1 - Introduction

Abstract

Volcanic seismology is a science about seismic signals originating from volcanoes and associated with volcanic activity. The study of the origin of these signals, their spatial-temporal distributions, their relationships with volcanic processes, and using them as an instrument to investigate the volcano deep structure and to predict a volcanic eruption together create the subject of volcanic seismology. A volcano is a vent or chimney, which connects a reservoir of molten matter known as magma, in the depths of the crust of the Earth, with the surface of the Earth. The material ejected through the vent frequently accumulates around the opening, building up a volcanic edifice. A volcanic eruption is a process of material transport from the Earth's depths to the surface. According to their origin within the volcanic edifice, the volcanic eruptions may be of central (or summit) type with an eruption of the summit crater, flank (or lateral) type, with an eruption of the flank crater, or fissure type, when the eruption takes place from an elongated fissure, rather than from a central vent. Magnitude of eruption is described by Volcanic Explosivity Index (VEI) that combines the total volume of explosive products, the eruptive cloud height, descriptive terms, eruption type, duration, and so forth, and have the grades from 0 to 8. The rupturing along the fractures and faults as well as the eruptive activity produces the Earth's surface as earthquakes. The site of initial radiation of seismic waves in the interior is earthquake focus, or hypocenter; its projection to the surface is the epicenter.