The 12 900 years BP Laacher See eruption: estimation of volatile yields and simulation of their fate in the plume
The 12 900 years BP Laacher See eruption: estimation of volatile yields and simulation of their fate in the plume
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12900 年 BP Laacher See 喷发：挥发性产量的估计及其在羽流中的命运模拟
DOI：
10.1144/gsl.sp.2003.213.01.19
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
T. Hansteen
中科院分区：
文献类型：
--
作者：
C. Textor;P. M. Sachs;Hans;T. Hansteen
本文用改进的岩石学方法估算了德国Laacher See火山12900年BP喷发的挥发性气体。玻璃夹杂物斑晶和基质玻璃取样超过拉彻见火山灰剖面进行了分析，同步辐射X射线荧光显微探针和电子显微探针，以获得卤素，硫和水的发射质量。这些数据被用来初始化数值羽流模型ATHAM，以调查羽流中火山气体的命运，并估计注入平流层的挥发性物质。每种挥发性组分的清除效率取决于其与液态水和冰的相互作用。我们发现的清除效率为c.5%的硫物种，和只有c.30%的卤化氢，尽管它们的高水溶性。我们的模拟显示，由于快速的羽流上升和喷发柱的高度，大部分水凝物冻结成冰。由于拉赫尔湖喷发时大气环境干燥，液态水的数量不足以完全溶解HCl和HBr，因此大部分可以到达平流层。
Abstract We estimated the volatile emissions of the 12 900 years BP eruption of Laacher See volcano (Germany), using a modified petrological method. Glass inclusions in phenocrysts and matrix glasses sampled over the Laacher See tephra profile were analysed by synchrotron X-ray fluorescence microprobe and electron microprobe to obtain the emitted masses of halogens, sulphur, and water. These data were used to initialize the numerical plume model ATHAM in order to investigate the fate of volcanic gases in the plume, and to estimate volatile masses injected into the stratosphere. The scavenging efficiency of each volatile component depends on its interactions with both liquid water and ice. We found a scavenging efficiency of c.5% for the sulphur species, and of only c.30% for hydrogen halides, despite their high water solubility. Our simulations showed that the greatest fraction of hydrometeors freeze to ice, due to the fast plume rise and great height of the eruption column. For the dry atmospheric conditions of the Laacher See eruption, the amount of liquid water was not sufficient to completely scavenge HCl and HBr, so that a large proportion could reach the stratosphere.