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1.
在五大连池火山区流体化学研究原有工作的基础上，对火山群的重要区段开展了野外踏勘、气体普查，特别是用放射性气体测量方法对火烧山、老黑山、笔架山、药泉山等火山区进行了Tn、Rn测量。通过大量实测资料，分析和研究了Tn、Rn等气体和火山、火山活动、断裂构造、断裂活动性及其他地质条件的关系，初步查明了五大连池火山区的气体组成特征、分布和形成规律，对地下主要气体的成因、气体和火山构造活动及其它地质条件的关系进行了初步探讨，并提出了对五大连池火山区气体观测的初步设想和建议。 相似文献
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气体地球化学监测结果显示,2002—2003年地幔来源CO2、He和CH4的含量出现明显的异常变化;2003年火山区深断裂型泉群逸出气体He的3He/4He比值都出现了异常升高,2004年该比值明显降低。热储型长白聚龙泉群逸出He中3He/4He比值2003年上升缓慢,2004年持续上升,其中逸出He中幔源He含量在2004年明显增加。2002—2004年天池火山区逸出气体及其He同位素异常变化与该区地震活动呈一定的对应关系,其中锦江泉群在2004年下半年地震活动趋势减弱后,异常明显减弱;而长白聚龙泉群在地震活动减弱后,异常反而明显增加,显示热储型泉群岩浆来源气体异常释放明显滞后于深断裂型泉点。上述异常特征对识别和判定火山区深部岩浆异常活动及预测未来火山地震可能有重要意义 相似文献
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中国火山温泉主要分布在吉林长白山、云南腾冲和黑龙江五大连池等火山区。这些火山虽然处于休眠状态,但大面积的温泉分布指示着岩浆房存在的可能性。本文总结了前人研究成果,分析了中国主要火山区温泉气体地球化学特征,并探讨了温泉气体在火山监测中的应用。长白山、腾冲和五大连池火山区温泉气体地球化学性质类似,都以CO2为主要气体,含量在80%以上,最高可达99%以上,其它气体组分包括CH4、N2、O2、SO2、H2S、He和H2等。长白山火山温泉气体中氦同位素比值（3He/4He）最高,约为4—6RA,CO2中碳同位素比值（δ13C）为-7.9‰—-1.3‰,CH4中碳同位素为-48.0‰—-28.7‰;腾冲火山温泉气体氦同位素比值为3—5.5RA,CO2中的碳同位素为-6.49‰—-2.07‰,CH4中碳同位素为-23.5‰—-9.3‰;五大连池火山温泉气体氦同位素比值约为3RA,CO2中的碳同位素比值为-9.6‰—-3.1‰,CH4中碳同位素为-47.2‰—-44.4‰。3个火山区的温泉气体均显示地幔来源的岩浆气体特征,并在上升运移过程中受地壳或古俯冲物质的影响。 相似文献
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《高原地震》2018,(4)
水热爆炸和构造地震事件的区分一直以来是学术界的一个难题。腾冲火山区构造地震事件频繁,且历史上发生过多次水热爆炸事件,因此,该区是研究构造地震和水热事件特征及其区分的理想区域。通过分析腾冲火山地震监测台网记录到的2008～2017年地震观测波形和地表形变数据,在火山区共识别出21个可靠的水热爆炸事件,然后进一步对发生在2014年的典型水热爆炸事件进行卓越周期频谱分析,并和相应的构造地震事件进行对比讨论。结果表明:火山区水热爆炸事件共分为2种类型;水热爆炸事件的卓越周期频率主要在0. 02～0. 06 s范围内变化,小于构造地震事件0. 02～0. 15 s的卓越周期;水热爆炸事件卓越周期频率正态分布更加集中,且平均的卓越周期和均方差都相对要小。结合国际国内已有的水热爆炸研究,认为2014年4月20号发生的水热爆炸事件可能由深部火山区地质构造诱发的气体喷发,或者是深部火山区地质构造诱发的原有堵塞喷发造成,其余20次能量较弱的水热爆炸事件则是浅部堵塞气体喷发形成。该研究方法为水热爆炸事件和构造地震事件的区分提供了参考,并对腾冲火山区水热活动异常变化的识别提供了新的判断依据。 相似文献
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腾冲火山区形变分析 总被引：1，自引：0，他引：1
腾冲火山群是我国目前仍具喷发危险的火山群。本文首先对火山区的地壳运动背景进行了总结分析,然后介绍了火山区的形变监测情况,再依据1998～2004年的水准测量及2002～2004年GPS观测成果,参考重力变化及其它观测资料分析火山区岩浆的活动特征,最后得出主要结论:相对欧亚板块,腾冲火山区总体具有向西南的顺时针旋转运动;火山区的形变变化受岩浆和断层活动两方面控制;火山区西南部发生了较强烈的下沉运动,可能由于岩浆和水的流失及放气等原因引起;以固东—腾冲断裂的西支为界,水平位移在断层两侧分别向东西两个方向运动,2002～2003年运动更剧烈些,断层活动表现为明显的拉张特征。综合各种资料表明火山目前活动量较小,近期喷发的危险性不大。 相似文献
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五大连池火山区的地震活动特征及其成因的初步探讨 总被引：1，自引：0，他引：1
通过对1981～1988年这一时期内五大连池火山区的地震和人工爆破记录的分析和整理,讨论了本区的岩浆侵入活动,总结了本区的地震活动特征,并对本区内地震活动成因机制进行了初步的探讨。结果表明:五大连池火山活动与地震活动存在着密切的联系,它们有着共同的成因机制即本区的岩浆侵入活动,火山区地震活动的不同特征反映着火山的活动性。火山区的小震及微震是由于岩浆侵入时期岩浆充填地下微裂隙和岩浆回落时期穹窿塌陷所致;火山区外围的中强地震是由于岩浆侵入活动诱发了讷木尔河深大断裂所致。 相似文献
8.
