Chapter 12 The Dynamic Planet
There are two types of time, which are ___ and ___
Absolute and relative
List four Earth's continental shields
African, Angaran, Indian, Brazilian, Australian, Canadian, Scandinavian, Baltic
At which of the following locations does subduction occur?
Along collision zones between continental and oceanic plates
Folded layers of rock can form a wavelike pattern of troughs and crests. The layers near the crust form
An anticline
Which of the following is an example of a first order of relief?
An ocean basin
In 1912, German geophysicist and meteorologist, Alfred Wegener first proposed the ___ hypothesis about the Earth's land mass migration.
Continental drift
A ___, or heartland region, is an old and stable part of the continental crust.
Craton
Which of the following gives the correct sequence of layers in the Earth, from the surface to the center?
Crust, asthenosphere, lower mantle, core
The area at the surface directly above the subsurface location where seismic waves are initiated is termed the
Epicenter
Radioactivity dating only can be used to measure relative time (T/F)
False
Since the core's mass is about one third of Earth's entire mass, the volume of the core is also of one third 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 moment magnitude scale is based on energy released and is less accurate than Richter's scale, which is based on the amplitude of seismic waves (T/F)
False
The oceanic crust is less dense than the continental crust (T/F)
False
When rock strata are strained beyond their ability to remain an intact unit, displacement occurs in a process known as
Faulting
The motion of seismic waves is initiated in a subsurface area along the fault plane called the
Focus, or hypocenter
Compared to oceanic crust, continental crust is
Generally more complex on content and structure
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
Volcanic activity located away from plate boundaries is associated with
Hot spots
The transportation and deposition of materials by media powered by solar energy is the
Hydrologic cycle
The geologic cycle is composed of three subsystems: ___,___, and ___
Hydrologic, rock and tectonic
Three basic rock types are ___ (fire-formed, molten), ___ (from settling out), and ___ (transformed from any other rock through extreme heat or pressure).
Igneous, sedimentary, and metamorphic
Knowledge of Earth's interior is derived from
Indirect evidence involving the analysis of seismic waves
Earth's magnetic field
Is variable, and it has phased to zero some nine times during the past 4 million years
The principle 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
Which layer of the planet forms 80% of Earth's total volume, and has an average density of 4.5g/cm3?
Mantle
Which of the following gives the correct sequence of layers in the mantle, from bottom to top?
Mantle; upper mantle; asthenosphere
People often say that California is going to "fall into the ocean". This idea is totally wrong because the San Andreas fault would have to be a ___ fault associated with ___ forces for this to happen.
Normal; Tension
Two most abundant chemical elements in Earth's crust are ___ and ___
Oxygen and silicon
Wegener used ___ to name a supercontinent approximately 225 million years ago.
Pangea
The asthenosphere can be described as
Plastic-like
Vertical elevation differences in a local landscape are referred to as
Relief
An instrument used to record vibrations in the crust is the
Seismograph
Which of the following is incorrectly matched?
Shearing- stretching
A continental ___ is a region with a craton is exposed at the surface
Shield
If you were paranoid of earthquakes, which of the following area would be the safest to live?
Shield
The Earth's dominant materials are ___ and ___
Silicon and iron
The combination eggiest of ___ (powered by internal energy) and ___ (powered by the sun through motion of air, water, and ice) create Earth's continental crust
Tectonic activity and weathering and erosion
Heat energy and new materials are brought to the surface from the interior by the
Tectonic cycle
Normal faults are associated with
Tension forces
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 solid
Which of the following is true of the earthquake in the Liaoning Province of NE China on February 4, 1975?
The quake was successfully forecasted and 3 million people were evacuated
The most detailed order of relief applies to ____ order relief features.
Third
A hypsographic curve is a graph that shows the Earth's surface by surface area and elevation in relation to sea level (T/F)
True
A residual "synclinal ridge" may form within a trough of a fold (T/F)
True
Depth of earthquake focus increases with increasing distance from the ocean trench (T/F)
True
Ocean floor subducts under continents because the ocean floor is denser than continental material (T/F)
True
Orogeny means mountain generating (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., the 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 (T/F)
True
The fluid outer core generates 90% of Earth's magnetic field (T/F)
True
The magnetic stripes found around mid-Atlantic ride were due to the magnetic reversal (T/F)
True
The mean sea level is at 0 m (T/F)
True
Uniformitarianism assumes that the same physical processes we see today are a key to understand the processes that have been operating throughout the geologic time (T/F)
True
The most active tectonic regions of North and South America are on the
Western coasts
Which of the following is incorrectly matched?
radioactive decay heat-exogenic energy source
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 centers
When geologists or archaeologists dig downward into a unit of rock or sediment, they are digging "back in time". This fact is base on the principle of
superposition
List three types of stress
tension
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
List four evidences Wegener used to prove his hypothesis
-coastal lines -fossils -rock types and mountain belts -ancient climates
List three types of play boundaries
-divergent -convergent -transform
Which of the following plays a role in the shaping of Earth's surface?
-gravity -the action of wind, water,and ice -the radioactive decay of atoms
Which of the following is true of the asthenosphere?
-it contains pockets of increased heat -it flows -it carries the lithospheric plates
The San Andreas system in California is an example of a
-strike-slip fault -transform fault -right-lateral motions
Rocks are subjected to stress due to
-tectonic forces -gravity -pressure from overlaying rocks
Approximately what percentage of Earth's surface is exposed above sea level?
29%
The oceanic crust thickness is about ___ km, and the average continental crust thickness is ___ 30 km.
5 and 30
Convergent plates boundaries are characteristics of
collision zones between plates
Which of the following lists the correct sequence of divisions in the geologic time scale, from largest to smallest?
eon,era,period,epoch
