularly detailed field-based studies of eruption deposits and petrologic reconstructions of eruption run-up processes, will help refine our understanding of historical volcanism and associated hazards in the Canary Islands. (C) 2021 Elsevier B.V. All rights reserved.