Homework 5 10 points Name: __________________
Due Date: In Lab next week Lab: M W 1 2
Review
Questions (2 points each)
2. The _Moho________
is the boundary between the crust and the mantle. Below this point, the speeds
of seismic waves __increase________
rapidly with depth.
4. P waves, or primary seismic
waves, oscillate _longitudinally________________,
or __parallel____
to the direction of transmission. The can travel through solids and liquids
alike. S wares, or secondary (shear) waves, oscillate __transversely_____
(at 90°
or
right_ angles) to the direction of
transmission. They can pass through solids only.
6. There are at least three
sources of heat for the earth's interior. One is _radioactivity__,
in which the energy of the particles emitted during decay are captured by the
surrounding rock and rapidly degraded to heat. Another is leftover heat from the
_accretion_
of solid bodies as the earth was forming (the kinetic energy of colliding bodies
such as asteroids that is turned into heat as the bodies are stopped by the
earth). A third is _gravitational__ energy created as
heavier minerals sink toward the center of the earth during the differentiation
of crust, mantle, and core.
8. The three types of plate
boundaries are _convergent___,
_divergent____,
and __transform__.
(See pages 109 ff.) At __divergent________
boundaries, such as the mid-Atlantic Ridge, the plates are moving away from each
other and new crust is being formed. At __convergent___
boundaries, plates are colliding and either crumpling up to make new mountain
ranges (such as the Himalayas) or sliding one under the other to make deep-sea
trenches and lines of volcanoes. At _transform_______
boundaries, such as the San Andreas Fault, plates are slipping laterally
(parallel to the boundary) and creating earthquakes.
10. Radioactivity can be used to
determine the age of a rock by comparing the relative amounts of _parent___
and _daughter____
substance with the half-life of the _parent_____
and the amount of the __daughter_______
that was present originally.
(everybody got two points for this one since it wasn’t clearly explained in the book)