EVR-1001 Lecture Notes - Lecture 6: Dissolved Organic Carbon, Water Cycle, Weathering
22 Oct 2016
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Document Summary
The transfer of water from oceans to the atmosphere to the land & back to the oceans. Driven by solar energy: evaporation of water from oceans. Consists of numerous processes that produce rocks & soils. Depends on the tectonic cycle for energy and the hydrologic cycle for water. Physical weathering (freeze, thaw) produces sediment such as gravel, sand, and silt. Chemical weathering occurs when weak acids in water dissolve chemicals from rock. The initial chemical composition and specifics of formation (temperature & pressure) determine the chemical nature of the rocks. The chemical & physical nature of the rocks in turn affects the elements released during weathering. Carbon is the element that anchors all organic substances. Carbon has a gaseous phase: enters atmosphere (co2 nad ch4) through respiration, fires & diffusion, removed from the atmosphere by photosynthesis. Carbon enters the biota through photosynthesis and then is returned by respiration or fire: when organisms die, decomposittino of their remains releases carbon.
