The role of gender and age in fracture distribution following the 2008 Wenchuan earthquake

This study explored demographic variations among victims injured in the 2008 Wenchuan earthquake. The study analyzed records of 2,148 patients who were hospitalized with earthquake-related injuries in 14 hospitals between May 12 and May 21 of 2008. We tested the effects of gender and age on the incidence of fractures and amputations. Although more women than men were hospitalized as earthquake victims, the results indicated that a higher incidence of pelvic fracture in women was the only statistically significant injury with regard to gender. Age had a more complex effect on the rate and pattern of fractures. Children younger than 15 years old were the most likely to sustain skull fractures and amputations. The elderly were the most likely to be associated with limb fractures. Adult men were the most likely to suffer spine fractures and adult women rib fractures. The paper concludes with an interpretation of the results in the context of China’s rural conditions and discusses implications for post-disaster emergency operations and planning.     

Secondary geological hazard analysis in Beichuan after the Wenchuan earthquake and recommendations for reconstruction

The Wenchuan earthquake, also known as 2008 Sichuan Earthquake, occurred along the Longmenshan fault zone on 12 May 2008 at 14:28:01.42 CST (06:28:01.42 UTC). It caused serious damage to structures in the region. Beichuan is a town which is within these severely damaged areas. According to the earthquake intensity distribution map of 2008 Wenchuan earthquake officially released by the China Earthquake Administration, the earthquake intensity in Beichuan was XI on the China seismic intensity scale. As the earthquake occurred in a mountainous area, there were thousands of landslides, rockfalls, debris flows, and surface ruptures triggered by the earthquake over a broad area. These secondary geological hazards substantially increased the human, social and economic impact of the earthquake. This paper presents a post-earthquake analysis on the secondary geological hazards in Beichuan. The risk analyses associated with construction of the National Earthquake Memorial Museum in Beichuan are assessed and recommendations on risk mitigations for the mass reconstruction over the ruins are also provided based on this field study.     

Examples of geomorphologic and geological hazards in Algeria

We present three geomorphologic and geological phenomena that have occurred in Algeria in recent years: (i) the Bab El Oued mudflow on 11 November 2001, which claimed several hundred lives, (ii) a soil collapse induced by sand liquefaction triggered by the Boumerdes earthquake (M _w = 6.8) on 21 May 2003, and (iii) landslides that are threatening Constantine city, for which a hazard map is presented using a qualitative approach. We briefly describe and analyze these natural disasters, and in the first two cases propose the application of geophysical techniques such as ambient noise recordings and electrical imagery to help evaluate their extent and potential threat. Finally a landslide hazard map of Constantine is proposed.     

Cosmogenic nuclide exposure ages for moraines in the Lago San Martin Valley, Argentina

At several times during the Quaternary, a major eastward-flowing outlet glacier of the former Patagonian Ice Sheet occupied the Lago San Martin Valley in Argentina (49°S, 72°W). We present a glacial chronology for the valley based on geomorphological mapping and cosmogenic nuclide (¹⁰Be) exposure ages (n = 10) of boulders on moraines and lake shorelines. There are five prominent moraine belts in the Lago San Martin Valley, associated with extensive sandar (glaciofluvial outwash plains) and former lake shorelines. Cosmogenic nuclide exposure ages for boulders on these moraines indicate that they formed at 14.3 ± 1.7 ka, 22.4 ± 2.3 ka, 34.4 ± 3.4 ka to 37.6 ± 3.4 ka (and possibly 60 ± 3.5 ka), and 99 ± 11 ka (1σ). These dated glacier advances differ from published chronologies from the Lago San Martin Valley based on ¹⁴C age determinations from organic sediments and molluscs in meltwater channels directly in front of moraines or in kettleholes within end moraine ridges. The moraine boulder ages also point to possible pre-LGM glacial advances during the last glacial cycle and a key observation from our data is that the LGM glaciers were probably less extensive in the Lago San Martin Valley than previously thought.     

