Database Structure and Description

The GVESD consists of three main tables: a volcano table (VOLCAT), a volcanic earthquake swarm table (SWARMCAT), and an eruption table (ERUPTCAT). The volcano table contains general information on 149 volcanoes active between 1979-1989. This table also serves as the parent table for the rest of the database. A sample record of the volcano and swarm table is shown in figure 2.

Figure 2. An example record from the Global Volcanic Earthquake Swarm Database. The top box shows the information contained in the volcano table. The middle portion shows one swarm record from the swarm table. The bottom portion shows text excerpted from the original reports.

Volcano Table

The volcano name, geographical region, latitude, longitude, and volcano number used within the database are drawn directly from Volcanoes of the World Data File 1992, an update of Volcanoes of the World (Simkin and others, 1981; Simkin and Siebert, 1994). The Volcanoes of the World Data File was expanded to include the volcano elevation, edifice height, morphology, compositional range of erupted products, tectonic framework, and a short geologic summary of each volcano (time is local unless otherwise stated). This supplemental information was taken from the List of the World Active Volcanoes, a special issue of the BVE, (Katsui and others, 1971), and Volcanoes of North America, (Wood and Kienle, 1990).

Earthquake Swarm Table

The volcanic earthquake swarm table holds over 600 records containing summary information related to each swarm and includes the dates of occurrence, durations, and the uncertainties in these measurements. Other parameters related to swarms such as the swarm type (see definitions below), the event type, the magnitude and intensity of the largest shock, the number of felt and unfelt events, and a short summary of the seismic instrumentation are included with each swarm record. This summary information is supplemented with an extended field that contains text excerpted from the original reports. A reference list is included with each record. See figure 2 for an example.

Eruption Table

The eruption table contains summaries of over 160 eruptions associated with well-documented earthquake swarms. It includes information pertaining to eruptive activity, such as dates of activity, eruption intensity (Volcano Explosivity Index), and character of the eruption. This information is drawn from the BVE and the Smithsonian InstitutionĘs Global Volcanism Program eruption data file. The eruption table does not include all eruptions that occurred during the time period covered by the database. The following sections contain detailed descriptions of parameters in each of the above tables.

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