Cycles and interactions

Step 1 — Read the observation: Carbon remains in limestone for a long interval. Step 2 — Recall the relevant idea: A reservoir stores material within an Earth-system cycle. Step 3 — Connect the observation to the idea: The scenario is an illustration of reservoir. Step 4 — Check the limit: This short scenario illustrates the concept; it does not establish every detail or exclude every other influence in a real situation.

Step 1 — Read the observation: A river transports a measured mass of sediment each day. Step 2 — Recall the relevant idea: A flux is a rate of transfer between reservoirs. Step 3 — Connect the observation to the idea: The scenario is an illustration of flux. Step 4 — Check the limit: This short scenario illustrates the concept; it does not establish every detail or exclude every other influence in a real situation.

Step 1 — Read the observation: Ocean water evaporates and later falls as inland rain. Step 2 — Recall the relevant idea: Water moves among reservoirs through processes including evaporation, condensation, precipitation, and runoff. Step 3 — Connect the observation to the idea: The scenario is an illustration of water cycling. Step 4 — Check the limit: This short scenario illustrates the concept; it does not establish every detail or exclude every other influence in a real situation.

Step 1 — Read the observation: Plants absorb atmospheric carbon dioxide during photosynthesis. Step 2 — Recall the relevant idea: Carbon moves among air, organisms, oceans, and rocks through biological and geological processes. Step 3 — Connect the observation to the idea: The scenario is an illustration of carbon cycling. Step 4 — Check the limit: This short scenario illustrates the concept; it does not establish every detail or exclude every other influence in a real situation.

Step 1 — Read the observation: Melting ice exposes darker ground that absorbs more sunlight. Step 2 — Recall the relevant idea: A feedback occurs when a change produces effects that influence the original change. Step 3 — Connect the observation to the idea: The scenario is an illustration of feedback. Step 4 — Check the limit: This short scenario illustrates the concept; it does not establish every detail or exclude every other influence in a real situation.

Step 1 — Read the observation: Sunlight warms a surface that emits infrared radiation. Step 2 — Recall the relevant idea: Energy enters, transfers through, and leaves Earth systems rather than recycling identically to matter. Step 3 — Connect the observation to the idea: The scenario is an illustration of energy flow. Step 4 — Check the limit: This short scenario illustrates the concept; it does not establish every detail or exclude every other influence in a real situation.