海南岛近海海域7个沉积岩芯的现代沉积速率及其分布特征

利用多道α能谱仪,对2005年8～9月在海南岛近海采集的7个沉积岩芯进行了210Pb的沉积速率测定,探讨了海南岛近海陆架上现代沉积速率的区域性分布特征,结果表明:位于港湾内的B1168站位由于沉积物供应充足,有最高的沉积速率,达2.9 cm/a;位于河口海湾附近且受沿岸流影响的B289站位,有很高的沉积速率,可达1.6 cm/a,沉积环境较稳定;位于西南海底沙脊区北缘且靠近昌化江河口的B97、B135、B10站位也有较高沉积速率,分别达到1.0、0.89和0.47 cm/a,在表层都出现了210Pb放射性活度倒置的现象,表明所处区域有较强混合作用;处于西南外陆架的C4站位受北部湾环流影响,沉积速率为0.6 cm/a;位于东部外陆架的B377站位处于上升流区,沉积速率较低,为0.21 cm/a.可见,海南岛近海陆架上的现代沉积速率存在着明显的区域分布:在物质来源丰富的沿岸流作用区和河口区附近,现代沉积速率很高;在陆架环流沉积作用区,现代沉积速率也较高;在水深较大的外陆架上,由于沉积物供应相对匮乏,沉积速率一般较低;在近岸潮流沙脊区,由于水动力很强,无法形成现代细粒沉积.同时,在陆架上,沉积速率有随着水深的增加而降低的趋势.由此可见,海南岛近海海域的沉积速率与该区的物质供应、水动力条件和海底地形等因素有密切关系.     

海南岛4—9月短时强降水的天气型和环境参数特征

利用海南岛加密自动站逐小时降水资料、ERA5再分析资料,对海南岛短时强降水日环流配置进行了天气学分型,并进一步探讨了各天气型下海南岛短时强降水的时空分布、环流形势和关键环境参数特征。结果表明：(1)海南岛短时强降水有明显的日变化特征,呈单峰型,主要出现在15:00—19:00。(2)海南岛短时强降水的天气型主要有南海低压槽、华南沿海槽、西南低压槽和冷锋型。(3)南海低压槽、华南沿海槽、西南低压槽和冷锋型短时强降水分别占37%,31%,16%和16%。南海低压槽和华南沿海槽型主要出现在7、8和9月;西南低压槽型除9月外,其余各月份均可能出现;冷锋型绝大多数出现在4、5月。(4)南海低压槽和华南沿海槽型整层湿度条件都较好,不稳定能量较大,垂直风切变较弱。西南低压槽型不稳定能量较大,湿度条件一般,垂直风切变较弱。冷锋型存在明显的上干下湿特征,垂直风切变最大,0～6 km风速差75%分位大于10 m/s,不稳定能量最小。     

Playing Lotto with Rotto? Tourism,the environment and gambling with the ethos of a Western Australian island

Rottnest Island is a popular holiday destination offshore from Perth, the capital city of Western Australia. Rottnest (or Rotto) attracts approximately 500 000 visitors annually. The island is managed by a statutory government authority, the Rottnest Island Authority (RIA), for the purposes of providing recreation and holiday facilities and services, and protecting its natural and cultural values. While there are advantages in management by one body, there appears to be a conflict in managing both the tourism business and the environment, largely as a result of funding issues. While further tourism development would boost the RIA's self-funded operating budget, increased pressures may compromise the island environment and the Rottnest ethos, which revolves around a relaxed and casual social ambiance. The RIA aims to develop Rottnest as a model for sustainability, but are dilemmas surrounding economic sustainability potentially risking the island's environmental and social sustainability? This paper concludes that in the pursuit of economic returns from tourism, Rottnest Island's environmental and social values face an uncertain future.     

山东蓬莱大黑山岛碱性火山岩地球化学特征

庙岛群岛中的大黑山岛出露碱性火山岩,对研究壳-幔过程及黄、渤海演化具重要意义。文中作者对大黑山岛火山岩的常、微量元素、K-Ar年龄及Nd-Sr-Pb同位素体系进行测试确定。结果表明,岩石属钠质碱性玄武岩系列,岩浆岩喷发可分为8Ma前和8Ma后两个阶段;岩石常量元素含量除K2O、Na2O外差异小;随着火山岩的演化,岩浆源区深度变大;大黑山火山岩Nd-Sr-Pb同位素比值与夏威夷洋岛玄武岩相似,其岩浆的地幔端元组分为PREMA DM,又以PREMA为主,并有MORB物质混入。     

