Earth Science Topics: 22 Subjects Briefly Explained

Direct Knowlege Contributor Megan Matheney
  • By Megan Matheney, Technical Writer
  • Megan Matheney is a professional technical writer specializing in material relating to Earth sciences, environmental economics, and developmental economics. Megan has a B.S. in Geophysics from the University of Texas at Austin. She also holds an M.S. in Environment and Sustainable Development from the University of Glasgow. She is motivated by her desire to learn and help those around her.

There are several elements of our planet we don’t understand well. The average person like you or I might know information about the weather, but what about the dynamics of glaciers? You might also have an idea about the creation of mountains, but do you understand how tectonic plates continue to impact our geography? These deeper dives into the elements of the planet fall under the study of Earth Science topics.

Earth Science topics include various elements of the natural makeup of the planet. The study of each area of specialization helps magnify the focus of research projects for more useful findings. The topics in Earth Science most often studied continue to change as more information emerges from research. Because of this, the questions in Earth Science are dynamic and always expand in new and profound ways. The study of these topics helps to increase human knowledge of the planet’s makeup and how it changes over time.

Earth Science is an incredible subject to study because it incorporates many other sciences. Physics, chemistry, and biology all play a role in this field. Let’s review the several topics of interest in Earth Science and overview why they are essential. You might see things you are vaguely familiar with suddenly become vast areas to explore in your studies.

Fields in Earth Science Focusing on Surface Water

Earth Science topics range from the depths of our planet to the atmosphere, and even to the stars. Some of the issues you might recognize (looking at you geology). But others, not so much. Pedology? Speleology? Even an Earth Science term like Geophysics might give you an idea of the gist of the field, but what exactly are the details? Here you’ll find 22 areas of study in Earth Science explained to help you figure out if you want to study one, work in one, or just understand what all these rock people are doing.

1. Glaciology

Glaciology is an Earth Science topic concerned with every aspect of ice on landmasses. It uses various methods to evaluate the properties and structures of glacier ice, the dynamics of ice flow, its distribution and formation, and the interactions of ice with climate. This method is particularly important these days with the effects that climate change has on global ice. Climate change means the rate of icecap and glacier melting is increasing rapidly, and negatively affects ocean levels and animal habitats. Outside of our planet, the study is also vital for understanding other planetary bodies with water and ice. For example, Mars and Europa could be significant water-bearing bodies one day when humans begin venturing off Earth.

2. Oceanography

Oceanography, alternatively known as oceanology, is the Earth Science topic focusing on biological and physical aspects of the ocean. It covers a wide range of areas, given that the beaches are so enormous and unexplored. Geophysical fluid dynamics, ocean currents, waves, ecosystem dynamics, seafloor geology, plate tectonics, and fluxes of various physical and chemical properties within the oceans and their boundaries are all included. Because oceans play a vital role in climate change, understanding them is necessary for preventing and adapting to further changes.

Earth Science Subjects Relating to Subsurface and Other Water

3. Hydrogeology

Hydrology also studies the distribution, quality, and movement of water on Earth and other known planets. It is sometimes used interchangeably with hydrogeology. That said, it technically is not limited to water within or relating to geologic formations. Within Hydrology are the subdivisions of hydrogeology, surface water hydrology, and marine hydrology. It looks at environmental watershed sustainability, water resources, and the water cycle as a whole, including on other planetary bodies.

4. Hydrology

Hydrology also studies the distribution, quality, and movement of water on Earth and other known planets. It is sometimes used interchangeably with hydrogeology. That said, it technically is not limited to water within or relating to geologic formations. Within Hydrology are the subdivisions of hydrogeology, surface water hydrology, and marine hydrology. It looks at environmental watershed sustainability, water resources, and the water cycle as a whole, including on other planetary bodies.

Interdisciplinary Earth Science Fields Involving Chemistry and Physics

5. Geochemistry

Geochemistry is a field of Earth Science that applies chemical principles better to understand the Earth as well as other planets. It takes the perspective of chemical interactions to explain the Earth’s interior, crust, oceans, atmosphere, and more. This perspective means looking at the implications of the distribution, migration, and abundance of chemical elements and their isotopes. And these same principles apply to other planets as well and help scientists understand all the terrestrial bodies in our solar system. All scientists need are some excellent telescopes, light spectrometers, or maybe a rover if they’re lucky.

