Methods of Investigation used by Geoscientists
(Manduca and Kastens, 2012) . The processes and products that Earth scientists explore are often challenging to observe because they occur over long time periods or long in the past; they are remote - deep within the interior of Earth, at the bottom of the ocean, or on another planet, for example; or they occur over large spatial scales. To overcome these challenges, Earth scientists utilize several strategies for focusing their data collection and observations and testing their hypotheses, including:
- Comparing products of modern processes to those found in the past: Connecting the present to the past was encoded in the geosciences in the 1800's with the development of the concept of uniformitarianism. But Earth scientists go far beyond what was originally conceived by James Hutton and codified by Charles Lyell. Today, we study rocks, sediments, ice - any records we can find that record fluctuations of key parameters in the past. Examples include:
- Monitoring and measuring the behavior of modern turbidity currents and deposits to understand deep sea rocks that now host natural resources
- Developing physical models of deltas to understand ancient delta deposits
- Studying past extinction and rapid climate change events to better understand current climate change and its potential effects
- Studying geographically or temporally specific examples to deduce underlying processes: Earth scientists work with a single planet, and must develop an understanding of fundamental processes from an historical record and modern processes. As a result, time and location are critically important in determining which examples are important and interesting. Examples include
- Studying the occurrence of large earthquakes to determine the physical processes that result in the generation of tsunamis.
- Studying stratigraphic sections around the world that cross a single event, such as a mass extinction, to determine the nature and extent of the event.
- Developing multiple converging lines of inherently incomplete data: Earth scientists are very aware that the rock record provides a very limited window into the past, and multiple lines of evidence are required to test any hypotheses. As a result, collaboration is an essential component of Earth science, bringing people together with different areas of expertise. Examples include:
- Seismologists conducting an experiment to see structures at depth working with geologists who map features at the surface.
- Climate scientists working with geomorphologists to model the effects of changing rainfall patterns on the evolution of the landscape.
When testing hypotheses using these strategies, Earth scientists may collect detailed descriptions, perform experiments, develop models, and compare descriptions and results (for more information about these methods, see additional resources. The ultimate test of the hypothesis, however, is its ability to explain the observations from the natural world (Manduca and Kastens, 2012) . Those observations may take the form of descriptions of rock types or soils in the field, laboratory measurements of the age of a rock, satellite observations of ocean temperatures, etc.
Teaching the methods of investigation
The single most important thing you can do in your teaching is to be explicit in highlighting and describing the methods you are using.
Connections to big ideas, essential principles, and fundamental concepts about methods of investigation in the geoscience literacies
- Earth Science Big Idea 1. Earth scientists use repeatable observations and testable ideas to understand and explain our planet.
- Fundamental concept 1.3. Earth science investigations take many forms. Earth scientists do reproducible experiments and collect multiple lines of evidence. This evidence is taken from field, analytical, theoretical, experimental, and modeling studies.
- Fundamental concept 1.4. Earth scientists must use indirect methods to examine and understand the structure, composition, and dynamics of Earth's interior.
- Fundamental concept 1.5. Earth scientists use their understanding of the past to forecast Earth's future.
- Fundamental concept 1.6. Earth scientists construct models of Earth and its processes that best explain the available geologic evidence.
- Climate Literacy Essential Principle 5. Our understanding of the climate system is improved through observations, theoretical studies, and modeling.
- Fundamental concept B. Environmental observations are the foundation for understanding the climate system. ...
- Fundamental concept C. Observations, experiments, and theory are used to construct and refine computer models that represent the climate system and make predictions about its future behavior. Results from these models lead to better understanding of the linkages between the atmosphere-ocean system and climate conditions and inspire more observations and experiments.
- Atmospheric Science Essential Principle 6. We seek to understand the past, present, and future behavior of Earth's atmosphere through scientific observation and reasoning.
- Fundamental concept 6.1. Our understanding of Earth's atmosphere comes from analysis, interpretation, and synthesis of accurate and purposeful observations of the atmosphere, ocean, biosphere, land surface, and polar regions.
- Fundamental concept 6.2. Data about Earth's atmosphere are gathered by direct (in situ) measurement of temperature, precipitation, wind, pressure, and other variables, as well as by indirect (remote sensing) measurements taken at a distance using ground-based, satellite, and airborne instruments.
- Fundamental concept 6.3. Our understanding of Earth's atmosphere allows scientists to develop numerical (computer) models that can be used to simulate Earth's weather and climate. Such models are fundamental to modern weather analysis and forecasting and are essential to scientists' efforts to understand Earth's past climate and predict future climate.
- Fundamental concept 6.4. To generate predictions, numerical models must begin with observations of Earth's atmosphere and the planet's land and ocean surfaces. These data are used to provide starting conditions for models that are as complete as possible.
- Ocean Science Essential Principle 1. The ocean is largely unexplored.
- Fundamental concept d. New technologies, sensors, and tools are expanding our ability to explore the ocean. Ocean scientists are relying more and more on satellites, drifters, buoys, subsea observatories, and unmanned submersibles.
- Fundamental concept e. Use of mathematical models is now an essential part of ocean sciences. Models help us understand the complexity of the ocean and of its interaction with Earth's climate. They process observations and help describe the interactions among systems.
- Fundamental concept f. Ocean exploration is truly interdisciplinary. It requires close collaboration among biologists, chemists, climatologists, computer programmers, engineers, geologists, meteorologists, and physicists, and new ways of thinking.
Additional resources about the methods of science at Visionlearning
- Read more about observation and description as a method of hypothesis testing in Description in Scientific Research
- Read more about Modeling in Scientific Research
- Read more about Experimentation in Scientific Research
- Read more about Comparison in Scientific Research
- Read more about Scientists and the Scientific Community, Scientific Institutions and Societies, and The How and Why of Scientific Meetings