华南沿海地区验潮站资料反映的海平面变化与海岸升降

根据收集到的２５个验潮站资料,表明近几十年来华南沿海海平面大约平均以１．４５ｍｍ／ａ的速率上升,与全球海平面升高速率１．５ｍｍ／ａ接近。由各验潮站海平面的升降速率与全球海平面平均升高速率比较,得到验潮站所在海岸地壳速率在４．４～－４．１ｍｍ／ａ之间。其运动方向与由滨海相样品反映的晚更新世及全新世以来的海岸升降趋势大体相同,即现今海岸主要为中、晚全新世以来的继承性运动。     

华南沿海海平面的变化速率

应用回归分析和切比雪夫拟合二种方法，根据验潮资料研究了华南沿海海平面的变化速率，进而结合区域研究近２０年来华南海平面的变化特征，并讨论了将其用于地震趋势分析的可能性。     

东南沿海末次盛冰期古海平面标志与地震的关系—100m以上最低海平面…

东南沿海末次盛冰（２１￣１４ｋａＢ．Ｐ．）滨海相沉积垂相分布多在海拔３８￣－５０．８ｍ的范围内，以正向分布（海平面附近及以上）、正负向混合分布及负向（海平面以下）分布在断块交界区或其附近，是强震的主要发生地。在滨海相沉积垂向分愈离散的区段。其地震活动性也愈强，本研究地区不存在末次盛冰期－１００ｍ以下的最低海平面，那些局部在外陆架海底发现的－１００ｍ以下的滨海相沉积，可能与地壳呈长趋势下沉作用有关。     

东南沿海末次盛冰期古海平面标志与地震的关系──-100m以下最低海平面问题质疑

东南沿海末次盛冰期（２１～１４ｋａＢ．Ｐ，）滨海相沉积垂相分布多在海拔３８～－５０．８ｍ的范围内，以正向分布（海平面附近及以上）、正负向混合分布及负向（海平面以下）分布在断块交界区或其附近，是强震的主要发生地。在滨海相沉积垂向分布愈离散的区段，其地震活动性也愈强，本研究地区不存在末次盛冰期－１００ｍ以下的最低海平面，那些局部在外陆架海底发现的－１００ｍ以下的滨海相沉积，可能与地壳呈长趋势下沉作用有关     

Contemporary crustal deformations in the Izu peninsula,Honshu, Japan and acceleration of plate bending in the northernmost part of the Philippine Sea plate

Since the beginning of the anomalous vertical crustal movement in the Izu peninsul, Honshu, Japan, many repeated precise levellings have been carried out by the Geographical Survey Institute. Trilaterations covering the entire Izu peninsula have also been carried out by the Geographical Survey Institute. A new technique is developed to adjust the results of levellings, because they had been carried out for different epochs along each levelling route and because of rapid vertical crustal movements. In conventional least-squares adjustment of levelling network, only corrections to the approximate height are assumed to be unknown, while in the present analysis a special model in which rates of vertical deformation at any bench marks are also assumed to be unknown, is adopted. In addition, tidal stations along the coast of the Izu peninsula yield the rate of vertical crustal movement from analysis of tidal data independent of levelling data. We select several special bench marks in which rates of vertical movement are determined by tidal analysis, thereafter special adjustment is applied according to the type of network.The results show that the peninsula is inclined to the south-west. Uplift in the northeastern part of the peninsula is accompanied by remarkable subsidence in the southwest. The rate of contemporary inclination is many times higher than the rate during the period from 1929 to 1972.The deformation is concentrated in the area whereNakamura (1979, 1980) pointed out the bending of the Philippine Sea plate. The mode and rate of the detected crustal deformation suggest the accelerated bending of the peninsula. There are some local uplift that deviate from the general pattern of deformation. The most remarkable land uplift was observed near Ito, a city within the peninsula, and the focus of this uplift migrated with time. The accelerated plate bending will produce an extension at the earth's surface and contraction in the deeper part of the subcrustal layer, additionally it triggered the intrusion of magma from the deeper part to the shallower. Moreover, the accelerated plate bending also triggered seismic swarms and destructive, earthquakes in and around the peninsula.