What is Geophysics?
Being a former field in classical physics, geophysics has established itself as an independent science more than a hundred years ago. In the broadest sense, geophysics is a geoscience describing the earth and its surroundings by physical methods. It used to include meteorology and oceanography, which later became independent disciplines. Nowadays, geophysics therefore mainly focuses on the physics of the solid earth as well as the upper (conductive) atmosphere, with processes covering many scales in both space and time. Concerning its study subjects, geophysics belongs to the geosciences like geology and meteorology, however regarding its way of scientific conduct, it belongs to physics.
Volcanism, earthquakes and continental drift are especially spectacular phenomena studied by geophysicists. When does a volcanic eruption happen? How does an earthquake start? Why and where do valuable resources reservoirs develop? What are the main forces and processes behind these activities? What does the dynamics of the inner earth look like? How is the interior of the earth structured ? Which interactions are taking place between solid earth, ocean and atmosphere? All of these are topics, which have been key aspects of geophysical research and will remain so in the future.
By studying the structure and dynamics of the earth' interior, geophysics massively contributes to the concept of "global plate tectonics". It addresses the development of the earth, the generation of oceanic and sedimentary basins, continents, mountains and the associated processes like earthquakes and volcanism. Furthermore, current environmental and climate topics are investigated with geophysical methods.
Applied geophysics investigates the upper layers of the earth and fundamentally contributes to the search for resources and waste deposition. This makes it a viable economic factor. Together with other disciplines of geosciences, geophysics substantially contributes to medium and long term natural hazard management as well as resource development and environmental protection.
Since the deeper interior of the earth cannot be accessed by drilling, geophysicists apply indirect methods to get information about the deep underground and its processes. These techniques include the observation of temperature, gravity and magnetic fields and the examination of seismic waves due to earthquakes.
If physics conducts controlled and idealized laboratory experiments, nature dictates the experiments in geophysics. In addition, geophysical measuring expeditions often need to be done in difficult to access and remote areas. Geophysicists observe the natural phenomenas or analyze and interpret the data measured in the field. Heavy computational simulation become more and more important to understand complex processes in the earth. Modeling, which means predicting observations by computing and model representation, can be difficult and expensive. Implementing models to an executable program is another important aspect of geophysical work. Hence, supercomputing is common in geophysics. It is used to process large quantities of observational data and calculate sophisticated models. Gained model results are verified against observations, the variations between model and observation can help to improve modeling.