Grades 9-12 Earth Science Content Standards

"Standards without asterisks represent those that all students are expected to achieve in the course of their studies. Standards with asterisks represent those that all students should have the opportunity to learn."

Earth's Place in the Universe

1. Astronomy and planetary exploration reveal the structure, scale, and change of the solar system over time.
As a basis for understanding this concept, students know:
a. how the differences and similarities among the sun, the terrestrial planets, and the gas planets may have been established during the formation of the solar system.
b. evidence from Earth and moon rocks for the solar system's formation from a nebular cloud of dust and gas approximately 4.6 billion years ago.
c. evidence from geological studies of the Earth and other planets that the early Earth was very different from today.
d. evidence that the planets are much closer than the stars.
e. the sun is a typical star and is powered by nuclear reactions, primarily the fusion of hydrogen to form helium.
f. evidence for the dramatic effects of asteroid impacts in shaping the surface of planets and their moons, and in mass extinctions of life on Earth.
g.* evidence for the existence of planets orbiting other stars.

2. Earth-based and space-based astronomy reveals the structure, scale, and change over time of stars, galaxies and the universe.
As a basis for understanding this concept, students know:
a. the solar system is located in an outer edge of the disc-shaped Milky Way galaxy which spans 100,000 light years.
b. galaxies are made of billions of stars and form most of the visible mass of the universe.
c. evidence that all elements with an atomic number greater than that of Lithium have been formed by nuclear fusion in stars.
d. stars differ in their life cycles, and visual, radio, and X-ray telescopes collect data that reveal these differences.
e.* accelerators boost subatomic particles to energy levels that simulate conditions in the stars and in early history of the universe before stars formed.
f.* evidence that the color, brightness and evolution of a star are determined by a balance between gravitational collapse and nuclear fusion.
g.* how the red-shift from distant galaxies and the cosmic background radiation provide evidence for the "big bang" model that suggests that the universe has been expanding for 10 to 20 billion years.

Dynamic Earth Processes

3. Plate tectonics operating over geologic time has changed the patterns of land, sea, and mountains on the Earth's surface.
As the basis for understanding this concept, students know:
a. features of the ocean floor (magnetic patterns, age, and sea floor topography) provide evidence for plate tectonics.
b. the principal structures that form at the three different kinds of plate boundaries.
c. how to explain the properties of rocks based on the physical and chemical conditions in which they formed, including plate tectonic processes.
d. why and how earthquakes occur, and the scales used to measure their intensity and magnitude.
e. two kinds of volcanoes, one with violent eruptions producing steep slopes and the other with voluminous lava flows producing gentle slopes.
f.* explanation for the location and properties of volcanoes that are due to hot spots and those that are due to subduction.

Energy in the Earth System

4. Energy enters the Earth system primarily as solar radiation and eventually escapes as heat.
As a basis for understanding this concept, students know:
a. the relative amount of incoming solar energy compared with EarthÕs internal energy and the energy used by society.
b. the fate of incoming solar radiation in terms of reflection, absorption, and photosynthesis.
c. the different atmospheric gases that absorb the EarthÕs thermal radiation, and the mechanism and significance of the greenhouse effect.
d.* the different greenhouse conditions on Earth, Mars, and Venus, their origins and climatic consequences.

5. Heating of Earth's surface and atmosphere by the sun drives convection within the atmosphere and oceans, producing winds and ocean currents.
As a basis for understanding this concept, students know:
a. how differential heating of the Earth results in circulation patterns in the atmosphere and oceans that globally distribute the heat.
b. the relationship between the rotation of the Earth and the circular motion of ocean currents and air in pressure centers.
c. the origin and effects of temperature inversions.
d. properties of ocean water such as temperature and salinity can be used to explain the layered structure of the oceans, generation of horizontal and vertical ocean currents, and the geographic distribution of marine organisms.
e. the distribution of rain forests and deserts on Earth in bands at specific latitudes.
f.* the interaction of wind patterns, ocean currents, and mountain ranges that results in the global pattern of latitudinal bands of rain forests and deserts.
g.* features of the ENSO cycle (El Ni–o) in terms of sea-surface and air temperature variations across the Pacific, and some climatic results of this cycle.

6. Climate is the long term average of a region's weather and depends on many factors.
As a basis for understanding this concept, students know:
a. weather (in the short run) and climate (in the long run) involve the transfer of energy in and out of the atmosphere.
b. effects on climate of latitude, elevation, topography, as well as proximity to large bodies of water and cold or warm ocean currents.
c. how the Earth's climate has changed over time, corresponding to changes in the Earth's geography, atmospheric composition and/or other factors (solar radiation, plate movement, etc.).
d.* use of computer models to predict the effects of increasing greenhouse gases on climate for the planet as a whole and for specific regions.

Biogeochemical cycles

7. Each element on Earth moves among reservoirs in the solid Earth, oceans, atmosphere, and organisms as part of biogeochemical cycles.
As a basis for understanding this concept, students know:
a. the carbon cycle of photosynthesis and respiration, and the nitrogen cycle.
b. the global carbon cycle in terms of the different physical and chemical forms of carbon in the atmosphere, oceans, biomass, and fossil fuels, and the movement of carbon among these reservoirs.
c. movement of matter among reservoirs is driven by the Earth's internal and external sources of energy.
d.* the relative residence times and flows of carbon in and out of its different reservoirs.

Structure and Composition of the Atmosphere

8. Life has changed Earth's atmosphere and changes in the atmosphere affect conditions for life.
As a basis for understanding this concept, students know:
a. the thermal structure and chemical composition of the atmosphere.
b. how the composition of the Earth's atmosphere has evolved over geologic time including outgassing, the origin of atmospheric oxygen, and variations in carbon dioxide concentration.
c. the location of the ozone layer in the upper atmosphere, its role in absorbing ultraviolet radiation and how it varies both naturally and in response to human activities.

California Geology

9. The geology of California underlies the state's wealth of natural resources as well as its natural hazards.
As a basis for understanding this concept, students know:
a. the resources of major economic importance in California and their relation to California's geology.
b. the principal natural hazards in different California regions, and the geological basis of those hazards.
c. the importance of water to society, the origins of California's fresh water, and the relationship between supply and need.
d.* how to analyze published geologic hazard maps of California and use the map information to identify evidence of geological events of the past and predict geological changes in the future.