关键词: 全球, 地震, 火山, 分区

Abstract: 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 500km 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(1966-1972) to Phillippine Arc(1973-1981).

Key words: global, earthquake, volcano, zoning