Chapters 22 and 23

the theory of continental drift is credited to

Alfred wegener

magnetic surveys of the ocean floors reveal

Alternating strips of normal and reversed polarity paralleling the Mid-Atlantic Ridge

seismic waves are classified as body waves and surface waves. An example of a body wave is a

Primary wave (p wave)

transform faults are areas of crustal

accommodation and plate movement

Earth's liquid and solid layers were discovered by studying the propagation of seismic waves through Earth's interior. P-waves and s-waves

all of the above

If the path of polar wandering found from two continents are not the same, then we can say that

at least one of the continents has moved

the ocean crust

becomes progressively older away from the mid-ocean ridges

body waves

come in 2 principal types; refract at EArth's boundary layers; travel through Earth's interior following an earthquake

continental crust extends farther down into the mantle than oceanic crust because

continental crust is thicker than oceanic crust

earth's layer with the most brittle layer is

crust

divergent boundaries are areas of

crustal formation

The lithosphere rides on top of the asthenosphere. Lithospheric movement causes

earthquakes, volcanic activity, and mountain building activity

which the following is not a type of tectonic plate boundary

fault plate boundary

Earth's magnetic field is attributed to the

flow of molten is hot enough to flow as a plastic solid

The core of Earth is probably composed of

iron and nickel

the mantle is composed of

iron-rich silicate rocks

motion of a p-wave is

longitudinal

Alfred Wegener supported his theory of continental drift by

making a connection between the rocks, rock structure, and plant and animal fossils found in both Africa and South America

the longest mountain chain in the world is the

mid ocean ridge

spreading centers occur along

mid ocean ridges

Because S-waves do not travel through Earth's outer core, scientists inferred that the outer core is

molten liquid

earth's magnetic field

never appreciably changes and is centered at EArth's core

when the magnetic field of earth is reversed

newly formed mineral grains on the ocean floor are magnetized according to the new orientation of the magnetic field.

secondary waves can travel through all areas of the Earth except the

outer core

We can say that Earth's crust floats on the mantle because

part of the mantle is hot enough to flow as a plastic solid

Most of Earth's seismic activity, volcanism, and mountain building occur along

plate boundaries

convergent boundaries areas of

plate collision

Rocks with an imprint of Earth's magnetic code contain

polarity, latitude of origin and the direction of the magnetic pole at the time of formation

continental crust is very buoyant compared to oceanic crust because continental crust

predominantly composted of granitic, whereas oceanic crust is composed of basaltic

the inner core is solid because

pressure from the weight of the surrounding layers prevents the inner core from melting.

The fastest seismic wave is a

primary wave

convergent boundaries are

regions of great mountain building, areas of plate subduction, and regions of plate collision

Earth's internal layers were discovered by studying

seismic waves

earthquake p waves are most like

sound waves because they are longitudinal

seismic waves are like

sounds waves, because they are longitudinal

the outer core

spins, which produces earth's magnetic field

what kind of forces act on the crust at divergent boundaries

tensional forces that stretch the crust and generate a spreading center

the theory of plate tectonics states that

the lithosphere is broken up into several plates that move about as a result of convective motion in the asthenosphere.

according to the theory of seafloor spreading, large quantities of molten rock rises up along

the mid ocean ridges

which plate subjects when oceanic and continental plates meet and why

the oceanic plate subjects beneath the continental plate because the oceanic plate is most dense

the velocity of a seismic wave depends on

the type of material it travels through

according to plate tectonic theory, the San Andreas fault is a

transform fault

the thickness of the Earth's crust

varies from about 5 km under the oceans to about 70 km under the continents

the balance of gravitational and buoyant forces acting on the crust determines its

vertical postion

Regions in which earthquakes are common are also regions in which

volcanoes are common

Wegener's theory of continental drift

was not accepted by the scientific community of Wegener's time