Kilauea's Eruptive Activity: A Unique Pattern After Four Decades

Henrik Larsen

5 min read

Post on May 06, 2025

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The Pre-2018 Eruptive Phase: A History of Puu Ō`ō

Characteristics of the Puu Ō`ō Eruptions:

The decades-long effusive eruptions from the Puu Ō`ō vent defined Kilauea's eruptive activity for a significant period. This phase was characterized by:

• Lava flow patterns and their impact on the surrounding landscape: Relatively slow-moving lava flows steadily built up the landscape, creating extensive pāhoehoe and ʻaʻā flows that dramatically altered the geography of the East Rift Zone. These flows sometimes reached the ocean, creating dramatic coastal interactions and adding new land to the island.
• Frequency and intensity of eruptions during this period: The eruptions were relatively frequent, though the intensity varied. Periods of intense activity were interspersed with less active phases, offering a somewhat predictable cycle of activity. Scientists meticulously monitored these fluctuations to improve forecasting capabilities.
• Monitoring techniques used during this phase: Early monitoring heavily relied on visual observations and basic seismic monitoring. Over time, more sophisticated techniques, including gas monitoring, ground deformation measurements using tiltmeters and GPS, and thermal imaging, were implemented to refine understanding and improve eruption forecasting.

Shifting Dynamics and Precursors to Change:

While the Puu Ō`ō eruptions seemed stable, subtle changes indicated an impending shift:

• Seismic activity and ground deformation preceding changes: Prior to the 2018 eruption, there were subtle increases in seismic activity and ground deformation in the East Rift Zone, hinting at magma movement beneath the surface. These changes, though initially subtle, provided early warnings for those monitoring the volcano.
• Changes in gas emissions or lava composition: Slight shifts in the composition of volcanic gases or changes in their emission rates were also observed. These subtle chemical changes signaled shifting magma dynamics beneath the surface.
• Any noticeable changes in the eruption rate or style: The rate of lava effusion from Puu Ō`ō showed fluctuations, with periods of increased and decreased activity. While not immediately alarming, these changes, when considered together with other data, were important precursors to the dramatic events of 2018.

The 2018 Lower East Rift Zone Eruption: A Paradigm Shift

Magnitude and Intensity:

The 2018 Lower East Rift Zone (LERZ) eruption marked a dramatic paradigm shift in Kilauea's eruptive activity. Its scale and intensity were unprecedented in recent history:

• Volume of lava erupted and its geographical impact: The sheer volume of lava erupted during the 2018 LERZ eruption was staggering, vastly exceeding the output of previous Puu Ō`ō eruptions. This resulted in the destruction of hundreds of homes and the dramatic alteration of the landscape. New fissures opened up, significantly changing the topography of the region.
• Fissure eruption development and their spatial distribution: Instead of a single eruptive vent, the 2018 eruption involved multiple fissures erupting simultaneously along the LERZ, significantly expanding the affected area.
• The impact on infrastructure and the local community: The eruption caused widespread destruction of infrastructure, including homes, roads, and other critical facilities, forcing mass evacuations and causing significant disruption to the lives of the local community.

Geological Implications:

The 2018 eruption profoundly altered Kilauea's geological landscape:

• Magma pathways and their alteration: The eruption revealed new or reactivated magma pathways, significantly changing our understanding of the volcano's plumbing system.
• Changes in the volcano's structure and stability: The massive lava effusion altered the volcano's structure and potentially its stability, leading to ongoing research into long-term consequences.
• Long-term effects on the surrounding environment: The effects of the 2018 eruption on the surrounding environment, including changes in water quality, vegetation, and wildlife, continue to be studied.

Post-2018 Eruptive Activity and the Current State of Kilauea

Summit Activity and Halemaumau Crater:

Since the 2018 LERZ eruption, Kilauea's activity has shifted to its summit:

• Lava lake level changes and their correlation with other volcanic activity: The Halemaumau crater now hosts a persistent lava lake, whose level fluctuates, often correlating with seismic activity and gas emissions. These changes are closely monitored for indications of future eruptive behavior.
• Gas emissions and their implications for air quality: Significant gas emissions from the lava lake impact air quality in the surrounding area, requiring ongoing monitoring and public advisories.
• Current monitoring strategies employed by USGS Hawaiian Volcano Observatory: The USGS Hawaiian Volcano Observatory (HVO) employs a sophisticated array of monitoring techniques, including seismic networks, GPS, gas sensors, and thermal imaging, to closely monitor Kilauea's activity and provide timely warnings.

The Evolving Understanding of Kilauea's Behavior:

The 2018 eruption and its aftermath have significantly advanced our understanding of Kilauea:

• New volcanic models and predictions based on the recent data: Scientists are developing refined models of Kilauea's magma system and eruptive behavior based on the wealth of data collected during and after the 2018 eruption.
• Improved hazard assessment methods for the volcano: Hazard assessment methodologies have been improved, incorporating the lessons learned from the 2018 event to better predict future eruptive activity and mitigate risks.
• Future research directions and their potential implications: Ongoing research focuses on understanding the long-term consequences of the 2018 eruption and improving forecasting capabilities to ensure the safety of local communities.

Conclusion:

Kilauea's eruptive activity over the past four decades has demonstrated a remarkable shift, from the prolonged Puu Ō`ō effusive eruptions to the catastrophic 2018 LERZ event and the subsequent summit activity. This evolving pattern highlights the dynamic nature of Kilauea and underscores the importance of continued monitoring and research. The insights gained are not only crucial for hazard mitigation but also significantly advance our understanding of volcanic processes. To stay informed about Kilauea's eruptive activity and the latest scientific findings, visit the USGS Hawaiian Volcano Observatory website and learn more about Kilauea's eruptive activity. Staying updated on the latest Kilauea volcano news is essential for understanding the unique patterns of Kilauea's eruptive activity and ensuring community safety.