腾冲火山区地震构造应力场研究 总被引：5，自引：2，他引：3
通过对腾冲火山区强震和中小地震震源机制制解分析,对火山区构造应力场方向空间分布,以及震源类型和破裂特征作了研究。利用腾冲火山区中小地震地震波资料,计算得到的地震震源处剪应力强度值,对火山区应力场强度或初始应力状态进行了研究。腾冲火山区构造庆力场主要为北北东－北东－北东东向,接近水平的压应力场。腾冲火山区凛环境剪应力场高值区所包围的低剪应力值分布区。腾冲火山区地震震源具有多种类型,震源破裂具有多种形 相似文献
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五大连池近代火山老黑山火烧山火山喷发过程的考察研究 总被引：4，自引：0，他引：4
作者在已有工作的基础上,以当代火山学的研究思路和观点,为恢复五大连池两个近代火山,老黑山火烧山的喷发历史过程进行了野外考察研究工作。老黑山火山锥是由三套不同的碎屑堆积物组成。在锥体的南侧、东侧和西侧以及北测和北西侧有５个熔岩溢出口,按它们形成先后关系,认为有早、中、晚三期熔岩流。本文还对老黑山火山锥上的寄生火山、结壳熔岩与渣状熔岩的分布、流动特点及形成的控制因素进行了分析讨论。最后得出结论：老黑山火山是经多期次喷发活动形成的。火烧山火山锥是一碎屑化泡沫化程度很低的浮岩块和熔岩碎块组成,同老黑山有明显区别。 相似文献
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在河北省怀来县后郝窑地区，对地下气体运移变化的影响因素进行了野外模拟实验研究。选择３个试验点，对地下气体的扩散作用，物理化学影响因素及水压效应等进行了模拟实验，主要研究Ｈ２，ＣＯ２气体运移变化机制。实验研究表明，Ｈ２，ＣＯ２气体运移变化机制不尽相同，水压效应对Ｈ２，ＣＯ２等地下气体运移影响相当明显 相似文献
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本文叙述了新发现的有关五大连池老黑山,火烧山两座近代火山喷发过程的清化清文料档案的主要内容。在此基础上讨论了火山发过程及有关问题,同时评议了这些史料的学术价值． 相似文献
14.
William I. Rose Jr. Richard D. Cadle Leroy E. Heidt Irving Friedman Allen L. Lazrus Barry J. Huebert 《Journal of Volcanology and Geothermal Research》1980,7(1-2)
Gas samples were collected by aircraft entering volcanic eruption clouds of three Guatemalan volcanoes. Gas chromatographic analyses show higher H2 and S gas contents in ash eruption clouds and lower H2 and S gases in vaporous gas plumes. H isotopic data demonstrate lighter isotopic distribution of water vapor in ash eruption clouds than in vaporous gas plumes. Most of the H2O in the vaporous plumes is probably meteoric. The data are the first direct gas analyses of explosive eruptive clouds, and demonstrate that, in spite of atmospheric admixture, useful compositional information on eruptive gases can be obtained using aircraft. 相似文献
15.
