Early warning system using tilt sensors in Chibo,Kalimpong, Darjeeling Himalayas,India

The National Flash Flood Prevention Project, which mainly consists of non-structural and supplementary structural measures, has been conducted for 6 years in China. Some preliminary achievements have contributed to the prevention of flash flood in China. Based on the latest information, this article introduces China’s flash flood prevention system, primarily from the perspective of its development process, components, investment, and characteristics. To date, the system has incorporated many distinguished large-scale features such as the largest rain gauge network (approximately 0.5 million stations) in the world, massive disaster observation and preparedness networks, people-and-expert combined monitoring and forecasting data integration system, and a vast implementation area. Based on its early achievements and some typical case investigations of such flash flood prevention system, the article also discusses China’s prospects for preventing flash flood disasters in the future.     

Correlation of predicted seismic response using hybrid modelling with EPRI/TPC lotung experimental data

The hybrid modelling method is presented herein along with the equivalent linearization method to take account of the strain-dependent non-linearity of soils in a soil-structure interaction (SSI) seismic analysis. A refined substructuring of the soil-structure system is utilized and two separate analyses are made to determine the soil free-field and SSI motions induced by earthquake excitation. This method is used to predict the seismic response of a 1/4-scale containment model built in the seismically active area of Lotung, Taiwan. The results obtained show excellent correlation with the field test results.     

Mineral inclusions in zircons of para- and orthogneiss from pre-pilot drillhole CCSD-PP1, Chinese Continental Scientific Drilling Project

The pre-pilot drillhole CCSD-PP1, Chinese Continental Scientific Drilling Project (CCSD), with depth of 432 m, is located in the Donghai area in the southwestern Sulu terrane. The core samples are mainly comprised of paragneiss, orthogneiss and ultramafic rock with minor intercalated layers of eclogite and phengite-bearing kyanite quartzite. All analyzed paragneiss and orthogneiss samples were overprinted on amphibolite facies retrograde metamorphism. Coesite and coesite-bearing ultrahigh-pressure (UHP) mineral assemblages were identified by Raman spectroscopy and electron microprobe analysis as inclusions in zircons separated from paragneiss, eclogite and phengite-bearing kyanite quartzite samples. In the paragneiss samples, UHP mineral inclusion assemblages mainly consist of Coe+Omp+Grt+Phe, Coe+Jd+Phe+Ap preserved in the mantles (M) and rims (R) of zircons. These UHP mineral inclusion assemblages yield temperatures of 814–852 °C and pressures of ≥28 kbar, presenting the P–T condition of UHP peak metamorphism of these country rocks. According to the mineral inclusions and cathodoluminescence images of zircons, the orthogneisses can be divided into two types: UHP (OG1) and non-UHP (OG2). In OG1 orthogneisses, low-pressure mineral inclusion assemblage, mainly consisting of Qtz+Phe+Ab+Ksp+Ap, were identified in zircon cores (C), while coesite or coesite-bearing UHP mineral inclusions were identified in the mantles (M) and rims (R) of the same zircons. These features suggest that the OG1 orthogneisses, together with the paragneisses, phengite-bearing kyanite quartzite and eclogite experienced widespread UHP metamorphism in the Sulu terrane. However, in the zircons of OG2 orthogneiss samples, no UHP mineral inclusions were found. Inclusions mainly comprised Qtz+Phe+Ap and were identified in cores (C), mantles (M) and rims (R) of OG2 zircons; the cathdoluminescence images of all analyzed zircons showed clear zonings from cores to rims. These features indicate that the OG2 orthogneisses in pre-pilot drillhole CCSD-PP1 did not experience UHP metamorphism. Therefore, we should not rule out the possibility that some orthogneisses in Sulu terrane might represent relatively low-pressure granitic intrusives emplaced after the UHP event.