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
