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Journal of Earth Science 2019年第5期30卷 1020-1030页

作者： Siyuan Ma Chong Xu key laboratory of active tectonics and volcano Institute of Geology China Earthquake Administration

This paper presents the landslide hazard assessment and slope-failure function using two Newmark displacement models regressed by regional and global station records. Taking the 2008 Wenchuan M_w 7.9 earthquake area as an example, based on the topographic and geological data of the study area, we prepared a factor-of-safety(Fs) map and a critical acceleration(ac) map, respectively. Then using these two simplified Newmark models, two displacement maps were compiled by combining the ac map and peak ground acceleration(PGA) map. By virtue of the actual landslide inventory of the Wenchuan earthquake, we constructed the slope-failure probability curves of the two Newmark models. The results show that the abilities to predict landslide occurrence of the two simplified Newmark models are largely identical, by which the assessment results can well delineate the macroscopic distribution of coseismic landslides, and most predicted landslide cells are distributed on the two sides of the Beichuan-Yingxiu fault, especially Pengguan complex rock mass in the hanging wall of this fault. The probability equations of two Newmark models are roughly the same, though the parameters vary slightly. The probability equation proposed in this paper can be applied to the Wenchuan region and other areas with similar tectonic environments.

关键词： Wenchuan earthquake seismic landslides Newmark displacement peak ground acceleration(PGA)

Magmatic Processes of Ashi volcano, Western Kunlun Mountains, China

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Acta Geologica Sinica(English Edition) 2014年第2期88卷 530-543页

作者： YU Hongmei XU Jiandong ZHAO Bo SHEN Huanhuan LIN Chuanyong key laboratory of active tectonics and volcano Institute of GeologyChina Earthquake Administration

The Ashikule volcanic cluster （AVC） in western Kunlun Mountains is located in a graben region at the convergence of the Altun and Kangxiwa fault zones,and consists of more than 10 main volcanoes and dozens of *** Ashi volcano lies in the central part of the volcanic *** lithology,chemical composition and texture of Ashi volcanic rocks were studied in detail,and their implication in magmatic processes was *** phenocrysts in Ashi volcanic rocks consist mainly of plagioclase and pyroxene,and the statistical results of phenocryst contents show that the rocks can be subdivided into two *** group A,the content of pyroxene phenocrysts is generally higher than that of plagioclase phenocrysts,but an inverse relation occurs in group *** TAS diagram,the compositions of both groups fall into the trachyandensite field,but they are obviously concentrated into two *** two clusters exist also in the oxide *** pyroxene phenocrysts comprise augite,bronzite and hypersthene,and their Mg# histogram shows two *** phenocrysts with reaction rim are observed in rocks of both *** An values of the core are generally 30-40,and those of the rim are 44-48,which are closer to those of euhedral *** bronzites are in equilibrium with the melt,and two sets of magma depths,i.e.,18-25 km and 13-18 km,can be estimated by using thermobarometer proposed by *** hypersthenes are not in equilibrium with the melt,and can be assigned to *** crystal size distribution （CSD） curves of plagioclase appear as kinked lines indicative of magma *** above analyses show that two magma pockets might exist beneath the Ashi *** is likely that they are connected with each *** one has more evolved and contains more acidic magma,and the other is a trachyandensite magma pocket characterized by *** magma from the upper part of the trachyandensite magma pocket might mix with more acidic magma,r

关键词： texture chemical composition crystal size distribution Ashi volcano Ashikule volcanic cluster

Preparation of earthquake-triggered landslide inventory maps using remote sensing and GIS technologies:Principles and case studies

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Geoscience Frontiers 2015年第6期6卷 825-836页

作者： Chong Xu key laboratory of active tectonics and volcano Institute of GeologyChina Earthquake Administration

Inventory maps of earthquake-triggered landslides can be constructed using several methods,which are often subject to obvious differences due to lack of commonly accepted criteria or principles,To solve this problem,the author describes the principles for preparing inventory maps of earthquake-triggered landslides,focusing on varied methods and their criteria,The principles include the following key points：all landslides should be mapped as long as they can be recognized from images;both the boundary and source area position of landslides should be mapped;spatial distribution pattern of earthquake-triggered landslides should be continuous;complex landslides should be divided into distinct groups;three types of errors such as precision of the location and boundary of landslides,false positive errors,and false negative errors of earthquake-triggered landslide inventories should be controlled and reduced;and inventories of co-seismic landslides should be constructed by the visual interpretation method rather than automatic extraction of satellite images or/and aerial photographs,In addition,selection of remote sensing images and creation of landslides attribute database are also discussed in this paper,Then the author applies these principles to produce inventory maps of four events：the 12 May 2008 Wenchuan,China M_w 7.9,14 April 2010 Yushu,China M_w 6,9,12 January 2010 Haiti M_w7.0,and 2007 Aysen Fjord,Chile M_w 6.2,The results show obvious differences in comparison with previous studies by other researchers,which again attest to the necessity of establishment of unified principles for preparation of inventory maps of earthquake-triggered landslides.

