Land and Environment

The Earth system is often described as a series of overlapping layers, starting from the central core and extending to the most remote areas at the edge of space. It can also be thought of as a system where rocks, water, air, and life coexist. The Earth system first forms a whole, whose components are largely interconnected at all scales of time and space.

The Earth-Environment module explores the connections between the main components of the Earth system: the solid earth, the hydrosphere, the atmosphere, and the biosphere. Its aim is to describe and explain some of the most striking interactions and to show the extent to which these complex processes and interactions control our entire environment, including our daily lives, our safety (natural hazards and disasters), and the prospects for human survival on Earth.

Hours per week:

CM: 30  

TD: 30   

TP: 12

This represents 72 hours of classroom time. This equates to 48 teaching blocks of 1.5 hours (20 lecture blocks, 20 tutorial blocks, and 8 practical blocks).

The module is organized as a short introductory lecture followed by the following three thematic blocks, which follow one another in the module schedule:

1. Inner Earth
2. External soil and geological hazards
3. External Earth, hydrosphere, and risks

The main objectives of the Earth & Environment module are:

1. provide knowledge and skills at the end of the Bachelor's degree program on the interactions between the different components of the Earth system, focusing mainly on the solid Earth and hydrosphere, and to a lesser extent on the atmosphere and biosphere;
2. illustrate how certain terrestrial processes and their interactions can control our immediate environment for better or worse, helping us in our daily lives or, conversely, threatening us, particularly during natural disasters and under the influence of natural hazards;
3. provide basic skills (introduction) in the sciences that enable people to understand the dangers that the Earth system can pose to humans and their immediate environment. This knowledge is referred to as risk science, or more formally, cindynics.

To better anchor the module in reality and facilitate connections and exchanges between the different disciplines covered, the Earth & Environment sessions alternate between presenting concepts and methods on the one hand, and applications systematically focused on a territory where all the topics discussed are perfectly expressed: Iceland. In this territory, applications will take the form of simple calculations, exploration of time series, use of digital tools, and critical analysis of physical and chemical data, maps, and/or historical documents.

Basic knowledge of geosciences and oceanography at the L2 level, allowing the content of this module to build on some general knowledge.

Recommended prerequisites:

Prior reading of general documentation on climate change, ocean dynamics, the concept of waves, geodynamics, earthquakes, volcanoes, etc.

Knowledge is assessed on a continuous basis.

For Block 1, assessment will be based on continuous evaluation of the concepts and methods covered in lectures and graded tutorials and practicals.

In Block 3, assessment takes the form of a short booklet combining simple risk calculations and the analysis of a specific question related to the topics covered in Block 3. 

Blocks 2 and 3 allow students to work on skills related to preparing for an oral exam (assessment in block 2) and preparing for a written exam (assessment in block 3).

The speakers are identified by their initials (Frédéric Bouchette = FB; Cécilia Cadiot = CC; B. Gibert = BG; Mathieu Ferry = MF; Fleurice Parat = FP).

Introduction to the Earth & Environment module

The introduction has two objectives: (i) to provide an overview of what will be covered in the module and present Iceland's characteristics in detail, and (ii) to introduce the risk science vocabulary that will be needed throughout the module (enabling students to better understand what is covered in class with a view to reusing this content in risk-oriented approaches).

Session 1 [1.5 hours; FB]: The concept of complex coupling (history, formulation in physics and natural sciences, etc.). How couplings between different components of the Earth system influence humans and the biosphere. The session shows the consequences of some of these couplings on our daily lives, on resources, on our security, and on the prospects for human evolution in the Earth's environment.  The session does not specifically address couplings specific to geoscience, but focuses primarily on the concept of coupling and its various forms (threshold, feedback, runaway, sensitive chaos, asymptotic behavior, etc.). This is an introductory session.

