Physical Geology Overview

Study Notes

Geology Overview

Definition: Geology is the scientific study of Earth.
Physical Geology focuses on Earth's materials, surface and internal changes, and the driving forces behind these changes.

Resource Consumption

Average American consumption of materials:
- Nonmetals: ~8.666 kg/year
- Metals: ~147 kg/year
- Energy: 958 gallons of petroleum, 1908 kg of coal, 2775 m³ of natural gas, 0.06 kg of Uranium.

Earth as a System

Closed Systems: Permit energy exchange but not matter with surroundings.
Open Systems: Allow both energy and matter to flow in and out.

Earth Systems Components

Atmosphere

Composed mainly of nitrogen; supports life.
Divided into layers:
- Troposphere: Lowest layer where weather occurs; warms from the base.
- Stratosphere: Contains ozone layer; temperature remains constant up to 20 km, then gradually increases until 50 km.
- Mesosphere: Temperature decreases until mesopause, reaching about -90°C above 80 km.
- Thermosphere: Temperature increases due to solar radiation absorption; location of the International Space Station (330-435 km altitude).

Hydrosphere

Refers to all water on or near Earth’s surface.
Oceans cover 71% of Earth's surface; 97.5% is saltwater, 2.5% is freshwater (from glaciers, groundwater, rivers, lakes).

Ocean Geography

Northern Hemisphere: Known as the land hemisphere (61% land, 39% water).
Southern Hemisphere: Known as the water hemisphere (81% water, 19% land).
Pacific Ocean: Largest and deepest ocean; spans from Arctic to Antarctic Oceans.
Indian Ocean: Third largest, primarily in the Southern Hemisphere, bordered by Asia, Africa, Australia, and Antarctica.
Atlantic Ocean: Second largest, bordered by Europe, Africa, and the Americas.
Arctic Ocean: Smallest and shallowest, only 7% the size of the Pacific Ocean.
Antarctic Ocean: Also known as the Southern Ocean; defined by Antarctic Convergence, located around 50° south latitude.

Biosphere

Encompasses all living and once-living materials.
Earth is the only known location to support life; includes ecosystems from soil to rainforests and oceans.

Geosphere

Solid, rocky component of Earth, differentiated into Crust, Mantle, and Core.
Planetary Differentiation: Process leading to Earth's layered structure based on material density.
Lithosphere: Uppermost mantle and crust; rigid, prone to stress leading to earthquakes.
Asthenosphere: Below lithosphere, where convection occurs, extending to 660 km depth.
Mesosphere: Lower mantle, from 660 km to 2900 km depth; strengthens with depth.
Outer Core: Liquid layer from 2900 km to 5150 km; generates Earth's magnetic field via convection.
Inner Core: Solid core from 5150 km to Earth's center, composed primarily of solid iron due to immense pressure.

Layering of the Earth

Layering based on Physical Properties: Describes structure based on density.
Layering by Chemical Properties: Distinguishes layers as solid or liquid, affected by strength and state.
Crust Thickness: Ranges from 5 km to 80 km, the thinnest layer of the Earth.

Description

Explore the fascinating aspects of Physical Geology, including the Earth's materials, surface changes, and the energy resources utilized by an average American. This quiz delves into how the Earth operates as a system, differentiating between closed and open systems. Test your knowledge on the scientific study of the Earth and its components.