Volcanic Hazards in an Evolving Earth: Monitoring Magmatic Systems, External Forcing and Beyond

The Earth has evolved dynamically since its formation about 4.5 billion years ago, driven by continuous internal and surface processes. Magmatic systems, driven by Earth’s internal heat engine, have evolved from widespread primordial magmatism during early crustal formation to complex, localized activities associated with plate tectonics, mantle plumes, and subduction zones. Volcanoes and hydrothermal systems provide valuable insights into Earth’s magmatic processes, which often result in crustal deformations due to the injection, accumulation, and movement of magmatic fluids. Depending on complex physical conditions, these processes can be further influenced by various external and dynamic factors. Exogenous processes do not affect the general trend of magmatic inflation and the rate of increase in magma injection or accumulation, but rather modulate the driving factors. The interplay between endogenous forces (such as magmatic activity) and exogenous factors (such as tectonic stresses or atmospheric phenomena) complicates the understanding and prediction of hazards. The hazards associated with magmatic systems have increased worldwide as communities increasingly settle near these systems to capitalise on their economic and environmental benefits while also disrupting the natural processes through artificial impact. Such regions include the Cascades, the Nordic countries, the Southern Alps, Southeast Asia, and numerous volcanic islands. Under the current scenario of climate change and changing weather patterns, this further complicates the intricate feedback response between endogenous and exogenous forces. This review offers a novel synthesis of the interplay between endogenous and exogenous processes governing magmatic systems, highlighting how external forces modulate volcanic and hydrothermal activity across spatial and temporal scales. We propose a conceptual framework linking external stress perturbations with internal magma dynamics, emphasizing feedback mechanisms during different stages of the eruption cycle. By integrating multi-source geophysical, geodetic, and climatic observations, the study identifies knowledge gaps in understanding how natural forcing affects magmatic inflation, deformation, and eruption forecasting. Under the current scenario of global climate change and increasing anthropogenic impacts, such an integrated perspective is essential for advancing next-generation volcanic monitoring and hazard mitigation strategies.