GEOGRAPHY & CARTOGRAPHY CALCULATOR
Intervalvolcanic Explosivity Index
A precise tool.
What is the Intervalvolcanic Explosivity Index & How does it work?
The Volcanic Explosivity Index (VEI) is a logarithmic scale that quantifies the size and intensity of volcanic eruptions based on erupted tephra volume, eruption column height, and eruption duration.
Values range from 0 (non‑explosive) to 8 (mega‑colossal), with each increment representing roughly a ten‑fold increase in erupted material. This scale helps scientists compare historic and prehistoric eruptions.
The VEI can be estimated using measurable parameters such as erupted volume (V) and column height (H). The simplified relationship is expressed as follows:
VEI = \log_{10}\left(V\right) + 0.5\,H
V = erupted tephra volume (km³), H = eruption column height (km)
Parameters
Result
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Frequently Asked Questions
What is the Volcanic Explosivity Index?
The VEI is a scale from 0 to 8 that measures the size and intensity of volcanic eruptions, with each step representing about a tenfold increase in erupted material.
How do I estimate the VEI using this calculator?
Enter the erupted volume and column height into the calculator to get an estimated VEI value.
What does a VEI of 0 mean?
A VEI of 0 indicates non-explosive eruptions with minimal volcanic ash or tephra.
Can I use this calculator for historical eruptions?
Yes, you can estimate the VEI for both recent and historical eruptions using available data on erupted volume and column height.
What is the difference between a VEI of 5 and 6?
A VEI of 6 represents eruptions that are about ten times larger than those with a VEI of 5, involving significant tephra columns and widespread ash distribution.
How does the VEI help in comparing volcanic eruptions?
The VEI provides a standardized way to compare the magnitude of different volcanic eruptions, both historic and prehistoric, by quantifying their explosive power.
What additional parameters can affect the VEI estimation?
While volume and column height are key, other factors such as eruption duration, ash composition, and lava flow characteristics can also influence VEI estimates.
Results are for informational purposes only and do not constitute professional advice.