Earth and Environment

The Earth system is often described as a series of overlapping layers, extending from the core to the outermost regions at the edge of outer space. It can also be thought of as a system in which rocks, water, air, and life coexist. First and foremost, the Earth system forms a whole, whose components are extensively interconnected across all scales of time and space.

The Earth and Environment module explores the interactions between the main components of the Earth system: the solid Earth, the hydrosphere, the atmosphere, and the biosphere. Its goal is to describe and explain some of the most striking interactions and to demonstrate the extent to which these complex processes and interactions shape our entire environment—including our daily lives, our safety (natural hazards and disasters), and humanity’s prospects for survival on Earth.

Number of hours:

CM: 30  

TD: 30   

TP: 12

Let’s assume 72 hours of in-person student instruction. This consists of 48 1.5-hour teaching blocks (20 lecture blocks, 20 discussion blocks, and 8 lab blocks).

The module is organized as a short introductory session followed by the three thematic blocks listed below, which occur in sequence throughout the module’s schedule:

1. Inner Earth
2. Outer Earth and Geological Hazards
3. The Outer Earth, the 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 regarding the interactions between the various components of the Earth system, focusing primarily on the solid Earth and hydrosphere, and to a lesser extent on the atmosphere and biosphere;
2. to illustrate how certain Earth processes and their interactions can influence our immediate environment—for better or for worse—helping us in our daily lives or, conversely, posing a threat to us, particularly during natural disasters and in response to natural hazards;
3. to provide basic (introductory) scientific knowledge that enables people to understand the dangers the Earth system may pose to humans and their immediate environment. This body of knowledge is known as risk science, or, more formally, cindynics.

To better ground the course in reality and facilitate connections and exchanges among the various disciplines covered in the module, the Earth & Environment sessions alternate between, on the one hand, the presentation of concepts and methods and, on the other hand, applications that are systematically focused on a region where all the topics discussed are perfectly exemplified: Iceland. In this region, practical applications will take the form of performing simple calculations, exploring time series, using digital tools, and critically analyzing physical and chemical data, maps, and/or historical documents.

Basic concepts in geosciences and oceanography at the L2 level, which provide a foundation for this module by building on some prior knowledge related to general education.

Recommended prerequisites:

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

Assessment is based on continuous evaluation.

For Block 1, assessment will consist of ongoing evaluation of the concepts and methods covered in class, as well as graded tutorials and lab sessions.

For Block 3, the assessment takes the form of a short booklet that combines simple risk calculations with the analysis of a specific question related to the topics covered in Block 3. 

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

The contributors 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 to present Iceland’s characteristics in detail, and (ii) to introduce the risk science vocabulary necessary throughout this module (enabling students to better internalize what is covered in class with a view to applying this knowledge in risk-oriented approaches).

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

Session 2 [1.5 hours of lectures and practicals]: Introduction to the study of couplings within the Earth system, across different time and spatial scales. Overview of the physical, mechanical, and chemical characteristics of the various coupled processes that will be covered in the course.

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

Block 1: Deep Couplings and Their Relationship to Other Components of the Earth System

Content: 7.5 lectures; 10.5 tutorials; 3 practicals = 21 hours of in-person instruction (14 FdS blocks of 1.5 hours each)

Sessions 1, 2, and 3 (Lecture; 3 lectures + 3 tutorials + 1.5 lab sessions) - Internal Structure of the Earth - Differentiation of the Earth.

Introduction to experimental petrology (tools, concepts) for understanding the Earth’s internal structure and deep-seated processes. Concepts of phase transitions and phase equilibrium, mineralogy, and physical properties (PREM model, Birch experiment), and the relationship between internal structure and geodynamics (density, moment of inertia, convection, etc.).

Lecture/Lab: Tour of the High-Pressure Laboratory + lectures and labs on modeling melting and crystallization processes based on simple phase equilibrium diagrams and observations of thin sections of mantle and magmatic rocks.

Sessions 4 & 5 (Lecture; 1.5 CM + 3 TD + 1.5 TP) Geochemical Tracing of Deep Processes

The concepts of recycling, mass balance, and geochemical cycles by combining petrogeochemical approaches at different scales (analysis of trace elements, radiogenic and stable isotopes, and volatile elements in minerals and rocks) while establishing connections between the various internal and external layers.

In particular, during the tutorials and lab sessions, we will discuss the carbon cycle and the processes of decarbonation and hydration in subduction zones, as well as mantle metasomatism processes, and we will review the chemical transfer of carbon and sulfur between the asthenosphere, lithosphere, hydrosphere, and atmosphere.

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

Sessions 6, 7, and 8 (FP: 1.5 lectures + 1.5 recs; BG: 1.5 lectures + 3 recs) Mineral Resources and Geothermal Energy

The objective of this section is to establish a connection between deep processes and supergene processes—we will link deep processes to the diversity of surface rocks and also discuss the processes responsible for the high concentrations of rare elements and metals in rocks. We will examine how rocks at the surface become enriched with rare elements and metals to reach concentrations of economic interest. This approach combines geochemical tracing with low-pressure, low-temperature experimental petrology to understand the enrichment processes. Finally, we will examine the processes by which heat transfer from the Earth’s depths to the surface can lead to the concentration of geothermal resources.

