(TEST 1) Earth Science, Lecture pt 1 (ch 1 and 2) Flashcards
What is Geology?
Geology is the study of the solid Earth, but it consists
of more than just studying rocks
What are some ways geologists study the Earth?
- Formation and composition of the planet
- Monitoring how the Earth evolves through time
- Locating and extracting mineral resources
- Causes/effects of natural disasters (i.e.
earthquakes, floods, landslides, etc.) - Evolution of life
- Changing of Earth’s climate through time
- Groundwater flow through the subsurface
Historically, what are the two two main branches of geology?
- Physical geology
- Historical geology
What is the new third branch of geology?
Environmental geology
What is environmental geology?
The application of geologic information to the entire spectrum of interactions between people and their physical environment
What are the two main categories of environmental problems:
- Geologic hazards
- Earth (or natural) resources
What are some renewable resources?
- Soils
- Water
What are some non-renewable resources?
- Mineral and rock
- Energy
What is tragedy of the commons?
Where the self-interest of individuals can result in the destruction of a common, or shared, resource
What are the steps of the scientific method?
- Gather data from observations or experiments
- Formulate a question
- Develop a hypothesis to explain the data/observations
- Gather new data to test hypothesis
- Analyze results to validate (or falsify) original hypothesis
When does a theory become a theory?
If a hypothesis is validated through repeated testing, then we can propose the hypothesis become a theory.
What is the geocentric theory?
Where the planets revolve around the Earth
What is the heliocentric theory?
Where the planets revolve around the Sun
When did the heliocentric theory get adopted?
15th century
What is a scientific law?
A statement that completely describes a specific phenomenon, with a mathematical equation
In what 2 ways can geologic time be described?
- Relative age dating
- Absolute age dating
What is the law of superposition?
In undisturbed sediments, the oldest rocks are found at the bottom and the youngest at the top.
How much of the Earth’s history does humans occupy?
0.05%
How is human population growing?
In a non-linear exponential behavior
What is the carrying capacity?
A population that a system can support indefinitely
What is the ecological footprint?
The supply of biologically productive land/sea area needed to support the lifestyle of humans
What is the ecological footprint of the US?
24 acres per person
What is sustainability?
Where a system or process can be maintained for an indefinite period of time
What hypothesis best explains the formation of the solar system?
Nebular hypothesis
What is the nuclear fusion of the Sun?
Hydrogen and Helium
What energy does the Sun release?
Electromagnetic radiation
What are the terrestrial planets?
Mercury, Earth, Venus, and Mars
What are the gas planets?
Jupiter, Saturn, Uranus, and Neptune
How big are comets?
1 - 10 km in diameter
What theory explains how the universe was formed?
Big Bang Theory
How old is Earth?
4.5 billion years old
What is Jupiter’s moon?
Europa
What is Saturn’s moon?
Enceladus
What is the Earth’s composition?
Crust, Mantle, Outer Core (Liquid), Inner Core (Solid)
What following 5 conditions must be met in order to be classified as a mineral?
- Be naturally occurring
- Generally Inorganic (i.e. non-biologically produced)
- Solid
- Have a definable chemical composition composed of one or more elements
- The individual atoms have an orderly arrangement in a crystalline structure
What is color in a mineral?
Part of visible light that is reflected by a mineral
What is streak in a mineral?
Color of the mineral when powdered
What is luster in a mineral?
The way a mineral surface scatters light
What is hardness in a mineral?
The ability of a mineral to resist scratching.
What is crystal habit in a mineral?
The ideal shape of minerals
What is specific gravity in a mineral?
How heavy the mineral feels
What does fracture look like?
Has no cleavage, bonding is the same in all directions
What does cleavage look like?
Mineral breaks with specific orientations in relation to the
crystal structure; various directions (3D)
Currently there are over ____ minerals on Earth
5,000
What are the most common group of minerals referred to?
Rock-forming minerals
What is the most common group of rock-forming minerals?
Silicates (contains Si and O)
What is a rock?
An aggregate or assemblage of one or more types of minerals
What are the two ways that a rock can be held together?
- Clastic texture
- Crystalline texture
What is clastic texture?
Grains are stuck together by natural cement
What is crystalline texture?
Crystals interlock with one another like pieces of a jigsaw puzzle
