Overview of the 2018 eruption of Kilauea Volcano, Hawaii

September 3rd (Tuesday), 6 p.m., Teton Co. Library Auditorium – Open to Public. Presentation: “Overview of the 2018 eruption of Kilauea Volcano, Hawaii, Presented by Bob Tilling, Volcanologist Emeritus, United States Geological Survey.

Kilauea Volcano on the Big Island of Hawaii is one of the most active—and best-monitored—volcanoes on Earth.  Because of its frequent and readily accessible eruptions, Kilauea provides a natural laboratory for studying basaltic volcanism.  Through April 2018, Kilauea had been erupting at two sites:  (1) a lava lake within Halemaumau Crater at the summit caldera, active since 2008; and (2) at Pu’u ‘O’o and nearby vents in the middle East Rift Zone (MERZ), nearly continuously active since 1983.  Then these long-term, simultaneous eruptions began to change drastically over the next several weeks.  On 30 April, the Pu’u ‘O’o crater floor collapsed, ending its 35-year-long activity and triggering increased seismicity and deformation downrift of the vent.  On 1 May, Kilauea summit began to deflate, along with dropping of the level of the active Halemaumau lava lake.  Collectively, these phenomena signaled that magma clearly was moving downrift, prompting the Hawaiian Volcano Observatory (HVO) to issue a notice of potential eruptive activity in the Puna District (southeastern part of the Island of Hawaii).   New ground cracks opened on 2 May in Kilauea’s lower East Rift Zone (LERZ), within and adjacent to the Leilani Estates subdivision.  The next day, the first of numerous fissure eruptions broke out, initiating what would develop into Kilauea’s most voluminous LERZ eruption and summit collapse event in at least the past 200 years.  On 4 May, Kilauea was struck by a magnitude-6.9 earthquake—the most powerful in Hawaii since the magnitude-7.2 shock in 1975—that involved substantial movement on its south flank. 

 

Lasting four months, the 2018 LERZ eruption was socially disruptive and highly destructive, causing the evacuation of  ~2,000 residents, destruction of more than 700 dwellings, and burial of many miles of roads by lava.  Yet, for volcanologists, this eruption—arguably the best-documented eruption in the world to date—provided an unprecedented opportunity to observe and measure hazardous volcanic phenomena, employing state-of-the-art monitoring techniques.  The new data now available are refining our understanding of the operative processes at basaltic shield volcanoes, such as magma-transport dynamics, caldera collapse, small-scale explosive activity, vigorous lava effusion, and volcanic degassing.  In his lecture, Bob Tilling will present a summary—complemented by some video clips—of the highlights of the 2018 Kilauea eruption, focusing on new insights gained from studies of it, and on the effective response of scientists and public officials to the volcanic threats posed during the eruption.