What are Geology and Geophysics?

What is Geology?

Geology is the study of the Earth. It includes composition and material, structure, processes, and history. Geology encompasses several special areas of study, including at least the following.

Geochemistry is the study of the distribution of chemicals in the Earth and atmosphere.  Geomorphology is the study of landforms and underlying structures.  Historical Geology is the study of the Earth’s evolution.  Paleobotany is the study of plant life in the geologic past.  Paleogeography is the study of Physical Geology in the geologic past.  Paleontology is the study of past life observed in the geologic record (fossils).  Physical Geology is the study of processes, materials and morphology of the Earth.  Sedimentology is the study of sediment deposition.  Stratigraphy is the study of relationships of rock strata.  Structural Geology is the study of geologic structures such as faults and folds.  Tectonics deals with large scale Earth structures such as tectonic plates and its deep interior.  Volcanology is the study of volcanoes and volcanic processes.

 What is Geophysics?

Geophysics is the study of the Earth by quantitative physical methods. It is an applied science and includes the Earth’s interior, crust, oceans, atmosphere and magnetosphere. Applications are broad and can include magnetic studies related to the Earth’s interaction with the Sun; plate tectonics and the interior of the Earth; petroleum and mineral exploration; environmental and engineering analyses; and even archaeological investigations. Special areas of study include the following, among others.

Seismology is the study of seismic data. There are generally three catagories of seismic data. Reflection seismic data is most commonly used for petroleum exploration because of its resolution and level of detail. Refraction seismic data is used mostly to define major layer boundaries within the Earth. Earthquake seismic data is used to study the Earth’s deep internal structure.

Potential Fields studies involve work with the Earth’s gravity, magnetic and electric fields. Traditionally gravity and magnetic data have been used in early stages of petroleum exploration. Magnetics is used extensively for mineral exploration as well. Although there are some applications for electrical methods in petroleum exploration, they are mostly tools for mineral exploration, as well as environmental analyses. Micro-gravity measurements are used in engineering analyses.

For an explanation of my background image, which shows elements of both gravity and magnetic data, go to Background Image. For a discussion and my point of view about specific concepts with regard to gravity and magnetic data interpretation go to Issues.

Remote Sensing methods utilize data collected by radar systems, cameras, infrared sensors and microwave receivers. Imagery derived from airborne and satellite data are used to identify major surface or near-surface structures and areas of varying composition including vegetation, rock types, heat flow etc. Typically aircraft or satellites collect the data. Ground penetrating radar (GPR), collected in relatively smaller areas on land, is a radar system that is frequently used to interpret near surface areas, particularly for environmental, engineering or archaeological applications.