Active Hawaiian Volcanoes Summary

A Graphical View

Modified USGS map of lava flows (in red) erupted in approximately the past 1,000 years shown on the Island of Hawaii (the names of the three youngest volcanoes on the island have been added for clarity). Notice that Kilauea Volcano is 90% covered with young flows! Map Source and more details.

"active", "dormant" and "extinct" volcano terms explained
    As you read through the table aobr, you might wonder what it really means when a volcanologist classifies a volcano as "active", "dormant" or "extinct". The terms seem clear enough but the reality is often quite difficult to determine at some volcanoes, particularly those with very infrequent or poorly know eruptive histories. Extinct volcanoes where the last eruption was very long ago, and many times longer than the typical reccurence interval for different types of volcanic systems, can be safely regarded as extinct. These time periods are measured in hundereds of thousands of years. At the other end of the spectrum, it usually takes some humanly recorded or verifiable historical magmatic event to call a currently non-eruptive volcano "active". The terms "dormant" and "extinct" as commonly applied to Quaternary volcanoes are more imprecise because what determines this distinction is not a set period of time since last volcanic event. Instead, it is based on a relationship between the time since last eruption (or other known magmatic event such as intrusion or gas exhalation) and the frequency of eruptions before that last event. If the latter was changing with time (getting more or less frequent), this will affect our judgement of the potential for a fututre eruption. Or, if the eruptive history is poorly known, this will limit our ability to predict the probability of future activity. Ultimately there is often no simple yes or no answer for whether a compound volcano active at least once in the last 10,000-50,000 years is extinct or not. Instead it is a coin toss between calling a volcano dormant or extinct, so we try to provide as much additional information as possible with this assigned status so that other people can evaluate how certain we are of this assessment.