关键词： Earthquake-triggered landslides Inventory Principle GIS Aerial photographs Satellite images

Define the Energy Cone Threshold and Extent of Tianchi volcano

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Journal of Earth Science 2012年第5期23卷 768-774页

作者：万园许建东潘波 key laboratory of active tectonics and volcano Institute of GeologyChina Earthquake Administration

Energy cone is a unique but characteristic slope that describes the extent of deposits left around a volcano by various fiowage phenomena, usually regarded as the boundary of pyroclastic and the source region of lahar. The energy cone value is determined as 0.07 by the energy-Hne model com- bined with the parameters of plume height and gradient, and the energy cone spread extent is defined by the numerical simulation method LAHARZ to simulate with this value based on the 1 ： 50 000 digi-tal elevation model of Tianchi （天池） volcano, and the source region profiles in the north and south slope can prove the correctness of this threshold. This energy cone threshold and extent can be used as the reference of pyroelastic flow and lahar simulation.

关键词： energy cone energy-line pyroclastic lahar LAHARZ.

Seismogenic Capability of the Northeastern Segment of the Longmenshan Thrust Zone and its Tectonic Role at the Eastern Tibetan Plateau

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Acta Geologica Sinica(English Edition) 2017年第5期91卷 1930-1931页

作者： SUN Haoyue HE Honglin SHI Feng GAO Wei key laboratory of active tectonics and volcano Institute of Geology China Earthquake AdministrationBeijing 100029 China

Objective The occurrence of the devastating Wenchuan earthquake not only caused huge economic loss and deaths but also raised a question whether or not it would trigger any destructive earthquakes on its neighboring s... 详细信息

关键词： TP Seismogenic Capability of the Northeastern Segment of the Longmenshan Thrust Zone and its Tectonic Role at the Eastern Tibetan Plateau

Late Quaternary Large Earthquakes on the Western Branch of the Xiaojiang Fault and Their Tectonic Implications

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Acta Geologica Sinica(English Edition) 2015年第5期89卷 1516-1530页

作者： LI Xi RAN Yongkang CHEN Lichun WU Fuyao MA Xinquan CAO Jun key laboratory of active tectonics and volcano Institute of Geology China Earthquake Administration Earthquake Administration of Yunnan Province

The Xiaojiang fault is a major active left-lateral fault along the southeastern margin of the Tibetan *** largest historical earthquake in Yunnan Province, with a magnitude 8 and a mean coseismic left-lateral displacement of ~ 6.9 m, occurred on the western branch of the Xiaojiang *** this fault is important in understanding current deformation and kinematic characteristics of the Tibetan *** and stretches have been well undertaken on the Xiaojiang fault, while paleoseismic research work is always the weak link on this *** investigate the paleoseismic history and large earthquake activity of the Xiaojiang fault, we opened a large trench at the northern edge of Caohaizi sag pond on the western branch of the Xiaojiang *** paleoseismic events have been identified, and named E1 through E6 from the oldest to the *** and woods are abundant, 20 samples were dated to constrain the ages of the paleoseismic events at 40 000–36 300 BC, 35 400–24 800 BC, 9 500 BC–AD 500, AD 390–720, AD 1120–1620 and AD 1750–*** associate the youngest event E6 with the 1833 M8 *** E4, E5 and E6 show a continuous record of the western strand of the Xiaojiang fault in the late Holocene, with a average recurrence interval of 370–480 *** earthquake recurrence in the late Holocene is far less than the recurrence of 2000–4000 yr posed in previous ***, the seismic hazard on the Xiaojiang fault should be ***, the irregular recurrence of large earthquakes on the Xiaojiang fault and other faults in the Xianshuihe-Xiaojiang system, indicates the uneven southeastward extrusion of the Sichuan-Yunnan block along the southeastern margin of the Tibetan Plateau.

