当前位置: X-MOL 学术J. Volcanol. Geotherm. Res. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Tracking the behaviour of persistently degassing volcanoes using noble gas analysis of Pele's hairs and tears: A case study of the Masaya volcano (Nicaragua)
Journal of Volcanology and Geothermal Research ( IF 2.4 ) Pub Date : 2021-02-25 , DOI: 10.1016/j.jvolgeores.2021.107212
Simone Cogliati , Sarah Sherlock , Alison Halton , Kerry Reid , Hazel Rymer , Simon Kelley

We provide evidence that noble gasses (NGs) trapped in Pele's hairs and tears can be used as a tool to monitor the degassing behaviour of persistently active volcanic systems. We investigated 4He, 36Ar, 40Ar abundances and 4He/40Ar* and 40Ar/36Ar isotopic ratios in samples collected in March 2015 and March 2016 from Masaya volcano (Nicaragua). The resurgence of a lava lake in December 2015 provided the opportunity to monitor NG variations during a specific volcanic event. The variations in the NG abundances of individual glass particles are here attributed to solubility-controlled NG fractionation between melt and bubbles, and consequently correlated with sample vesicularity and vesicle size. Inhomogeneous incorporation of 36Ar, along with kinetic mass fractionation during magma degassing, vesiculation and fast-quenching of the samples after eruption, are the mechanisms that control the variability of the 40Ar/36Ar ratios observed in the samples. From March 2015 to March 2016, our data indicate a general increase of mean 40Ar* abundances from 1.9E−8 ± 1.4E−8 cc/g to 9.3E−8 ± 8.9E−8 cc/g and decrease in mean 4He/40Ar* ratios from 0.37 ± 0.15 to 0.18 ± 0.13. We ascribe this to the upward migration of a gas-rich magma from depth that recharged the shallow magmatic reservoir of Masaya at some point between the two collection periods. Since this model agrees well with the physical volcanology of Masaya and with gas plume measurements spanning our collection period, we suggest that NG in Pele's hairs and tears can be further used as a valuable tool to monitor degassing processes at Masaya volcano and, when samples are available, at other persistently degassing systems (e.g. Etna, Hawaii).



中文翻译:

使用对贝利的头发和眼泪的稀有气体分析来跟踪持续脱气的火山的行为:马萨亚火山(尼加拉瓜)的案例研究

我们提供的证据表明,困在贝利的头发和眼泪中的稀有气体(NGs)可用作监测持续活动的火山系统脱气行为的工具。我们研究了4 He,36 Ar,40 Ar丰度和4 He / 40 Ar *和40 Ar / 362015年3月和2016年3月从马萨亚火山(尼加拉瓜)采集的样品中的Ar同位素比。2015年12月,熔岩湖的复兴为特定火山事件期间监测天然气变化提供了机会。单个玻璃颗粒的NG丰度的变化在此归因于熔体和气泡之间的溶解度控制的NG分离,因此与样品的囊泡性和囊泡大小相关。36 Ar的不均匀掺入以及喷发后样品的岩浆脱气,囊泡化和快速淬灭过程中的动力学质量分馏是控制40 Ar / 36变异性的机制样品中观察到的Ar比。从2015年3月到2016年3月,我们的数据表明平均40 Ar *丰度从1.9E -8 ±1.4E -8 cc / g普遍增加到9.3E -8 ±8.9E -8 cc / g,平均降低4他/ 40Ar *比率从0.37±0.15到0.18±0.13。我们将其归因于富含天然气的岩浆从深处向上迁移,这在两个收集期之间的某个时间点为马萨亚浅岩浆储层补充了能量。由于此模型与Masaya的物理火山学以及整个采集期的气羽测量非常吻合,因此我们建议将Pele的头发和眼泪中的NG进一步用作监测Masaya火山脱气过程的有价值的工具,以及在采样时可在其他持续除气系统(例如,埃特纳火山,夏威夷)上使用。

更新日期:2021-03-31
down
wechat
bug