Periodic Reporting for period 2 - MODERATE (Magma Outgassing During Eruptions and Geothermal Exploration)
Periodo di rendicontazione: 2022-10-01 al 2024-03-31
Magmatism is central to planetary evolution, controlling volcanic eruptions and most geothermal systems. The presence of volatiles (water, carbon dioxide, sulfur, etc) regulates magma buoyancy, storage and transport. When magma are subjected to certain changes in pressure and temperature conditions volatiles exsolve (akin to uncorking a bottle of Champagne) and either accumulate or escape magma, influencing the probability and style of an eruption. Understanding the controls on magma-gas coupling is thus fundamental to resolve volcanic activity as well as manipulate its response to drilling operations when harnessing geothermal energy near magma. This project aims to constrain Magma Outgassing During ERuptions And geoThermal Exploration (MODERATE).
MODERATE is a timely, innovative, interdisciplinary project aiming to radically broaden our understanding of magma-gas coupling in volcanic and superhot, geothermal systems. The objectives are to: 1) constrain the impact of external forcing mechanisms (i.e. decompression, temperature changes, shear and pressure oscillations from shaking, impact and rupture) on the formation of gas bubble (i.e. vesticulation), 2) quantify the development of gas bubble connectivity (i.e. permeability) to allow gas release, and 3) define manipulationstrategies to moderate magma outgassing and alleviate the risk of volcanic eruption associated with drilling and borehole operations.
A map of magma vesiculation and permeability under a wider range of conditions and stressing scenarios than everachieved before will allow us to resolve current conundrums and explore new regimes to control permeability in magma. This innovative effort will allow us to moderate magma outgassing, thus enabling direct access to magma energy and eventually providing a means to control outgassing and alleviate eruption potential.
MODERATE is a timely, innovative, interdisciplinary project aiming to radically broaden our understanding of magma-gas coupling in volcanic and superhot, geothermal systems. The objectives are to: 1) constrain the impact of external forcing mechanisms (i.e. decompression, temperature changes, shear and pressure oscillations from shaking, impact and rupture) on the formation of gas bubble (i.e. vesticulation), 2) quantify the development of gas bubble connectivity (i.e. permeability) to allow gas release, and 3) define manipulationstrategies to moderate magma outgassing and alleviate the risk of volcanic eruption associated with drilling and borehole operations.
A map of magma vesiculation and permeability under a wider range of conditions and stressing scenarios than everachieved before will allow us to resolve current conundrums and explore new regimes to control permeability in magma. This innovative effort will allow us to moderate magma outgassing, thus enabling direct access to magma energy and eventually providing a means to control outgassing and alleviate eruption potential.
The goal of the project MODERATE is to resolve the evolution of, and conditions controlling, magma-gas coupling, which is key to understand volcanism as the presence of gas influence volcanic eruptions; this is also important to deep geothermal exploration which (in search of more energy) is increasingly approaching magma reservoir. Understanding magma-gas coupling will help us define strategies to moderate magma outgassing and pioneer next-generation geothermal energy directly from magma. Thus the MODERATE project relies on the development of novel equipment to manipulate magma under a range of controlled conditions as experienced during volcanic eruptions or during geothermal drilling. So far in the project, we have developed most of this novel equipment (e.g. Magma shaking machine to study the effect of earthquakes on magma; a high-temperature impact drop tower to study the effect of ballistic impact or rock crushing on magma properties, and a large furnace to study how magma evolve when it flows in a borehole.). We have also undertaken field campaigns in New Zealand and USA to study the vestige of magma-gas couling by examining the network of vesicles (pores) frozen into volcanic rocks (cooled from magma). Finally, we have used existing models and developed new computer simulations to evaluate how magma would respond to geothermal drilling, depending on the drilling practices utilised. Here are some of the results obtained so far:
We have demonstrated that we can model the evolution of aggregates of melt droplets that agglutinate, whilst loosing gas, which is important to model the gas emitted between explosions at active volcanoes or to control gas los from magma at the bottom of a well. We have also shown that the occurrence of earthquakes damages volcanic rocks and their ability to release gas; next we will attempt these complex experiments on magma. Finally we have shown that drilling into magma causes changes in pressure and temperature that influence the properties of magma: it causes gas loss and crystallisation. In the coming years we will work to evaluate how these changes would influence the mobility of magma.
We have demonstrated that we can model the evolution of aggregates of melt droplets that agglutinate, whilst loosing gas, which is important to model the gas emitted between explosions at active volcanoes or to control gas los from magma at the bottom of a well. We have also shown that the occurrence of earthquakes damages volcanic rocks and their ability to release gas; next we will attempt these complex experiments on magma. Finally we have shown that drilling into magma causes changes in pressure and temperature that influence the properties of magma: it causes gas loss and crystallisation. In the coming years we will work to evaluate how these changes would influence the mobility of magma.
Thus fas, a wide range of informative findings have been obtained that is advancing the state-of-the-art (i.e. associated with gas loss from magma and rocks when subjected to evolving conditions), but the greatest advances will arise once 1) we use the newly developed equipment to experiment on magma under previously untested conditions, and 2) sufficient data is obtained to develop new relationships or revise existing ones. The observations made during the field campaigns, the experimental results, and the numerical models developed show great promises to the expansion of our understanding of magma-gas coupling, which, in the next 2.5 years, will help us define strategies to moderate magma outgassing and pioneer next-generation geothermal energy directly from magma. Indeed, a review of recent research findings has been done to argue that accessing magma represents a necessary new frontier that needs to be met in order to increase our sustainability (energy, ore, etc), our resilience to volcanic hazards and better resolve the pulse of the Earth which regulates the Earth's climate against the anthropogenic forces that prompt climate change.