2018 Hawaii earthquake at Kīlauea (May 4, 2018)
A magnitude 6.9 earthquake struck near Kīlauea on May 4, 2018, during an active eruption. It caused multiple injuries, two deaths, infrastructure damage and widespread monitoring and emergency response.
Overview
On May 4, 2018, a strong earthquake with an estimated magnitude of 6.9 occurred near the south flank of Kīlauea on the island of Hawaiʻi at about 12:33 p.m. local time. The quake coincided with an ongoing eruptive episode at Kīlauea and lava outbreaks that were active in the same general area. The event led to two confirmed deaths and dozens of injuries, and prompted emergency response and evacuations in affected communities. For contemporaneous reports and official summaries see incident summaries.
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Geologic and tectonic setting
Kīlauea is an active shield volcano located on the southeastern side of the island of Hawaiʻi, formed over the Hawaiian hotspot. Earthquakes in the region commonly relate to the movement of magma, adjustments on the volcano's rift zones, and the gravitational loading of the volcanic edifice. Seismic swarms and larger shock events often accompany periods of eruptive activity when magma migrates, pressurizes, or drains from reservoirs beneath the volcano. Regional seismic monitoring and scientific interpretation were carried out by agencies and observatories tracking these processes and monitoring seismicity.
Seismic characteristics and sequence
The magnitude 6.9 event was the most energetic quake in the immediate eruption sequence and produced numerous aftershocks and continued elevated seismicity in the days that followed. Scientists interpreted the timing and location of the shock as being related to subsurface magma movement and changes in stress on Kīlauea's south flank. The earthquake was widely felt across the island and caused rockfalls and ground cracking in some locations near the epicenter; detailed hypocenter and depth information was provided by seismological agencies tracking the sequence epicenter data.
Damage, human impact, and response
Communities closest to the volcano experienced structural damage, road and utility disruptions, and local infrastructure impacts. Emergency services conducted search and rescue, medical response, and evacuations where necessary. Reported human impacts included two fatalities and 28 injuries; other consequences included power outages, damage to buildings and roads, and interruptions to local water and transportation systems. Authorities issued safety notices and coordinated recovery and assistance measures.
Lava activity connection and monitoring
The earthquake occurred amid active lava outbreaks and was part of the broader 2018 Kīlauea eruptive episode. The interplay between seismic events and eruptive behavior highlighted the role of magma pressure changes, dike intrusions, and summit adjustments in driving both earthquakes and surface lava flows. Ongoing scientific monitoring of seismicity, ground deformation, gas emissions, and lava activity provided the data used by volcanologists and emergency managers to assess hazards and inform the public about lava and eruption status.
Significance and lessons
This event underscored how volcanic eruptions and tectonic earthquakes can be tightly linked, producing rapid changes in hazard conditions for nearby residents. It reinforced the need for resilient infrastructure, public preparedness, real-time monitoring, and clear communication between scientists and emergency managers. Post-event studies of the May 4 earthquake and the 2018 eruption sequence have contributed to improved understanding of rift-zone processes and volcano-tectonic interactions in Hawaiʻi.
- Event date: May 4, 2018
- Reported magnitude: 6.9
- Location: near Kīlauea's south flank
- Reported casualties: two deaths, 28 injuries
Author
AlegsaOnline.com 2018 Hawaii earthquake at Kīlauea (May 4, 2018) Leandro Alegsa
URL: https://en.alegsaonline.com/art/133733