TRACKING AN ACTIVE ERUPTION FOR INSIGHT INTO THE DYNAMICS BEHIND PLANETARY VOLCANIC FEATURES

Planetary geology involves the investigation of stagnant morphologies to gain insight into long-ceased processes on other planets. On rare occasions, we have unique opportunities to witness the dynamic processes that create similar features on Earth, often learning more in an instant about the processes behind the formation of features we see on other planets than after years of speculative study. Such an opportunity recently arose with the May 2 eruption of Kilauea’s Southeast Rift Zone. At the time of this abstract, the eruption has lasted 101 days and deposited lava of varying thickness over an area of 35.5 km². Lava variably erupted from 24 fissures, with the longest-lived eruptions occurring at Fissures 22 and 8 at peak eruption rates of 500 m³/s. These eruptions generated spatter cones at the fissures and sinuous lava channels that transported lava to the Pacific Ocean at peak speeds of 22 mph. During the eruption, the Kilauea caldera floor subsided significantly and the inner caldera of Halema’uma’u drained of lava and expanded in area, resulting in a drastically changed landscape at Kilauea.

During the eruption, features formed that have distinct similarities to volcanic features observed on the Moon and Mars. A small rampart with a short channel that formed during the initial stages of eruption at Fissure 22 is very similar to a small cone and channel observed in Mare Tranquillitatis, the Moon. The Fissure 22 rampart, channel, and marginal levees formed within days, suggesting the analogous cone on the lunar surface resulted from a day(s)-long, low-volume eruption. In the Fissure 8 channel, terraces similar to those observed within Athabasca Valles, Mars formed in the channel wall as the depth and width of lava within the channel decreased and are, therefore, indicative of the level of lava within the channel. Also, sinuous lava channels formed at Fissures 8 and 22 have a similar morphology to channels observed on the Moon and Mars, with diverging and converging channel branches surrounding streamlined islands in the channel interiors. In Hawaii, these islands are kipukas of pre-existing terrain surrounded by lava, and they formed within months of the onset of the eruption. These and other analogous features will be explored to gain insight into the timing and dynamics behind the formation of enigmatic planetary features.