火山灾害与监测

世界各地几乎都有火山分布,平均每年约有50次喷发。火山喷发在给人类创造财富的同时也带来许多灾害。火山灾害取决于火山喷发的类型、性质、规模和所处的地点等因素。火山喷发动力作用引起冲击波、地震、海啸、滑坡、泥石流等灾害,火山喷出的气体、灰烬、碎屑流和熔岩流等也会造成很大灾害。由于火山造成的灾害严重又来得突然,因此必须采取有效的防范措施,认真监测以掌握火山活动的脉搏。火山监测工作主要有两方面,一是基础地质调查,二是火山活动指标的监视和测量。在中国,具有潜在危险的火山主要分布在长白山、五大连池、台湾、雷琼、腾冲以及西昆仑阿什库勒等地,其中潜在危险最大的是长白山火山。     

长白山天池火山监测工作进展

长白山天池火山是我国最具有潜在喷发危险的活火山。本文介绍了天池火山监测系统建设的基本情况，报道了近些年在火山地震监测、大地形变监测以及地球化学监测等方面的工作进展。     

汤加火山的构造背景及其“1·15”大喷发过程的初步观测分析

2022年1月15日南太平洋海域的汤加火山大喷发引起了全球关注。此次喷发事件的火山喷发指数(VEI)预估在5级左右,触发的海啸和释放的火山灰等火山碎屑物质对汤加的其他地区造成了灾难性的破坏,引起的海啸波对环太平洋沿岸地区也造成了不同程度的影响。本文对汤加火山所处的大地构造背景进行了简要概括;结合前人的资料,对汤加火山破火山口的结构进行了详细的描述;基于初步观测数据,对此次火山喷发的量级和对全球气候产生的潜在影响进行了简要分析;最后对我国境内以长白山天池火山为代表的活动火山的分布及其监测情况做了概述性介绍。     

火山学述评

火山学研究有了长足的进步。本文总结近些年全球火山学研究各个方面的成果,包括对火山基本概念的新的认识、火山机构、火山的各种分类、火山岩石学和地球化学、火山岩相学、评估火山爆发大小的火山爆发指数、岩石和地球化学分类、各种常量和微量元素区分图、活火山分布与板块构造理论的关系、活火山给人类带来的灾害与利益和活火山的监测、曾经的火山活动与生物毁灭、单成因火山研究等。火山—构造是未来火山学研究的一个方向,通过火山与构造关系的研究以揭示火山的分布和地球的演化。火山喷出的岩浆是其通过地下以岩墙或管道形式为通道运移到地表的结果。中朝边境上的长白山的位置是个特例,应当值得深入的研究。中国分布有许多新生代火山,它们是否为单成因火山、这些火山在成分上是否有演化规律、它们的分布与大地构造的关系等都有待深入和系统的研究。     

活火山的监测与喷发预报

我国存在活火山,而且还存在像长白山天池火山这样具有潜在灾害性大喷发危险的活火山［１～３］,并已引起有关方面的高度重视。目前,正在组织对长白山天池火山、云南腾冲火山和黑龙江五大连池新期火山的监测与研究。这是我国第一次开展对活火山的监测,为了使监测更为有...     

火山学述评

火山学研究有了长足的进步。笔者总结近些年全球火山学研究各个方面的成果,包括对火山基本概念的新的认识、火山机构、火山的各种分类、火山岩石学和地球化学、火山岩相学、评估火山爆发大小的火山爆发指数、岩石和地球化学分类、各种常量和微量元素区分图、活火山分布与板块构造理论的关系、活火山给人类带来的灾害与利益和活火山的监测、曾经的火山活动与生物毁灭、单成因火山研究等。火山—构造是未来火山学研究的一个方向,通过火山与构造关系的研究以揭示火山的分布和地球的演化。火山喷出的岩浆是其通过地下以岩墙或管道形式为通道运移到地表的结果。中朝边境上的长白山的位置是个特例,应当值得深入的研究。中国分布有许多新生代火山,它们是否为单成因火山、这些火山在成分上是否有演化规律、它们的分布与大地构造的关系等都有待深入和系统的研究。     

五大连池老黑山、火烧山的火山喷发特征

从野外调查及火山喷发观测记录入手, 结合国内外火山研究的新进展, 在火山成因类型、喷发方式及喷发前兆等方面讨论了五大连池老黑山、火烧山的火山喷发特征。指出老黑山、火烧山的火山成因类型属于单成因火山, 喷发方式不是简单的中心式喷发, 而是经历了裂隙式喷发后转为中心式喷发。通过火山喷发观测记录的分析及与国外火山对比, 揭示出此次火山喷发是有前兆的, 其前兆特征对监测预报未来火山喷发有借鉴意义。     

