Gaiagraphy
Alexandra Arènes
Related terms: Critical Cartography, Critical Zone, Critical Zone Observatory, Diagrammatics, Earth System Science, Gaia, Mapping
Related authors:
Gaia-graphy consists of two terms: Gaia and graphy. Graphy for cartography, i.e., describing, tracing and narrating the Earth. And Gaia, the Earth, whose habitability is maintained by interactions between living organisms, rocks, air and water, according to the Gaia hypothesis developed by James Lovelock and Lynn Margulis in the 1970s.
0. From the Globe to the Critical Zone
Planet Earth. The Globe, or planetary view, depicts Earth as if seen from outer space. This aligns with the cartographic imaginary of points defined on a map by longitude and latitude, which is based on the Cartesian grid. Here, all life forms, including humans, are so distant that they become invisible. This creates a cognitive dissonance since there is no commensurability between the lived experience of being situated in the critical zone – “the (mostly continental) layers from the top of the canopy to the mother rocks […] foregrounding the thin, porous and permeable layer where life has modified the cycles of matter by activating or catalyzing physical and chemical reactions” (Arènes, Latour and Gaillardet 2018, 121) – and the image provided by the planetary view. In Cartesian maps, there is no room for following the distribution and entanglement of all human and non-human forms of life.
To represent the Earth in a novel form – as a kind of new new world to be discovered yet again – we, in collaboration with a philosopher, a geochemist, several architects and a historian of science, created a new projection principle: a ‘Gaia-graphy’ which relies on image and imagination (Arènes, Latour and Gaillardet 2018; Ait-Touati, Arènes and Grégoire 2022). The projection reverses the order of strata and places the Earth’s core as well as the mantle at the periphery of the projection (see the video animation). The skin of the Earth has been, so to speak, reversed like a glove so that we are now inside a deep set of envelopes instead of simply inhabiting a space on the surface of the planet. There is now all the room available to scale up any of the various layers making up the Critical Zone. In a kind of anamorphosis, the layers that are critical for life on Earth are now fully visible.
1. The Earth reversed
Thus, the superficial becomes central, providing a much better feel for what is necessary for every life form to subsist, while reconstructing a view of the Earth and its biogeochemical and energetic circles that is much more concrete, dynamic, complex, heterogeneous and reactive. At the border of the vortex simulating the atmosphere, with the soil, the fractures, the trees and the roots all around us and weighing on us, we may now begin to feel bound by revolving cycles.
We are now situated within the critical zone, a different space and spatial principle compared to that of the globe.
Hence, we can now grasp the Earth as a helix, a vortex, or as a series of nested merry-go-rounds swirling at different velocities with the chemical elements or molecules cascading from one circle to the next in both directions. What is central is not state stability but migratory states, each with its movements, weaving atoms and organisms together. A cycle is how one element or molecule – water, sulphur, CO₂ – shifts from one circle to the next. We are offered a dynamic vision; everything moves and is transformed, no matter what element is being considered. We are not looking for the position of a position but for the signature of an event. The Earth appears clearly as doubly bounded, at the centre by quick cycles and at the periphery by slow tectonic moves. In the middle are all the movements of intermediary speed and scale. The two main sources of energy are represented: both ‘geophysical’ energy coming from deep Earth and the much more distant and most relevant energy coming from the sun. We all live in this maelstrom, spiralling in between those three sets of forces: deep Earth, sun and living forms. This is the conflation of tectonic and solar forces as they contribute to what could be called the ‘cosmotectonic’ circulation of matter.
2. The carbon cycle
The lower atmosphere at the centre does not float in unbounded space but is strongly coupled with the soil surface. If we pollute the atmosphere or otherwise mess it up, there is no other horizon to which we could escape, contrary to the impression given by the traditional planetary view.
3. The atmosphere trapped inside the geological
By modifying the traditional projection that left the human on the surface of a sphere in the middle of an infinite universe, we have attempted to open a space for Gaia, a first attempt to be able to face Gaia (Latour 2017). There is still an infinite space, but it is no longer that of an isotropic universe; it is that of the infinitely complex, folded, bounded and interwoven geochemical cycles initially born in the critical zone, the only territorial attachment that we might be ready, at the time of the Anthropocene, to study and to care for (Arènes, Latour, and Gaillardet 2018).
4. A cosmogram for the critical zone
A cosmogram is a spatial, visual or volumetric material representation that orders the world in a particular cultural system or cosmology, producing a framework within which human and non-human phenomena can be understood. In this sense, it can be seen as a conceptual model that attempts to show the chaos of the cosmos, of the world, in an organised form, acting as a reduction of the world, of the cosmos (Tresch 2007; Aït Touati 2024). What cosmograms should we be creating today? Does the critical zone, as a new understanding of the Earth, require a cosmogram, a representation that captures this cyclical dis-order of Gaia?
