Deep magma transport control on the size and evolution of explosive volcanic eruptions

TL;DR

This paper demonstrates through numerical simulations that deep magma interconnections significantly influence the size, evolution, and termination of explosive eruptions, highlighting limitations in current eruption size forecasting methods.

Contribution

It introduces a model considering deep magma connections, revealing their critical role in eruption dynamics and challenging existing forecasting approaches.

Findings

Deep magmatic interconnections control eruption size and evolution.

Numerical simulations reproduce observed eruption magnitude-intensity relationships.

Current imaging limitations hinder accurate eruption size predictions.

Abstract

Explosive eruptions are the surface manifestation of dynamics that involve transfer of magma from the underground regions of magma accumulation. Evidence of the involvement of compositionally different magmas from different reservoirs is continuously increasing to countless cases. Yet, models of eruption dynamics consider only the uppermost portion of the plumbing system, neglecting connections to deeper regions of magma storage. Here we show that the extent and efficiency of the interconnections between different magma storage regions largely control the size of the eruptions, their evolution, the causes of their termination, and ultimately their impact on the surrounding environment. Our numerical simulations first reproduce the magnitude-intensity relationship observed for explosive eruptions on Earth and explain the observed variable evolutions of eruption mass flow rates. Because deep magmatic interconnections are largely inaccessible to present-day imaging capabilities, our results imply a limit to eruption size forecasts based on observations and measurements during volcanic unrest.