Quantitative Tectonic Markers of Large Coastal Earthquakes in Fujian, Guangdong, Taiwan and Hainan——with a Discussion of Qualitative Indicators     

Bi Fuzhi Yuan Youshen Institute of Crustal Dynamics  State Seismological Bureau  Beijing 《《地质学报》英文版》1997,71(4):395-406

This paper expounds the quantitative tectonic indicators and some qualitative indicators of large earthquakes in the coast areas of Fujian, Guangdong, Taiwan and Hainan. The main quantitative indicators include uplift amplitude of the Moho, Quaternary and Late Holocene coasts. The paper also gives a brief account of the research method on quantitative indicators of surface uplifted zones. Taiwan is a famous neotectonic zone and an area of large earthquakes in the world. There is only one large-earthquake area in each of Fujian, Guangdong and Hainan Provinces. Along the coast large earthquake areas there are certainly many remains of crustal activity. Among these remains, coast activity, taking the sea level as the accurate marker horizon, can determine not only the amplitude of coastal elevation and subsidence in a certain period, but also the cycle and rate of positive or negative movements.  相似文献   

苏北海岸带潮成辐射砂脊群的形成及其古地理意义   总被引：3，自引：3，他引：3       下载免费PDF全文

赵娟  范代读  李从先 《古地理学报》2004,6(1):41-48

南黄海潮成辐射砂脊群的面积约为20000km2，以160° 的角度从弓京港向海展开。它与以弓京港为顶点的辐聚辐散潮流场相伴而生。60余个钻孔揭示，毗邻海区辐射砂脊体系的江苏沿岸平原上存在一个面积约3000 km2潮成砂区，其顶点位于东台，同样呈扇形以130°的角度向东展开。在潮成砂区内潮成砂质沉积单元位于冰后期海侵型砂坝-湖沉积层之上，二者之间具明显的冲刷面。砂坝-湖沉积层位于晚更新世基底硬粘土层之上，二者之间有较长的沉积间断。潮成砂沉积层上覆潮坪沉积层，二者呈渐变关系。以潮成砂层底部的侵蚀面为界，其下为海侵序列，其上为海退序列。古潮流的研究揭示，潮成砂区内同样存在辐聚辐散的古潮流场，其顶点位于东台附近。由此推断，沿海平原的潮成砂区内也是辐射状潮成砂脊体系，它形成于全新世海退时期。由于长江和黄河三角洲的前展，以东台为顶点的潮成砂脊体系逐渐暴露成陆。陆上和海域潮成辐射砂脊群形成于相同的潮汐动力环境，但处在不同的发育阶段，前者形成于全新世中期，后者发育于全新世晚期。矿物分析揭示，陆上和海区的潮成辐射砂脊体系主要由长江和黄河沉积物组成，其中长江沉积物由南向北运移，且时间较早；黄河沉积物由北向南运移，时间较迟，这种泥沙的运移趋势一直延续至今。随着海平面上升趋于减缓，长江三角洲增长，江苏海岸线向外推进，苏北潮成砂区逐渐出露成陆。1128年黄河由苏北入海，大量的黄河沉积物的加入，加快了本区海岸线的推进速度。潮成辐射砂脊体系与辐聚辐散的潮流场相伴而生，全新世最大海侵以来，辐聚辐散的潮流场的位置曾经历三次变化，第一次以长江古河口湾为顶点，第二次位于现今陆上潮成砂区，第三次位于以弓京港为顶点的现代海域，代表了潮成辐射砂脊体系发育的三个阶段。只是长江古河口湾的潮成辐射砂脊体系由于河流的巨大改造作用，可能未很好保存，至今未发现典型的辐射砂脊体系。  相似文献   

大连市滨海河谷地下水资源开发利用的可行性     

王卫东  宋庆春  李宝兰  巩建伟 《华北地质》2004,27(4):268-272

大连市是我国严重缺水地区之一 ,至 2 0 0 5年城市缺水为 110 4 2 .5× 10 4m3 ,占需水量的 17.1% ,其中大连城区 (金州以南地区 )缺水 9890× 10 4m3 ,占缺水量的 89.6 %。开发利用滨海河谷地下水资源 ,建立滨海河谷型地下水库 ,不仅可以治理大连地区严重的海水入侵问题 ,增加水资源量 ,满足当地农业及生活用水 ,同时可弥补城市供水的不足。根据前人工作成果分析及野外实地勘查 ,大连市适于建设河谷型地下水库的滨海河谷有 2 2条 ,建成后的总库容量 10 36 0 2 .9× 10 4m3 ,开采资源量 2 5 76 6 .88× 10 4m3 ,可增加开采资源量 12 5 4 2 .4 5× 10 4m3 。  相似文献   

Impact of a Tropical Cyclone on Coastal Upwelling Processes     

A. D. Rao  S. V. Babu  S. K. Dube 《Natural Hazards》2004,31(2):415-435

A three-dimensional numerical model is described to study theresponse of a coastal ocean excited by a tropical cyclone in the Bay of Bengal. The numericalexperiments have been carried out using the model to understand the dynamics and thermodynamics ofthe ocean due to different cyclonic systems approaching in different directions. In the firstexperiment, the model is used to simulate the vertical thermal structure of the ocean as a response ofpassage of the less intensified 1997 cyclone, which was skirting the east coast of India before crossingthe Bangladesh coast. The simulations are compared with the buoy data available during the storm period.In the next experiment, it is considered an idealized cyclone with hurricane winds movingnormal to the east coast of India crossing between Visakhapatnam and Kakinada to evolve thermalstructure and currents of the ocean. A net decrease of the SST of 6–7 °C is simulated whenthe severe cyclonic storm moved over the coastal ocean.  相似文献   

A Numerical Study on Coastal Defence at Chennai and Related Management Strategies     

