OSAT Earth Science (OK108) study guide
OSAT Earth Science (OK108) · Work through your exam, one topic at a time.
The OSAT Earth Science (OK108) is a subject-area certification assessment used in Oklahoma's teacher certification process for candidates who intend to teach Earth science at the secondary level. It is designed for people who already hold or are completing an educator preparation program and need to demonstrate content knowledge in the geosciences before entering or advancing in the classroom. The OSAT Earth Science (OK108) study guide has 9 sections and about 2,575 words.
01Foundations of Scientific Inquiry and Earth Science Practices
Domain 1 focuses on how Earth scientists build and test explanations: observation, hypothesis, variables, controls, measurement, models, maps, and uncertainty. Expect items that ask you to evaluate an investigation rather than recall a definition.
294 words, about 1 min02Astronomy and the Earth–Moon–Sun System
Domain 2 tests the Earth–Moon–Sun system and broader astronomy: motions, seasons, phases, eclipses, tides, solar-system structure, stars, and evidence from light. Earth rotates west-to-east once per sidereal day (23 h 56 min); the solar day is 24 h.
298 words, about 1 min03Earth Materials: Minerals, Rocks, and the Rock Cycle
Domain 3 examines minerals, the three rock classes, and the rock cycle, including how texture and composition record origin. A mineral is naturally occurring, inorganic, solid, with an ordered atomic structure and a definite but variable composition.
291 words, about 1 min04Plate Tectonics, Earth's Interior, and Structural Geology
Domain 4 connects plate motion to earthquakes, volcanoes, Earth’s layered interior, and rock deformation. Plate boundaries: divergent (extension, ridges, normal faults), convergent (compression, subduction or collision, reverse faults), transform (shear, strike-slip).
298 words, about 1 min05Surface Processes, Weathering, Erosion, and Soils
Domain 5 covers weathering, erosion, mass wasting, streams, groundwater, glaciers, wind, coasts, and soil formation. Weathering breaks rock in place; erosion transports sediment.
293 words, about 1 min06Earth History, Stratigraphy, and the Fossil Record
Domain 6 tests relative and absolute dating, stratigraphy, correlation, and the fossil record. Relative dating principles: superposition, original horizontality, lateral continuity, cross-cutting relationships, inclusions, and faunal succession.
269 words, about 1 min07Atmosphere, Weather, and Climate
Domain 7 covers atmospheric structure, weather systems, climate controls, and climate change. The atmosphere is mostly nitrogen and oxygen; water vapor, carbon dioxide, and ozone are minor but radiatively important.
274 words, about 1 min08Oceans, Hydrosphere, and the Cryosphere
Domain 8 examines ocean basins, water chemistry, circulation, waves and tides, groundwater, watersheds, and ice. Oceans cover about 71% of Earth; salinity averages about 35‰.
265 words, about 1 min09Earth Science Instruction, Assessment, and Laboratory Safety
Domain 9 focuses on planning inquiry, assessing learning, and maintaining a safe Earth science lab and field program. Inquiry lessons should be phenomenon-based, with students asking questions, planning investigations, analyzing data, and constructing explanations.
293 words, about 1 min