2013 年芦山MS7.0 地震前甘孜台地电阻率变化分析

A trend increase in apparent resistivity has been observed in the N30°E monitoring direction at Garze Seismic Station since July 2011. This increase trend in geo-electric resistivity has been observed in the N60°W direction since 2012. During the period of the increase, the national highway No.317 was expanded in the monitoring area, so the potential electrodes in the N30°E direction had to be moved 10m towards the current electrodes. We interpreted the electric sounding data of Garz6 Seismic Station with a horizontally layered model. Analysis based on this model showed that the shift of potential electrodes can cause a 4 l-l.m rise to the measurements in the N30°E direction. Therefore, apparent resistivity of the two directions increased in the same time in 2012 after offsetting the effects from electrodes shift. Sensitivity coefficients of the two observation directions were also obtained using the model. Sensitivity coefficients of both directions were negative for the shallow layers, which can well explain the unexpected annual variations of Garze Seismic Station. In order to quantitatively analyze the effects from the expansion of the national highway on the observation, we constructed a finite element model based on the electrical structure. Analysis results also suggested that the expansion of the national highway could only cause a 0. 15 Ω·m decrease in the N60°W monitoring direction and 0. 1 Ω· m increase in the N30°E direction. Additionally, the valley values of annual variation of 2013 were distinctively higher than that of other years since 2008, meaning that there was an abnormal rise in apparent resistivity in the two observation directions at Garz~ Seismic Station before the Lushan earthquake. However, the rise was contrary to the decline variation before the Wenchuan earthquake. Therefore, it is still unsure whether or not the rise variation is related to the Lushan earthquake.     

Improving fleet efficiency to maximise economic yield in a Western Australian prawn fishery

The Shark Bay trawl fishery is Western Australia's most valuable prawn fishery (worth AUD$25 million in 2014). The 18-vessel fleet targets western king prawns (Penaeus latisulcatus), brown tiger prawns (P. esculentus) and also retains saucer scallops (Ylistrum balloti) and blue swimmer crabs (Portunus armatus). Increased fuel prices, falling prawn prices and lower catches of other species, following extreme environmental events, have impacted fishery profits. A biomass dynamics model with an economic component indicated that total revenue levels start to decline when annual effort increases beyond ~ 200 fishing days per boat. Annual effort required to achieve MEY, when based solely on prawn fishing, is 115–150 days per boat after accounting for fixed and variable fishing costs and annual fishing efficiency increases of 1–2%. From 2007–2014, the adjusted effort was 188–192 days per boat. Fishing occurred between March and November during 7–8 fishing periods, separated by 5–8 day (low catchability) moon closure periods. An empirical daily profit assessment (2007–2015), accounting for recruitment variation, daily prawn size compositions, monthly market prices for different prawn species and sizes, and daily fishing costs, showed vessels made profits on ~ 115–160 days and losses on ~ 15–55 days per year, when fishing occurred near the full moon. The fishery benefitted in 2013–2015 by starting later in the year and better targeting within-season effort. This management strategy within the effort-control framework, which improved profitability, maintained higher spawning stocks and reduced ecosystem fishing impacts, has wider application in prawn fishery management.     

Industry response to the 2003 set net restrictions for protection of Maui′s dolphin

Marine reserves and gear restrictions are common forms of marine resource management; they impact on fishers both directly and indirectly. In 2003 New Zealand set net fishers were required to abandon set netting along a substantial section of the North Island′s West Coast in order to eliminate the chance of entangling the critically endangered Maui′s dolphin. A study of some 100 set net fishers, found that the immediate, and short term effects of the 2003 set netting area closures had little impact on the catch and effort levels of fishers. Participation in the fishery increased immediately prior to the restrictions and remained at a similar level for the following four years. Incumbent fishers performed better than new entrants and exiters. Trends in Annual Catch Entitlement (ACE) prices appear not to have been affected by the set net restrictions.     

