although these eruptions generally have a steady eruption rate, larger outbreaks of lava have been observed at many flow-dominated eruption sites. for example, the leading edge of the prometheus flow field moved between observations by "voyager" in 1979 and "galileo" in 1996. although generally dwarfed by explosion-dominated eruptions, the average flow rate at these compound flow fields is much greater than what is observed at similar contemporary lava flows on earth. average surface coverage rates of per second were observed at prometheus and amirani during the "galileo" mission, compared to per second at kīlauea.