Introducing our New Career-of-the-Month Column!


Geologist at work

Geoscientists and hydrologists study the composition, structure, and other physical aspects of the Earth, and the Earth’s geologic past and present by using sophisticated instruments to analyze the composition of earth, rock, and water. Many geoscientists and hydrologists help to search for natural resources such as groundwater, minerals, metals, and petroleum. Others work closely with environmental and other scientists to preserve and clean up the environment.

Geoscientists usually study and work in one of several closely related geosciences fields:

  • Geologists study the composition, processes, and history of the Earth. They try to find out how rocks were formed and what has happened to them since their formation. They also study plant and animal fossils.
  • Geophysicists use the principles of physics, mathematics, and chemistry to study not only the Earth’s surface, but also its internal composition, ground and surface waters, atmosphere, oceans, and magnetic, electrical, and gravitational forces.
  • Hydrologists study the quantity, distribution, circulation, and physical properties of water and the water cycle.


Within these major geoscience fields, there are numerous subspecialties:

  • Petroleum geologists map the subsurface of the ocean or land as they explore the terrain for oil and gas deposits. They use sophisticated instrumentation and computers to interpret geological information.
  • Engineering geologists apply geologic principles to the fields of civil and environmental engineering, offering advice on major construction projects and assisting in environmental remediation and natural hazard-reduction projects.
  • Mineralogists analyze and classify minerals and precious stones according to their composition and structure, and study the environment surrounding rocks in order to find new mineral resources.
  • Sedimentologists study the nature, origin, distribution, and alteration of sediments, such as sand, silt, and mud. These sediments may contain oil, gas, coal, and many other mineral deposits.
  • Paleontologists study fossils found in geological formations to trace the evolution of plant and animal life and the geologic history of the Earth.
  • Stratigraphers examine the formation and layering of rocks to understand the environment which formed them.
  • Volcanologists investigate volcanoes and volcanic phenomena to try to predict the potential for future eruptions and hazards to human health and welfare.
  • Glacial geologists study the physical properties and movement of glaciers and ice sheets.
  • Geochemists study the nature and distribution of chemical elements in groundwater and earth materials.


Geophysicists specialize in areas such as geodesy, seismology, and magnetic geophysics. Geodesists study the Earth’s size, shape, gravitational field, tides, polar motion, and rotation. Seismologists interpret data from seismographs and other geophysical instruments to detect earthquakes and locate earthquake-related faults. Geomagnetists measure the Earth’s magnetic field and use measurements taken over the past few centuries to devise theoretical models that explain the Earth’s origin. Paleomagnetists interpret fossil magnetization in rocks and sediments from the continents and oceans to record the spreading of the sea floor, the wandering of the continents, and the many reversals of polarity that the Earth’s magnetic field has undergone through time. Other geophysicists study atmospheric sciences and space physics.

Hydrologists often specialize in either underground water or surface water. They examine the form and intensity of precipitation, its rate of infiltration into the soil, its movement through the Earth, and its return to the ocean and atmosphere. Hydrologists use sophisticated techniques and instruments. For example, they may use remote sensing technology, data assimilation, and numerical modeling to monitor the change in regional and global water cycles. Some surface-water hydrologists use sensitive stream-measuring devices to assess flow rates and water quality.

Oceanographers use their knowledge of geosciences, in addition to biology and chemistry, to study the world’s oceans and coastal waters. They study the motion and circulation of ocean waters; the physical and chemical properties of the oceans; and how these properties affect coastal areas, climate, and weather. (Biological oceanographers, often called marine biologists, study the distribution and migration patterns of the many diverse forms of sea life in the ocean; they are categorized as biological scientists.)

Some geoscientists and hydrologists spend the majority of their time in an office, but many geoscientists and hydrologists spend a large part of their time in the field. Fieldwork often requires working long and irregular hours identifying and examining geological formations, studying data collected by remote sensing instruments, conducting geological surveys, constructing field maps, and using instruments to measure the Earth’s gravity and magnetic field. They often perform seismic studies, for example, which involve bouncing energy waves off buried layers of rock, to search for oil and gas or to understand the structure of the subsurface layers. Similarly, they use seismic signals generated by an earthquake to determine the earthquake’s location and intensity. In laboratories, they examine the chemical and physical properties of specimens. They study fossil remains of animal and plant life or experiment with the flow of water and oil through rocks.

Some specialists, such as volcanologists, often take field trips that involve significant physical activity and some risk. They work in warm or cold climates and in all kinds of weather. In their research, they may dig or chip with a hammer, scoop with a net, and carry equipment in a backpack. Oceanographers may spend considerable time at sea on academic research ships. Geologists frequently travel to remote field sites by helicopter or 4-wheel-drive vehicles and cover large areas on foot. Many exploration geologists and geophysicists work in foreign countries, sometimes in remote areas and under difficult conditions. Travel often is required to meet with prospective clients or investors.

A bachelor’s degree is adequate for a few entry-level positions, but most geoscientists and hydrologists need a master’s degree, which is the preferred educational requirement for most research positions in private industry, Federal agencies, and State geological surveys. A Ph.D. is necessary for most high-level research and college teaching positions, but is generally not required for other jobs.

Many colleges and universities offer bachelor’s and graduate degrees in the geosciences. Traditional geoscience courses emphasizing classical geologic methods and topics (such as mineralogy, petrology, paleontology, stratigraphy, and structural geology) are important for all geoscientists. People who study physics, chemistry, biology, mathematics, engineering, or computer science may also qualify for some geoscience positions if their course work includes geology.

