  This study analyzes Io's thermally detected volcanic outbursts and
mini-outbursts, generally called bright transient eruptions. We examine their
evolving characteristics over the history of outburst observations between the
Voyager flybys in 1978 and 2022. We catalog, compare, and interpret the data of
these bright transient eruptions from several spacecraft flybys and numerous
ground-based observation campaigns. To test the spatiotemporal behavior of
these events, we compare them to a population of randomly spaced, stochastic
events with an equal likelihood of occurrence anywhere on Io's surface. We find
that the aggregate of all outbursts is consistent with a random distribution
across Io, whereas mini-outbursts strongly prefer the trailing hemisphere (180
to 360 W). On shorter timescales, however, outbursts show a significant change
in spatiotemporal behavior before and after the year 2012. Outbursts from 1995
to 2007 favor the northern leading hemisphere, while outbursts from 2013 to
2021 favor the southern trailing hemisphere. These temporally separated
clusters of outbursts are remarkably similar to Io's two primary mountainous
regions, indicating that outbursts may be related to mountain-forming activity.
These trends show how bright transient eruptions are distinct from Io's other
forms of volcanism. These could be essential constraints to assess models of
Io's interior heat transport between tidal generation and volcanic
distribution.
