Earth Science Topics: 22 Subjects Briefly Explained

Earth Science topics range far and wide, from the depths of the our planet to the atmosphere, and even to the stars. Some of the topics 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.

Fields in Earth Science Focusing on Surface Water

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 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 very important 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 oceans are so enormous and unexplored. Geophysical fluid dynamics, ocean currents, waves, ecosystem dynamics, sea floor 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

Hydrogeology is a sub-field of geology that specializes in the movement and distribution of groundwater in the soil and rocks of the Earth’s crust. It looks at the water cycle in relation to geology, thus focusing on conditions of water resources and sustainability in the ground. This is increasingly vital as a growing human population and uneven distribution of water creates local scarcities. If we don’t find solutions soon, this scarcity can lead to conflicts and crises in health and safety.

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; however, 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

10. Geochemistry

Geochemistry is a field of Earth Science that applies chemical principles to better 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 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 good telescopes, light spectrometers, or maybe a rover if they’re lucky.

11. Geophysics

Geophysics concerns itself with the physical properties and processes of the Earth and its surrounding environments. This 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 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

5. Petrology

Petrology is a branch 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 classify them. This is the field that gave us the terms sedimentary, igneous, and metamorphic petrology, which are the three main subdivisions of Petrology.

6. Paleontology

This field Earth Science topic studies the life that existed in the past, from about 11,700 years ago and earlier. This is accomplished by studying fossils to determine the interactions and evolution of organisms with each other and their environments. Not only can we thank Paleontology for some really 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

7. 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 soil of an area is important for engineers, geologists, regional planners, and agriculturalists. They need to understand soil to build sturdy structures, grow food, and maintain ecosystem balance.

8. Edaphology

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

9. 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, 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 classificaitaon. Instead, it looks at coil classification, morphology, and formation. But, like Edaphology, it is also very important 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 negative environmental circumstances, as does green chemistry. Rather, 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 human 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 environment, 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 (or gemmology) 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 quality. These classifications are based on 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 an Earth Science field within that of geology that studies the crystal structure, physical properties, and chemistry of minerals and mineralized artifacts. However, unlike gemology, it doesn’t focus on precious or semiprecious minerals of value. Rather, it entails the study of all aspects of all minerals. This includes distribution and occurrence in nature, making it an important 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 important 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 even photography and sociology of volcanoes. Volcanologists study these aspects and monitor volcano activity to understand eruptions. The goal is to be able to predict them in the future, saving countless lives.

Earth Science Subjects Regarding The Geological Exterior

18. Geology

Probably the Earth Science topic everyone already knows a little bit about. 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 is therefore treated 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 created by biological, physical, or chemical processes operating near the surface of the Earth. Geomorphologists focus on understanding 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 can be defined as 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 another type of rock), 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 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 sphere), and its orientation in space. It also looks at how these properties change over time, and looks 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, and more. 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 really get a feel for it. Read more here about recent earth science discoveries or what to do with a degree in the earth sciences.


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3 thoughts on “Earth Science Topics: 22 Subjects Briefly Explained”

  1. I love all the new words I learned! If I had to pick one, I think I’d choose edaphology; beyond just plants, I’d be curious to know how soil impact the insects and potentially even the large animals in the area.

  2. The least obvious definition was “speleology,” the study of caves and its features, interesting! Mineralogy is fascinating to me, as the composition of rocks are not found so easily on the surface of the earth, but rather below. The growth of soil sciences can help those in developing countries with practical ways to grow food on a cost-effective scale.

  3. It’s interesting to note how our society has evolved over the years. Everyone used to have a much more rounded education, but now we’re pushing for a more refined focus. This narrower vision is leading to some incredible discoveries, but could it lead to problems (environmental or otherwise) if we aren’t looking at the whole picture?


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