Seismic mode «drumbeats»: promoting and supporting eruption of andesitic and dacitic volcanoes and their features (overview)

Abstract

During extrusive eruptions of andesitic and dacitic volcanoes, in some cases, squeezing of viscous lava was accompanied by the occurrence of «drumbeats» earthquakes. The peculiarities of this earthquake regime are: their close energies, similarity of wave forms, and quasi-periodicity over a long period of time (from several hours to months). The article provides an overview of the micro-earthquakes of the regime «drumbeats» recorded on several volcanoes of our planet during the extrusion of extrusive domes: Redout (the Aleutian Islands), St. Helens (the Cascade Mountains, North America), Soufriere Hills (Montserrat Island, the Lesser Antilles), Pichincha (the Andes, South America). During the eruption of Kizimen Volcano (Kamchatka Peninsula) in 2010–2013 the «drumbeats» mode was observed during the movement of a viscous lava flow. According to the record form, earthquakes of the «drumbeats» regime refer to hybrid or long-period earthquakes, with prevailing frequencies within the range of 0.3–7 Hz.

Keywords

• volcano
• earthquake
• seismicity
• drumbeats
• lava flow
• extrusive dome