大连湾60多年来生态环境地质演化

依据对大连湾60多年来沉积柱的生态环境地质演化研究，发现其污染变化可以分为3个时期：①1933－1974年为洁净时段；②1974－1989年为污染较重时段；③1989－1997年为严重污染时段。若视第一时段的污染度为0，则第二时段的污染度为第一时段的8倍，第三时段的污染度为第一时段的25倍，可见污染度增加是非常迅速和严重的。其中Cd、Pb、As、S、Zn5种元素含量增加最快。1997年大连湾表面沉积物中Cd、Hg、Pb、As的含量分别为自然背景值的81．42倍、6．0倍、7．54倍、3．82倍，表明大连湾污染的严重性。研究发现自1950年以来大连湾生物多样性急剧下降，说明污染度增加已对生命健康造成严惩的影响。大连湾的臭水套已成为一个生物多样性异常低下的、超级污染的环境，是一颗巨大的隐性化学定时炸弹。     

应用改进的相干算法提高三维地震资料解释精度

作者在文中详细探讨了C1、C2和C3三种相干算法及其。根据三维地震数据体的特点提出了实用的相干算法，并编制了相应的软件。我们对三种相干算法对应相干数据体的解释结果进行了细致的分析，C2相干算法基本能够平衡提高横向分辨率和信噪比之间的矛盾，而C3相干算法则取得了更精确的效果。     

The relationships between earthquakes and positions of the sun and moon（Ⅱ）——Sometemporalcharacteristicsoftheaftershocksequencesofstrongearthquakes

Ｔｈｅｒｅｌａｔｉｏｎｓｈｉｐｓｂｅｔｗｅｎｅａｒｔｈｑｕａｋｅｓａｎｄｐｏｓｉｔｉｏｎｓｏｆｔｈｅｓｕｎａｎｄｍｏｏｎ（Ⅱ）——Ｓｏｍｅｔｅｍｐｏｒａｌｃｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆｔｈｅａｆｔｅｒｓｈｏｃｋｓｅｑｕｅｎｃｅｓｏｆｓｔｒｏｎｇｅ...     

Research on the seismotectonics of the Jan－uary 17，1995 Hanshin M7．2 earthquake

ＲｅｓｅａｒｃｈｏｎｔｈｅｓｅｉｓｍｏｔｅｃｔｏｎｉｃｓｏｆｔｈｅＪａｎ┐ｕａｒｙ１７，１９９５ＨａｎｓｈｉｎＭ７．２ｅａｒｔｈｑｕａｋｅＺＨＵ－ＪＵＮＨＡＮ１）（韩竹君），ＦＵ－ＨＵＲＥＮ２）（任伏虎），ＹｕｊｉｒｏＯｇａｗａ２）（小川雄二郎）ａ...     

Seismic anisotropy beneath Tibet: evidence for eastward extrusion of the Tibetan lithosphere?

Strong seismic anisotropy beneath Tibet has recently been reported from the study of SKS shear wave splitting. The fast split waves are generally polarized in an easterly direction, close to the present day direction of motion of the Tibetan crust relative to stable Eurasia, as deduced from Holocene slip rates on the major active faults in and around Tibet. This correlation may be taken to suggest that the whole Tibetan lithosphere is being extruded in front of indenting India and that the anisotropic layer is the deforming asthenosphere, that accommodates the motion of the Tibetan lithosphere relative to the fixed mantle at depth. Uncertainties about this motion are at present too large to bring unambiguous support to that view. Assuming that this view is correct however, a simple forward model is used to compute theoretical delay times as a function of the thickness of the anisotropic layer. The observed delay times would require a 50–100 km thick anisotropic layer beneath south-central Tibet and an over 200 km thick layer beneath north-central Tibet, where particularly hot asthenosphere has been inferred. This study suggests that the asthenospheric anisotropy due to present absolute block motion might be dominant under actively deforming continents.     

Astronomical calibration of the Matuyama-Brunhes boundary: Consequences for magnetic remanence acquisition in marine carbonates and the Asian loess sequences

We have compiled 19 records from marine carbonate cores in which the Matuyama-Brunhes boundary (MBB) has been reasonably well constrained within the astronomically forced stratigraphic framework using oxygen isotopes. By correlation of the δ¹⁸O data to a timescale based on astronomical forcing, we estimate astronomical ages for each of the MBB horizons. In all but one record the MBB occurs within Stage 19.

