Natural Hazards and Plate Tectonics Flashcards

Vocabulary flashcards covering the fundamentals of natural hazards, Earth's internal structure, and plate tectonic theory based on the lecture transcript.

Natural Hazard

A naturally occurring event or process that has the potential to cause damage, injury, or loss of life.

Disaster

A hazard that causes significant damage, loss of life, or disruption to society.

Catastrophe

An extremely severe disaster with widespread destruction and long-lasting impacts.

Vulnerability

How susceptible people, buildings, or communities are to damage from a hazard.

Risk

The combination of the probability of a hazard occurring and its consequences.

Mitigation

Actions taken to reduce the impacts of natural hazards before they occur, such as building earthquake-resistant structures or land-use planning.

Magnitude

A measure of the size or strength of a natural event.

Frequency

How often a natural event occurs.

Return Period

The average amount of time between events of a given magnitude.

Compositional Layers

The classification of Earth into the crust, mantle, and core.

Lithosphere

The rigid outer layer of Earth made of the crust and uppermost mantle.

Asthenosphere

A weak, partially molten layer beneath the lithosphere that allows tectonic plates to move.

Mesosphere

The stronger lower mantle located beneath the asthenosphere.

Outer Core

A layer made of liquid iron and nickel whose movement generates Earth's magnetic field.

Inner Core

The solid center of Earth made of iron and nickel.

Differentiation

The gravity-driven process in which dense materials sank to Earth's center while lighter materials rose toward the surface.

Earth's Age

Approximately $4.6$ billion years old.

Alfred Wegener

The scientist who proposed the Continental Drift Hypothesis and the existence of the supercontinent Pangaea.

Sea-floor Spreading

The formation of new oceanic crust at mid-ocean ridges, a concept proposed by Harry Hess.

Magnetic Reversal

A reversal of Earth's magnetic field that creates symmetrical magnetic stripes in the oceanic crust.

Major Tectonic Plates

There are $7$ major plates that make up Earth's lithosphere.

Divergent Plate Boundary

A boundary where two plates move apart, forming new crust and commonly creating mid-ocean ridges or continental rift valleys.

Convergent Plate Boundary

A boundary where two plates move toward one another; it can lead to subduction where oceanic crust is destroyed.

Transform Plate Boundary

A boundary where two plates slide past one another, neither creating nor destroying crust, but often causing earthquakes.

San Andreas Fault

A prominent example of a transform plate boundary.