Session 2 [1.5 hours CM, FP]: Introduction to the study of couplings within the Earth system, at different timescales and spatial scales. Presentation of the physical, mechanical, and chemical characteristics of the various coupled processes that will be covered in the course.

Session 3 [1.5 hours; FB]: Concepts of cindynics (risk theory), presentation of concepts of danger, hazards, severity, probability of occurrence and return period, resilience, vulnerability, resistance, protection, prevention, risks, challenges, Farmer's diagram and methods used to calculate natural risks. The course clearly echoes the highly interdisciplinary nature of these approaches and the need to consider the couplings within the Earth system in this work.

Block 1: Deep couplings and their relationship with other components of the Earth system

Content: 7.5 CM; 10.5 TD; 3 TP = 21 hours of classroom teaching (14 FdS blocks of 1.5 hours)

Sessions 1, 2, and 3 (FP; 3 CM + 3 TD + 1.5 TP) - Internal structure of the Earth - Differentiation of the Earth.

Introduction to experimental petrology (tools, concepts) to understand the internal structure of the Earth and deep processes. Notions of phase change and phase equilibrium, mineralogy and physical properties (PREM model, Birch experiment), link between internal structure and geodynamics (density, moment of inertia, convection, etc.).

Lab work/practical work: Visit to the High Pressure Laboratory + lab work and practical work on modeling fusion and crystallization processes using simple phase equilibrium diagrams and observations of thin sections of mantle and magmatic rocks.

Sessions 4 & 5 (FP; 1.5 CM + 3 TD + 1.5 TP) Geochemical tracing of deep processes

Concept of recycling, mass balance, and geochemical cycle by combining petro-geochemical approaches at different scales (study of trace elements, radiogenic and stable isotopes, and volatile elements in minerals and rocks) while linking the different internal and external envelopes.

During the tutorials and practical sessions, we will discuss the carbon cycle and the processes of decarbonation and hydration in subduction zones, mantle metasomatism processes, and we will review the chemical transfers of carbon and sulfur between the asthenosphere, lithosphere, hydrosphere, and atmosphere.

Lectures and practicals: Modeling of deep processes (recycling, metasomatism, melting, etc.) based on trace element and isotope concentrations in magmas + Studies of hydration and dehydration processes in mantle rocks based on thin section observations (peridotites, serpentinites) and thermodynamic models.

Sessions 6, 7, and 8 (FP: 1.5 CM + 1.5 TD; BG: 1.5 CM + 3 TD) Mineral resources and geothermal energy

The aim of this section is to establish the link between deep processes and supergene processes. We will establish the link between deep processes and the diversity of surface rocks, and will also discuss the processes that cause high concentrations of rare elements and metals in rocks. We will see how rocks on the surface concentrate rare elements and metals to reach concentrations of economic interest. The approach combines geochemical tracing and experimental petrology at low pressure and low temperature to understand the enrichment processes. Finally, we will see how heat transfer from the depths of the Earth to the surface can lead to the concentration of geothermal resources.

Block 2: Solid Earth - Hydrosphere - Climate Couplings

Content: 7.5 CM; 13.5 TD; 3 TP = 24 hours of classroom teaching (16 FdS blocks of 1.5 hours)

Sessions 1 & 2 (RC; 1.5 CM + 4.5 TD): Impact of external forcings and climate on the dynamics of the Solid Earth = Effects of glacial, hydrological, and erosion-sedimentation cycles on lithosphere deformation, seismic and volcanic activity. These two sessions combine a lecture component (physical geodynamics, response to surface load through isostasy or flexure) and a tutorial component (practical application through exercises on "typical" cases, e.g., the effect of glacier melt on volcanic activity in Iceland).

Session 3 (RC; 1.5 CM + 1.5 TD): Solid Earth-Sea Level Interactions. A lecture on relative sea level (= vertical movements + eustasy) at the global and regional scale in relation to climate change. A tutorial on the case study of a subsiding delta (Mississippi, Nile, Rhône), potentially with analysis of tide gauge time series.