关键词： Xiaojiang fault sag pond large trench paleoearthquake recurrence interval Sichuan-Yunnan block

Detailed Inventory Mapping and Spatial Analyses to Landslides Induced by the 2013 Ms 6.6 Minxian Earthquake of China

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Journal of Earth Science 2016年第6期27卷 1016-1026页

作者： Yingying Tian Chong Xu Xiwei Xu Jian Chen key laboratory of active tectonics and volcano Institute of GeologyChina Earthquake Administration School of Engineering and Technology China University of Geosciences

On July 22, 2013, an earthquake （Ms 6.6） occurred in Minxian, Gansu Province of China, causing a large number of landslides. Based on high resolution remote sensing images before and after this event, we made the visual interpretation to these coseismic landslides, and prepared a detailed inventory. The inventory registers totally 6 478 landslides in the study area. Of them, 3 322 landslides are larger than 100 m2. Based on 5 m resolution DEM, these landslides were used to perform spatial analyses using landslide number density （LND） and landslide area percentage （LAP）. The results show that the highest LND and LAP values are in the elevation range of 2 300-2 500 m and steeper slopes. Slopes facing E, SE, S and SW directions, slopes with larger absolute curvature values, ridges, scopes of gravel beds of Late Pleistocene （Qp） and the VIII-degree seismic intensity are more prone to sliding with high LND and LAP values. The largest LND and LAP values are in the scopes of 0.08 and 0.24 g, respectively. According to landslide distribution, we infer that F2-2 branch of Lintan-Dangchang fault is the seismogenic fault. With the increasing distances to this branch fault and drainages, LND and LAP values tend to decrease.

关键词： Minxian Earthquake landslide inventory spatial analyses landslide number density (LND) landslide area percentage (LAP).

Study of Distal Pyroclastic-flow Stratum from Tianchi volcano in 1215(±15) Eruption:Pyroclastic-flow Over Water

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Acta Geologica Sinica(English Edition) 2013年第1期87卷 73-81页

作者： ZHAO Bo XU Jiandong LIN Chuanyong Institute of Geology China Earthquake Administration State key laboratory of active tectonics and volcano Institute of GeologyChina Earthquake Administration

In this paper, we describe three strata at the distal part of the pyroclastic-flow from the Tianchi volcano in 1215 （±15） eruption. One of the strata with crosslayers that are different from typical pyroclastic-flow strata may come from a ground-surge. The grain-size and scanning electron microscopy （SEM） analysis was performed to study the origin of the pyroclastic-flow. Characteristics of grain-size distribution show that it is similar with the ash cloud. Through the SEM analyses, we found some quench structures with less damage on the surfaces of the vitric pumices. These phenomena indicate that there has been hydration in the transportation processes at the distal of pyroclastic-flow. It has partly changed the transportation mechanism of pyroclastic-flow, which transitions form dense flow to diluted flow. This paper develops a new distal pyroclastic-flow model in the Tianchi volcano that can be divided into three stages, i.e. the quench stage, expanding stage and depositing stage.

关键词： Tianchi volcano pyroclastic-flow grain-size analyses scanning electron microscopyanalyses quench structures

Extrusion deformation process of ground surface during the Lushan earthquake in China

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Geodesy and Geodynamics 2017年第2期8卷 84-89页

作者： Yuzhu Bai key laboratory of active tectonics and volcano Institute of GeologyChina Earthquake Administration

Based on finite element method, the extrusion deformation process of ground surface during the Lushan earthquake （April 20, 2013） is investigated in this work. In order to construct the finite element model of Lushan earthquake structure, the geophysical layer model of Lushan area, the frictional characteristic of slip-weaken along the fault surface, and the Coulomb failure criterion are considered. Through the computation and the comparison with achievement on the Lushan focal dynamics, our researches indicate that：（1） The most extrusion deformation of ground surface occurred in the initial phase of earthquake procession, i.e., between the fourth and sixth seconds after the earthquake occurred. （2） Between the first and sixth seconds after the earthquake, the extrusion deformation concentrates on the surface projection of earthquake fault. （3） Between the first and third seconds after the earthquake, the extrusion deformation of ground surface is very tiny. Meanwhile, the extrusion deformation reaches maximum at the sixth second after earthquake. （4） After 6 s of Lushan earthquake, the extrusion deformation spread out of earthquake structure projection. （5） During the earthquake, the maximum of extrusion deformation on ground surface is larger than the final deformation of the post-earthquake, in other words, the ground extrusion deformation will lastly reach a relatively small value after the Lushan earthquake occurred.

关键词： Lushan earthquake Extrusion deformation Finite element method

New Chronology of the Quaternary Tengchong Volcanic Swarm,SW China and the Discovery of a Holocene volcano

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Acta Geologica Sinica(English Edition) 2017年第5期91卷 1940-1941页

作者： LI Ni ZHAO Yongwei ZHANG Liuyi key laboratory of active tectonics and volcano Institute of GeologyChina Earthquake Administration Guangzhou Institute of Geochemistry Chinese Academy of Sciences

Objective The Tengchong volcanic field is located at the eastern edge of the convergence zone between India and *** tomographic results show that the subducting Indian Plate is imaged clearly as high-V anomalies beneath Burma and dips eastward with a high angle in the uppermantle, and then it flattens in the mantle transition zone.

关键词： New Chronology of the Quaternary Tengchong Volcanic Swarm,SW China and the Discovery of a Holocene volcano OSL AMS