汶川地震灾区汛期地质灾害督导与地质灾害防治

“5.12”汶川特大地震发生后,灾区防灾形势异常严峻,为增强灾区各级政府应急抢险技术力量,省主利害部门积极协调组织多支专业队伍开展灾区汛期地质灾害督导、排查、巡查、应急抢险调查及防治知识宣传培训等工作,极大地提升了各级政府地质灾害防治能力,取得了显著的防灾减灾效果,为夺取灾后恢复重建及全省地质灾害防治工作的重大胜利提供了坚实保障.     

Chromite alteration processes within Vourinos ophiolite

The renewed interest in chromite ore deposits is directly related to the increase in Cr price ruled by international market trends. Chromite, an accessory mineral in peridotites, is considered to be a petrogenetic indicator because its composition reflects the degree of partial melting that the mantle experienced while producing the chromium spinel-bearing rock (Burkhard in Geochim Cosmochim Acta 57:1297–1306, 1993). However, the understanding of chromite alteration and metamorphic modification is still controversial (e.g. Evans and Frost in Geochim Cosmochim Acta 39:959–972, 1975; Burkhard in Geochim Cosmochim Acta 57:1297–1306, 1993; Oze et al. in Am J Sci 304:67–101, 2004). Metamorphic alteration leads to major changes in chromite chemistry and to the growth of secondary phases such as ferritchromite and chlorite. In this study, we investigate the Vourinos complex chromitites (from the mines of Rizo, Aetoraches, Xerolivado and Potamia) with respect to textural and chemical analyses in order to highlight the most important trend of alteration related to chromite transformation. The present study has been partially funded by the Aliakmon project in collaboration between the Public Power Corporation of Greece and Institute of Geology and Mineral Exploration of Kozani.     

X-ray Diffraction of Dust Particles in Spring Beijing

X-ray diffractometry was utilized to study the mineralogical characteristics of the inhalable particles (PM10) sampled during two dust storms in Beijing city on March 18th and May 21st, 2008. We confirm, for the first time, that there stably exists ammonium chloride in the atmosphere when temperature is low. The total sulfates particles were affected by relative humidity. Both species and concentration of sulfates decreased first and then grew back by the end of each dust storm. Koninckite, a phosphate mineral never reported as particulate aerosol before, was identified. Meanwhile, our result shows that a chemical modification on dust minerals occurs during long range transportation. PM10 samples collected during the period of dust storms were dominated by crustal minerals such as quartz, illite/ smectite, illite, chlorite, feldspar and calcite, and were notably higher in concentration than that in normal periods of time. The amounts of total sulfates, calcite and feldspar altered in each dust storm. It is derived from 24-hour isentropic backward trajectories that two dust events in spring 2008 originated in different sources.     

5.12汶川8级地震次生地质灾害的基本特征及其形成机制浅析

5.12汶川8级大地震沿龙门山断裂带形成长350多km,宽约50 km的地表破裂带,触发了1万多处崩塌、滑坡、泥石流(碎屑流)地质灾害,其中巨型灾害体87处、大型灾害体606处,形成了136个较大规模的堰塞湖。地震地质灾害的链生特征显著,形成地震-崩塌、地震-滑坡-碎屑流-堰塞湖-堰塞坝溃决-泥石流等典型地质灾害链。地震次生地质灾害具有分布范围广、数量多、种类全、密度大、强度高、致灾重的特点。在部分地区,崩塌、滑坡和碎屑流的分布面积占地震极重灾区面积的30%~58％,甚至高达80％。据初步统计,崩塌、滑坡和碎屑流共导致大约2万人死亡,其中北川县老县城滑坡导致1 600多人死亡。地震次生地质灾害主要沿断裂带、河谷和交通线分布。崩塌、滑坡的破裂源主要位于河流拐弯处靠近侵蚀岸一侧、山脊两侧及坡肩部位,这与上述部位对地震动峰值加速度的放大作用直接相关。地震次生地质灾害主要受地震动峰值加速度和地形控制,其次为岩性、斜坡结构、活动断裂、人类工程活动。许多大型崩塌、滑坡还具有高速远程的特征,部分崩塌、滑坡 碎屑流位移达数km,速度高达100~300 m/s,其运动轨迹复杂多变,常常导致多处人员伤亡,是高山峡谷地区地质灾害风险评估和减灾防灾必须面临的新课题。根据上述情况,文中对汶川地震次生地质灾害的基本特征、分布规律和主要影响因素进行了初步总结,并对地震滑坡的形成机制和运动模式进行了初步探讨。首次提出高山峡谷地区单一斜坡上呈阶梯状多级滑动的群发性地震滑坡的形成模式:强烈地震往往引起剧烈的地面震动,而高陡的山脊及其坡肩部位对地震波具有明显的放大作用,因此,上述部位往往是地震滑坡的高易发地段,当地震动峰值加速度超过不稳定性斜坡的临界峰值加速度时,斜坡失稳破坏形成一系列的群发性滑坡,从上到下往往形成阶梯状多级滑动的滑坡群,此种模式适用于残坡积层、风化层地震滑坡和主滑面较缓的地震基岩滑坡。最后,指出了今后应重点研究的科学问题,并对防灾减灾措施提出了一些建议。     