火山喷发机制、气候效应及火山地球工程

火山是地球内部与表层系统连接的纽带,是地球充满生机活力的体现.减轻大型火山喷发对全球气候和环境的影响是地球科学的重大研究主题.提出探索岩浆储库的累积组装和演变规律,研究火山喷发的触发机制,聚焦地球内、外层圈的相互作用,认识火山活动与全球气候和表层环境变化的互馈关系,构建火山地球工程的理论体系和技术框架,是减轻火山灾害对全人类不利影响的关键.其中,基于岩浆动力学和火山学的岩浆通道系统研究,将会为火山活动的预测和监测提供新的理论依据.火山活动的影响是全球性的.所以,我们要抢占先机,在深化火山喷发机制理论研究和构建减轻火山灾害影响的工程技术体系等方面有所作为.      

陆域强震及火山空天监测集成系统可行性研究

随着空间技术，空间对地预测技术和天测技术的发展，已经逐渐在陆域强震及火山灾害的监测预测领域发挥作用。近几年，有关部门进行了陆域强震及火山活动前兆异常的卫星热红外遥感（TIRS）、全球卫星定位系统（GPS）、合成孔径雷达差分干涉测量（D-INSAR）、天文时纬残差异常、引潮力触震机制和地理信息系统（GIS）等地震与火山短临期监测预测的实验与预研究，在基础理论和应用方法方面都有了相当的研究基础，实验和研究认为，这些空天观测技术是响应高频地壳运动的有效手段，如果将这些分散的科研力量和研究成果通过集成比较完整的空天监测预测体系，争取在我国主要强震火山省区建成强震火山灾害的空间、天测、地面、深部地质与宏观异常（简称空天地深宏）相结合的立体监测系统，将使我国的地震监测预报水平进入高技术发展阶段。     

岩浆补给作用对硅质火山岩浆系统演化的制约

硅质火山喷发作为大陆地壳岩浆活动的重要表现，在研究大陆地壳形成与演化、探讨岩浆过程与动力学机制等方面具有重要的价值，其通常所表现的强烈爆炸式喷发，甚至可以导致全球性的环境和气候变迁。硅质岩浆系统在开放体系中不同来源岩浆的贡献和相互作用是目前研究的热点问题。持续的岩浆补给可以延长岩浆存储的时间，促进岩浆房的对流、岩浆的分异演化以及晶体 熔体的分离和晶粥的再活化，同时也是触发火山喷发的重要机制之一。此外，岩浆补给以及硅质岩浆的晶体 熔体演化过程也是火山喷发产物多样性的原因，导致同一火山在其活动过程中喷发产物规律性的变化，如富晶体火山岩、贫晶体火山岩、火山岩成分分层、以及复活岩穹和中央侵入体等。因此，岩浆补给作用是制约硅质火山岩浆系统演化和火山岩成分多样性的重要因素，也是活动火山监测和灾害评估的重要依据。岩石学、岩石地球化学、矿物(长石、石英、石榴子石、锆石等)同位素及成分变化，以及模拟实验、地震层析成像等研究为揭示硅质岩浆系统中的岩浆补给作用和复杂岩浆过程提供了多种视角。     

火山信息系统建立方法研究——以长白山火山区为例

火山喷发是严重的地质灾害之一。全球各地都有火山分布 ,我国也有近千座火山。其中长白山火山、五大莲池火山和腾冲火山是我国最具潜在灾难性喷发危险的活火山。以长白山火山为例 ,阐述用建立火山信息系统的方法监测、预测、评估火山灾害 ,达到减灾、防灾的目的     

Application of hot spring gases to the study of active volcanoes in the Changbaishan Mountain region,Northeast China

The authors reviewed the history of geochemistry involved in active volcano monitoring and analyzed the relationship between variations in volcanic gas composition observed at the Changbaishan Volcano Observatory and volcanic activities. It is concluded that both geochemical method and routine gas analysis can provide the information about volcanic activity and earthquake activity, and both of them can play an important role in predicting volcano eruption.     

河北沧州小山火山的ESR年代学研究

河北沧州小山火山是河北平原,包括华北平原少有的出露地表的第四纪火山,也可能是华北平原区最后一个活动的火山。因此,此火山极其重要,可是至今没有确切的年代学数据。本次研究分别从小山火山地表和钻孔中采集了7个样品,进行了电子自旋共振测年。每个样品都分选出了石英颗粒,这表明火山堆积物不是纯的凝灰岩,而是火山活动时,同时带有地表物质的混入。样品ESR测年结果在误差范围内一致,平均值为41.4±8.6ka。小山火山活动可能发生于41ka BP.,测年结果表明小山火山最后一次活动在晚更新世晚期。     

A model for developing best practice volcano monitoring: a combined threat assessment,consultation and network effectiveness approach

