Earth Science Flashcards
Lithosphere
The rough outer part of the earth, consisting also the upper most of the mantle.
Asthenosphere
The upper layer of the earths mantle, located below the lithosphere, plastic flow and convection is thought to occur
Core
The core is made primarily of iron and nickel and has two parts, an inner solid core and an outer liquid core
Seismic waves
waves of energy that travel through the Earth’s crust, caused by earthquakes
Continental drift
movement of the plates of the Earth’s crust in relation to each other
Pangaea
a super-continent that existed about 225 million years ago. All of the landmasses that existed at this time were joined together to form this super-continent.
Panthalassa
The vast sea surrounding the supercontinent of Pangaea
Plate tectonics
the theory concerning the movement of the continental plates
Convection current
circular movement that occurs when warmer, less dense fluid particles rise and cooler, denser fluid particles sink
Continental crust
the plates of the Earth’s crust that make up the land
Oceanic crust
one of the types of crust that makes up the Earth’s outer layer. Oceanic crust is thinner than continental crust and made up of dense, heavy rocks such as basalt.
Boundaries
the edges of tectonic plates
Subduction
process in which two tectonic plates push against each other, and oceanic crust sinks below the less dense continental crust
Destructive plate boundaries
Destructive plate boundaries: a convergent boundary where two plates collide
Hotspots
a localised place where an activity occurs
Mantle
thick layer inside the Earth, below the crust. Most of the mantle is solid rock, although the upper part is molten rock called magma.
Conservative plate boundaries
boundaries between sliding plates, like the San Andreas Fault in the United States
Laurasia
one of the two smaller continents created when the supercontinent Pangaea broke apart about 200 million years ago
Gondwanaland
one of the two smaller continents created when the supercontinent Pangaea broke apart about 200 million years ago
Tremors
vibration on the Earth’s surface caused by an earthquake
Epicentre
the point on the Earth’s centre directly above the site where an earthquake originates
Triangulation
finding a location by using at least three different sources of detection
Seismograph
an instrument used to detect and measure the intensity of an earthquake
Richter scale
a scale that measures the amount of energy released during an earthquake
P-waves or Primary waves
compression waves that move through the Earth in the same way that sound waves move through air
S-Waves
the second set of waves to be detected after P-waves. During seismic activity, secondary waves or S-waves travel in the form of transverse waves.
Body waves
waves that travel through the interior of the Earth; P-waves and S-waves are said to be body waves
Surface Waves
(or L-waves) earthquake waves which travel only through the Earth’s crust; they are responsible for the majority of an earthquake’s destructive power
Seismologists
a scientist who studies earthquakes
Meltdown
the melting of a nuclear-reactor core as a result of a serious nuclear accident
Tsunamis
a powerful ocean wave triggered by an undersea earth movement
Volcanos
natural opening in the Earth’s crust connected to areas of molten rock deep inside the crust
Magma
a very hot mixture of molten rock and gases, just below the Earth’s surface, that has come from the mantle
Lava
mixture of molten rock and gases that has reached the Earth’s surface from a volcano
Volcanic Bombs
large rock fragment that is blown out of erupting volcanoes; also known as a lava bomb
Extinct volanos
describes a volcano that has not erupted for thousands of years and is effectively dead
Active volcanos
describes a volcano that is erupting or has recently erupted
Dormant
describes a volcano that has not erupted for more than 20 years but is not considered extinct
