Geology Flashcards

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Questions and Answers

In order from closest to the surface to furthest inside Earth, what are the scientific names for the layers of Earth?

Lithosphere, asthenosphere, lower mantle, outer core, inner core

How is the lithosphere different from the crust?

The lithosphere is the crust and part of the upper mantle. The crust does not include the upper mantle.

What is the relationship between the lithosphere and the asthenosphere?

The lithosphere sits on top of the asthenosphere and is moved around via convection currents.

What is the asthenosphere made of?

The asthenosphere is made of magma, which is heated, almost melted rock. Signup and view all the answers

How do we know what the inside of Earth looks like?

We know because we can measure how seismic waves move through the interior of Earth. Signup and view all the answers

Where do seismic waves come from?

Usually from earthquakes and volcanoes, but some have been measured from the use of powerful weapons. Signup and view all the answers

What is the difference between the inner and outer core?

The inner core is a solid ball of nickel and iron; the outer core is liquid but made of the same metals. Signup and view all the answers

What are 3 ways P and S waves are different?

P waves move faster than S waves, P waves can move through fluids while S waves cannot, and P waves move in the direction of the force while S waves move perpendicular to it. Signup and view all the answers

Which piece of evidence for continental drift and plate tectonics came first?

The fit of the continents was the first and easiest observation made to suggest the continents moved from earlier positions. Signup and view all the answers

What happens at subduction zones?

At subduction zones, two plates collide and one goes under the other back into the mantle where it is melted down and recycled. Signup and view all the answers

What happens at areas of sea-floor spreading?

Seafloor spreading occurs where two plates are pulling apart under the ocean, allowing magma to come up and cool forming brand new crust. Signup and view all the answers

Why does the sea-floor show magnetic striping?

The magnetic stripes are a result of the magnetic poles changing position every few thousand years. Signup and view all the answers

What is the epicenter of an earthquake?

The epicenter is the location on Earth's surface where an earthquake is centered. Signup and view all the answers

What happens when oceanic and continental crust meet?

Oceanic crust, being denser, usually sinks below continental crust into a subduction zone. Signup and view all the answers

What is the newest continent?

Zealandia Signup and view all the answers

What are some characteristics of a continent?

A well-defined area Signup and view all the answers

What is the mantle?

The mantle (aka asthenosphere) is the area below the lithosphere, consisting of a layer of magma that is plastic and has a malleable consistency. Signup and view all the answers

What is the lithosphere?

The lithosphere is the crust and uppermost part of the mantle, making up the tectonic plates. Signup and view all the answers

What are P-waves?

P-waves (Primary Waves) move the fastest and result from compression due to the movement of plates or eruptions. Signup and view all the answers

What types of volcanoes are there?

All of the above Signup and view all the answers

What is plate tectonics?

Plate tectonics refers to the movement of Earth's plates and is supported by evidence like fossils of the same organisms found on different continents. Signup and view all the answers

What is density?

Density is the amount of mass in a given unit of volume. Signup and view all the answers

What is the crust?

The crust, in the lithosphere, along with the uppermost part of the mantle, makes up the tectonic plates. Signup and view all the answers

What is the outer core?

The outer core is liquid, composed of iron and nickel. Signup and view all the answers

What is the asthenosphere?

The asthenosphere is the area below the lithosphere, consisting of a layer of magma that is plastic. Signup and view all the answers

Study Notes

Earth's Layers

Layers of Earth from surface to center: lithosphere, asthenosphere, lower mantle, outer core, inner core.
Lithosphere includes the crust and part of the upper mantle, whereas the crust is solely the outer layer.

Lithosphere and Asthenosphere Relationship

Lithosphere floats on the asthenosphere, allowing for movement due to convection currents.
Asthenosphere consists of nearly melted rock with a plastic consistency, enabling lithospheric mobility.

Seismic Waves and Earth's Interior

Seismic waves, generated primarily by earthquakes and volcanoes, provide insights into Earth's internal structure.
Inner core is solid (nickel and iron), while outer core is liquid but composed of the same metals.

Properties of P and S Waves

P waves are faster than S waves and can travel through fluids, while S waves cannot.
P waves move in the same direction as the force, whereas S waves move perpendicular to the force direction.

Evidence for Continental Drift

Fit of continents is a key observation supporting continental drift theories, indicating prior positions of landmasses.

Plate Interactions

Subduction zones occur where two tectonic plates collide; the denser oceanic plate sinks beneath the continental plate.
Seafloor spreading happens at divergent boundaries, creating new oceanic crust from rising magma.

Magnetic Striping

Magnetic striping on the ocean floor results from periodic reversals of Earth's magnetic poles that affect new crust formation.

Earthquake Dynamics

Epicenter is the point on Earth’s surface directly above the origin of an earthquake.

Oceanic vs Continental Crust

At the convergence of oceanic and continental crust, the oceanic plate is subducted due to its higher density.

Zealandia as the Newest Continent

Zealandia is recognized as the newest continent based on geological criteria.

Definition of a Continent

A continent is characterized by distinct elevation, geology, defined area, and thicker crust than the ocean floor.

The Mantle's Role

The mantle, or asthenosphere, consists of malleable magma facilitating plate movements through convection currents.

Tectonic Plates

Lithosphere comprises the tectonic plates, integrating crust and the uppermost mantle.

Types of Volcanoes

Volcanoes vary in explosiveness; types include shield, cinder cone, and composite.
Lava classifications: pahoehoe, aa, blocky, and pillow lava.

Fossils in Plate Tectonics

Fossil evidence identifies the presence of similar organisms across continents, supporting plate tectonic theories.

Density Definition

Density represents the mass contained in a specific volume, a critical property in geological studies.

Crust Composition

The crust is a component of the lithosphere, alongside the uppermost mantle, forming tectonic plates.

Outer Core Characteristics

The outer core is a liquid layer composed of iron and nickel, contributing to Earth's magnetic field.

Summary of Properties of Asthenosphere

Also referred to as the mantle, it resides beneath the lithosphere, characterized by soft, flowing magma and convection currents that drive tectonic plate movement.

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Description

Test your knowledge of Earth's layers with these flashcards. Learn about the lithosphere, asthenosphere, and the different components that make up the Earth from its surface to its core. Perfect for geology students looking to reinforce their understanding.