Block 2: Interactions Between the Solid Earth, the Hydrosphere, and the Climate

Content: 7.5 CM; 13.5 TD; 3 TP = 24 hours of in-person instruction (16 FdS blocks of 1.5 hours each)

Sessions 1 & 2 (Lecture; 1.5 CM + 4.5 TD): Impact of External Forcings and Climate on the Dynamics of the Solid Earth = Effects of glacial cycles, hydrological cycles, and erosion-sedimentation on lithospheric deformation, seismic activity, and volcanic activity. These two sessions combine a lecture component (physical geodynamics, response to surface load via isostasy or flexure) and a lab component (practical application through exercises on “typical” cases, e.g., the effect of glacier melt on volcanic activity in Iceland).

Session 3 (Lecture; 1.5 CM + 1.5 TD): Solid Earth–Sea Level Interactions. A lecture segment on relative sea level (= vertical movements + eustasy) on global and regional scales in relation to climate change. A lab session on a case study of a subsiding delta (Mississippi, Nile, Rhône), potentially including an analysis of tide gauge time series.

Sessions 4/5/6/7/8 (CC; 4.5 lectures; 7.5 tutorials; 3 lab sessions): Volcanic Hazards. These sessions will cover volcanic hazards (6 hours) and expand on these topics to include the impact of volcanoes on climate (3 hours), linking them to issues of interactions with the hydrosphere and atmosphere. The course will also include a section on the coupling between internal processes and the Earth’s surface (e.g., volcanic plume/Iceland) using remote sensing (InSAR/GPS) (6 hours).

Block 3: Interactions and Risks Focused on the Hydrosphere and the Atmosphere

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

Two sessions—one preparatory and one follow-up (1.5 lecture hours + 1.5 tutorial hours)—are devoted to writing a short paper (4 pages): selecting a topic from a pre-selected list, developing an outline with guidance, defining a writing strategy (content/form), and writing methods.

Sessions 1 & 2 (Lecture; 1.5 CM + 1.5 TD): Weather and oceanic forcings, and weather, oceanic, and coastal hazards. The course demonstrates how meteorological and oceanic forcings (waves, wind, atmospheric pressure, and temperature gradients—including internal ones, which are relevant to Iceland) control coastal hydrodynamics and, consequently, potentially meteorological, oceanic, and coastal hazards (flooding, erosion). Principles, examples, and case studies from Iceland.

Sessions 3 & 4 (Lecture; 1.5 CM + 1.5 TD): Impact of storms on the coast (weather-sea risk). Quantification of driving forces 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 measure of vulnerability). Application to the case of marine weather hazards in Iceland (Exercise).

Sessions 5 & 6 (Lecture; 1.5 CM + 1.5 TD): The course presents ocean-atmosphere couplings dominated by dynamics and their morphological implications for the coastal zone and the continent. Concepts covered in the course include, for example: (i) the definition of meteorological-oceanic indices (NAO, etc.) as markers of climate and large-scale ocean-atmosphere instabilities and 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, boundary waves, seiches, tides). The course then focuses on developing scenarios in which perturbations to the weather-ocean signal caused by other components of the Earth system (a volcanic eruption, an earthquake, etc.) can completely alter these dynamics. Systematic examples are drawn from the North Atlantic and Iceland.

Sessions 7 & 8 (FB; 1.5 CM + 1.5 TP): This two-part session focuses on quantifying water levels at the coast (a quintessential coupled process) under various trend-based or catastrophic scenarios: (i) volcanic eruption, (ii) tsunamis, (iii) storms, (iv) sea-level rise due to global change (role of thermal expansion/ice melt, rebound). This session enables students to quickly calculate these different scenarios in terms of run-up (change in water level along the coastline) and steady-state water level using simple equations. Students are guided to compare orders of magnitude of input energy and orders of magnitude of response in terms of hazard. This session revisits the concepts of hazard severity and return period covered in Session 2 and introduces the analysis of long-term trends. This session builds on the work conducted in Block 2 on water levels (Block 2, Session 3).

Sessions 9 & 10 (1.5 lab + 1.5 lab): Double session in physical experimentation (wave flume or digital wave flume). A gravitational landslide generates a tsunami wave in a wave flume and, after propagation, produces certain morphodynamic effects on the coastal zone. Study of similarity, qualitative analysis of cascading and coupled effects, preliminary quantification (run-up, displaced volume, mobilized energy). This simultaneously illustrates terrestrial couplings, the role of the hydrosphere in energy transfer, and the final effect on a key human habitat (the coastline), while putting the quantification of the hazard into perspective.

Sessions 11 & 12 (1.5 lecture hours + 1.5 lab hours): More advanced concepts in cindyniques (using examples from the hydrosphere)