In the Earth System, energy and matter are exchanged by cycles, connections, between the spheres. In this activity we will explore the hydrologic (water) cycle, Wilson cycle, Milankovitch cycles, and biogeochemical cycles like the carbon, nitrogen and sulfur, and phosphorus cycles.
The Hydrologic (Water) Cycle
The hydrologic cycle involves the continuous circulation of water in the Earth-Atmosphere system. At its core, the water cycle is the motion of the water from the ground to the atmosphere and back again. Of the many processes involved in the hydrologic cycle, the most important are, evaporation, transpiration, condensation, precipitation, and runoff.
Movement of the tectonic plates through time to rift continents. This cycle initiates with a continental rift which breaks up a continent, and leads to the formation of an ocean basin between two lithospheric plates.
Milankovitch cycles are related to Earth’s place in space, sometimes referred to as the exosphere. The shape of Earth's orbit (eccentricity), angle Earth's axis is tilted with respect to Earth's orbital plane (obliquity), and the direction Earth's axis of rotation is pointed (precession).
A biogeochemical cycle is a pathway by which a chemical substance moves through biotic (biosphere) and abiotic (geosphere, atmosphere, and hydrosphere) compartments of Earth. These cycles include the carbon, nitrogen and sulfur, and phosphorus cycles.
1. Select a cycle from those listed above. Search the internet for information regarding your cycle.
a. Which spheres do you think your cycle connects?
b. How do you think this cycle is important to geology?
Figure 1.4: “The Water Cycle” (Public Domain; Howard Perlman and John Evans, USGS)
Figure 1.5: Derivative of “Rock Cycle in Wilson Cycle” (CC-BY-SA 4.0; Fabirichter via Wikimedia Commons) by Chloe Branciforte.
Figure 1.6: “Milankovitch Cycles and Their Role in Earth's Climate” (Public Domain; NASA/JPL-Caltech)
Figure 1.7: “Carbon in Deep Earth” (CC-BY-SA 4.0; Mice of Mu via Wikimedia Commons)
Figure 1.8: “Nitrogen Cycle” (Public Domain; EPA)