Abstract The Changbaishan volcanic field located on the Gaima (Gaema, Gaiman) Plateau has witnessed plateau-forming eruptions along with the uplift of the Gaima Plateau. The Tianchi basaltic lava shield volcano was formed at the main peak of Changbaishan, with cone construction eruptions that formed a huge and steep trachytic composite cone on the gentle lava shield. At the peak of the Millennium Eruption (ME), the height of the eruption column reached 25 km and the bulk volume of tephra was about 120 km 3 . The ME eventually formed Tianchi caldera, after which several eruptions occurred, albeit of a much smaller scale. The magmas involved in the shield-forming eruptions are characterized by both alkalic series trachybasalt and basaltic trachyandesite and subalkalic tholeiite and basaltic andesite. In the cone-construction and ignimbrite-forming eruption stages, the magma is completely composed of alkalic series trachyte and comendite. The largest negative Eu anomalies observed in ME magmas indicate that plagioclase was strongly crystallized and differentiated.

Abstract Volcanic eruptions, despite causing large-scale disasters, also provide important natural resources and are an effective way to understand the Earth's internal structure and its evolution. Herein, a comprehensive review is presented on recent progress in geophysical imaging of the structure and origin of intraplate volcanoes in Mainland China. We primarily focus on the Changbaishan, Wudalianchi, Tengchong, Hainan and Ashikule volcanoes as they are currently active and hence pose potential hazards during future eruptions, particularly the Changbaishan volcano. The Changbaishan and Wudalianchi volcanoes are widely believed to be caused by the dehydration of the stagnant Pacific slab in the mantle transition zone along with wet upwelling in the big mantle wedge. There are a number of different views regarding the formation mechanism of the Tengchong volcano. Some studies suggest that a big mantle wedge structure is also present under eastern Tibet, and the Tengchong volcano has a deep origin, similar to volcanism in NE China. Others suggest that the Tengchong volcano is caused by a local and shallow process. Most tomographic studies suggest that the Hainan volcano is a hotspot, and its track has been located in SE China by combining seismological, geochemical and numerical modelling data. A gap exists between the subducted Indian Plate and the Tarim lithosphere beneath the Ashikule volcano, which provides a channel for asthenospheric upwelling to give rise to intraplate volcanism in the Ashikule basin. The interactions of lithospheres may produce shear heating of the subcontinental lithospheric mantle, which can generate localized melting. This process has been proposed as an explanation for the intraplate volcanism in Ashikule.

Abstract China has numerous active volcanoes, and more than 10 erupted in the Quaternary. Although a modern eruption event has not occurred in China, the potential risk from volcanic hazards should be noted. With the development of geodetic technologies including the Global Positioning System (GPS), levelling and interferometric synthetic aperture radar (InSAR), volcanologists can now detect the present-day deformation state of China's active volcanoes. In this paper, we summarize the present-day deformation patterns, magma sources and magma plumbing systems of China's active volcanoes between 1970 and 2013. The results show that the most active volcano in China is the Changbaishan volcano; it showed significant inflation from 2002–03, with the deformation becoming gradually weaker after 2003, indicating that it had been experiencing a magma process during 2000–10. A point source at a depth of c. 10 km was responsible for the observed deformation. The Leiqiong volcanic field showed a trough pattern deformation during 2007–10, which was interpreted as a dyke intrusion model. Fluctuant deformation patterns were shown in the Tengchong volcanic field. The Longgang volcanic field had experienced a volcano-wide uplift during the 1970s and 1990s. Deformation was observed in the Tatun volcanic field from 2006–13, and two shallow sources account for the observed deformation. These volcanoes merit further monitoring given possible evidence of deformation. No obvious deformation related to volcanic activity was observed at the Ashikule volcanic field from 2003–11. The results provide a basic introduction to the deformation state of China's active volcanoes, and may be helpful for evaluating the activity levels of China's volcanoes and mitigating the risks of future volcanic hazards.

Abstract Volcanic eruptions, as major natural disasters, often cause considerable numbers of casualties and economic losses. Given the substantial potential hazards posed to society, volcanic eruptions have become a central concern for national public safety systems. This paper introduces the risk degrees and classification of activity of major active volcanoes in China, reviews early warning policies in the government response to volcanic eruptions, compares the early warning levels of China and the USA, and proposes an early warning theme adapted to the characteristics of volcanic activity in mainland China. The current volcanic warning system of China still has considerable room for improvement; therefore, improvements in monitoring volcanic activities and the antihazard capacity of volcanic eruption in the future are urgently needed.

