Kilauea's recent eruption, Episode 44, occurred during the Merrie Monarch Festival, a significant cultural event in Hawaii. This timing adds an intriguing layer to the volcanic activity, as the festival's festivities and the volcano's eruptions coexisted in a unique way. The eruption began with a series of precursory lava flows from the south vent in Halemaumau, leading to the eventual fountaining that lasted for 8.5 hours. What makes this event particularly notable is the contrast between the precursory activity and the eventual fountaining. While more than 50 precursory lava flows emerged from the south vent, only the north vent erupted lava fountains, reaching a maximum height of about 800 feet. This disparity highlights the unpredictable nature of volcanic eruptions and the importance of monitoring and understanding the various phases of volcanic activity.
The eruption's impact extended beyond the summit, with tephra falling on areas such as Hawaii Volcanoes National Park, Kilauea Military Camp, Highway 11, and parts of Volcano Golf Course and Volcano Village. The ash and Pele's hair were reported as far as Ninole, about 35 miles away in North Hilo, demonstrating the far-reaching effects of volcanic activity. The Volcano Alert Level/Aviation Color Code was raised to Warning/Red due to the hazardous conditions on the ground and in the air, leading to temporary closures of parts of the national park and Highway 11.
The eruption also presented challenges for gas monitoring, as the predominant downwind direction during trade winds resulted in Crater Rim Drive being buried under tephra and no longer drivable. Gas monitoring stations were partially buried or damaged by tephra fall, making it difficult to measure volcanic gas emissions. However, the southerly kona winds during Episode 44 pushed the plume over Highway 11, allowing for the measurement of sulfur dioxide emission rates averaging more than 200,000 tonnes per day, a value comparable to the 2018 lower East Rift Zone eruption.
The eruption's aftermath included a series of earthquakes just south of Halemaumau, with 15 shallow earthquakes of magnitude 2 or smaller occurring between 4 p.m. and midnight. These earthquakes, though small, were felt by Hawaiian Volcano Observatory staff in the area. The region had been showing sparse small earthquakes during the past few weeks to months, and satellite-based observations showed upward movement of the area on the south rim of the crater, possibly by as much as 5 inches. The origin of this deformation is not yet known, and further monitoring is necessary to understand its implications.
Episode 44 holds significance in comparing the ongoing episodic eruption at the summit of Kilauea to previous episodic eruptions. While there were 47 episodes at the start of the Pu'u'u'o'o eruption before activity transitioned to effusive lava flows, only 44 episodes came from the Pu'u'u'o'o vent alone. This comparison highlights the evolving nature of volcanic eruptions and the importance of understanding the specific characteristics of each eruption.
In conclusion, Kilauea's Episode 44 eruption during the Merrie Monarch Festival presented a fascinating interplay between volcanic activity and cultural events. The eruption's precursory activity, fountaining, and impact on the surrounding areas demonstrate the dynamic and unpredictable nature of volcanic eruptions. The challenges in monitoring and understanding volcanic gas emissions, as well as the earthquakes and deformation associated with the eruption, underscore the ongoing need for vigilance and research in volcanic activity.
