Definitions Flashcards
Seismic waves
A seismic wave is a type of wave that is generated by an earthquake or other seismic activity. It is a form of energy that travels through the Earth’s crust and measured by a seismograph.
Continental drift
The continental drift theory was made by a German meteorologist named Alfred Wegener. He proposed that the continents were breaking apart and rejoining in a process that he called continental drift.
Pangaea
Pangaea or Pangea was a supercontinent that existed during the late Paleozoic and early Mesozoic eras, forming 300 million years ago.
Supercontinent
A landmass made up of most or all of Earth’s land
Panthalassa
The Superocean that surrounded the supercontinent Pangaea.
Plate tectonics (aka. Tectonic plates)
Gigantic pieces of the Earth’s crust and uppermost mantle. They are made up of oceanic crust and continental crust.
Mantle
The thick layer of hot, solid rock between the Earth’s crust and the molten iron core. The mantle is the thickest layer of the Earth and is the second most outer layer.
Convection current
A convection current is a flowing fluid that moves due to a temperature or density difference within the material.
Continental crust
The continental crust is the outermost layer of the earth’s lithosphere. It forms the landmasses and the continents on Earth. It is rich in silicates and aluminum minerals.
Oceanic crust
The oceanic crust is the outermost layer of Earth’s lithosphere that is found under the oceans and formed on mid-ocean ridges. It is rich in magnesium and silicate minerals.
Ocean ridge
The ocean ridge is an underwater mountain range formed by the tectonic plates that are constantly altered and moved by the heat from the Earth’s core.
Subduction
Subduction is a geological process in which one tectonic plate moves beneath another plate and is forced to sink into the mantle. This process often leads to the formation of volcanoes, earthquakes, and mountain ranges.
Laurasia
Laurasia was a supercontinent during the Mesozoic Era, comprising most of the landmasses that now make up the Northern Hemisphere. It existed alongside another supercontinent, Gondwana, which comprised the Southern Hemisphere. Over time, Laurasia split apart into the continents of North America, Europe, and Asia.
Gondwanaland
A supercontinent believed to have formed 800 to 650 million years ago
Anticline
When compressional forces result in a bend upwards
Syncline
When compressional forces result in a bend downwards
Fault
A fault is a fracture or break in the Earth’s crust where the rock on either side has moved relative to the other. This movement can be caused by tectonic plate movement or other geological forces.
Rift valley
A rift valley is a geological formation that occurs when the Earth’s crust is pulled apart by tectonic forces, creating a long, narrow depression or valley.
Horst
A horst is a geological feature that is formed by the movement of tectonic plates. It is a raised block of land that is bounded by fault lines on either side. It is commonly found in areas of active tectonic activity, such as along the edges of continents or mountain ranges.
Slip fault
A slip fault, also known as a dip-slip fault, is a type of fault where the rock on one side of the fault plane moves vertically in relation to the other side, typically due to tension in the Earth’s crust.
Epicentre
The point on the Earth’s surface above the focus
Focus
The point inside the crust where the pressure is released.
Seismograph
An instrument that measures and records details of earthquakes, such as force and duration. It plots this data on a seismogram.
Richter scale
The strength, or magnitude of an earthquake is measured using the Richter Scale ranging from 0-10. Every
Tremor
A tremor is a small earthquake that is often caused by the movement of tectonic plates. The shaking can usually be felt by people and can sometimes cause damage to buildings and other structures.
Volcano
A volcano is a geological formation that occurs when magma, ash, and gas escape from the Earth’s crust through a vent or fissure. Volcanoes can be active, dormant, or extinct, depending on their history of eruptions. When a volcano erupts, it can release lava, ash, and other materials that can cause destruction and impact the environment.
Magma
Molten rock under the Earth’s surface
Lava
Molten rock on the Earth’s surface
Volcanic bomb
A volcanic bomb is a large rock fragment that is ejected during a volcanic explosion. These rocks can range in size from a few centimeters to several meters in diameter. They are typically made up of solidified magma or lava that has been blasted out of the volcano at high speeds.
Fold
As the plates push together, the continental crust is squashed together and forced upwards
Magnitude
In geology, magnitude refers to the intensity or strength of an earthquake. It is a measure of the seismic energy released during an earthquake, often expressed as a numerical value on the Richter scale.
Intraplate Earthquakes
Types of earthquakes the occur inside of a tectonic plate
Supercontinent
The assembly of most or all of Earth’s continental blocks or cratons to form a single large landmass.
Supercontinent
The assembly of most or all of Earth’s continental blocks or cratons to form a single large landmass.
Lithosphere
The lithosphere is the solid, outer part of Earth that includes the crust and the upper mantle.
Supercontinent
The assembly of most or all of Earth’s continental blocks or cratons to form a single large landmass.
The four pieces of evidence for continental drift
- The apparent fit of continents
- Fossil Correlation
- Rock and Mountain correlation
- Paleoclimate Data
Footwall
A foot wall in geology refers to the block of rock that lies beneath a mineral deposit. It is the opposite of the hanging wall, which is the rock block that lies above the deposit.
Seafloor spreading
Seafloor spreading is a natural process that occurs at the bottom of the ocean, where new oceanic crust is formed through volcanic activity. As the molten rock cools and solidifies, it creates new crust that pushes the older crust away from the mid-ocean ridge. This process is responsible for the continuous movement of the tectonic plates and the expansion of the ocean floor.
Syncline
A syncline is a geological feature where rock layers curve downwards in a U-shape, resembling a trough or basin. It is the opposite of an anticline, which is a geological feature where rock layers curve upwards in an arch shape. Synclines are often formed during the process of mountain building, when compressive forces cause layers of rock to fold and deform.
Anticline
An anticline is a geological formation where rock layers are folded into an arch-like shape with the oldest rocks located at the center and younger rocks on the outer edges. It is formed by compressional forces that cause the rock layers to buckle and bend upwards.
Hanging wall
A hanging wall is a block of rock that lies above an inclined fault plane or a mineral vein. It is called a hanging wall because it appears to be hanging above the footwall, which is the block of rock that lies beneath the fault plane or vein.
