Introduction to Plate Tectonics: Earth's Structure and Foundations

Fill-in-the-blank practice flashcards covering Earth's internal structure, heat transfer mechanisms, seismic wave behavior, magnetic field generation, mechanical layers, and plate tectonics concepts.

Energy for change on Earth comes as heat from an external source, which is the Sun, and an internal source, which is __________ in Earth's core and mantle.

radioactive decay

Heat from radioactivity drives plate tectonics, leading to the 'roughing' of the outer surface by building oceans, mountains, continents, volcanoes, and __________.

earthquakes

__________ is defined as a measure of the average kinetic energy of the molecules that make up a substance.

Temperature

Heat energy transferred in bulk motion or flow of a fluid mass is known as __________.

convection

In this model of convection, as wax heats up near the flame, it expands and __________.

rises

When differentiated based on chemical composition, Earth's three layers from inside outward are the core, mantle, and __________.

crust

Compared to continental crust, oceanic crust is thinner and __________ dense.

more

Earth's core has a radius of approximately $3400\,\text{km}$ and is mostly composed of __________.

Iron

The deepest well drilled into Earth reaches a depth of approximately __________.

$$11\,\text{km}$$

__________ waves do not travel through liquids and are stopped at the mantle/core boundary, showing that the outer core is liquid.

S

In metallic bonds, __________ are free to roam, which generates an electrical current.

electrons

The spinning of Earth causes the metallic liquid outer core to move, creating an electrical field that generates Earth's __________.

magnetic field

In this diagram, the axis connecting the North and South Magnetic Poles is tilted by __________ from Earth's geographic axis.

$$11.5^\circ$$

The __________ is the plastic, flowable layer of the mantle upon which the lithosphere floats.

asthenosphere

Surface lithospheric plates move passively across the globe because they are dragged by convection in the __________.

asthenosphere

Earth's surface is divided into __________ major plates along with a variety of smaller ones.

seven

The Continental Drift Hypothesis proposed in the early 1910s was rejected because it lacked a sufficient __________ mechanism.

driving

At divergent boundaries, tectonic plates move apart and rising magma cools to form new __________.

lithosphere

The __________ Fault in California is a prominent example of a transform plate boundary.

San Andreas

At a convergent boundary where an oceanic plate subducts under a continental plate, the ocean floor forms a deep ocean __________.

trench

As depicted in the diagram, oceanic crust forms at a mid-oceanic ridge and its age __________ as distance from the ridge increases.

increases

The Andes mountain chain was created by collision between two __________.

plates