摘要
地震和火山都反映了地球表层的构造活动,因而地震活动区往往也是火山活动区。根据全球大震、火山活动目录,分析研究了全球地震、火山分布的特征。描述了各区的地震、火山活动分布,总结了地震、火山活动强度的时、空分布特征。全球地震、火山活动可以分为碰撞带、大陆区和大洋区。大陆地震以其片状的分散分布而不同于板块边缘的带状分布,大陆火山活动比大洋火山更受应力场的影响。大洋区地震活动相对较弱,岩浆活动主要是平静的岩浆溢出与洋中脊的扩张,往往没有形成火山喷发。有记录的火山喷发主要来自深部地幔的热柱。俯冲-碰撞活动区地震活动与火山喷发最强烈,大角度俯冲的弧后火山活动最强,当板块运动方向与板块边缘走向成小角度相交时,缺少正面俯冲的动力,火山活动相对平静。>500km深震的地段,火山活动较弱。火山与地震强烈活动的大多在大地水准面(Geoid)异常高的区域。地震与火山平均纬度随时间表现出同步的变化外,火山和大震活动也显示了大致同步的变化。
Volcano and earthquake, both are significant phenomena and subsequences of plate motion.Great importance has been attached to the connection between volcano and earthquake in recent years. Global partitioning of earthquake and volcano is an important prerequisite for the study of the spatial and temporal distributions of global earthquakes and volcanoes, as well as global tectonic and contemporary geodynamics. On the basis of statistic analysis on Earthquake Catalogs of USGS National Earthquake Information Center and Volcano Catalog of Smithsonian Institution, and applications of the concept of three tectonic systems（ Ma et al., 2003） ,the correlation study between volcano and earthquake distributions was made in this paper. Based on the statistics of subareas,the global modern tectonics can be divided into three systems： continent,ocean ,and collision zone. Continental earthquakes are widely spaced, differing from strap-like distribution in the plate boundaries. The major distinction of continental volcanoes from oceanic one is the existence of continental lithosphere with various crust thicknesses and ages. The continental volcanoes are more sensitive to tectonic stress field,e, g. the continent rifts are induced by lithospheric extension. Oceanic crust is young,thin and relative homogeneous,with weak seismicity. Magmatism is dominanted by smooth extrusion of lava and expansion of ridges in mid-ocean. Most records of volcano eruptions are related to hot plume from deep mantle in islands. Subduction-collision zone has the maximum severity of earthquakes and volcano eruptions. The seismicty is caused by extrusion from plate collision, and the volcanism is related with dehydration,decline of solidus, and uplift of arcs. The tremendous energy from plate collision is the fundamental cause of earthquake and volcano. The violent seismic and eruption activities are mostly correlated with geoid highs. The deep subduction zones with focal depth greater than 500kin have weak eruptions, lacking historic records, or large eruptions with VEI≥4. The average latitude of earthquakes behaves in a synchrony way with that of volcanoes, and their spatial distribution changes in synchronous phases. In the first half period of last century （ 1902-- 1953） ,the great eruptions with VEI greater than 5 were in eastern Pacific,such as the 1902 eruption of Santa Maria in Guatemala,the 1912 Trident eruption in Alaska,the 1932 eruption of Azul in Chile. And the seismicity were the most violent in Eurasia continent. In the middle period（1956--1980）, the eruptions were concentrated in north Pacific, such as the 1956 eruption of Bezymianny in Kamchatka,the 1976 eruption of Augustine in Alaska,and the 1980 eruption of St. Helens In USA. The large earthquakes migrated from northern Pacific（1954--1965）, Japan Arc（196611972） to Phillippine Arc（ 1973--1981 ）.
出处
《地震地质》
EI
CSCD
北大核心
2009年第4期573-583,共11页
Seismology and Geology
基金
国家自然科学基金(40674056)
"十一五"国家科技支撑计划项目(2006BAC01 B040104)
科学技术部社会公益专项(2001DIA10003
2002DIA20009)共同资助
关键词
全球
地震
火山
分区
global, earthquake, volcano, zoning
