The largest effusive basaltic eruptions are associated with caldera collapse and are manifest through quasi-periodic ground displacements and moderate-size earthquakes^1,2,3, but the mechanism that governs their dynamics remains unclear. Here we provide a physical model that explains these processes, which accounts for both the quasi-periodic stick–slip collapse of the caldera roof and the long-term eruptive behaviour of the volcano. We show that it is the caldera collapse itself that sustains large effusive eruptions, and that triggering caldera collapse requires topography-generated pressures. The model is consistent with data from the 2018 Kīlauea eruption and allows us to estimate the properties of the plumbing system of the volcano. The results reveal that two reservoirs were active during the eruption, and place constraints on their connectivity. According to the model, the Kīlauea eruption stopped after slightly more than 60 per cent of its potential caldera collapse events, possibly owing to the presence of the second reservoir. Finally, we show that this physical framework is generally applicable to the largest instrumented caldera collapse eruptions of the past fifty years.

最大的喷发玄武岩喷发与破火山口塌陷有关，并通过准周期性地面位移和中等规模地震^{1,2,3表现出来}，但控制其动力学的机制仍不清楚。在这里，我们提供了一个物理模型来解释这些过程，它解释了火山口顶部的准周期性粘滑塌陷和火山的长期喷发行为。我们表明，正是火山口坍塌本身维持了大规模的喷发，并且触发火山口坍塌需要地形产生的压力。该模型与 2018 年基拉韦厄火山喷发的数据一致，使我们能够估计火山管道系统的特性。结果表明，两个水库在喷发期间处于活跃状态，并限制了它们的连通性。根据该模型，基拉韦厄火山喷发在其潜在火山口坍塌事件的 60% 以上后停止，可能是由于第二个水库的存在。最后，我们展示了这个物理框架通常适用于过去五十年来最大的仪器化破火山口崩塌喷发。