J. S. Mani 《Natural Hazards》2004,31(2):523-536

Chennai coast, right from the inception of Madras harbourin the year 1876, has been experiencinghostile conditions such as (i) coastal erosion, (ii) sandbar formation at the entrance to inlets, (iii) sea water ingression and (iv) change insea bed elevation, etc. In addition, construction of a new satellite harbour, about18 km north of Madras harbour has produced a negative impact on the delicatecoastal features such as (i) Pulicat lake, (ii) Ennore shoals, etc. Construction ofthis satellite harbour has led to the accumulation of sand south of the southbreakwater of the harbour and its accelerated growth is of concern to an inletlocated 2.6~km south of the harbour. `Coastal erosion', a perennial problemassociated with north Chennai sea front for the past 100 years has been addressedin this paper. The paper discusses on a long term solution and details of themethodologies to be adopted for effective management of the coast. Thesolution presented in this paper is based on numerical model study consideringthe nearshore currents and wave induced sediment transports.  相似文献   

Precise/ Small Sample Size Determinations of Lithium Isotopic Compositions of Geological Reference Materials and Modern Seawater by MC-ICP-MS   总被引：6，自引：1，他引：6  

Alistair B. Jeffcoate  Tim Elliott  Alex Thomas  Claudia Bouman 《Geostandards and Geoanalytical Research》2004,28(1):161-172

The Li isotope ratios of four international rock reference materials, USGS BHVO-2, GSJ JB-2, JG-2, JA-1 and modern seawater (Mediterranean, Pacific and North Atlantic) were determined using multi-collector inductively coupled plasma-mass spectrometry (MC-ICP-MS). These reference materials of natural samples were chosen to span a considerable range in Li isotope ratios and cover several different matrices in order to provide a useful benchmark for future studies. Our new analytical technique achieves significantly higher precision and reproducibility (< ± O.3%o 2s) than previous methods, with the additional advantage of requiring very low sample masses of ca . 2 ng of Li.  相似文献   

A macroscale analysis of coastal steepening around the coast of England and Wales   总被引：1，自引：0，他引：1  

J A Taylor  A P Murdock  N I Pontee 《The Geographical journal》2004,170(3):179-188

Coastal steepening potentially presents an array of management issues in the form of financial implications of sea defence degradation, increased risk posed to the hinterland as wave attenuation is reduced, 'coastal squeeze' and statutory requirements in the light of the Habitats Directive. The extent to which coastal steepening has occurred throughout England and Wales has been investigated through use of a GIS and dataset based on historical Ordnance Survey map information. Data were collected along 1084 selected profile lines, positioned so as to be geomorphologically representative of the coast. Features recorded from each map year included the positions of mean high water (MHW) and mean low water (MLW), the relative movements of which infer changing intertidal gradients. The results presented in this paper are on a subject and scale not previously published. It is revealed that 61% of the coastline studied has experienced a tendency towards steepening. Of the remainder, 33% has flattened, and 6% has experienced no rotational movement. This tendency towards steepening has been the dominant movement on each of the west, south, and east coasts.  相似文献   

海岸带临港工业、海运物流与全球化大生产的探讨   总被引：5，自引：0，他引：5  

田汝耕  张振克  朱大奎 《世界地理研究》2004,13(2):1-8

海岸带是世界人口密集、经济发达的地带，在全球经济一体化和全球化大生产中具有重要的地位。近半个世纪以来，海岸带临港工业迅速崛起并持续高速发展，依托海港建设、大型船舶运输发展起来的临港工业和海运物流，在跨国公司的运作下形成了现代意义上的全球化大生产。这种生产方式使资源贫乏的日本快速发展成发达国家；深圳赤湾临港工业区成为中国高效益工业的典范。本文着重讨论了海岸带经济建设中大力发展临港工业对地区、国家和全球经济的影响，指出中国21世纪应大力开发利用海岸带港湾资源、重点建设全球化大生产的大进大出的基地，建立若干个具有国际竞争力的海岸带产业中心，推动国民经济持续、快速发展。  相似文献   

A geomatics data integration technique for coastal change monitoring     

J. P. Mills  S. J. Buckley  H. L. Mitchell  P. J. Clarke  S. J. Edwards 《地球表面变化过程与地形》2005,30(6):651-664

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Estimation of regional material yield from coastal landslides based on historical digital terrain modelling     

C. J. Hapke 《地球表面变化过程与地形》2005,30(6):679-697

High‐resolution historical (1942) and recent (1994) digital terrain models were derived from aerial photographs along the Big Sur coastline in central California to measure the long‐term volume of material that enters the nearshore environment. During the 52‐year measurement time period, an average of 21 000 ± 3100 m³ km^?1 a^?1 of material was eroded from nine study sections distributed along the coast, with a low yield of 1000 ± 240 m³ km^?1 a^?1 and a high of 46 700 ± 7300 m³ km^?1 a^?1. The results compare well with known volumes from several deep‐seated landslides in the area and suggest that the processes by which material is delivered to the coast are episodic in nature. In addition, a number of parameters are investigated to determine what influences the substantial variation in yield along the coast. It is found that the magnitude of regional coastal landslide sediment yield is primarily related to the physical strength of the slope‐forming material. Coastal Highway 1 runs along the lower portion of the slope along this stretch of coastline, and winter storms frequently damage the highway. The California Department of Transportation is responsible for maintaining this scenic highway while minimizing the impacts to the coastal ecosystems that are part of the Monterey Bay National Marine Sanctuary. This study provides environmental managers with critical background data on the volumes of material that historically enter the nearshore from landslides, as well as demonstrating the application of deriving historical digital terrain data to model landscape evolution. Published in 2005 by John Wiley & Sons, Ltd.  相似文献