Cosmochemists investigate the occurrence and distribution of the elements throughout the universe.

 Economic Geologists explore for and develop geologic materials that can be utilized profitably, including fossil fuels, metals, industrial minerals, and water.

 Engineering Geologists apply geologic data, techniques, and principles to the study of rocks, soil, and groundwater for the purpose of evaluating geologic factors that influence the planning, design, construction, operation, and maintenance of engineered structures such as dams, bridges, tunnels, buildings, and airports.

 Environmental Geologists study the interactions between the Earth, hydrosphere, atmosphere, biosphere, and human activities and work to solve problems dealing with pollution, waste disposal, and hazards such as flooding, erosion, earthquakes, and volcanic activity.

 Geochemists investigate the distribution and migration of chemical elements in rocks, soil, and groundwater systems.

 Geomorphologists study the development of landforms and landscapes in relation to underlying geologic structures, climatic changes, and surficial processes.

 Geologists investigate the materials, processes, products, and history of the Earth.

 Geophysists apply principles of physics, such as magnetic, electric, and gravitation fields, to study the physical properties of Earth from the surface to interior.

 Geodynamacists study plate tectonics to determine how processes within the Earth affect the features of the crust.

 Glaciologists study the physical properties, distribution, and movement of glaciers and ice sheets.

 Hydrogeologists study of the abundance, distribution, movement, and quality of water resources.

 *Job descriptions from American Geological Institute.

 Hydrologists deal with surficial water, both liquid and solid, its properties, circulation, and distribution; for example, they study river systems to predict flooding.

 Marine Geologists investigate ocean basins, continental shelves, and coastal environments.Mineralogists study the formation, composition, and properties of minerals.

 Oceanographers investigate the physical, chemical, biological, and geological aspects of  the ocean.

 Paleoecologists study the function and distribution of ancient organisms and their  relationship to their environment.

 Paleontologists study fossils to understand past life  forms, identify changes in life, and reconstruct  past environments. 

Paleoclimatogists/Paleoceanographyers interpret past global changes and predict future changes  from past records.

 Petroleum Geologists explore for and are involved in the development of oil and natural gas resources.

 Petrologists study the origin, occurrence, structure, and history of rocks by analyzing the mineralogy, chemical composition, and grain relationships.

 Planetary Geologists study the planets and their moons to understand the evolution of the solar system.

 Sedimentologists study the origin, distribution, and alteration of sedimentary rocks, such as sandstones, siltstones, and shales.  Oil, coal, and natural gas occur in these types of rock.

Seismologists use earthquake waves to interpret the structure of the Earth and analyze earthquake activity to predict and assess earthquake hazards.

Soil Scientists study soils and their properties for evaluating agricultural productivity and to detect and remediate contaminated soils.

Stratigraphers investigate the age relationships, distribution, composition, fossil content, and geologic properties of rock units on a local, regional, and global scale throughout geologic time.

Structural Geologists study structures, such as folds, faults, and fractures, and relate these structures to the geologic forces that form them.

Volcanologists investigate volcanoes to understand these natural hazards and predict future eruptions.