G. Capasso M. L. Carapezza C. Federico S. Inguaggiato A. Rizzo 《Bulletin of Volcanology》2005,68(2):118-134
Significant changes in the helium and carbon isotopic composition of shallow thermal waters vs. gas and a crater fumarolic gas have been recorded at Stromboli prior and during the 2002–2003 eruption. The3He/4He ratios corrected for air contamination (Rc/Ra), and δ13C of fumarolic gases gradually increased from May to November 2002 before the eruption onset. These variations imply early degassing of a gas-rich magma at depth that likely fed both the intense Strombolian activity and small lava overflows recorded during that period. The lava effusion of late December 2002 was shortly preceded by a marked Rc/Ra decrease both in water and fumarolic gases. Comparison of He/CO2 and CH4/CO2 ratios in dissolved gas and with values rules out the Rc/Ra decrease due to an increasing input of radiogenic4He. The Rc/Ra decrease is attributed to the He isotope fractionation during rapid magma ascent and degassing. A new uprising of 3He-rich magma probably occurred in January to February 2003, when Rc/Ra ratios displayed the highest values in dissolved gases ever measured before (4.56 Rc/Ra). The increase in He/CO2 and CH4/CO2 ratios and decrease in δ13C of dissolved CO2 was recorded after the 5 April 2003 explosive paroxysm, likely caused by enhanced gas-water interaction inducing CO2 dissolution. No anomalous Rc/Ra values were recorded in the same period, when usual Strombolian activity gradually resumed.Editorial responsibility: H Shinohara 相似文献
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Phreatic eruptions occurred at the Meakandake volcano in 1988, 1996, 1998, 2006, and 2008. We conducted geochemical surveillance
that included measurements of temperature, SO2 emission rates, and volcanic gas composition from 2003 to 2008 at the Nakamachineshiri (NM), Northwest (NW), and Akanuma
(AK) fumarolic areas, and the 96–1 vent, where historical eruptions had occurred. The elemental compositions of the gases
discharged from the different areas are similar compared with the large variations observed in volcanic gases discharged from
subduction zones. All the gases showed high apparent equilibrium temperatures, suggesting that all these gases originated
from a common magmatic gas. The gases discharged from each area also exhibited different characteristics, which are probably
the results of differences in the conditions of meteoric water mixing, quenching of chemical reactions, and vapor-liquid separation.
The highest apparent equilibrium temperatures (about 500°C) were observed in the case of NW fumarolic gases, despite the low
outlet temperature of about 100°C at these fumaroles. Since the NW fumaroles were formed as a result of the 2006 phreatic
eruption, the high-temperature gas supply to the NW fumarole suggests that the phreatic eruption was caused by the ascent
of high-temperature magmatic gases. The temperatures, compositions, and emission rates of the NM and 96–1 gases did not show
any appreciable change after the 2006 eruption, indicating that each fumarolic system had a separate magmatic-hydrothermal
system. The temperatures, compositions, and emission rates of the NM fumarolic gases were apparently constant, and these fumaroles
are inferred to be formed by the evaporation of a hydrothermal system with a constant temperature of about 300°C. The 96–1
gas compositions showed large changes during continuous temperature decrease from 390° to 190°C occurred from 2003 to 2008,
but the sulfur gas emission rates were almost constant at about four tons/day. At the 96–1 vent, the SO2/H2S ratio decreased, while the H2/H2O ratio remained almost constant; this was probably caused by the rock-buffer controlled chemical reaction during the temperature
decrease. 相似文献
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The maximum height attained by a volcanic eruption cloud is principally determined by the convective buoyancy of the mixture of volcanic gas + entrained air + fine-sized pyroclasts within the cloud. The thermal energy supplied to convection processes within an eruption cloud is derived from the cooling of pyroclastic material and volcanic gases discharged by an explosive eruption. Observational data from six recent eruptions indicates that the maximum height attained by volcanic eruption clouds is positively correlated with the rate at which pyroclastic material is produced by an explosive eruption (correlation coefficient r = + 0.97). The ascent of industrial hot gas plumes is also governed by the thermal convection process. Empirical scaling relationships between plume height and thermal flux have been developed for industrial plumes. Applying these scaling relationships to volcanic eruption clouds suggests that the rate at which thermal energy is released into the atmosphere by an explosive eruption increases in an approximately linear manner as an eruption's pyroclastic production rate increases. 相似文献
18.
白浮监测点断层土壤气的变化特征 总被引：1，自引：0，他引：1
文中介绍了北京南口—孙河断裂带上白浮断层土壤气四个不同集气深度H_2/Ar,N_2/Ar,CO_2/Ar,~4He/~(20)Ne,~4He/~(40)/Ar,~(40)Ar/~(36)Ar比值与地震活动,降雨等的关系,得到各项指标的变化与地震的发生具有一定的关系,但受季节变化的影响。通过断层剖面的工作,证明该断层具有较强的活动性。 相似文献