June 22 - September 21, 2017
The chart shows how much earthquake activity we are detecting at different volcanoes relative to their background levels. Numbers represent total earthquakes near that volcano for that week. The size of the box reflects how that number compares to the background rate. The color of the box describes how much energy was released near that volcano in all of that week's earthquakes added together. The darker the color, the more energy was released (see legend, below.)
More often than not, vigorous earthquake activity near a volcano does not mean that the volcano will erupt. The Alaska Volcano Observatory evaluates volcano hazards and assigns alert levels by interpreting seismic data along with other types of observations such as satellite imagery and GPS measurements. AVO publishes alert levels for volcanoes in Alaska and Siberia here.