Geography Chapter 12 Final Review

The oceanic crust thickness is about _____km, and the average continental crust is _____km

5km, 30km1

Which of the following gives the correct sequence of layers in the Earth, from the surface to the center?

Crust, asthenosphere, lower mantle, core

Since the core's mass is about 1/3 of Earth's entire mass, the volume of the core is also of 1/3 of the Earth's entire volume. T/F?

False

The density of material below the Moho is less than that above it. T/F?

False

The oceanic crust is less dense than the continental crust. T/F?

False

The principal of buoyancy and balance, when applied to Earth's crust, helps us to explain fluctuations in Earth's outer crust, a property known as

Isostatic adjustment

Wegener used ___ to name a supercontinent approximately 225 million years ago

Pangaea

Which of the following is not an example of an age-relationship based on absolute dating?

The Coconino formation in the Grand Canyon is older than the Kaibab formation

Which of the following statements about Earth's core is NOT true?

The inner core is believed to be liquid and the outer core is solid

Depth of earthquake focus increases with increasing distance from ocean trench. T/F?

True

Earth was once in a molten state, during which materials became sorted based on density. T/F?

True

Ocean floor subducts under continents because the ocean floor is denser than continental material. T/F?

True

The Hawaiian Islands were formed as a result of a rising plume of magma from the mantle. T/F?

True

The Moho mirrors the surface topography, i.e., high places on the surface of the Earth overlies areas in which the Moho descends to greater depths and vice versa. T/F?

True

The age of the sea floor increases with increasing distance from a mid-ocean ridge

True

The fluid outer core generates 90% of Earth's magnetic field. T/F?

True

The magnetic stripes found around mid-Atlantic ridge were due to the magnetic reversal. T/F?

True

Uniformitarianism assumes that the same physical process we see today are a key to understand the process that have been operating throughout the geologic time. T/F?

True

Which of the following is true of the asthenosphere?

all of the above

Which of the following plays a role in the shaping of Earth's surface?

all of the above

At which of the following locations does subduction occur?

along collision zones between continental and oceanic plates

List 4 evidence Wegener used to prove his hypothesis

coastal lines, fossils, rock type and mountain belt, and ancient climate

Convergent plate boundaries are characteristics of

collision zones between plates

In 1912, German geophysicist & meteorologist, Alfred Wegener first proposed the ___ hypothesis about the Earth's land mass migration.

continental drift

List 3 types of plate boundaries

divergent, convergent, transform

Which of the following lists the correct sequence of divisions in the geologic time scale, from largest to smallest?

eon, era, period, epoch

The decay rate is expressed as _______, the time required for one half of the unstable atoms in a sample to decay into "daughter" isotopes.

half-life

The youngest epoch in the geologic time scale is ________

holocene

The transportation and deposition of materials by media powered by solar energy is the

hydrolic cycle

The geologic cycle is composed of three subsystems:

hydrolic cycle, rock cycle, tectonic cycle

Three basic rock types are ___(fire-formed, molten), ___(from settling out), and ___(transformed from any other rock through extreme heat or pressure)

igneous, sedimentary, metamorphic

Knowledge of Earth's interior is derived from

indirect evidence involving the analysis of seismic waves

The Earth's dominant materials are ______ &_______

iron & silica

Earth's magnetic field

is variable, and it has phased to zero some nine times during the past 4 million years

There are two types of time which are

relative and absolute

Several large, linear lakes are formed in East Africa. This is evidence of what process?

rifting

Divergent plate boundaries are characteristics of

sea-floor spreading

When geologists or archaeologists dig downward into a unit of rock sediment, they are digging "back in time". This fact is based on the principal of

superposition

Heat energy and new materials are brought to the surface from the interior by the

tectonic cycle

Which of the following is an endogenic process?

volcanism

Which of the following are located along the mid-ocean ridge

volcanoes

Which of the following is an exogenic process?

weathering

Radioactivity dating only can be used to measure relative time. T/F?

False

Which layers of planet forms 80% of Earth's total volume, and has an average density of 4.5g/cm3?

mantle

Which of the following gives correct sequence of layers in the mantle, from bottom to top

mantle, upper mantle, asthenosphere

Two most abundant chemical elements in Earth's crust are

oxygen and silicon

The asthenosphere can be described as

plastic-like

Which of the following is incorrectly matched?

radioactive decay heat exogenic energy source