Study of ionospheric anomalies due to impact of typhoon using Principal Component Analysis and image processing

Principal Component Analysis (PCA) and image processing are used to determine Total Electron Content (TEC) anomalies in the F-layer of the ionosphere relating to Typhoon Nakri for 29 May, 2008 (UTC). PCA and image processing are applied to the global ionospheric map (GIM) with transforms conducted for the time period 12:00?C14:00?UT on 29 May, 2008 when the wind was most intense. Results show that at a height of approximately 150?C200?km the TEC anomaly is highly localized; however, it becomes more intense and widespread with height. Potential causes of these results are discussed with emphasis given to acoustic gravity waves caused by wind force.     

Civilian monitoring video records for earthquake intensity: a potentially unbiased online information source of macro-seismology

We collected and analyzed 68 civilian monitoring videos recording the scenes of the May 12, 2008, Wenchuan earthquake. These video recordings are shared online by volunteers after the earthquake. Intensity was estimated by visual inspection of the playback video recordings. Comparing to traditional media accounts, these video records have the distinctive unbiased feature in obtaining local intensity due to their dynamic and repeatable nature. We argue that with proper guidance for providing the necessary information of the location and time when sharing these data online, civilian monitoring videos are potentially more and more useful in the citizen-powered macro-seismology.     

水温突降-缓升型的响应机理之冷水下渗学说的研究——以重庆北温泉水Fe3+、Mn2+对汶川地震的响应为例

深井水温观测在中国已经开展了20多年,但目前对于水温响应机理的研究还不充分.而且利用温泉水对水温响应机理研究甚少.本文在2008年5月12日汶川8.0级地震前后,即2008年5月1日至7月4日,对重庆北温泉水(距震中约400 km)进行采样监测,发现泉水水温水量发生较大变化:震后水温下降了1℃:海拔相对较高的BWQ-2、BWQ-3、BWQ-4相继断流,监测点BWQ-1的水量增加了15 L/s;与此同时.各泉点Fe~(3+)、Mn~(2+)浓度于地震当日成倍增长,随后逐渐减小,7月4日时浓度与5月1日相当.重庆北温泉位于四川盆地东部边缘地带,受汶川地震强烈影响导致冷水下渗作用,海拔相对较高而温度较低的温泉水改道,并有其他来自裂隙或者地表的低温水汇入温泉含水层,Fe~(3+)、Mn~(2+)浓度的变化从水化学上印证了冷水下渗学说.     

北川通口电站震后恢复防渗加固工程

在“5·12”汶川大地震中,北川通口水电站遭受到了重创,大坝的渗漏量加大,已影响到大坝的安全运行。通过对该水电站坝基采取帷幕灌浆的方法进行处理,在具体施工过程中对关键环节进行了控制。实践证明,大坝渗漏量比地震前的渗漏量还有降低,达到预期效果,确保了大坝运行安全。     

