Introduction to Earth Sciences

The following sections are included:

• Preface
• Contents

Our objective in this chapter and the next one is to recall some of the basic notions of the earth sciences, especially the earth’s composition, and to introduce seismic waves, thus allowing us to understand the solid earth’s interior before we turn to the key topics of this book, which are (i) Earthquakes and volcanoes, (ii) energy resources, and (iii) climate change…

How can scientists — more precisely geophysicists and geochemists — find out what is happening deep inside the earth? The temperatures are too high, the pressures are extreme, and the distances are too vast for drilling (see Figure 1.8). How did geophysicists determine that the mantle is solid, the outer core is liquid, and the inner core is solid? To do so, scientists relied on seismic waves (elastic waves) — waves generated by earthquakes and explosions that travel through the earth and across its surface to reveal the structure of the interior of the planet. Thousands of earthquakes occur every year, and each one provides a glimpse of the earth’s interior…

Earth has many functions. It provides food through the farming of its soils. It provides energy resources (e.g., oil, gas, and coal) and minerals (e.g., gold, diamonds, uranium, and thorium). But Earth also kills, even more frequently these days, with earthquakes and volcanic eruptions being the major sources of destruction…

Our objective here is to make observations which lead to the validation of the tectonic plate theory.

Changes in Earth’s climate can have huge effects on our lives and even on our survival. Therefore it is important to understand future climate change and prepare for its potential effects.

We have divided the climate-change lectures into four chapters. In this chapter, we define climate, then visit the notions of heat, and temperature. These notions are central to an understanding of climate change from a geophysics perspective.

Electromagnetic (EM) radiation is all around us and in the entire universe. Yet EM radiations are hard to get a handle on. Although we see with light, which is an EM radiation, we can appreciate the beauty of a Fiji coral reef in blue waters (see Figure 6.1), the warmth of sunshine and the sting of sunburn. These observations are brought to us by electromagnetic waves. In other words, electromagnetic fields cannot be seen, but nonetheless they are real and can work (by applying forces) on objects and exchange energy. It took scientists until the 1890s, to accept this fact…

Let us finally discuss climate change. The exchange of heat between the Sun and the earth is the main driver of the climate model. As we described in Chapters 5 and 6, this heat-exchange mechanism is the radiation. It is carried out through an electromagnetic radiation exchange, so we will start by describing the fundamental laws of radiation exchange before using them to predict the ground temperature and to describe the greenhouse effect.

What causes climate change? A major factor is that humans started emitting more greenhouse gases only after the advent of the industrial era, which began in the late 1700s. Given that there are large temperature fluctuations well before the 1700s, as we described in Chapter 5, what were the reasons for these climate changes? And how about the recent observations of large concentrations of greenhouse gases in the atmosphere? Our objective here is to answer these questions. We will describe how the Sun’s output affects climate change as well as other natural processes that may cause climate change. We will also discuss how the human activities affect climate change. We will start by describing tools for determining past climates, including Earth’s climate millions of years ago.

Energy may be the most important scientific and technological challenge of the twenty-first century. Energy is essential to modern life. Without it, many billions of people would be left cold and hungry, and long-distance communications would be extremely difficult. In most places, economic growth and energy demand are closely correlated. The availability and use of energy, especially electricity, are sometimes considered a direct measure of the economic well-being of a society. Our objective here is to provide a comprehensive description of this problem and some of its present solutions.

In the previous chapter, we briefly summarized the types of characteristics of energy resources by focusing on their overall contributions to world energy consumption. In this chapter and the next two chapters, we provide a more-detailed scientific and technological description of development and production of these resources. We will focus on biomass (also referred to as feedstocks), solar, and wind-energy resources in this chapter…

Our objective here is to provide a basic description of source rocks and of the basic principles of seismology. The understandings of source rocks and seismology are fundamental in oil and gas exploration and production.

Our objective is to provide a basic understanding of the key steps in oil and gas exploration, production, and monitoring (EPM) from a scientific and technological point of view.

The following sections are included:

• Appendix A: Global Climate Model (GCM)
• Appendix B: Answers to some of the Quizzes and Exercises

The following section is included:

• Index