6. Geophysics

Geophysics concerns itself with the physical properties and processes of the Earth and its surrounding environments. This area includes the Earth’s shapes, internal structure, composition, plate tectonics, volcanism, and gravitational and magnetic fields. It also involves the use of quantitative methods for its analysis, primarily seismic waves and vibrations. These vibrations travel through Earth materials, and measuring them allows scientists to make models and predictions. Geophysicists work in all fields, but one of the most common is resource location. They send seismic vibrations through the rock to be able to create “pictures” of the internal structure. Using these pictures, they predict which formations hold minerals, oil, gas, water, and other resources.

Topics in Earth Science with Biological Aspects

7. Petrology

Petrology is a specific area of geology that studies and classifies rocks. It looks at the conditions in which they form, thus using chemical properties, structure, texture, and distribution of occurrence to organize them. This area is the field that gave us the terms sedimentary, igneous, and metamorphic petrology. These topics are the three main subdivisions of Petrology.

8. Paleontology

This field Earth Science topic studies the life that existed in the past, from about 11,700 years ago and earlier. This study is accomplished by studying fossils to determine interactions and evolutions of organisms with each other and their environments. Not only can we thank Paleontology for some great dinosaur movies, but it also helps us understand the past of the Earth and evolution of all species. In the last century, advances in the field led to measurements of DNA and genomes, contributing to modern science and knowledge.

Areas of Earth Science With a Focus on Soils

9. Soil Science

Soil Science is the study of the outer shell of the Earth’s crust, where vegetative life can develop with the appropriate nutrients. It studies the biological, chemical and physical, and fertility properties of the soil, providing valuable information for other fields. Understanding the land of an area is vital for engineers, geologists, regional planners, and agriculturalists. Overall, they need to understand soil to build sturdy structures, grow food, and maintain ecosystem balance.

10. Edaphology

As one of the branches of soil science, Edaphology is the study of soils and their influence and interaction with living organisms, especially about plants. For example, Edaphology studies conservation of land and practices that influence erosion, soil loss, and plant growth. This branch is particularly useful for evaluating how humans and our cultivation techniques affect soil, natural environments, and agricultural success.

11. Pedology

Pedology is the second of the two main branches of soil science. It studies all aspects of soils, including their chemical and physical properties, the mapping and description and mapping of soil units, the role of organisms in soil production, and their physical and chemical properties in their natural environment. Because it doesn’t focus on how soils influence living things like plants, it differs from Edaphology in classification. Instead, it looks at coil classification, morphology, and formation. But, like Edaphology, it is also vital for understanding agricultural sustainability.

Environmental Earth Science Subjects

12. Environmental Chemistry

Environmental Chemistry explores biochemical and chemical phenomena that occur in natural settings. But keep in mind that it does not aim to reduce pollution or adverse environmental circumstances, as does green chemistry. Instead, it uses scientific methods and principles to study chemicals in soil, air, water, and the atmosphere. It then relates findings to human and natural biological activity, as well as other Earth Science topics and scientific fields. The social activities most relevant to Environmental Chemistry are urban city air pollution, local toxic substance leaks, and global changes in atmospheric or oceanic chemical concentrations.

13. Environmental Science

Unlike Environmental Chemistry, Environmental Science looks at the broader picture of the entire environment, aiming to find solutions to environmental problems. It studies interactions of the chemical, physical, and biological components of the situation, as well as how human activities affect them. Climate change, pollution, and natural resource management are some of the main areas of focus in this field. Thus, some of the primary goals are finding and managing sustainable, renewable, and alternative sources for energy and consumables items.

Earth Science Areas Looking at Minerals

14. Gemology

Gemology is the branch of Earth Science that studies natural and artificial gemstone materials. There are thousands of minerals in existence, and each of them comes in many shapes and forms. Gems are those that are considered precious or semiprecious due to rare qualities. Researchers and jewelers need to have extensive education and professional training to identify the various minerals and determine their condition. These classifications exist on the crystal structure, refractive index, specific gravity, and individual qualities such as color and pleochroism. The study also includes investigating how to create synthetic gem-quality minerals and how to cut or process them into attractive shapes for jewelry or display.

