Landforms Ch 3
Approximately what percentage of Earth's surface is exposed above sea level?
29 percent
The average elevation of exposed land is
875 m (2870 ft.)
Terranes refer to
displaced and migrating pieces of Earth's crust
A sudden release of energy along a fault is a
earthquake
The west coasts of north and south america are dominated by
mountain ranges
the San andreas is what kind of fault
strike- slip fault
Which of the following represents a surface feature whose relief is opposite that expected based on the fold pattern in the rocks of which it is composed?
synclinal ridge
18. Which of the following can lead to the formation of mountains? A. plate collisions and volcanic activity B. exposure of plutons by erosion of surrounding landscape C. faulting D. All of these
D. All of these
Volcanic activity located away from plate boundaries is associated with
Hotspots
When continental crust collides with continental crust
a large mountain range often forms
An orogeny is an
episode of mountain building
Vertical elevation differences in a local landscape are referred to as
relief
Which of the following is true of the magma formed from subducted ocean floor material that is eventually incorporated into continental crust? A. The composition of the magma changes from a low silica content to a higher silica content by the incorporation of sediments and other materials when it melts. B. The magma that forms in this way tends to produce more violent volcanic eruptions than magma derived directly from the aesthenosphere. C. Batholiths may form from the rising magma. D. All of these may occur. E. The composition of the magma changes from a low silica content to a higher silica content by the incorporation of sediments and other materials when it melts and The magma that forms in this way tends to produce more violent volcanic eruptions than magma derived directly from the aesthenosphere only
D. All of these may occur.
Which of the following is a cause of warping? A. mantle convection B. hot spots C. isostatic adjustment D. All of these.
D. All of these.
Which of the following is incorrect? A. The highest mountain above sea level has an elevation of 8848 m (29,028 ft.). B. The greatest ocean depth is -11,030 m (-36,198 ft.). C. The ratio of land area to ocean area is approximately 140 to 360 million km (or, 1:2.5). D. Mean sea level is at 875 m (2870 ft.).
D. Mean sea level is at 875 m (2870 ft.).
Roc layers slope downward toward the axis of a fold in a
syncline
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
24. A cinder cone is formed from relatively __________ viscosity magma with a __________ gas content.
low; high
T/F An earthquake with a high rating on the moment magnitude scale can receive a low rating on the Mercalli scale.
True
T/F Compressional forces associated with converging plates produce blocks that move upward relative to the footwall block; this is called a thrust or reverse fault.
True
T/F Felsic magma produces more violent eruptions that mafic magma.
True
T/F The Hawaiian Islands are near one end of a hot-spot track that stretches to Alaska.
True
Small areas of high strain along a fault are termed
asperities
21. Volcanic activity generally does not occur A. along sea-floor spreading centers. B. around the perimeter of the Atlantic Ocean basin. C. in association with hot spots over plumes in the mantle. D. in the circum-Pacific belt.
B. around the perimeter of the Atlantic Ocean basin.
T/F Geologically speaking, the continents began forming relatively recently
False
Which of the following is an example of a first order of relief
an ocean basin
Explosive volcanic eruptions
are most often associated with composite volcanoes
A Basin formed in a volcano flowing an eruption is a
caldera
The nucleus of old crystalline rock in each of the principal continental masses is called a
continental shield, or craton.
A fracture in a rock along which movement can occur is a
fault
At a strike-slip fault,
lateral shearing occurs
Many of the islands of Indonesia (Java, Sumatra, Borneo), which are located adjacent to a subduction zone next to the edge of the continental shelf of SE Asia, consist of felsic lava. This means that the lava which produces these islands is derived from
the melting of continental shelf material along with ocean floor material.
Fault types are defined by
the relative motion of the hanging wall and footwall
The concept of "orders of relief" refers to
the scale of features
The undulating form that gives Earth's surface its character and general configuration is called
topography
High mountains consisting of tightly folded and overthrust sedimentary rock layers, as well as metamorphic rocks, are formed
during plate collisions
The area at the surface directly above the subsurface location where seismic waves are initiated is termed the
epicenter
Domes can be formed by
up warping associated with magma movement
Which of the following statements about shield volcanoes is true? A. They occur in shield areas of Earth. B. They are subject to violently explosive eruptions. C. They form from mafic magma. D. They consist of tremendous quantities of pyroclastics.
C. They form from mafic magma.
Divisions among topographic regions are based on
arbitrary criteria regarding height or other descriptive criteria that are in common use.