- Moussallam, Yves Dr.
The atmosphere that allows our planet to sustain life was formed early in the Earth’s history, from gases emitted by volcanoes.
These gases, or volatile elements, are constantly recycled back into the deep earth at subduction zones, where tectonic plates sink into the mantle. During this process the sinking plate subjected to increasing heat and pressure releases volatiles which, added to the mantle, induce melting and fuel volcanic explosions, completing the cycle. While this depiction of the earth’s giant recycling factory is well established conceptually, we do not know how efficient it is. We can estimate how much goes in, but have little idea what proportion is released back to the atmosphere, and what proportion remains trapped at depth. This question is crucial if we want to understand how our atmosphere formed and our planet became able to sustain life. In the present-day context, characterizing how much gas comes out of the giant recycling factory is also key to understanding volcanic effects on climate, volcanic emissions being significant but poorly constrained parameters in current climate models.
The “Trail by Fire” project, funded by the 2015 bursary from Land Rover and the Royal Geographical Society (with the Institute of British Geographers) is an ambitious scientific expedition which will attempt to quantify the total amount of volatiles released by volcanoes along the Nazca subduction zone. Our objective is to provide the first accurate estimate of the flux of volatile species (H2O, CO2, SO2, H2, CO, HCl, HF, H2S and OCS) emitted by volcanoes along the entire length of the Nazca plate subduction zone (~6000 km). The journey will take us from the Southern tip of Chile all the way to the Equator. We will cross the cordillera through some of Earth’s highest roads and climb the tallest volcanoes in an attempt to understand the Earth’s giant recycling factory.
Land Rover have turned a Defender 110 into the world’s first 4x4 volcano observatory, able to reach and measure active volcanoes never studied before. Just as an ambulance is effectively a mobile hospital, the Land Rover will be a mobile scientific laboratory. During the four month expedition from Peru to Southern Chile, the Land Rover will be our transportation, our living space, and our workshop. Through special modifications installed by Land Rover's Special Vehicle Operations, it will provide a power supply for our instruments and computers, and will even become a volcanic monitoring tool itself – fitted with spectrometers for traversing volcanic plumes. In effect, the Land Rover will be the seventh member of our team.
Updates on the Expedition: Deep Carbon Observatory Blog