15. Mineralogy

Similar to gemology, mineralogy is a field that studies the crystal structure. Other areas of interest include physical properties and chemistry of minerals and mineralized artifacts. However, it doesn’t focus on precious or semiprecious metals of value. Instead, it entails the study of all aspects of all minerals. This study includes distribution and occurrence in nature, making it a required field for mining and resource extraction.

The Tectonic Plates and Related Earth Science Topics

16. Tectonics

Tectonics is the scientific study of rock deformations that make up the Earth’s crust. It describes how the plates of the crust move over time, leading to the formation of continents, oceans, mountains, and trenches found on the surface of the planet. It is essential for guiding geologists and geophysicists in the search for resource deposits, as well as studying and predicting events such as earthquakes and volcanoes.

17. Volcanology

Speaking of volcanoes, Volcanology (also spelled as Vulcanology) is the scientific study of lava, magma, volcanoes, and related geochemical and geophysical phenomena. It also deals with the formation, distribution, and event photography and sociology of volcanoes. Volcanologists study these aspects and monitor volcano activity to understand eruptions. In short, the aim is to be able to predict them in the future, saving countless lives.

Geological Exterior Geology of Jebel Shams, OMan

Earth Science Subjects Regarding The Geological Exterior

18. Geology

Probably the Earth Science topic with which everyone has experienced. Geology is the discipline of Earth Science that studies the solid Earth, its composition, and the processes by which it changes over time. It also includes the study of these areas for natural satellites or terrestrial planets, such as the Moon or Mars. Modern geology overlaps all Earth Sciences, including atmospheric sciences and hydrology, and exists as one of the significant parts of integrated planetary science and Earth systems.

19. Geomorphology

Geomorphology is the study of the evolution and origin of bathymetric and topographic features. Overall, these features emerge through biological, physical, or chemical processes operating near the surface of the Earth. Geomorphologists focus on understanding the reasons why landscapes and sediments formed and exist in their current states. As a result, this allows them to predict future changes and answer large-scale questions about how the surface of the planet works.

20. Sedimentology

Sedimentology is the study of sediments like silt, clay, and sand. It includes studying the processes of their formation, deposition, diagenesis (one type of rock changing into a different kind of stone), and transport. Sedimentologists apply their knowledge to understanding sedimentary rocks and related structures that have formed from these sediments. Under the premise that geologic processes of the modern Earth are the same as in the past, we can reconstruct and understand past environments by comparing modern formations to portions of those found in ancient sedimentary rocks.

Miscellaneous Fields in Earth Science

21. Geodesy

If you thought the Earth was a perfect sphere, Geodesy is here to prove you wrong. This area is the branch of Earth Science that studies and measures the Earth’s gravitational field, geometric shape (which happens to be somewhat like an egg rather than a sphere), and its orientation in space. It also looks at how these properties change over time and look at the same characteristics of other planets. Phenomena included in the study include tides, plate tectonics, magnetic field fluctuation, and gravity strength. All of these characteristics affect sensitive activities, like GPS navigation and space exploration.

22. Speleology

You’re probably suspicious that we’re just making up words now, but Speleology is, in fact, an Earth Science topic. It focuses on the study of caves, looking at their features, physical properties, structure, and inhabitant life forms, as well as how these change over time. Scientists in Speleology measure rates of formation of stalactites, stalagmites, chemical solutions of limestone. Studying caves helps understand past human and other animal life, resource dispersal such as that of water, and landform formation such as that of sinkholes.

Of course, each of these Earth Science topics could (and surely does) have a book written on it. If something caught your eye, check out some more articles on the subject to get a feel for it. Read more here about recent Earth Science discoveries or what to do with a degree in the Earth Sciences.


While each of the Earth Sciences topics covered in this article relates to one another tangentially, they are vastly different subjects of study. Professionals engage with these questions and issues their entire careers to help contribute to the greater understanding of planets and Earth in particular. Without these topics to help develop the natural sciences, we would still have many questions about the world around us. 

What topics in Earth Science do you believe will grow in importance in the future? 

What connections do you see between biology, chemistry, and physics within these areas of study? 

Which topic within Earth Science do you find the most intriguing or open for further study?