Periodicity and driving forces of volcanism

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• 作者：N.L. Dobretsov^a ; ^b ; ^{DobretsovNL@ipgg.sbras.ru" class="auth_mail" title="E-mail the corresponding author}
• 关键词：periodicity ; volcanism ; mantle plume ; spreading ; subduction ; eruption volume
• 刊名：Russian Geology and Geophysics
• 出版年：2015
• 出版时间：December 2015
• 年：2015
• 卷：56
• 期：12
• 页码：1663-1670
• 全文大小：301 K

文摘

The volume and style of volcanism change periodically, with cycles of three main scales, which have different causes and effects. Short cycles of volcanic activity last from tens to thousands of years and are associated with periodic accumulation of magma in shallow chambers and its subsequent eruptions. The eruptions either have internal causes or are triggered externally by variations in solar activity, tidal friction, and Earth’s rotation speed. Medium-scale cycles, hundreds of thousands to millions of years long, are due to changes in spreading and subduction rates. Long cycles (30–120 Ma) are related to ascent of mantle plumes, which take away material and heat from the core-mantle boundary and change the convection rate. These appear to be the major controls of the average periodicity. Acceleration of asthenospheric convection caused by periodic plume activity pulses can change spreading rates and, correspondingly, the relative positions of moving plates. The medium-scale periodicity of volcanism is illustrated by the examples of Kamchatka and Japan, where the intensity of subduction magmatism changes periodically in response to the opening of back-arc basins (Shikoku, Sea of Japan, and South Kurile basin).