Abstract Knowledge management plays an important role in scientific research and provides a basis for technical development in the era of Big Data. Studies of Cenozoic volcanoes in China have been undertaken for more than half a century, generating plentiful relevant literature and data. However, these data have stayed scattered between different authors and libraries, and this hampers management and access. Based on theories, knowledge bases and related technologies, we developed the Knowledge Base of Cenozoic Volcanoes (KBCV) to collect such volcanic data in China. The directory tree of the KBCV is structured based on five levels according to the volcano distribution, magma origin, data type and file format. The KBCV supports querying, searching and browsing. It can provide well-managed Cenozoic volcanic data and technical support for scientific research and public communication. The KBCV is still in its early stages and is imperfect with respect to data completeness and universalization of the system, and efforts are being made to continuously develop and popularize the system.

Abstract China has a rich record of Holocene volcanism that is relatively little known outside the country. It is encountered in large stratovolcanoes in the NE, linked to subduction of the Pacific plate (e.g. Changbaishan), in smaller volcanoes on the Tibetan margin, associated with the collision of India and Eurasia (e.g. Tengchong, Ashishan), and in more isolated centres, possibly resulting from mantle upwelling (e.g. volcanoes in Hainan island). This makes China a natural laboratory for studies of intraplate volcanism, and significant progress in understanding its nature and origins has been made over the past quarter century. Here, we introduce the first publication in English to provide a comprehensive survey of the state of knowledge and research highlights. Accordingly, we provide an overview of the dynamics, geology, geochemistry, volcanic histories and geophysical studies of 14 volcanic areas associated with the Holocene documented thus far. The special publication represents a benchmark reference on the topic but, as importantly, we hope that it will stimulate new, international collaborations aimed at deepening our understanding of the origins, history, hazards and associated risks of China's volcanoes.

Abstract By synthesizing relevant research findings from China and other countries, this paper discusses the distribution and eruption types of volcanoes in China. An analysis of the spreading characteristics of volcanic ash possibly caused by volcanic eruptions such as those from Changbaishan is presented, and the impact of volcanic ash on aviation flight safety, as well as several key methods of monitoring volcanic ash, are discussed. This paper also outlines the operational process of China's aviation industry in addressing volcanic ash and compares and analyses the handling of volcanic ash by civil aviation industries globally. Further, ways of dealing with volcanic ash are then suggested for China's aviation industry.

Abstract Following decades of geological surveys and studies, 14 active volcanic fields have been identified in China. Evidence for Holocene volcanism in several of these areas highlights the need to understand and monitor volcanic hazards in those regions. Six volcano observatories have thus been established in the past 40 years. This work reviews China's national capability and history of volcano monitoring, with emphasis on the Changbaishan–Tianchi Volcano Observatory and the Tengchong Volcano Observatory. The Changbaishan–Tianchi Volcano Observatory (CTVO) was constructed in 1996 and began monitoring in 1999, with limited recorded observations dating back to 1973. Currently, CTVO is the largest and most advanced observatories in China. The monitoring network of the CTVO incorporates 11 seismic and 15 GPS stations, two levelling routes and three gas geochemistry sampling points. The Changbaishan–Tianchi Volcano experienced unrest during 2002–05, evidenced in elevated levels of seismicity and ground deformation, as well as shifts in gas geochemistry. After 2006, the volcano returned to quiescence, with activities at background levels as recorded in 1973–2001. The monitoring network of Tengchong Volcano Observatory incorporates eight seismic stations, 20 GPS points, 95 levelling points and three gas geochemistry sampling points. The observations made since 1965 indicate significant seismicity, with more than 3000 events recorded in 2011, mostly related to regional tectonics. Tengchong is known for its widespread hot springs, with temperatures up to 105°C recorded at Dagunguo spring. The four other observatories are Longgang Volcano Observatory, Jingbohu Volcano Observatory, Wudalianchi Volcano Observatory and Qiongbei Volcano Observatory. They are equipped with seismic, geodetic and geochemical monitoring equipment. These areas saw only low levels of activity over the past several decades, but related fault systems are relatively active. In a relatively short time, China has gained considerable experience in observatory design and volcano monitoring and has trained up a sizeable task force, laying the foundation for sustained volcano monitoring at the national level. Future efforts must focus on maintaining and expanding observational capacity, as well as gaining better dynamic understanding to inform volcano hazard assessment.