Complex staged emplacement of a basaltic lava: The example of the July 1974 flow of Kīlauea

Biass, S.; Houghton, B. F.; Llewellin, E. W.; Curran, K. C.; Thordarson, T.; Orr, T. R.; Parcheta, C. E.; Mouginis-Mark, P.

Abstract

Basaltic lava flows can be highly destructive. Forecasting the future path and/or behavior of an active lava flow is challenging because topography is often poorly constrained and lava has a complex rheology and emplacement history. Preserved lavas are an important source of information which, combined with observations of active flows, underpins conceptual models of lava flow emplacement. However, the value of preserved lavas is limited because pre-eruptive topography and, thus, syn-eruptive lava flow geometry are usually not known. Here, we use tree-mold data to constrain pre-eruptive topography and syn-eruptive lava flow geometry of the July 1974 flow of Kīlauea (USA). Tree molds, which are formed after advancing lava encloses standing trees, preserve the lava inundation height and the final preserved thickness of lava. We used data from 282 tree molds to reconstruct the temporal and spatial evolution of the ~ 2.1 km-long July 1974 flow. The tree mold dataset yields a detailed dynamic picture of staged emplacement, separated by intervals of ponding. In some ponded areas, flow depth during emplacement (~ 5 m) was twice the preserved thickness of the final lava (2–3 m). Drainage of the ponds led to episodic surges in flow advancement, decoupled from fluctuations in vent discharge rate. We infer that the final breakout occurred after the cessation of fountaining. Such complex emplacement histories may be common for pāhoehoe lavas at Kīlauea and elsewhere in situations where the terrain is of variable slope, and/or where lava is temporarily perched and stored.

Citation

Biass, S., Houghton, B. F., Llewellin, E. W., Curran, K. C., Thordarson, T., Orr, T. R., Parcheta, C. E., & Mouginis-Mark, P. (2025). Complex staged emplacement of a basaltic lava: The example of the July 1974 flow of Kīlauea. Bulletin of Volcanology, 87(4), Article 30. https://doi.org/10.1007/s00445-025-01817-0

• Journal Article Type: Article
• Acceptance Date: Mar 21, 2025
• Online Publication Date: Mar 31, 2025
• Publication Date: Mar 31, 2025
• Deposit Date: Apr 14, 2025
• Publicly Available Date: Apr 14, 2025
• Journal: Bulletin of Volcanology
• Print ISSN: 0258-8900
• Electronic ISSN: 1432-0819
• Publisher: Springer
• Peer Reviewed: Peer Reviewed
• Volume: 87
• Issue: 4
• Article Number: 30
• DOI: https://doi.org/10.1007/s00445-025-01817-0
• Keywords: ʻAʻā and Pāhoehoe, Eruption dynamics, Lava Drainage and Ponding, Kīlauea, Physical volcanology, Fissure eruptions
• Public URL: https://durham-repository.worktribe.com/output/3780782