Volcanic Explosivity Index (VEI). A simple 0-to-8 scale of increasing eruption explosivity, with each interval representing an order of magnitude increase. The VEI combines total volume of explosive products, eruptive cloud height, and other descriptive measures of eruption. As examples,the 1570 effusive eruption of Masaya (Nicaragua) was a VEI 0 event, the 1980 eruption of Mount St.Helens was a VEI 5, and the Pleistocene Lava Creek Tuff eruption of Yellowstone Calderas was a VEI 8. If the fields are left blank, the search will filter results based on VEI.
This field describes the compositions of rock composing from the volcano. If specific compositions are checked, the search will filter results for VOLCANOES that have that composition of rock, NOT specific eruptions of that composition. For example, checking "rhyolite" will filter for volcanoes that are composed partly of rhyolite, even if those volcanoes have also produced basaltic or andesitic eruptions. We can also get rid of the "No Data" button.
These terms filter results based upon the morphology of the volcano and specific features on or within that volcano. For example, a shield volcano may also have fissure vents, cinder cones, and a caldera. Similarly, a caldera may contain lava domes or craters.
Filters results based on activity type. For example, events may be filtered according to whether or not lahars, pyroclastic flows, or lava flows were generated.
Discredited eruptions are observations or reports that GVP has determined were not eruptions. For example, the media may report an eruption for a steam emission. Uncertain eruptions are ambiguous eruptions. For example, an observation of "sheep's wool" in Indonesia may refer to a white or gray emission; the presence/absence of ash is uncertain
The volumes are presented as Bulk Volumes in units of m3.
Eruption date ranges should be entered with the older date first in MM/DD/YYYY format. For BCE dates, simply add a minus sign (e.g. to find the Minoan Eruption of Santorini, Greece in ~1610 BCE you might enter -1630 to -1600). For years before present (BP), check the BP box (e.g. to return all the eruptions in the last 1000 years you would check "BP" and enter 1000 to 0000). Users should be cautioned that start dates are known to the month for 53% and to the day for 41% of eruptions in the database. End dates are known for ~41% of eruptions in the database.
Only countries containing volcanoes in the database will be displayed in the dropdown.