Geotalk: Dr Olivier Galland

GeoTalk, featuring short interviews with geoscientists about their research, continues this month with a Q&A with Dr Olivier Galland (University of Oslo), who tells us about his volcanology research and the importance of outreach in promoting the Earth sciences. If you’d like to suggest a scientist for an interview, please contact Bárbara Ferreira.

Olivier Galland at the foot of the Tromen Volcano, northern Patagonian Andes, Argentina, during a field expedition of Nov-Dec 2011. Photograph: Derya Gürer

First, could you introduce yourself and let us know a bit about your research topic(s)?

Becoming a volcanologist was my childhood dream, and my studies have always been oriented towards this goal. I first integrated the École Normale Supérieure in Lyon, then I completed my MSc and PhD degrees at the University of Rennes 1. I continued with a postdoc at the Norwegian Centre of Excellence for Physics of Geological Processes, University of Oslo, where I have become Senior Researcher.

My main research topics focus on the mechanics of fluid-rock systems and their implications on volcanic processes. In other words, what is the mechanical behavior of a system where a fluid of given properties flows into a deforming solid matrix? Such a system cannot be understood only from the point of view of the fluid or of the solid, but by the dynamic mechanical interplay between them. This fundamental mechanical loop controls numerous geological processes such as, among others, magma transport and emplacement in the Earth’s crust, hydraulic fracturing, and explosive volcanism. I have mostly addressed these processes through integration of field observations in volcanic systems and quantitative laboratory experiments.

Last year, you received an EGU Arne Richter Award for Outstanding Young Scientists for your “remarkable contribution to the understanding of volcanic and magma emplacement processes”. Could you summarize the research you have done in this area?

Magma transport plays a key role in the Earth’s dynamics, as it accounts for the main mass and heat transport through the crust. Although magmatism has been studied for more than a century, major questions have remained unsolved. For instance, geologists have assumed that volcanism can occur only in extensional tectonic settings, the extension providing space for magma pathways. This generally accepted assumption is contradictory with the occurrence of intense volcanic activity in the Andean Cordillera, where tectonic shortening has been coeval with volcanism. Part of my research work has demonstrated that volcanism can take place in compressional tectonic settings by focusing on a spectacular case study: the Tromen volcano, in the northern Patagonian Andes. Through several field campaigns at Tromen, we collected structural and geochronological evidence, which showed that the volcano built up during the regional tectonic shortening. To explain how magma can rise in such setting, I also designed a novel experimental apparatus that can simulate coeval tectonic deformation and the injection of low viscosity magma. The experimental results show that magma can migrate along thrust faults, strongly modifying our understanding of magma plumbing systems in active margins and volcanic arcs.

In 2008 you embarked on an exciting scientific expedition called the Andean Geotrail: “cycling 10,000 kilometers to discover the Earth and its resources”. Could you tell us about this adventure, including its aims and what you learnt from it?

The Andean Geotrail was a personal outreach project organized together with my partner, Caroline Sassier, also a geologist at the University of Oslo. The project was based on a 9-month cycling adventure in a spectacular geological environment: the Andean Cordillera. The aim was to use the adventure as a pedagogical tool to catch the attention of the young public and to trigger their curiosity through our own observations. This made Earth sciences less theoretical and more dynamic, and our hope was to create scientific vocations by sharing our scientific knowledge through a unique personal experience. Seventeen schools in France and Norway were associated, involving almost 600 pupils from 6 to 18 years of age.

During the expedition, we cycled from Ushuaia, southernmost Argentina, to Cuzco, Peru, and after the theft of our bikes, we walked to Nazca for a last 400 km long crossing of the Andes. We selected and visited more than 30 geological localities along the route to illustrate various implications of Earth sciences in our society (natural resources, natural hazards, geological landscapes). During the visits, we made our own observations and interviewed local geologists or workers. Since our return, we have presented the expedition in the involved schools and during public conferences, and produced an exhibition of our photographs.

By visiting the selected localities we obviously learnt a lot about the applications of Earth sciences in modern society. But overall, we gained an incredible human experience through the numerous encounters with the Andean populations.

You are also a keen photographer, and you were even one of the finalists of the 2012 EGU Photo Competition. How can Earth science photography contribute to promote the importance of geoscientific research among the wider public?

The most difficult challenge to attract the young generations is to overcome their initial reluctance to Earth sciences by catching their attention and triggering their curiosity about the Earth system. Our experience with the pupils during the Andean Geotrail clearly showed that it is a very challenging task without relevant support. During our conferences in the schools, the only way we managed to create a successful link with the pupils was to show them fantastic photographs of spectacular, unusual, strange and/or extreme geological patterns. Once this link has been established with the pupils, very interesting discussions started and it became possible to share our scientific knowledge with them.

Photography also has the potential to associate two communities that often barely interact: scientists and artists. In addition to be a fascinating scientific subject, the Earth and geological patterns are also unlimited sources of inspiration for artists and lovers of natural beauty. Photography of geological patterns is thus a precious way to promote geoscientific research and its associated challenges via artistic contemplation of the esthetic nature of the Earth.

Last but not least, what are your future research plans?

In the near future, I aim to expand my current work. I am leading a field-based project in the northern Patagonian Andes to unravel the structure of exhumed sub-volcanic systems emplaced in relation to thrust faults and folds, to better constrain the processes of magma transport in compressional tectonic settings. This is a good complement of the former project on Tromen volcano.

In addition, I aim to establish a quantitative bridge between volcano geophysics and laboratory models of volcanic processes. I am adapting my experimental apparatus to study the subtle ground deformation induced by the emplacement of magmatic dykes. Combined with new theoretical models, the provisional experimental results are expected to considerably help geophysicists to interpret ground deformation data monitored in active volcanoes with GPS and interferometry Radar (InSAR). In particular, this technique has the potential to provide a new tool to predict the location of forthcoming volcanic eruptions.

The Andean Geotrail project. Caroline Sassier lost in the immensity of the Bolivian Altiplano (4000 MOSL). Photograph: Olivier Galland


Bárbara Ferreira was the Media and Communications Manager of the European Geosciences Union from 2011 to 2019. Bárbara has also worked as a science writer specialising in astrophysics and space sciences, producing articles for the European Space Agency and others on a freelance basis. She has a PhD in astrophysics from the University of Cambridge.

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