This paper presents a combined approach to achieving best practice volcano monitoring through a review of New Zealand’s volcano-monitoring capability as established under the GeoNet project. A series of benchmark, consultation and network performance studies were undertaken to provide a comprehensive review of volcano monitoring in New Zealand and to establish plans for future improvements in capability. The United States Geological Survey National Volcano Early Warning System method was applied to benchmark the established monitoring networks against recommendations for instrumentation based on a volcano’s threat level. Next, a consultative study of New Zealand’s volcanology research community was undertaken to canvass opinions on what future directions GeoNet volcano monitoring should take. Once the seismic network infrastructure had been built, a noise floor analysis was conducted to identify stations with poor site noise characteristics. Noise remediation for poor sites has been implemented by either re-locating the site or placing sensors in boreholes. Quality control of Global Navigation Satellite System networks is undertaken through the use of multipath parameters derived from routine processing. Finally, the performance of the monitoring networks is assessed against two recent eruptions at Mount Tongariro and White Island. This combined approach can be used as a model to assess the need for future monitoring levels on any volcano.     

长白山天池火山双岩浆房岩浆作用与互动式喷发

广义的长白山火山在我国境内包括天池火山、望天鹅火山、图们江火山和龙岗火山,是我国最大的第四纪火山岩分布区。长白山各个火山区的火山活动具有此起彼伏的穿时性特征,天池火山之下地壳和地幔两个岩浆房具有上下呼应、互动式喷发之特点。一方面来自地幔的钾质粗面玄武岩浆直接喷出地表,在天池火山锥体内外形成诸多小火山渣锥;另一方面钾质粗面玄武岩浆持续补给地壳岩浆房,发生岩浆分离结晶作用和混合作用,形成双峰式火山岩特征并触发千年大喷发。西太平洋板块俯冲-东北亚大陆弧后引张是长白山天池火山喷发的动力学机制。     

Late Quaternary geology of Ambitle Volcano,Feni Island Group,Papua New Guinea

Ambitle Volcano (new name) is the most recently active of four eruptive centres that make up the mainly Pliocene–Pleistocene Tabar–Lihir–Tanga–Feni (TLTF) alkalic volcanic province, located in the New Ireland Basin, Papua New Guinea. Ambitle Volcano is a submarine and subaerial stratovolcano occupying all of Ambitle Island. The volcano rises 2500 m above the surrounding sea floor to sea level and, with a maximum elevation of 479 m above sea level, indicates a structure nearly 3000 m high. Volcanic deposits rest unconformably on Oligocene basement rocks of the New Ireland Basin. The cone of Ambitle Volcano is constructed mainly of lavas and pyroclastic and epiclastic rocks; lavas are commonly vesiculated. These lavas are strongly undersaturated and intermediate in composition (phonolitic tephrite and tephritic phonolite) with alkali basalt, tephrite and basanite and trachybasalt and trachyandesite also present. Syenite porphyry and monzonite stocks intrude the cone-forming mafic–intermediate sequence at Kabang–Matangkaka and in the upper Nanum River. The central part of the Ambitle Volcano is now modified as a prominent semi-circular topographic rim around the Nanum Valley. The Nanum Valley Crater (new name) is the product of large-scale summit failure of the SW flanks of the summit of the Ambitle Volcano. This event is dated no younger than 0.68–0.49 Ma. The Ambitle Crater (new name), the product of Late Quaternary resurgence of volcanism following sector collapse of Ambitle Volcano, is located in the NE portion of the Nanum Valley Crater. The crater is elongated NNE and measures 900 m × 550 m at its widest development. The strong NNE–SSW linearity of the western rim of Ambitle Crater is structurally controlled by the Kabang Fault. Tephra was erupted from the Ambitle Crater at 2300 ± 100 a and is widely dispersed throughout the Nanum Valley Crater and beyond. This is the youngest volcanic event in the TLTF volcanic province. The Niffin graben is a major NW–SE-trending structural corridor that transects Ambitle Island. The structural corridor is parallel to the NW–SE strike of the TLTF volcanic province suggesting it has been an important control on magmatism and volcanism. Presently active geothermal systems are located along Niffin graben structures in the western valleys of the island and in the Nanum Valley Crater. The volcanic rocks of Ambitle Volcano host porphyry Cu–Au style mineralisation and epithermal Ladolam-type Au mineralisation. Extensive exploration including surface sampling and subsurface drilling completed since 1983 on many prospects has not defined an economic resource.     