Effects of pulsed nutrient inputs on phytoplankton assemblage structure and blooms in an enclosed coastal area

The response of phytoplankton assemblage structure to terrestrial nutrient inputs was examined for the Gulf of Kalloni in the Northern Aegean Sea, a productive semi-enclosed coastal marine ecosystem. The study was focused on a typical annual cycle, and emphasis was placed on the comparative analysis between blooms developing after significant nutrient inputs from the watershed, and naturally occurring blooms. Baseline information was collected on a monthly basis from a network of stations located in the oligotrophic open sea and the interior and more productive part of the embayment. Intensive sampling was also carried out along a gradient in the vicinity of a river which was the most important source of freshwater and nutrient input for the Gulf. Phytoplankton assemblage structure was analyzed from 188 samples using diversity indices (Shannon and Average Taxonomic Distinctness), multivariate plotting methods (NMDS), multivariate statistics (PERMANOVA), and canonical correspondence analysis (CCA). Three characteristic assemblages were recognized: (1) an autumn assemblage developed under nutrient depleted conditions, having low diversity due to the dominance of two small diatoms, (2) a winter bloom of the potentially toxic species Pseudo-nitzschia calliantha occurring immediately after a nutrient peak and characterized by very low diversity, and (3) a naturally occurring early summer bloom of centric diatoms with relatively high diversity. The results of the study support the view that moderate nutrient inputs may have a beneficial effect on the functioning of coastal ecosystems, stimulating the taxonomic diversity through the growth of different taxonomic groups and taxa. On the other hand, a sudden pulse of high nutrient concentrations may greatly affect the natural succession of organisms, have a negative effect on the diversity through the dominance of a single species, and can increase the possibility of a harmful algal bloom development.     

柴达木盆地新构造运动主要特征与成因机制

研究表明，在壳幔结构、地球物理背景、沉积物结构、多层关地幔和构造样式等方面，达木盆地与中国东部新生代裂谷类伸展盆地具有可比性，应该归属 展性盆 。盆地伸展和收缩作用相间进行，伸展起因于地幔底辟；而收缩受两人因素影响；（１）盆地伸展作用受相邻造山带反作用诱导的挤压应力；（２）板块碰撞传递的远程板内应力。在此基础邮新的构造期达木盆地演化的“双层模式”，即地幔上隆－地壳伸展；被动挤压＋板内应力－地壳收缩     

近40a来海南岛南岸的相对海平面变化

根据海南岛榆林验潮站１９５４～１９９２年连续３９ａ潮位观测资料，经过统一基准面校正后，运用多种统计分析方法研究，得出近４０ａ来海南岛南岸的相对海平面变化呈上升趋势，相应的平均上升速率为０．６４ｍｍ／ａ，这一数值较近百年来１～２ｍｍ／ａ的全球海平面上升速率明显偏小，反映出同期海南岛南岸的地面是微弱抬升的。     

Vertical variations of the chlorophyll maximum during a red tide in a shallow lagoon

The results of eight sets of repeated observations on the vertical variations of the chlorophyll maximum layer in a shallow lagoon during a red tide show that these were more frequently hydrologically induced, rather than due to active vertical migrations of the red tide-forming organism. These results are discussed and compared to those existing in the literature, with special regard to the role of light and nitrogen in conditioning vertical migrations in red tide-forming dinoflagellates.     

海南岛海水鱼类单殖吸虫研究Ⅳ.海盘虫属两新种

对1996年4月采自海南岛万宁之美蝴蝶鱼 Chaetodon wiebeli Kaup 鳃上的海盘虫进行鉴定,发现两新种:(1)海南海盘虫,新种 Haliotrema hainanensis Pan & Zhang,sp.nov.,以其腹中央大钩和支持器结构的不同而区别于 H.annulocirrus Yamaguti,1968;(2)单孔海盘虫,新种 Haliotrema monoporosum Pan & Zhang,sp.nov.,以其腹联结片的结构和交接管长度的差异而不同于 H.canescens Yamaguti,1968.     

北黄海大鹿岛海域营养盐分布特征

根据１９９０年７月辽宁省海岛调查资料，本文讨论了北黄海大鹿岛海水营养盐（ＰＯ４－Ｐ，ＳｉＯ３－Ｓｉ，ＮＯ３－Ｎ，ＮＨ４－Ｎ，ＮＯ２－Ｎ）分布特征，并对海域环境质量作了初步评价。