Natural Hazards and Plate Tectonics Review

Comprehensive flashcards covering natural hazard definitions, map reading, Earth's mechanical and chemical layering, plate boundary types, volcanic activity, and seismic wave properties.

What is the distinction between a natural hazard and a natural disaster?

A natural hazard is a process that threatens humanity, life, and development, while a natural disaster is the occurrence of actual damage and loss of life.

What are the '4 A's' of mitigation?

Avoid (move away), Accept (recognize risk exists), Anticipate (gain knowledge), and Alter (modify the process or infrastructure).

What specific type of map is used to understand the surface of the land and its elevations?

A Topographic Map.

How do contour lines indicate the steepness of a slope?

Contour lines that are bunched together indicate a steep slope, while lines far apart indicate flat or gently sloping ground.

In coordinate systems, what line is equidistant between the North and South poles?

The Equator, which is the $0^{\circ}$ latitude line.

What is the difference between a small scale map and a large scale map?

A small scale map covers a large area with small features (zoomed out), whereas a large scale map covers a small area with large features (zoomed in).

According to the lecture, what provides internal heat energy for the Earth?

The coalescing of objects, comet impacts, and the decay of radioactive isotopes.

What isotope is used to date the Earth, and what does it decay into?

Uranium-238, which decays to lead.

What are the three chemical layers of the Earth?

The Core (metallic), the Mantle (heavy dense rock), and the Crust (thin outer skin).

Compare the composition and density of oceanic crust versus continental crust.

Oceanic crust is made of Basalt (rich in iron and denser), while continental crust is made of Granite (high in silica and less dense).

Which mechanical layer of the Earth is described as a 'soft plastic' that is ductile and can bend?

The Asthenosphere.

What are the three types of plate boundaries mentioned?

Convergent (coming together), Divergent (pulling apart), and Transform (sliding past each other horizontally).

How fast is the convergence at the East coast of Japan?

$9.1\,cm$ per year.

What is the relationship between a hot spot and the age of volcanic islands?

The islands get older as they move further away from the hot spot.

When was the last time Earth's magnetic field flipped directions?

$780,000$ years ago.

What scale of resistance to flowing defines honey compared to water?

Honey has medium viscosity while water has low viscosity.

Which volcanic substance is responsible for increasing the viscosity of magma?

Silicon Dioxide.

What are the characteristics of a Shield Volcano?

They occur at hotspots, exhibit quiet eruptions, and use low-silica basalt lava.

What are the '3 V's' required for an explosive Stratovolcano?

Viscosity, Volatiles, and Volume.

What was the 'most expensive natural disaster in U.S. History' mentioned in the notes?

The Northridge Earthquake on January 17, 1994.

What type of fault is the San Andreas fault?

A Strike-Slip fault within a transform plate boundary.

In a dip-slip fault, what is the 'hanging wall'?

The material located above the dipping fault line.

What is the difference between a Primary (P) wave and a Secondary (S) wave?

Primary waves compress and extend (longitudinal), while Secondary waves are stronger and move perpendicular to the wave direction.

How much more seismic energy is released by a magnitude 7 earthquake compared to a magnitude 6?

It takes $32$ magnitude 6 earthquakes to equal the energy of one magnitude 7 earthquake.

What is 'liquefaction' in the context of earthquake impacts?

A process that occurs when wet soils are present during shaking.