1750-2010年强火山喷发事件的时空分布特征

Spatial and temporal characteristics of large volcanic eruptions in 1750-2010

根据美国Smithsonian研究院全球火山计划发布的火山喷发年表,提取了1750-2010年逐次强火山喷发(火山爆发强度指数VEI≥4)事件的详细资料,按照地理纬度、海拔高度、发生年份及月份等要素进行分类统计,分析了1750年以来的全球强火山喷发的主要特征。结果表明:1750-2010年间强火山喷发多集中于环太平洋火山带以及苏门答腊岛—爪哇岛火山带上,并以赤道两侧地区(10°N^10°S)最多;1000~2000 m海拔高度上易多发强火山喷发事件;1月和4月是强火山喷发最为集中的月份,夏半年(4-9月)较冬半年(10月-次年3月)发生次数略多;强火山喷发具有15~25年和35~50年的年代际周期,且1870年以后强火山喷发周期变化较之前更为频繁,其中1750-1760年、1776-1795年、1811-1830年、1871-1890年、1911-1920年及1981-1995年强火山事件相对多发,其他时段则相对少发。

Based on the dataset provided by Smithsonian Institution Global Volcanic Programme, we extracted the large volcanic eruptions （Volcanic Explosivity Index 〉~ 4） events from 1750 to 2010, and then analyzed the main characteristics of large volcanic eruptions since 1750 by their geographic latitudes, elevations, years and months. The results showed that the most of large volcanic eruptions occurred around the margins of Pacific Ocean, and the islands of Sumatra and Java from 1750 to 2010, especially in the equatorial regions （10~ N-10~ S）. Large volcanic eruptions were mainly observed at elevations of 1000-2000 m, and in January and April. The number of the occurrences in the summer half-year （from April to September） was larger than that of the winter half-year （from October to next March）. Large volcanic eruptions had interdecadal fluctuations including 15-25 years and 35-50 years, which were detected by Morlet wavelet analysis, and more frequent cyclic fluctuation of volcanic eruption was found after 1870. There were more large volcanic eruptions events during the periods of 1750-1760, 1776-1795, 1811-1830, 1871-1890, 1911-1920, and 1981-1995.