基于独立分量分析的南极半岛GNSS网区域滤波

高精度GNSS速度场是研究地壳垂向运动及板块运动的基础,能够为冰川均衡调整（Glacial Isostatic Adjustment,GIA）的建模提供外部检核和新的约束.共性误差（Common Mode Error,CME）是区域连续GNSS时间序列中存在的一种与时空相关的主要误差源,通过空间滤波可有效的降低共性误差的影响,提高坐标时间序列的精度.目前广泛采用的主分量分析法（Principal Component Analysis,PCA）,基于二阶统计量（方差和协方差）进行处理,没有充分利用CME高阶统计信息.而独立分量分析ICA （Independent Component Analysis）,引入高阶统计量,能够分离出统计独立的非高斯信号.以南极半岛地区的15个GNSS站点为例,由于某些站点存在强烈的局部效应,因此引入了因子分析法首先对异常站进行剔除,然后对比分析了PCA和ICA方法在南极半岛地区区域滤波结果.结果显示,ICA的滤波效果要优于PCA,ICA滤波前后E、N、U三个方向RMS平均降低44.69%、26.94%、34.87%,不确定度分别降低37.43%,44.58%,55.86%,有效的降低了GNSS残差序列的发散性和速度的不确定度.     

Zircon U–Pb dating using LA-ICP-MS: Quaternary tephras in Boso Peninsula,Japan

Zircon U–Pb dating using LA-ICP-MS was applied to six Quaternary tephras in Boso Peninsula, central Japan: J1, Ks4, Ks5, Ks10, Ks11, and Ch2 in descending order. Accurate age determination of these tephras is of critical importance because they are widespread tephras in Japan and also relevant to a candidate site for the global boundary stratotype section and point of the early–middle Pleistocene boundary. Twenty grains were dated for each tephra and the following results were obtained. The J1 tephra had only 5 grains that yielded <2 Ma. The obtained age was ∼0.2 m.y. older than the stratigraphic age. No Quaternary ages were obtained from the Ks4 tephra. The Ks5 and Ks10 tephras had 10–12 grains that were ∼0.1–0.3 m.y. older than the stratigraphic age. The Ks11 tephra had 14 grains that yielded a weighted mean age of 0.52 ± 0.04 Ma (error reported as 95% confidence level), which was in agreement with the stratigraphic age. The Ch2 tephra had 16 grains that yielded a weighted mean age of 0.61 ± 0.02 Ma, which was also in agreement with the stratigraphic age. The good agreement between zircon U–Pb ages and the stratigraphy for Ks11 and Ch2 tephras validates the reliability of the established stratigraphy and our dating approach. The other tephras that yielded ∼0.1–0.3 m.y. older ages than the stratigraphy may indicate that the analyzed zircons were antecrysts that crystallized before eruption or they were detrital zircons incorporated during deposition.     

THE HISTORICAL RECORDS OF VOLCANIC ERUPTION IN THE KOREAN PENINSULA

The historical document record is of vital significance to determine the volcanic eruption history age in the volcanology research and it cannot be replaced by ¹⁴C dating and other methods. The volcanoes are widely distributed in the northeast area of China, but there is lack of relevant historical records. However, there are the records of the volcanic eruption in the historical documents of Goryeo Dynasty(AD918-1392)and Joseon Dynasty(AD1391-1910)in the Korean Peninsula which is separated by a river with China only. Some of the records have been widely used as important information to the research of Changbaishan Tianchi volcano eruption history by researchers both at home and abroad, but they have different opinions. On the basis of the historical documents in the Korean Peninsula, that is, the History of Goryeo Dynasty and the Annals of the Joseon Dynasty so on, the phenomena of volcanic eruptions, including the intuitive eruptive events and the doubtful volcanic eruption phenomenon such as "the ash fall", "the white hair fall", "the sky fire", "the dust fall" are investigated and put in order systematically in this paper. The results are as follows:1)The intuitive eruptive events are the 1002AD eruption of Mt. Halla volcano on Jeju Island, Korea Peninsula, and the 1007AD volcanic eruption offshore to the west of Jeju Island, Korea Peninsula, as well as the 1597AD eruption of Mt. Wangtian'e volcano in Changbai County, Jilin Province, China; 2)"The ash fall" is airborne volcanic ash, and those "ash falls" happening in 1265, 1401-1405, 1668, 1673 and 1702AD are possibly the tephra of Changbaishan Tianchi volcano; 3)"The white hair fall" is Pele's hair and it is speculated that the "white hair fall "happening in 1737AD is related to Changbaishan Tianchi volcanic eruption; 4)If regarding "the sky fire" as the volcanic eruption phenomenon, "the sky fire" happening in 1533AD is possibly the Changbaishan volcanic eruption event, and "the sky fire" in 1601-1609AD may be the eruptive event of the Longgang volcano in Jilin Province, China or Changbaishan Tianchi volcano; 5)"The dust fall" is recorded in many historical documents. However, "the dust fall" is not the volcanic ash fall but the phenomenon of loess fall. So, it is improper to determine the eruptive events of Changbaishan Tianchi volcano on the basis of "the dust fall".     

