Annual time-series analyses of total gaseous mercury measurement and its impact factors on the Gongga Mountains in the southeastern fringe of the Qinghai-Tibetan Plateau

Long-term monitoring programs for measurement of atmospheric mercury concentrations are presently recognized as powerful tools for local,regional and global studies of atmospheric long-range transport processes,and they could also provide valuable information about the impact of emission controls on the global budget of atmospheric mercury,their observance and an insight into the global mercury cycle. China is believed to be an increasing atmospheric mercury emission source. However,only a few measurements of mercury,to our knowledge,have been done in ambient air over China. The highly-time resolved atmospheric mercury concen-trations have been measured at Moxi Base Station （102°72′E 29°92′N,1640 m asl） of the Gongga Alpine Ecosystem Observation and Experiment Station of Chinese Academy of Sciences （CAS） from May 2005 to June 2006 by using a set of Automatic Atmospheric Mercury Speciation Analyzers （Tekran 2537A）. Measurements were carried out with a time resolution of every 15 minutes. The overall average total gaseous mercury （TGM） covering the measurement periods was 4±1.38 ng·m^-3 （N=57310）,which is higher than the global background level of approximately 1.5～2.0 ng·m^-3. The measurements in all seasons showed a similar diurnal change pattern with a high concentration during daytime relative to nighttime and maximum concentration near solar noon and minimum concentration immediately before sunrise. The presence of diurnal TGM peaks during spring and summer was found earlier than that during autumn and winter. When divided seasonally,it was found that the concentrations of TGM were highest in winter with 6.13 ± 1.78 ng·m^-3 and lowest in summer with 3.17 ± 0.67 ng·m^-3. There were no significant differences in TGM among wind sectors during each season. Whereas Hg generally exhibited significant correlations with the parameters,such as temperature,saturated vapor pressure,precipitation,ultraviolet radiation （UV） and atmospheric pressure at the whole measurement stage,and t     

Effect of the Zagros Mountains on the spatial distribution of precipitation

In order to examine the effect of the Zagros Mountains on precipitation, first, the annual and Seasonal rainfall indices （rain days frequency, rain amount, daily rainfall intensity, and heavy rains） from 43 stations in 1995 - 2004 between the 30° N to 35° N parallels over the mountain range were analyzed. Second, the effect of the Zagros Mountains was studied through the computation of the spatial correlations between the precipitation parameters and the topographic indices （station site elevation, station mean elevation within a radius of 2.5 km, mean elevation of 9 blocks along each of the eight Cartesian directions, and the elevation differences of these 9 blocks from the station mean elevation）. The results showed that in the cold season the maximal rainfall occurs on the upper range of west slope, while in warm season it spreads over the study area. The correlations between precipitation and elevation indices were positive on the north of the stations and negative on the south of the stations, that is, the higher elevations of the stations to the north force the uplifting of the moist air masses and increase rainfall at the stations, while the lower elevations to their south lead the movement of the moist air masses to the stations. This is due to the fact that these stations or slopes are exposed to the moist air masses coming from the Mediterranean Sea and the Persian Gulf. The heavy rain days and the summer sporadic rain events do not show significant correlations with the topographic indices. The findings indicate that the Zagros Mountains intensify the cold period frontal rains especially over the west slope and block the moist air masses from entering the interior parts of the country. Moreover, these mountains play a secondary role in creating rain days. But they are very important in the production of precipitation in the area. Therefore, their absence will decrease the amount of rainfall to their west and, in return, expand the dry climates of their west and east.     

台湾东部海岸山脉对弧陆碰撞的响应

台湾岛位于欧亚板块和菲律宾海板块的交界处,处在马尼拉海沟和琉球海沟两个方向相对的俯冲带的转换位置.由于从中新世以来吕宋岛弧与欧亚大陆斜向碰撞(弧陆碰撞)形成了今日台湾构造格局,特有的构造地质环境和正在进行中的块体增生使其成为地质学家的研究热点.针对吕宋岛弧海岸山脉段对弧陆碰撞的响应,本文综述了近年来海岸山脉年代学、地球化学、构造地质和利吉混杂岩等方面的研究成果,对海岸山脉的快速隆升和剥蚀特征进行了总结,并在此基础上指出了目前海岸山脉地质研究工作中存在的主要问题,提出今后的研究方向应集中在利吉混杂岩的形成机制、花东海盆洋壳性质和利用海岸山脉凝灰岩进行弧陆碰撞发展过程研究等几个方面.     

永安国家地质公园

位于福建省永安市北8公里处,处于闽中和闽西大山带之间的北东向沙溪河谷中,其东侧为戴云山脉,西侧属武夷山脉的东南坡。     

湖南水系：“四水一湖”

湖南省的水系可以概括为“四水一湖”,湘、资、沅、澧四水是湖南省的四大河流,从东南到西北依次贯穿于湖南省境,四大水系又串起各自的大小支流,四水都汇于洞庭湖,然后导入长江。四水一湖犹如湖南体内的经络,串起湖南的寸寸土地,它们对湖南的意义不言而喻。湖南省的这种水系分布,是它的地形地势所造就的。湖南东面有罗霄山脉,南方是南岭,西部为武陵山脉和雪峰山脉,北部是地势低平的洞庭湖平原,中部为丘陵和盆地,整个地势向北倾斜,呈马蹄形。因而,发源于湖南东、南、西三面山脉的河流最终流入洞庭湖,汇入长江。     

2010年青海玉树地震(Ms7.1)同震地表破裂及其与山脉隆升的关系

野外调查发现,2010年4月14日青海玉树Ms7.1级地震同震地表破裂带长约65km,破裂带走向为310°,破裂面向NE陡倾,地表破裂带由2部分组成,其中西侧部分长约19km,东侧部分长约30km,两者之间存在约15km的无破裂区。地表破裂以右阶雁行状破裂分布为主要特征,呈现左旋走滑性质,伴随有垂直位移。统计结果显示,同震地表破裂垂直位移 (dv)与水平位移 (dh)的比值在0.13~0.53之间,地貌累积dv与累积dh比值为0.27~0.63。同震dv/dh与地貌dv/dh的相似显示玉树南山的形成和玉树地震具有同样的运动学和动力学性质,玉树南山的形成是地质历史上沿玉树断裂多次类似于玉树地震的地震活动的结果,计算出需要1800~2600次地震才能造成玉树南山的隆升。前人研究本段断层地震复发周期为120~200年,计算出断层开始活动时间不晚于20万~40万年以前。     

玉秀挺拔壮丽装点欧洲大陆 世纪冰川冰峰点缀大自然宫殿 山脉绵延起伏 牵起六个国家--欧洲最高大的山脉 阿尔卑斯山极大的冲击着世人的视野

阿尔卑斯山是欧洲最高大,最宏伟的山脉。位于欧洲中南部,是西欧自然地理区域中最显要的景观。总面积约22万平方千米,长约1200千米,宽120～200千米,东宽西窄,平均海拔3000米左右。     

我国主要山脉名称的由来

天山：横贯新疆中部，西端伸人中亚的哈萨克斯坦，全长2500千米左右，南北宽250千米-300千米，气势雄伟壮观，好似拔地而起，高插云端，故名“天山”。     

数百万微型海星栖息于海底火山

据美联社报道，海洋科学家在勘查一片巨大的海底山脉时惊讶地发现数百万微型海星盘绕着它们的触角，尽可能地抓捕海洋急流中的食物。