Most magnetostratigraphic sections in Asian Loess place the MBB within a loess interval. Since loess deposition is presumed to be associated with glacial intervals, loess horizons should correspond to even-numbered oxygen isotope stages. A glacial age for the MBB is at odds with the results presented here, which firmly place the MBB within interglacial Stage 19. Inconsistency among the many loess sections and between the loess and the marine records suggests that the magnetic interpretation of loess sections may be more complicated than hitherto supposed.

The mean of the Stage 19 age estimates for the MBB is 777.9 ± 1.8 (N = 18). Inclusion of the single Stage 20 age results in a mean of 778.8 ± 2.5 (N = 19). The astronomical age estimate of the MBB compares favorably with an (unweighted) mean of 778.2 ± 3.5 (N = 10) from a compilation of ⁴⁰Ar/39^Ar results of transitional lava flows. Combining the two independent data sets yields a grand mean of 778.0 ± 1.7 (N = 28).

The new compilation shows virtually no trend in placement of the MBB within isotope Stage 19 as a function of sediment accumulation rate. We interpret this to mean that the average depth of remanence acquisition is within a few centimeters of the sediment-water interface.

Separating the cores into two geographic regions (an Indo-Pacific-Caribbean [IPC] Group and an Atlantic Group) results in a significant difference in the position of the mid-point of the reversal with respect to the astronomical time scale. The data presented here suggest a difference of several thousand years between the two regions. This observation could be caused by systematic differences between the two regions in sedimentation rate within the interval of interest, systematic differences in remanence acquisition, or by genuine differences in the timing of the directional changes between the two regions.     

电磁辐射异常分析方法研究

利用河北省电磁台网１９８８～１９９２年的观测资料，对不同台站不同方向的异常映震能力进行了分析研究。并运用信息论方法计算了各台信息水平作为其信息可信度的权系数，对各台资料采用加权平均的方法进行了合成处理，发现比平时采用的等权平均效果要好。同时对其异常频次的累加合成对应地震的异常特征进行了初步的探讨     

华北地区地震时间结构的多分形特征

利用固定半径法和直接计算法系统研究了华北地区（Ｎ３０°～４３°，λＥ１０６°～１２５°）１３个Ｋ表性子区地震时间结构的广义维数Ｄｑ—ｑ及标度指数谱ｆ（ａ）—ａ的特征，并与单—Ｄｑ—ｔ曲线进行了对比。结果表明；（１）华北地区地震时间结构为多分形结构，单一分形不能完整地描述其分形特征，应该用Ｄｑ—ｑ或ｆ（ａ）—ａ来加以分析；（２）华北强震前的０．５～２．０年．周围地区地震活动的时间多分形结构出现异常，主要表现为ｑ为负时Ｄｑ增大、ｑ为正时Ｄｑ减小，或ｆ（ａ）两端点下降，ａ跨度增大及顶点右偏等现象，这是对地震密集—平静现象的另一种描述；（３）华北地区地震时间多分形方法回顾性预报评分Ｒ＝０．４７，说明其有一定预报效能，是有前景的预报方法。     

Identification of Fei-Tsui arch dam from both ambient and seismic response data

This purpose of this paper is to study the dynamic characteristics of the Fei-Tsui arch dam using the seismic response data and the ambient vibration data. For the identification of dam properties from seismic response data, the multiple inputs from the abutment of the dam to represent the nonuniform excitations of seismic input motion are considered, and the ARX model is applied using the discrete-time linear filtering approach with least-squares approximation to identify the dynamic characteristics of the dam. The system modal dampings, natural frequencies and frequency response functions are identified. A comparison of the identified modal parameters is made among different seismic events. Post-earthquake safety evaluation of the dam can be made based on the identified model. Finally, the ambient vibration test of the dam is performed to identify the mode shapes along the dam crest.     

中国地表感热的气候计算及其分布

讨论了我国地表感热的气候计算问题,提出以鲍文比法为基础的感热气候计算式,并据此计算出全国215站月、年平均感热通量密度,进而分析了其在全国的时空分布特点。