Geology is the study of the earth and its history and is an exciting profession that typically combines indoor and outdoor work.  As a science, Geology is unique in its focus on time, from the beginning of the Earth during the birth of the Solar System more than 4 billion years ago, to the present.  Geology incorporates those aspects of astronomy, biology, chemistry, and physics important to understanding the Earth from the nickel-iron core to the top of the highest mountain.  A similar scientific foundation is used in understanding Earth's interactions with the atmosphere, the biosphere , and the hydrosphere .

Geologists may study earth materials — including minerals, rocks, or fossils — in an effort to understand what they are and how each of them is formed.  She or he may use the methods of chemistry, physics, or biology to analyze aspects of those materials or broader features of the Earth and its history.  Combining a knowledge of fossils and environmental indicators, other geologists construct an image of past environments, ecological systems, and geographies that reveal where vanished tropical or polar oceans have been and where eroded mountain ranges once stretched across continents long since changed in their shape and size.  Similar information is used to understand Earth systems and past climates in attempts to understand current and future environmental conditions on Earth. 

Geologists also apply their knowledge to the solution of societal problems.  They search the continents and sea floors for the minerals and fuels essential to modern society and look for fresh water used daily by the world's peoples.  Geologists commonly work with engineers in discovering pollution of the soil and groundwater, in developing plans for pollution control or remediation, in siting and developing waste disposal sites, in road and dam construction, or in evaluations of risk and planning designed to minimize the loss of life due to floods, volcanic eruptions, or earthquakes.