Study on Chemical Monitoring of Volcanic gas using an IR spectroscopy

红外光谱法监测火山气体化学成分的研究

基本信息

批准号：
05453008
负责人：
NOTSU Kenji
金额：
$ 5.38万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05453008/
关键词：
Volcanic gas Monitoring Remote measurement Infrared absorption spectroscopy HC1 SO_2 Unzen volcano Vulcano volcano 空気酸化

项目摘要

1. I have developed a remote detection system of chemical components in volcanic gas, on the basis of infrared (IR) spectroscopy. The IR light which had passed through the volcanic gas was collected with a Cassegrainian telescope and was introduced into an FT-IR spectrometer.2. The measurements were carried out at Unzen, Kirishima, Aso, Sakurajima and Asama volcanoes, Japan, and also at Vulcano volcano, Itary.3. It is found that IR absorption spectra of chemical components were obtained, when IR source is naturally available behind the volcanic gas. In the case of Unzen volcano, absorption spectra of HC1 and SO2 were clearly identified using IR emission from hot lava dome behind the volcanic gas as an IR light source. This is first remote detection of HC1 in volcanic gas. In order to estimate the column amount of HC1 and SO2 from the observed spectra, a non-linear least-square method was applied, and then SO2/HC1 ratios of volcanic gas were calculated. The results shows that this remote monitoring technique is capable of detecting temporal change in the SO2/HCl ratios of volcanic gases emmitting far away from the observation site. In the case of Aso volcano, hot water standing on the bottom of the summit crater could be used as an IR light source, and absorption spectra of volcanic gas filling the crater were observed. At Vulcano volcano, Italy, the hot ground surface of the fumarolic area could be used as an IR light source, and spatial distribution in the SO2/HCl ratios of volcanic gas was detected.4. In general, chemical compositions of volcanic gas change after releasing into the atmosphere, bacause oxidations of the gas proceed in the atmosphere. The conversion of H2S to SO2 was experimentally checked. Therefore, it is suggested that SO2 detected in this remote monitoring includes original SO2 in the fumarole and SO2 derived from oxidation of H2S in the atmosphere.

1。我根据红外（IR）光谱制定了火山气体中化学成分的远程检测系统。通过Cassegrainian望远镜收集了通过火山气的IR光，并被引入FT-IR光谱仪2。测量是在Unzen，Kirishima，Aso，Sakurajima和Asama火山，日本以及Itary.3的Vulcano火山进行的。发现当火山气后自然可用时，获得了化学成分的IR吸收光谱。在未开除的火山的情况下，使用火山气体后面的热熔岩圆顶作为红外光源的红色熔岩圆顶清楚地鉴定出HC1和SO2的吸收光谱。这是火山气中HC1的首次远程检测。为了从观察到的光谱中估算HC1和SO2的列量，应用了非线性最小二乘法，然后计算了火山气的SO2/HC1比率。结果表明，这种远程监测技术能够检测到远离观察地点的火山气体的SO2/HCl比率的时间变化。在ASO火山的情况下，站在山顶火山口底部的热水可以用作红外光源，并观察到火山气体充满火山口的吸收光谱。在意大利的Vulcano火山，烟气区域的热地面可以用作红外光源，并且检测到火山气的SO2/HCl比例的空间分布。4。通常，释放到大气中的火山气体变化的化学成分，气体的氧化在大气中进行。实验检查了H2S向SO2的转化。因此，建议在此远程监测中检测到的SO2包括富马罗中的原始SO2和来自大气中H2S氧化的SO2。