Sessions 4/5/6/7/8 (CC; 4.5 CM; 7.5 TD; 3 TP): Volcanic hazards. These sessions will address volcanic hazards (6 hours) and extend these aspects to the effect of volcanoes on climate (3 hours), linking them to issues of coupling with the hydrosphere and atmosphere. The course will also cover internal-surface coupling (e.g., plume/Iceland) using remote sensing (InSAR/GPS) (6 hours).

Block 3: Couplings and risks focused on the hydrosphere and atmosphere

Content: 10.5 CM; 6 TD; 6 TP = 21 hours of classroom time (15 FdS blocks of 1.5 hours)

Two sessions—one preparatory and one follow-up (1.5 CM + 1.5 TD)—are devoted to writing a micro-thesis (4 pages): choosing a topic from a pre-proposed list, constructing an outline with guidance, defining a writing strategy (content/form), and writing methods.

Sessions 1 & 2 (FB; 1.5 CM + 1.5 TD): Weather and marine forcing and weather and coastal risks. The course shows how meteorological and marine forcing (waves, wind, atmospheric pressure, temperature gradient, including internal temperature, which is relevant in Iceland) control coastal hydrodynamics and therefore potentially meteorological and marine hazards and coastal hazards (flooding, erosion). Principles, examples, case studies on Iceland.

Sessions 3 & 4 (FB; 1.5 CM + 1.5 TD): Impact of storms on the coast (weather-marine risk). Quantification of forcings and calculation of their impact on the coast. Calculation of parameters specific to marine weather risks (severity, return period, probability of occurrence, calculation of a form of vulnerability). Application to the case of marine weather hazards in Iceland (Exercise).

Sessions 5 & 6 (FB; 1.5 CM + 1.5 TD): The course presents the couplings dominated by ocean and atmospheric dynamics and their morphological implications for the coastal zone and the continent. The concepts covered in the course include: (i) definition of marine weather indices (NAO & co) as markers of climate and large-scale ocean/atmosphere instabilities/couplings, (ii) surface atmosphere/ocean couplings: wave growth, (iii) wave/wave/current couplings and rogue waves, (iv) feedback from terrestrial dynamics on ocean dynamics (tsunamis, edge waves, seiches, tides). The course then goes on to develop scenarios in which disturbances to the weather-marine signal by other components of the Earth system (a volcanic explosion, an earthquake, etc.) can completely alter this dynamics. Systematic examples are taken from the North Atlantic and Iceland.

Sessions 7 & 8 (FB; 1.5 CM + 1.5 TP): This double session focuses on quantifying the water level at the coast (a coupled process par excellence) under different trend or catastrophic scenarios: (i) volcanic eruption, (ii) tsunamis, (iii) storms, (iv) sea level rise due to global change (role of ice expansion/melting, rebound). The session enables these different situations to be quickly calculated in terms of run-up (change in water level at the coastline) and resting water level using simple laws. Students are asked to compare orders of magnitude of imposed energy and orders of magnitude of response in terms of hazard. The session allows students to review the concepts of hazard severity and return period seen in session 2, and to move on to the analysis of long-term trends. This session echoes the work done in block 2 on water level (Block 2, session 3).

Sessions 9 & 10 (1.5 TP + 1.5 TP): Double session in physical experimentation (channel or digital channel). A gravitational slip generates a tsunami wave in a wave channel and, after propagation, produces certain morphodynamic effects on the coastal zone. Study of similarity, qualitative analysis of chain and coupled effects, preliminary quantification (run-up, displaced volume, mobilized energy). This allows us to illustrate, in a single movement, terrestrial couplings, the role of the hydrosphere in energy transfer, and the final effect on a key territory for humans (the coastline), with a view to quantifying the hazard.

Sessions 11 & 12 (1.5 CM + 1.5 TP): More advanced concepts of cindynamics (using examples from the hydrosphere)