Most universities do not offer degrees in hydrology, but instead offer concentrations in hydrology or water studies in their geoscience, environmental science, or engineering departments. Students interested in hydrology should take courses in the physical sciences, geophysics, chemistry, engineering science, soil science, mathematics, aquatic biology, atmospheric science, geology, oceanography, hydrogeology, and the management or conservation of water resources.

Computer skills are essential for prospective geoscientists and hydrologists; students who have experience with computer modeling, data analysis and integration, digital mapping, remote sensing, and Geographic Information Systems (GIS) will be the most prepared entering the job market. Knowledge of the Global Positioning System (GPS)-a locator system that uses satellites-has also become essential. Some employers seek applicants with field experience, so a summer internship is often helpful.

Geoscientists must be inquisitive, able to think logically, and capable of complex analytical thinking, including spatial visualization and the ability to infer conclusions from sparse data. Geoscientists and hydrologists involved in fieldwork must have physical stamina. Because geoscientists and hydrologists usually work as part of a team with other geoscientists and with environmental scientists, engineers, and technicians, they must have good interpersonal skills. Strong oral and written communication skills also are important because writing technical reports and research proposals and explaining research results in person are important aspects of the work. Some jobs, particularly for petroleum geologists, require foreign travel, and for these positions knowledge of a second language is beneficial.

Geoscientists and hydrologists often begin their careers in field exploration or as research assistants or technicians in laboratories or offices. As they gain experience, they take on more complex and difficult assignments. Eventually, some are promoted to project leader, program manager, or to a senior research position. Those who choose to work in management will spend more time scheduling, budgeting, and reporting to top executives or clients. Geoscientists in research positions with the Federal Government or in colleges and universities frequently are required to design programs and write grant proposals in order to fund their research. Geoscientists in consulting jobs face similar pressures to market their skills and write proposals so that they will have steady work.

A number of states require geoscientists and hydrologists who offer their services directly to the public to obtain a license from a State licensing board. Licensing requirements vary by state but typically include education and experience requirements and a passing score on an examination. In states that do not require a license, workers can obtain voluntary certifications. For example, the American Institute of Hydrology offers certification programs in professional hydrology that have similar requirements to state licensure programs.

Geoscientists and hydrologists are employed in architectural, engineering, scientific, and technical consulting services, including oil and gas extraction companies. State agencies such as state geological surveys and state departments of conservation employ geoscientists. The Federal Government employs geologists, geophysicists, hydrologists, and oceanographers, mostly within the U.S. Department of the Interior for the U.S. Geological Survey (USGS) and within the U.S. Department of Defense. Many more individuals hold geoscience faculty positions in colleges and universities, but they are classified as college and university faculty. Ph.D.s may face competition for research and college teaching jobs, but graduates with a master’s degree in geoscience can expect excellent job opportunities.

The need for energy, environmental protection, and responsible land and water management will spur employment demand. Employment in management, scientific, and technical consulting services should continue to grow as more geoscientists work as consultants. These services have increased their hiring of geoscientists in recent years because of increased government contracting and private corporations’ need for technical assistance and environmental management plans. Moreover, many geoscientists and hydrologists monitor the quality of the environment, checking for problems such as deteriorating coastal environments and soil and water contamination-all of which will create employment growth for them. Highway building and other infrastructure projects will also be a source of jobs for engineering geologists. The petroleum, mineral, and mining industries offer higher salaries, but less job security, than other industries because economic downturns sometimes cause layoffs.

Many geoscientists work in the petroleum and natural gas industry, an industry that also employs numerous other workers whose jobs deal with the scientific and technical aspects of the exploration and extraction of oil and natural gas, including: Engineering technicians, Engineers, Science technicians, Surveyors, cartographers, photogrammetrists, and surveying and mapping technicians. Historically, employment of petroleum geoscientists has been cyclical and affected considerably by the price of oil and gas. When prices are low, oil and gas producers curtail exploration activities and may lay off geologists. When prices are high, companies have the funds and incentive to renew exploration efforts and to hire geoscientists in larger numbers. In the long term, continued high oil prices are expected to maintain demand for workers who can find new resource deposits. Geoscientists who speak a foreign language and who are willing to work abroad should enjoy the best opportunities as the need for energy, construction materials, and a broad range of geoscience expertise grows in developing nations.

Demand for hydrologists should also be strong as the population increases and moves to more environmentally sensitive locations. As people increasingly migrate toward coastal regions, for example, hydrologists will be needed to assess building sites for potential geologic hazards and to mitigate the effects of natural hazards such as floods, landslides, and hurricanes. Hydrologists also will be needed to study hazardous-waste sites and determine the effect of pollutants on soil and ground water so that engineers can design remediation systems. Increased government regulations, such as those regarding the management of storm water, and issues related to water conservation and deteriorating coastal environments will stimulate employment growth for these workers. Demand for hydrologists who understand both the scientific and engineering aspects of waste remediation should be strong.

There are few openings for new graduates with only a bachelor’s degree in geoscience, but these graduates may have favorable opportunities in related occupations, such as high school science teacher or science technician. Other occupations related to the physical environment include: Atmospheric scientists, Biological scientists, Chemists and materials scientists, Environmental scientists and specialists, Physicists and astronomers.

Source: Bureau of Labor Statistics, U.S. Department of Labor, Occupational Outlook Handbook, 2010-11 Edition, Geoscientists and Hydrologists, on the Internet at

Leave a Reply

Your email address will not be published. Required fields are marked *

Time limit is exhausted. Please reload CAPTCHA.