A toy model for approaching volcanic plumbing systems as complex systems

Abstract

Magmas form at depth, move upwards and evolve chemically through a combination of processes. Magmatic processes are investigated by means of fieldwork combined with geophysics, geochemistry, analog and numerical models, and many other approaches. However, scientists in the field still struggle to understand how the variety of magmatic products arises, and there is no consensus yet on models of volcanic plumbing systems. This is because eruptions result from the integration of multiple processes, rooted in the magma source either in the mantle or lower crust that feeds a complex network of magma bodies linking magma source and volcano. In this work, we investigate the potential of the network approach through a prototype of magma pool interaction and magma transfer across the crust. In network terms, it describes a diffusion process on a dynamic spatial network, in which diffusion and network evolution are intertwined: the diffusion affects the network structure, and reciprocally. The diffusion process and network evolution mechanisms come from rules of behaviour derived from rock mechanics and melting processes. Nodes represent magma pools and edges physical connections between them, e.g., dykes or veinlets.

Figures (1)

• Figure 1: Example of the toy model outputs with a) a homogeneous and b) a heterogeneous random distribution of magma pools. Node colours represent pressure, using a relative heat scale (from low to high: black, red, orange, yellow). In b) the four horizontal layers are composed alternatively of either many small capacity pools, or a few large capacity pools. Node size corresponds to the capacity of pools c. Note linear versus pulsating volcano output recorded by the green line (right-hand-side diagrams).