汶川5.12大地震地表次生灾害评价与分析

针对汶川5.12大地震,对由地震引起的地质次生灾害发生的坡度和坡向进行了统计,分析了地表破坏的易发坡度、坡向及其与震中的关系等。另外,分别以不同震中距为缓冲区、以平行中央断裂带的各级缓冲区、以等烈度区为缓冲区对地震引起的地表破坏的空间分布以及发生地表破坏的坡度在各级缓冲区中的变化进行了分析。结果表明:①地震引发的滑坡及滑坡群共5093个,总面积大约958km2;②在30°～44°坡度区间地表破坏发生的数量最大,42°坡度为地表破坏发生概率的拐点。主要的地表破坏发生在迎着地震波传播的坡向上;③随着震中距的增加,地表破坏的发生概率逐渐减小,震中距40km以内的速度减小非常迅速,40km以外则整体上缓慢减少,局部略有起伏。各缓冲区中发生地表破坏的平均坡度比缓冲区内的地形平均坡度大4°左右。④地震引发的地表破坏主要受到断裂带的控制,有64.17%的地表破坏发生在中央断裂带两侧10km范围内。⑤高地震烈度区域引发的地表破坏率远远大于低烈度区域,在烈度为Ⅺ度的区域内发生地表破坏率达到14.5%,而Ⅶ度烈度带上引发地表破坏率仅为0.01%。     

高密度电阻率法在四川青川张家沟滑坡勘查中的应用

文中阐述了高密度电阻率法的基本原理和技术方法,利用高密度电阻率法在四川汶川5·12大地震灾区进行滑坡地质勘察,确定主滑动面的位置、基岩的埋深及含水程度,并探讨了大地震灾区滑坡的特点。高密度电阻率法以其快速、高效、无损的特点,及事半功倍的效果,为灾区滑坡治理提供可靠的地球物理依据。     

三峡小江回水区真光层深度及其影响因素分析

为探讨三峡水库运行初期小江回水区水体的光学特性,2007年5月~2008年5月对回水区5个断面水下光合有效辐射(PAR)与常规水质指标进行监测,分析了真光层深度的时空特征及其影响因素.研究区域真光层深度空间差异不明显,但季节变化显著,冬季最高,夏季最低.回归分析表明光合有效辐射(PAR)衰减系数与透明度、总悬浮物浓度有显著的相关性(R2=0.861 9,R2=0.764),与叶绿素a相关性不明显(R2=0.011 3).进一步研究分析表明真光层深度、总悬浮物浓度、叶绿素a主要受小江河口流量、小江回水区水位的影响,复杂的水动力条件与独特的水文条件是影响三峡水库小江回水区真光层深度变化的主要因素.     

Track prediction of Indian Ocean cyclones using Lagrangian advection model

A new model has been developed for track prediction of Indian Ocean cyclones. The model utilizes environmental steering flow using the forecasts from a high-resolution global model and the effect due to earth??s rotation (the beta-effect) to determine the future movement of cyclone. A new approach based on vertical profile of potential vorticity is used to determine weights for different vertical levels for computation of mean steering current. Despite the fact that the model is based on the dynamical framework, the operational cost and time for running the model is only a fraction of what is needed by a normal numerical weather prediction model. This new approach will enhance flexibility in defining the initial position of the cyclone in the model, and also, it is possible to create a large ensemble of predicted tracks to assess the impact of the uncertainty of initial cyclone position on the predicted tracks. The performance of the model for ten cyclones, viz. GONU (02?C08 Jun, 2007), SIDR (11?C16 November, 2007), NARGIS (27 Apr?C04 May, 2008), RASHMI (25?C27 October, 2008) KHAI-MUK (14?C16 November, 2008), NISHA (25?C27 November, 2008), SEVEN (04?C08 December, 2008), BIJLI (14?C18 April, 2009), AILA (23?C26 May, 2009), and PHYAN (09?C11 November, 2009), have been tested in the present study. The forecast errors of the present model have been computed with respect to the Joint Typhoon Warning Center best track analysis positions. The forecast skill improvement (mean of ten cyclones) of the model with respect to the Climatology and Persistence (CLIPER) statistical model varies from 7 to 67?% between 12 and 72?h.     

都江堰市景区秦堰楼震后岩土工程调查分析与建议

都江堰市景区秦堰楼为重要的古建筑物,受“5．12”汶川大地震影响,古建筑物基础及主体均遭受不同程度的破坏,通过调查其变形破坏特征、规模,分析论述其变形破坏机制,并在场地整体及局部稳定性分析的基础上提出了较为详细的治理方案和建议。