1962-2008年辽宁省积雪变化特征

采用1962-2008年辽宁省52个气象观测站逐日积雪深度以及同期温度、降水资料,用统计方法和小波方法分析了辽宁省积雪气候变化规律。结果表明：近47 a辽宁省积雪日数呈不显著增加趋势,共增加了3 d;年最大雪深随时间变化呈不明显增加趋势,平均每10 a增加0.2 cm;年累积雪深也呈不显著增加趋势,气候倾向率为8.9 cm/10 a。从年代际变化来看,20世纪80年代前辽宁省积雪日数、年最大雪深和年累积雪深偏小;而20世纪80年代后至今,则经历了一个积雪日数、年最大雪深和年累积雪深均增加的过程。     

Low Frequency Characteristics of Tropical Pacific Wind Stress Anomalies in Observations and Simulations from a Simple and a Comprehensive Models

Low frequency characteristics of tropical Pacific wind stress anomalies in observation and simulations; from the CZ simple atmospheric model and COLA R15 AGCM are analyzed. The results show that ENSO event may be a multi-scale process, that is, ENSO time scale has the period longer than three yean; biennial oscillation and annual variability Dynamical characteristics are involved in the evolution process of wind stress anomaly with ENSO time scale: 1) the development and eastward movement of a cyclonic anomaly circulation in subtropical northwestern Pacific and weakening of Southern Oscillation result in the eastward propagation of westerly anomaly along the equator, there?fore, interactions between flows in subtropics and in tropics play an important role in the evolution of wind stress anomaly with ENSO time scale; 2) easterly and westerly anomalies with ENSO time scale are one kind of propagating wave, which differs from Barnett’s (1991). It is interesting that the evolution of observed and simulated wind stress anomalies with biennial time scale bears a strong resemble to that with ENSO time scale although their period it dif?ferent. Observed annual variability it weak during 1979-1981 and intensified after 1981, especially it reaches to max?imum during 1982-1984, and the spatial structure of the first mode is the ENSO-like pattern.     

参加第49届丹佛X射线年会有感

报道了第49届丹佛X射线年会的概况。会议期间,痒于微束装置及其分析技术、全反射技术与应用、探测器研制、薄层分析、样品制备、半导体材料分析等，受到广泛关注。     

中国大陆地壳应变能密度年变化率图像与强震活动关系的初步探讨

以现代构造应力场和地壳运动的观测结果为约束条件,利用有限元方法计算了中国大陆地壳应变能密度年变化率,三维有限元模型采用粘弹性本构关系,包含了中国大陆主要活动断裂带,在青藏高原考虑了因高海拔地势蓄集的附加重力势能和地壳山根浮力作用。     

SEDIMENT BUDGET OF THE ILLINOIS RIVER

1 BACKGROUND The Illinois River is the most significant river in the state of Illinois. The river drains nearly half of the state and has a drainage area of 28,906 mi2 (74,867 km2). Except for about a 4,000 mi2 (10,360 km2) area in Indiana and Wisconsin, the watershed is located in Illinois (see Fig. 1). The watershed contains the drainage basins of several of the state's significant rivers such as the Sangamon, LaMoine, Spoon, Mackinaw, Vermilion, Fox, Kankakee, and Des Plaines Ri…     

乌鸦嘴泉水电导率年变动态与地震关系分析

本文通过确立乌鸦嘴泉水电导率正常年动态变化 ,利用典型震例 ,分析乌鸦嘴泉水电导率年变动态与地震关系 ,讨论了引起水电导率年动态变化畸变的原因 ,并认为地震前兆异常是造成乌鸦嘴泉水电导率变化异常的主要原因     

汰内井水氡年变异常与台湾地区强震的关系

通过对汰内井水氡多年年变动态的分析,发现台湾地区强震前后汰内井水氡测值表现出持续高值的异常,这些异常多为中期与中短期异常,有时也有短临异常和震后效应。研究结果表明,汰内井水氡对台湾地区的强震有一定的映震能力,可为台湾地区的强震预测服务。