“Qui prononce le mot Gaia ou utilise l’expression critical zone renonce à l’illusion de la distance ontologique.” (Sloterdijk 2023)
5. The map of a critical zone observatory in the Vosges forest (France/German border)
Narrating the Earth is undoubtedly a multifaceted activity that cannot be captured in a single map. Gaia-graphy is also a way of mapping the critical zone in a situated way; of mapping local observation units – the critical zone observatories (CZO) – with their sensors located and embedded in the terrain; and of mapping the planetary dimension of each local observatory provided by the sensors, the series of instrumented places that constitute it, making the Earth’s connectivity perceptible. From this perspective, it is impossible to see the Earth from a distance – the reversed model, coupled with instruments that probe the Earth’s interior, plunges us into the complexity of a place that is local yet bustling from within.
During fieldwork conducted at different observatories (Arènes 2022, 2025), I had the opportunity to visit and interview scientists at the sites, tracing how their work is shaping new relationships with the Earth. The two maps presented here are part of an ongoing research project aimed at assembling an atlas of critical zones.
“Sense data are less descriptive simply of preexisting conditions and more productive of new environments, entities, and occasions of sense that come to stabilize as environmental conditions of concern.” (Gabrys 2016)
Maps and sensors concresce environments through the various viewpoints of the sensors that give us access to multiple realities. This concrescence of points of view (or “points of life” to borrow Emanuele Coccia’s [2018] term) gradually composes a more cosmopolitical understanding of territories, where more entities are taken into account without distinction between the living and the non-living.
Gaia-graphy maps animate the Western view of nature as a passive background. In the Gaia view, every animate, living or non-living, their metabolism and interactions generate a flow in the critical zone. This flow can be monitored and traced in critical zone observatories with specific sensors that record ground vibrations, sediment movements, water droplets, air particles, underground microorganisms, bird trajectories, snowmelt, nitrate circulation, and so on. As the critical zone is constantly being constructed and destroyed, constantly generating itself, Gaia-graphy transforms cartographic space into time, into a notation of events, of the intertwining of long and short-term dynamics by which we seek to capture the transformations of nature as a process, as Earth physis.
6. Subterranean micro-lives, Critical zone observatory map of Ploemeur, Brittany, west coast of France.
This map is part of a work in collaboration with critical zone scientists, a cartographic research conducted as part of the TERRA FORMA Equipex+ research programme (Arènes 2024).
Ploemeur-Guidel watershed, Brittany, France. Ocean, depleted wetland, wetland, urban area, impermeable soils, pumping station, salt water, fractured granite, wells, piezometers, packer, 100-year-old groundwater, 20-year-old groundwater, 1-year-old groundwater, granite/mischa schist contact zone, Lannenec pond, algae, nitrate, sulphate, oxygen, CO2, winds, humidity, rainfall, gases, rain gauges, flux tower, iron, radon, underground microorganisms, nutrients, biofilms, scientists, portable spectrometer, boat, wild boar, kaolin quarry, fault, beach, geophones, waves…
Three points to read and draw a Gaia-graphic map of a critical zone observatory:
- Reversing the Earth’s layers is the first step. This allows us to map the depths and subterranean environments that are often overlooked in maps representing only the surface of the land (or land use). A gradual depth measurement is applied to the model, as on a vertical profile. These gradual measurements are reported in the concentric circles.
- There is then a way of mapping and reading an observatory, which is usually a watershed, and can therefore be read from upstream to downstream. This is reflected on the map by a counterclockwise flow. We start upstream (on the left of the map) and end downstream. In the upper part of the map, a break signifies the larger landscape into which the watershed drains (this may be the ocean directly, or a larger river).
- Finally, the radius of the map reflects an important feature of the observatory, the internal structure that supports the ecosystem: this may be the seasons, the altitude, or the different instrumented locations with different landscape characterisations. The various elements of the observatory are then positioned according to these radii.
The map is structured in circles, the inner one reflects the phenomena happening in the atmosphere (temperature, winds, humidity, gas exchanges) and the outer one reflects the phenomena happening in the subterranean world (water paths at depth, microbial activity, chemical reactions, fractured rocks, the impact of urbanization on water resources through pumping, warming of the underground and subcontinental salt intrusion).
Below sea level, where the boundary between fresh and salt water is no longer so distinct, the subterranean pathways used by their flows make their way through a chaotic world, the fractured rocks of an ancient titanic collision that melted and mixed the hardest rocks, such as granite. In this secret world live ancient, liminal beings, half biotic, half abiotic, half organic, half mineral, half body, half environment. With little or no oxygen, these microorganisms will remain long after our installations and pumping stations have been swept away by the waves submerging the coast.
To understand these phenomena, scientists place sensors deep into the ground. For a few moments, let’s step into the CZO of Ploemeur-Guidel, situated a few kilometres off the coast:
Eliott and Camille, the geochemists, lower the probe into the well, which spits out a rusty, slimy substance that comes out with the water. This water, which may be older than we are, comes from a few hundred meters deep in the rocks, and has “seen” this fossilised mineral world, for a brief moment on the Earth’s time scale. Scientists record microbial activity in the underground world.
There is a striking contrast between barely visible instruments, unremarkable on the surface, and the richness and proliferation of what they can show us of the world below. There is nothing on the surface, and everything is happening beneath our feet, hidden from our view. We become aware of the intense reactivity below through the lens of an artesian well filled with biofilm, a colored, vibrant material in the water; or through the discharge of a very particular rust-colored water on the surface because it rises from the iron-laden depths: all these clues make us sense the intensity of what happens down there, a chthonian world.
