Why does the floor of calderas lift disproportionately without erupting? Researchers from UNIGE and Roma Tre used thermal and experimental models to explain one of the least-understood processes in volcanology: 'Caldera resurgence'
Calderas are huge topographic depressions with diameters of tens of kilometres formed by large volcanic eruptions and sometimes experience an inflation of their floor of up to a kilometer, caused by magma injection "caldera resurgence," has been observed several times and is one of the least understood in volcanology.
Why after an eruption does the new magma not produce another major eruption instead of resurgence?
The non-erupted magma after the caldera-forming eruption behaves as a "rubber sheet" that inhibits the rise to the surface of the newly injected magma.
Following eruption, magma remains in the magma reservoir, cools, increases viscosity and stops the fresh magma propagating and promotes caldera resurgence. Credit: UNIGE / Roma Tre
A caldera forms when a magma chamber is partially emptied by a large eruption and its roof collapses producing a depression at the surface. After this catastrophic event, in a slow process that can last thousands of years,