Earth Mechanics Flashcards
(43 cards)
Continental Crust
Crust that defines the landmasses (continents) on Earth. Usually older and less dense than the oceanic crust.
Oceanic Crust
The crust that supports the world’s oceans. It is relatively thinner and denser than continental crust.
Mantle
The mantle is the semi-solid, thickest layer between the crust and the core. The mantle contains iron and nickel, whose flow produces the Earth’s magnetic field.
Outer Core
The outer core is the upper half of the core region and the only liquid layer, also composed of iron and nickel.
Inner Core
The inner core is the hottest layer, found at the very center of the Earth. Pressures here are so extreme that it is solid, and its temperatures reach 5200 degrees celsius, equivalent to temperatures on the surface of the sun.
Magma
Magma is molten rock located under the Earth’s surface.
Lava
Lava is the term for magma flowing on the Earth’s surface.
Molten
(adj) To be melted by heat.
Density
Density is how compact something is. It is the quantity of something per unit volume, unit area, or unit length.
Geologic Continent
There are 6 geologic continents: Africa, Eurasia, North America, South America, Antarctica, and Australia). They are not defined by country borders, language, culture, or race/ethnicity, but by geologic features.
Continental Drift
Is the process by which continents are moving across the Earth’s surface over time.
Fossil
A fossil is the remain/impression of a prehistoric creature (as of today).
Glacier
A glacier is a flowing river of ice. They are found in cold regions, such as the poles, and are responsible for weathering and carving landscapes in many places.
Ice Age
The Ice Age is a long period of time when global temperatures shift to the colder range, causing the poles to expand towards the equator.
Land Mass
A land mass is a large body of land, such as a continent.
Pangaea
Pangaea was the supercontinent (had all of today’s continents) that existed about 300 million years ago.
Supercontinent
A supercontinent (such as Pangaea) was a large continent that typically was composed of several modern-day continents.
Alfred Wegner
Alfred Wedner was a scientist who first proposed that all of Earth’s continents were once combined into a supercontinent named Pangea.
Plate Tectonics
Is the theory that Earth’s crust is divided up into large sections, called plates, that are constantly moving and interacting with each other.
Divergent Boundary
The point where two tectonic plates are moving away from each other. Earthquakes here are common, and magma rises from the Earth’s mantle to the crust, creating an oceanic crust.
Convergent Boundary
The point where two tectonic plates are colliding. Depending on the density of the plates, one might submerge beneath the other, or both will force up into a mountain range.
Transform Boundary
Points where two tectonic plates are sliding past each other. As they rub against each other, a huge amount of pressure can build up, causing earthquakes.
Seafloor Spreading
Is when tectonic plates (oceanic) spread apart from each other because of convection in the mantle. The new material comes up to fill in the gaps left behind, creating a new oceanic crust. One example of sea-floor spreading is the mid-Atlantic ridge.
Boundary
Is where two tectonic plates meet.
