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Earth Sciences

[Earth - Australian National University]

- Main Focuses

Earth science or geoscience includes all fields of natural science related to the planet Earth. This is a branch of science dealing with the physical and chemical constitution of the Earth and its atmosphere. 

Earth science can be considered to be a branch of planetary science, but with a much older history. Earth science encompasses four main branches of study, the lithosphere, the hydrosphere, the atmosphere, and the biosphere, each of which is further broken down into more specialized fields. 

There are both reductionist and holistic approaches to Earth sciences. It is also the study of Earth and its neighbors in space. Some Earth scientists use their knowledge of the planet to locate and develop energy and mineral resources. Others study the impact of human activity on Earth's environment, and design methods to protect the planet. 

Some use their knowledge about earth processes such as volcanoes, earthquakes, and hurricanes to plan communities that will not expose people to these dangerous events.  


- Global Climate Models 

Global climate models (GCMs) are computer programs that use mathematical representations of the Earth's climate system to simulate how the climate responds to increasing greenhouse gas concentrations. They are based on the laws of physics and fluid dynamics, and use factors like water vapor, carbon dioxide, heat, and the Earth's rotation as inputs. GCMs are run on powerful computers and can produce petabytes of data, including readings every few hours across thousands of variables. 

A global climate model (GCM) is a complex mathematical representation of the major climate system components (atmosphere, land surface, ocean, and sea ice), and their interactions. Earth's energy balance between the four components is the key to long-term climate prediction.


- Earth Systems Models

A model organizes what we think we know about something to predict its behavior in the present, future, or past and its response to external influences. Models are particularly useful when direct controlled experimentation is difficult or impossible. 

The model can be a simple concept, such as: The heart is a circulatory pump. One possible prediction of this model is that blood in the body regularly flows through the heart. Or a model could be a series of mathematical equations solved by a computer. The second type of model can be built on the first model by applying the physical principles of a pump to calculate the amount of blood circulating through the heart in one minute.

Earth system models (ESMs) are computer codes that simulate the Earth's physical, chemical, and biological processes to study and project climate change and other environmental issues. ESMs are more comprehensive than global climate models (GCMs), which only represent physical atmospheric and oceanic processes. 

Earth system models (ESMs) integrate the interactions of atmosphere, ocean, land, ice, and biosphere to estimate the state of regional and global climate under a wide variety of conditions.


Sunrise over Earth_010322A
[A Beautiful Sunrise over Earth]

- Applications

The Earth sciences can include the study of geology, the lithosphere, and the large-scale structure of the Earth's interior, as well as the atmosphere, hydrosphere, and biosphere. 

The knowledge gained and the services provided by earth scientists help society cope with its environment in many ways. Their knowledge about the structure, stratigraphy, and chemical composition of the earth's crust helps us locate resources that sustain and advance our quality of life. 

Understanding the forces in the crust, and the natural processes on the surface allows us to anticipate natural disasters such as volcanoes and earthquakes, and geologic environments, such as damaging mining practices or improper waste disposal, gives us information to correct such practices and design more benign procedures for the future. 

Finally, a comprehensive perception of planetary physics will allow us to anticipate major changes in global environmental conditions and control or acclimate to those changes.  

Typically, Earth scientists use tools from geology, chronology, physics, chemistry, geography, biology, and mathematics to build a quantitative understanding of how the Earth works and evolves. 

Earth science affects our everyday lives. For example, meteorologists study the weather and watch for dangerous storms. Hydrologists study water and warn of floods. Seismologists study earthquakes and try to understand where they will strike. Geologists study rocks and help to locate useful minerals. 

Earth scientists often work in the field—perhaps climbing mountains, exploring the seabed, crawling through caves, or wading in swamps. They measure and collect samples (such as rocks or river water), then they record their findings on charts and maps. 


- The Four Earth Sciences

Many different sciences are used to learn about the Earth; however, the four basic areas of Earth science study are: geology, meteorology, oceanography, and astronomy. A brief explanation of these sciences is provided below.

  • Geology (Science of the Earth): Geology is the primary Earth science. The word means "study of the Earth." Geology deals with the composition of Earth materials, Earth structures, and Earth processes. It is also concerned with the organisms of the planet and how the planet has changed over time. Geologists search for fuels and minerals, study natural hazards, and work to protect Earth's environment. 
  • Meteorology (Science of the Atmosphere): Meteorology is the study of the atmosphere and how processes in the atmosphere determine Earth's weather and climate. Meteorology is a very practical science because everyone is concerned about the weather. How climate changes over time in response to the actions of people is a topic of urgent worldwide concern. The study of meteorology is of critical importance in protecting Earth's environment. 
  • Oceanography (Science of the Oceans): Oceanography is the study of Earth's oceans - their composition, movement, organisms and processes. The oceans cover most of our planet and are important resources for food and other commodities. They are increasingly being used as an energy source. The oceans also have a major influence on the weather, and changes in the oceans can drive or moderate climate change. Oceanographers work to develop the ocean as a resource and protect it from human impact. The goal is to utilize the oceans while minimizing the effects of our actions. 
  • Astronomy (Science of the Universe): Astronomy is the study of the universe. Here are some examples of why studying space beyond Earth is important: the moon drives the ocean's tidal system, asteroid impacts have repeatedly devastated Earth's inhabitants, and energy from the sun drives our weather and climates. A knowledge of astronomy is essential to understanding the Earth. Astronomers can also use a knowledge of Earth materials, processes and history to understand other planets - even those outside of our own solar system.


- AI in Earth Sciences

Artificial intelligence (AI) is a useful tool in some areas of earth science, such as geophysics. AI algorithms learn patterns from input and output data to create a training model. This can improve the efficiency of earth science data computation, even with complex datasets. 

AI is used for tasks such as:

  • Prediction
  • Anomaly detection
  • Event classification
  • Onboard decision-making on satellites

AI is popular in the geoscientific community because it allows for the analysis and assessment of large sets of information in a short time. 

For example, AI can be used to:

  • Identify contacts in gravity and magnetism
  • Classify lithofacies and characterize reservoirs from well-logs data in petrophysics
  • Generate exploration targets by comparing data from known deposits against data from the exploration area

AI can also provide high-speed alternatives for representing subgrid processes in climate models.



[More to come ...]


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