7. Map of underground microorganisms at Ploemeur CZO
In further mapping research, we draw maps of microorganisms in critical zone observatories, further exploring the blurring of biotic and abiotic conditions of our world, especially the subterranean biomass.
The meeting of geology and biology raises questions about time scales and how they converge in the study of an observatory: “For a geologist”, a scientist told me, “talking about the subsurface and the formation of rocks necessarily involves scales of hundreds of millions of years, but on top of that there is the activity of micro-organisms on the order of weeks or hours. [...] So we also have to imagine that the activity of microbial communities on an hourly scale will have an impact on things on time scales that are usually described as evolving over several hundred thousand years”. (A geochemist working with microbiologists, extracts from a workshop at the Institute of Physics of the Globe, December 2024)
In these subterranean worlds, the relationship between microorganisms and the abiotic parts of the critical zone is complex, with each one being connected to the others. Thus, the map considers the different scales that relate to the envelopes of the microorganisms: from caves to fractures, to networks and cells.
To summarise, these maps are recompositions made from heterogeneous materials: sensor data, ethnographic observations, qualitative interviews, images collected from scientists, redrawings, etc. We do not live disembodied on a globe. These cartographic experiments aim to situate us in the critical zone, amidst its dynamics, its flows, its complexity and its active entities. Why is the Earth becoming uninhabitable? What is our relationship with the elements of the world? The world’s unfolding comes to us via our sensory capacities (perceiving it and making sense of it). Existing entities are the set of elements that a population will activate with a certain number of filters or through the development of detection techniques to describe them to compose a world. There is, therefore, no world waiting to be seen: it is always a question of detecting elements to construct a world, or rather, shared worlds consisting of as many existing elements as a particular population has objectified. We gradually compose this world using the clues we receive and seek out. In today’s modern Western society, how can we multiply the ‘existents’, that is, all beings, things, and phenomena that come into existence in our world? The act of decomposition-recomposition, such as the practices advocated by Bruno Latour in An Attempt to a Compositionist Manifesto (2010), is more urgent than ever, and the description of the critical zone – this radical, compositionist alterity outlined by sensors – provides us a sense of how to recompose worlds without the globe. Repopulating the world as we gain a better understanding of it through sensors is a tedious and meticulous ant’s task that must be taken on in the face of the current devastating policies of ecological and ethnographic simplification.
Many thanks to Michael Flower and Daniel Irrgang for editing and reviewing this text.
The works presented received support from the ZKM museum of Art and Media in Karlsruhe, the OCZAR community (France), the TERRA FORMA Equipex + project (France CNRS), the IPGP (Institute of Physics of the Globe in Paris), the University of Manchester, and shaā architecture urbanism studio.
References
Ait-Touati, Frédérique, Alexandra Arènes and Axelle Grégoire. 2022. Terra Forma: A book of speculative maps. Cambridge, MA: MIT Press.
Ait-Touati, Frédérique. 2024. Théâtres du monde. Fabriques de la nature en Occident. Paris: La Découverte.
Arènes, Alexandra, Bruno Latour and Jérôme Gaillardet. 2018. “Giving Depth to the Surface – an Exercise in the Gaia-graphy of Critical Zones.” The Anthropocene Review 5 (2): 120-135.
Arènes, Alexandra. 2022. Design at the time of the Anthropocene: reporting from the Critical Zone. PhD thesis, University of Manchester.
Arènes, Alexandra. 2024. “Gaiagraphy”; https://gaiagraphie.com.
Arènes, Alexandra. 2025. Gaiagraphie. Carnet d’exploration de la zone critique. Paris: B42.
Coccia, Emanuele. 2018. The Life of Plants: A Metaphysics of Mixture. Cambridge: Polity Press.
Latour, Bruno. 2010. “An Attempt at a “Compositionist Manifesto”. New Literary History 41: 471-490.
Latour, Bruno. 2017. Facing Gaia: Eight Lectures on the New Climatic Regime. Translated by Cathy Porter. London: Polity Press.
Latour, Bruno, and Peter Weibel. 2020. Critical Zones: The Science and Politics of Landing on Earth. Cambridge, MA: MIT Press.
Lovelock, James. 1979. Gaia: A New Look at Life on Earth. New York: Oxford University Press.
Gabrys, Jennifer. 2016. Program Earth: Environmental Sensing Technology and the Making of a Computational Planet. Minneapolis: University Of Minnesota Press.
Gaillardet, Jérôme. 2023. La Terre habitable ou l’épopée de la zone critique. Paris: La Découverte.
Margulis, Lynn. 1998. Symbiotic Planet: A New Look at Evolution. Basic Books.
Sloterdijk, Peter. 2023. Le remord de Prométhée. Du don du feu à la destruction mondiale par le feu. Paris: Editions Payot & Rivages.
Tresch, John. 2007. “Technological World-Pictures. Cosmic Things and Cosmograms.” Isis 98 (1): 84-94.