Big Idea 1: The Earth is a system of systems

The Earth is composed of many systems, which cycle and interact in both space and time. It is also part of a multitude of systems, nested in larger systems such as the solar system and the universe. Systems are composed of an untold number of interacting parts that follow simple rules; they can and do evolve. For example:

Outlining the geologic history of any region demonstrates the concept of the Earth as a system of systems. Plate tectonics drives the formation of mountains. Subsequent weathering and erosion of the uplifted mountains leads to the formation of deltas in the adjacent shallow seas. And with uplifted continents, shorelines change and the distribution of marine communities are altered. The Mississippi River has moved a tremendous mass of sediment, generated from erosion and glacial outwash, from the interior of North America into the Gulf of Mexico. This flow of sediment has contributed to the formation of the Coastal Plain region, and continues to alter the coastline of Louisiana today.

The planet’s systems are intimately connected: the forces of one system affect other systems nested within it. As plates collide, systems that drive plate tectonics are obviously linked to the formation of mountains, but they are ultimately linked to and influence much smaller systems. The intense heat and pressure resulting from collisions can lead to the metamorphism of existing strata, or it can melt existing rocks to later form igneous rocks.

See Chapter 4: Topography for more information about the Mississippi River and its alluvial plain.

Each of the remaining ideas operates across multiple systems within the larger Earth system.