The 18.6-Year Periodicity of Great Earthquakes

详细信息   

• 责任者：Du Pinren (Institute of Geology ; China Earthquake Administration ; Beijing 100029 ; China) ; Zhao Junmeng
• 刊名：Chinese Journal of Geophysics
• 出版年：2011
• 卷期：54(9)
• 关键词：大震 ; great earthquakes ; 地震周期性 ; earthquake periodicity
• 页码：p.2256-2262
• 图表：illus., 4 tables, 28 refs.
• 分类号：0500
• issnNo：ISSN0001-5733
• isbnNo：CN11-2074/P

摘要

Dividing the world into 15 study areas and using the earthquake catalogue of Mw≥7.0 during 1900-2009, we make a statistical analysis of the relationship between seismicity of each area and the period of lunar nodal motion. The result shows that among the 15 areas, 10 areas exhibit an 18.6-year cycle of great earthquakes in statistical sense, which consists of a 12.4 year active section and a 6.2-year quiet section. In the eastern, northern, southern and western areas of the Circum Pacific seismic belt, such a periodicity is present and their active sections have certain regularity. In terms of seismic events during the sixth cycle （1991~2009）, this study has tested the stability and applicability of the 18.6 year periodicity derived from earlier five cycles （1900~ 1990）. It is found that most of periodicities are stable in the regions with such characters. The possible mechanisms of the 18.6-year periodicity are as follows. （1） Earthquakes are modulated by the 18.6-year tide via day and half-day tides. （2） Effect of fluid tide in upper mantle （tide within the Earth）. And （3） earthquakes are dictated by 18. 6-year tide through variation of Earth rotation.