2018 lower Puna eruption

2018 lower Puna eruption. This major volcanic event was a significant eruptive episode of Kīlauea volcano on the Island of Hawaiʻi. The eruption, which began in early May 2018, involved the collapse of the Puʻu ʻŌʻō vent and a subsequent downrift intrusion of magma into the Lower East Rift Zone. It produced voluminous lava flows from multiple fissures that devastated residential areas in the Puna district, leading to widespread destruction and a prolonged state of emergency.

Background and geological context

Kīlauea is one of the world's most active volcanoes and a prominent feature of Hawaiʻi Volcanoes National Park. For over three decades, its activity was centered at the Puʻu ʻŌʻō vent within the East Rift Zone. This period of sustained eruption, which began in 1983, was part of the volcano's ongoing effusive phase. The United States Geological Survey's Hawaiian Volcano Observatory continuously monitored the volcano's seismicity, ground deformation, and gas emissions. In April 2018, increased seismicity and inflationary tilt at the Kīlauea summit and Puʻu ʻŌʻō signaled a potential change in the magmatic system, preceding the dramatic events in Lower Puna.

Eruption sequence and major events

The eruption sequence commenced on May 3, 2018, following the rapid drainage of the Puʻu ʻŌʻō lava lake. This triggered a powerful earthquake swarm as magma intruded down the Lower East Rift Zone. The first fissure, Fissure 1, opened in the Leilani Estates subdivision. Over the following days, a series of additional fissures propagated northeast, with Fissure 8 becoming the dominant and most prolific vent by late May. Concurrently, the draining of the summit magma reservoir led to repeated collapse events at Halemaʻumaʻu crater, generating ash plumes and periodic explosions. The summit collapses were recorded by instruments at the Hawaiian Volcano Observatory and marked a significant shift in the volcano's behavior.

Impact and evacuations

The eruption's impact was severe and immediate. Mandatory evacuation orders were issued for thousands of residents in Leilani Estates and Lanipuna Gardens. The Hawaii County Civil Defense Agency managed the emergency response, opening shelters at the Pāhoa Community Center and Keaʻau Armory. Lava flows inundated entire neighborhoods, destroying over 700 homes, including the complete loss of the Kapoho Bay community and the famous Kapoho Tide Pools. Critical infrastructure was severed, with lava covering sections of Hawaii Route 132 and Hawaii Route 137, isolating communities. The Federal Emergency Management Agency issued a major disaster declaration for Hawaii County.

Lava flows and fissure activity

Lava flows from the fissure system, particularly the sustained channelized flow from Fissure 8, created extensive new land. The flows were characterized by fast-moving pāhoehoe and ʻaʻā lavas that advanced toward the ocean at Kapoho. The interaction of lava with seawater at the ocean entry generated laze, a hazardous plume of hydrochloric acid and volcanic glass particles. By early June, the lava flow had filled the entire Kapoho Bay, creating nearly 875 acres of new land. The activity at Fissure 8 constructed a significant spatter cone and fed a stable lava river that persisted for weeks, defining the eruption's most destructive phase.

Response and scientific observations

The scientific response was led by the United States Geological Survey and the Hawaiian Volcano Observatory. Teams conducted direct gas measurements, deployed new GPS and seismic stations, and used unmanned aerial vehicles for mapping and sampling. Data was shared with the National Oceanic and Atmospheric Administration for air quality and vog dispersion modeling. The Hawaiʻi Volcanoes National Park was closed for months due to hazardous conditions. The eruption provided an unprecedented opportunity to study rift zone propagation, caldera collapse mechanics, and the dynamics of high-effusion-rate lava flows, significantly advancing volcanology.

Category:2018 in Hawaii Category:Volcanic eruptions in Hawaii Category:Kīlauea Category:2018 natural disasters in the United States