Volcano monitoring in NZ and links to SW Pacific via the Wellington VAAC

Monitoring for natural hazards like earthquakes, volcanic eruptions and landslides in New Zealand is under taken by GNS Science through the GeoNet project, funded by the Earthquake Commission (EQC). The volcano monitoring function, which includes seismograph and GPS networks, visual observations, webcams, deformation, gas and chemical measurements, assesses the status of New Zealand’s 12 active volcanoes and disseminates warnings as necessary. Interaction with the Wellington VAAC addresses aviation concerns. Near-real-time data is obtained from the monitoring networks and processed via two data centres, with two Duty Officers who respond to pager alerts. Through the National Civil Defence Plan, the volcano monitoring function is delegated to GNS Science, which is responsible for setting the volcanic alert level at each volcano. The Alert level is then used by responding agencies, industries, utility providers and the public to set their response. The New Zealand alert level system is based on the current status of the volcano, and is not necessarily predictive. The aviation industry is one of these responding industries. As a consequence of the 1995 and 1996 eruptions of Ruapehu volcano, it became apparent that the aviation industry required more information than the standard VAAC data and an additional service known as VAAS (NZ Volcanic Ash Advisory System) was established by MetService NZ and GNS Science. This arrangement provides enhanced services to the airlines and ensures rapid dissemination and quantification of information like SIGMET and NOTAM. GNS Science has informal relationships with similar geological based organisations in SW Pacific countries, especially Vanuatu and the Solomon Islands, and is able to quantify information about eruptions in those countries. Similarly, MetService NZ has relationships and is able to obtain pilot reports and updates from the meteorological and air traffic control organisations.     

21世纪初10年火山与地球内部化学研究进展

进入21世纪,我国除了在长白山天池火山、五大连池火山和腾冲火山三个主要活动火山区进行监测与研究,还开展了中国其他第四纪火山区的活动火山调查工作,发现并确定了一些新的活动火山,如镜泊湖、大兴安岭、乌兰哈达等第四纪火山区中存在的全新世火山.自峨眉山大火成岩省被确定以来,我国近10年在大火成岩省研究方面取得了重要进展,并新确定了一些新的大火成岩省,如塔里木大火成岩省和措美大火成岩省,逐渐为国际地学界所接受.     

SO2 degassing from Turrialba Volcano linked to seismic signatures during the period 2008–2012

In 1996, after 150 years of relative calm, Turrialba Volcano was reawakening. A visible plume and serious damage to surrounding vegetation due to acid rain are the most obvious signals. As part of the Network for Observation of Volcanic and Atmospheric Change project, four gas-monitoring stations were initially installed on the west flank of the volcano with the purpose of measuring sulphur dioxide emissions during this period of increased activity using the scanning-differential optical absorption spectroscopy technique. We present here the results of semicontinuous gas flux measurements over a period of 5 years (from 2008 to 2012), providing a novel data set that documents a relatively rapid increase in SO₂ fluxes from around 350 t day^?1 to around 4,000 t day^?1 leading up to an eruptive period, followed by a gradual return to the former baseline values. Gas flux data were also compared with seismic data for selected periods of interest, providing insights into the link between degassing and seismicity. The most important result from this comparison is the identification of an inflexion point in the gas emissions followed by a clearly increasing trend in seismic activity, distinguishable 6 months prior to a phreatic eruptive event that occurred on 5 January 2010. This signal can be interpreted as a possible indicator of future eruptive events. Monitoring of SO₂ thus complements seismic monitoring as a forecasting tool for eruptive events. Such monitoring is critical considering the proximity of Turrialba to the Central Valley, an area inhabited by more than 50 % of Costa Rica’s population.     

长白山天池地区全新世以来火山活动及其特征

长白山火山全新世规模最大的喷发活动发生在公元1199-1200年,即800年前的大爆发,被确定为普林尼或布里尼(Plinian)式喷发。这次大爆发形成体积巨大的、分布广泛的以空中降落堆积物为主的火山喷发碎屑堆积物,在长白山火山周围,远至日本都留下了地质记录。文章辨认并划分了这次大爆发火山碎屑物的成因类型:火山喷发空中降落堆积物(airfalltephra)、火山碎屑流(pyroclasticflow)状堆积物和火山泥流(lahar)堆积物,并且点、面结合,近、远和国内、国外兼顾,分析了这些火山碎屑物的主要特征、分布和相互关系,进而确定这些火山碎屑物分别属于两次普林尼式爆发。第1次(早期)普林尼式爆发称赤峰期,火山喷发模式为:普林尼式喷发柱(赤峰空落浮岩层)-火山碎屑流(长白山火山碎屑流层),随即主要由火山碎屑流诱发火山泥流(二道白河火山泥流层);第2次(晚期)普林尼式爆发称园池期,喷发模式为:普林尼式喷发柱(园池空落浮岩火山灰层)-火山碎屑流(冰场火山碎屑流层)。在层序上将气象站期碱流岩置于800年前大爆发火山碎屑物之下是正确的,其时代为晚更新世-全新世早期。