胶东邓格庄金矿床矿物化学研究

本文研究了胶东邓格庄金矿床金银系列矿物、黄铁矿、石英和方解石的化学成分,金银系列矿物主要为银金矿和金银矿,含Pt等微量元素,与金矿化关系密切的黄铁矿以Fe亏损占优势,富Au、Te、As和Ag为特点;石英具高的Al、K、Cu、Pb和Zn,低的Li含量;黄铁矿、石英和方解石的稀土元素组成指示成矿热液可能有二种来源,方解石的稀土元素组成指示成矿热液为岩浆或深部来源。     

雷州半岛一次典型局地暴雨成因分析

利用ERA5再分析资料和实况资料,对发生在广东湛江的雷州半岛的一次典型局地暴雨进行对比分析和敏感性试验研究。结果表明：此次局地暴雨是由雷暴单体所造成,ERA5资料作为初始场能较好地模拟出高分辨率局地暴雨的生消过程、降水中心和主要降水时段。通过敏感性试验进一步研究发现,雷州半岛局地暴雨的关键是大气中水汽含量。减少雷州半岛土壤湿度,导致显热通量增大,潜热通量减少,增加雷州半岛土壤湿度,导致潜热通量增大,显热通量减少,但潜热通量和显热通量之和与参照试验基本相同,局地暴雨依然触发,土壤湿度不能决定局地暴雨触发与否,仅通过显热通量的大小提前或滞后触发局地暴雨。雷州半岛三面环海的海陆分布,下垫面非均匀加热,陆地相当于热源,对雷州半岛局地暴雨触发有决定性作用。     

Rates and patterns of erosion on inter-tidal shore platforms,Kaikoura Peninsula,South Island,New Zealand

This paper presents measured rates of erosion on shore platforms at Kaikoura Peninsula, South Island, New Zealand. Surface lowering rates were measured with a micro-erosion meter and traversing micro-erosion meter. The mean lowering rate for all shore platforms was 1·130 mm a⁻¹. Differences in lowering rates were found between different platform types and lithologies. The rate of surface lowering on Type A (sloping) mudstone platforms was 1·983 mm a⁻¹, and 0·733 mm a⁻¹ on Type B mudstone platforms (subhorizontal). On limestone platforms the lowering rate was 0·875 mm a⁻¹. A previously reported cross-shore pattern of surface lowering rates from Kaikoura was not found. Rates were generally higher on the landward margins and decreased in a seaward direction. Season is shown statistically to influence erosion rates, with higher rates during summer than winter. The interpretation given to this is that the erosive process is subaerial weathering in the form of wetting and drying and salt weathering. This is contrary to views of shore platform development that have favoured marine processes over subaerial weathering. Copyright © 1998 John Wiley & Sons, Ltd.     

The morphological development of alpine valley heads in the Antarctic Peninsula

Glaciation has continued in Antarctica for longer than anywhere else on Earth, so the long-term development of glaciated landforms can be investigated. Complex alpine valley heads up to 36 km wide are found in the Antarctic Peninsula. The largest of these may represent an advanced stage of alpine glaciation, having evolved from the earliest corries which could have developed around the early Oligocene. This study is based on a morphometric analysis of the plan form of 1680 alpine valley heads. This is a much larger sample than used by any previous study. Skewed distributions of dimensional properties (width, length and area) suggest that small corries are continually being added to the population, as older ones are enlarged and some eliminated by coalescence and ice sheet erosion. Very large features are found only in parts of Graham Land and Alexander Island, where lack of high-level ice sheet erosion has allowed the forms of mountain glaciation to dominate the landscape. The attainment of an equilibrium planform shape is suggested by the persistence of an equidimensional form, the development of characteristic or limiting values of other morphometric properties, e.g. planform closure and basin order, and by the intercorrelation of morphometric properties. A combination of branching and coalescence is fundamental in the development of corries. The latter results both in widening, which counteracts the tendency towards lengthening observed by other workers, and also in a limit to basin complexity. © 1998 John Wiley & Sons, Ltd.     

近30年雷州半岛季节性气象干旱时空特征

为进一步分析日尺度有效干旱指数(Effective Drought Index,EDI)的适应性,基于雷州半岛1984~2013年逐日降水资料进行验证,对比EDI和月尺度标准化降水指数(Standardized Precipitation Index,SPI)的干旱识别效果,进而结合线性趋势、M-K趋势检验和空间插值方法 ,分析雷州半岛季节性气象干旱时空特征。结果表明:(1)日尺度EDI和6个月时间尺度SPI(SPI-6)适用于雷州半岛的干旱监测,但EDI对严重干旱和突发干旱的识别比SPI-6更准确;(2)1984~2013年,雷州半岛秋冬季干旱频率和干旱站次比均呈减少趋势,但春夏季干旱频率和干旱站次比略有增加趋势;(3)春旱频率从南向北递增,重旱高频地区位于西北部,而夏季重旱高频区位于西部沿海;秋旱南部重于北部,高频中心在雷中西部沿海和曾家周边;冬季重旱以西部沿海、雷州市和徐闻县交界处频率最高。     

西南极乔治王岛菲尔德斯半岛火山岩同位素年代及地层对比

以K-Ar,(39)~Ar-(40)~Ar和Rb-Sr法对菲尔德斯半岛的火山岩进行了同位素测年。实验结果表明,半岛的火山作用从晚古新世开始,可能一直延续至中中新世的早期。其间,碧玉山段的岩石分别以Rb-Sr和(39)~Ar-(40)~Ar法测定了形成年龄,年龄值为54Ma和55Ma,属于晚古新世;岛上广泛分布的玛瑙滩段熔岩的K-Ar年龄区间为45～50Ma,为早始新世;化石山段从中始新世到渐新世;而最晚形成的岩块山段的时代为中中新世的早期。这些数据,与地质和古生物证据一起,对了解该区地层的相互关系和讨论火山作用提出了正确的认识。