Dynamics of large effusive eruptions driven by caldera collapse.

Area of Science:

• Geophysics
• Volcanology
• Earth Sciences

Background:

• Large effusive basaltic eruptions are linked to caldera collapse, exhibiting ground displacement and earthquakes.
• The underlying mechanism governing these volcanic dynamics remains poorly understood.

Purpose of the Study:

• To present a physical model explaining caldera collapse dynamics and long-term eruptive behavior.
• To investigate the role of caldera collapse in sustaining large effusive eruptions.

Main Methods:

• Development of a physical model incorporating quasi-periodic caldera roof collapse.
• Analysis of topography-generated pressures triggering caldera collapse.
• Application and validation of the model using data from the 2018 Kīlauea eruption.

Main Results:

• The model demonstrates that caldera collapse sustains large effusive eruptions.
• Topography-generated pressures are identified as triggers for caldera collapse.
• Analysis of the Kīlauea eruption revealed two active reservoirs with constrained connectivity.

Conclusions:

• The physical model successfully explains the dynamics of large effusive basaltic eruptions associated with caldera collapse.
• The Kīlauea eruption's cessation may be linked to the presence of a second reservoir, after approximately 60% of potential collapse events.
• The developed physical framework is broadly applicable to major caldera collapse eruptions observed over the last 50 years.