Seabed erosion and deposition related to the typhoon activity of the past millennium on the southeast coast of China     

Haixian Xiong  Yongqiang Zong  Guangqing Huang  Shuqing Fu 《地球表面变化过程与地形》2020,45(8):1695-1704

Catastrophic events often interrupt long-term Earth surface processes. In coastal areas, although millennial-scale trends of climatic and sea-level changes determine the trajectory of sedimentary landform evolution, storm and/or tsunami activity can cause abrupt changes in depositional conditions that may alter the long-term sedimentary processes. Here, we report a sedimentary hiatus that is widely observed from the late Holocene sedimentary sequence at the seabed along the southeast China coast. This hiatus was discovered by close temporal sedimentary and radiocarbon dating analyses of a seabed sedimentary sequence in the mouth area of the Pearl River estuary. The results suggest that a couple of metres in the middle to late Holocene sediment at the seabed were eroded by a catastrophic event happening c. 1000–800 cal. Years BP. In theory, a mega-tsunami generated from the Manila Trench could have caused such erosion at the seabed, but there is a lack of direct geological and historical evidence to support such a hypothesis. Much more likely, a super-typhoon struck the coast and caused the erosion. This hypothesis is strongly supported by the region's historical and geological records, which suggest a period characteristic of intense typhoons ranging from the Medieval Warm Period to the climate transition phase (c. 1000–600 cal. Years BP). During the subsequent Little Ice Age, deposition of sandy sediment continued, suggesting frequent but weaker typhoon activity. Over the past two centuries the deposition of sandy sediment and gravels began, implying the beginning of a phase of intensifying typhoon conditions, possibly a result of the recent warming climate. © 2020 John Wiley & Sons, Ltd.  相似文献   

Holocene sea-level changes and crustal movements in Morecambe Bay,northwest England     

Yongqiang Zong  Michael J. Tooley 《第四纪科学杂志》1996,11(1):43-58

Holocene stratigraphy from Skelwith Pool, on the northern side of Morecambe Bay, is described. Diatom and pollen analyses and radiocarbon dating have been undertaken for three sampling sites, from which eight sea-level index points have been obtained. These index points come from a small homogeneous area and similar palaeoenvironments. Some published sea-level index points from Morecambe Bay have been re-evaluated and validated by means of diatom analysis. An enhanced sea-level database with 28 index points has been used for the reconstruction of Holocene sea-level history. Relative sea-level rose rapidly around 6870–6510 BC at a maximum rate of +36.7 mm yr⁻¹. Subsequently, the rate of sea-level change has varied between −8 mm yr⁻¹ and +12 mm yr⁻¹. The rate of relative sea-level changes for the last 3500 years is not clear. Uplift driven by deglaciation is believed to have been interrupted in the early Holocene by a rapid rise in relative sea-level. Uplift restarted at 6510 BC but soon declined as glacio-isostatic recovery ended around 3800 BC in the Morecambe Bay area. Since then, crustal movements in the Morecambe Bay area have been minimal. Factors affecting the attitudes of the index points such as sediment compaction of the basal peat and variations in palaeotidal range during the Holocene have been considered. © 1996 John Wiley & Sons, Ltd.  相似文献   

东明县节约集约利用土地的几点做法   总被引：1，自引：1，他引：0  

宗学成  卞向阳 《山东国土资源》2009,25(11):63-64

在国家土地宏观调控政策趋紧的新形势下，如何破解土地制约瓶颈，缓解项目用地矛盾，确保经济又好又快发展，成为摆在各级政府面前亟待研究解决的一个难题。对此，东明县立足实际，经过反复论证和积极探索，坚持以政策“杠杆”为支点，找准土地政策和项目建设的最佳结合点，合理规划建设用地，确保了全县土地利用的总体平衡，走出了一条符合东明特点的科学合理利用土地之路。  相似文献   

徐州煤矿地质资料数据库建设及应用     

钱静  纵博  黄阳 《江苏地质》2023,47(2):159-165

通过对徐州煤矿地质资料的标准化整理，归纳并探讨多源数据融合的原则和标准，形成统一的空间坐标参数和数据格式，达到多源数据统一融合的目的。基于ArcGIS平台，建立涵盖基础地质、矿山开发利用、钻孔、采空区、塌陷及已治理区5大专题的煤矿地质资料数据库。项目成果纳入徐州自然资源“一张图”系统中，服务于矿政管理、矿地融合研究、工程建设新项目规划选址、国土空间规划等工作。  相似文献   

大部地区降水偏多冷空气活动频繁-2000年1O月-     

宗志平 《气象》2001,27(1)

10月份，全国大部地区降水量偏多，海南等省的一些地区发生暴雨洪涝灾害；气温接近常年，月内气温起伏较大；南方连阴雨日数多，日照时数偏少。长时间的阴雨寡照给我国秋收、秋种带来不利影响。气温变幅较大华南出现寒露风连阴雨时间长秋收秋播受影响  相似文献   

南京市降水酸度的分析          下载免费PDF全文

缪启龙  牛玉琴  唐名嵩  丁有本  宗光华 《大气科学学报》1988,11(3):377-382

本文用南京市1983—1985年3年10个环境监测站的降水酸度资料,分析了南京市降水酸度的时空分布特征。南京市降水酸度的pH值平均为5.09,pH值<5.60的酸雨频率百分数为42%。降水酸性正逐步增强,且城区重于郊区,郊区重于郊县。并指出:南京降水酸度与南京大气污染有一定的相关关系。  相似文献