True or False: Geologic hazards are simply
natural processes. They become hazards only when people try to live where these processes
occur.
True
Writings about fossils, gems,
earthquakes, and volcanoes date back to
the Greeks, more than 2300 years ago.
Certainly, the most influential Greek
philosopher was __________.
A. Plato
B. Aristotle
C. Pythagoras
D. Socrates
B. Aristotle
He published the “Theory of the Earth” in 1795. In this
work, he put forth a fundamental principle that is a pillar of
geology today: uniformitarianism.
James Hutton
In 1896, radioactivity was discovered. Using radioactivity
for dating was first attempted in _____ and
has been refined ever since.
1905
_________ means that events are placed in their proper sequence or
order without knowing their age in years.
Relative dating
These are the remains or traces of prehistoric life, and were also essential to
the development of a geologic time scale.
Fossils
The ____________ is a
dynamic mass of water that is continually
on the move, evaporating from the oceans
to the atmosphere, precipitating back to the
land, and running back to the ocean again.
hydrosphere
The global ocean is certainly the most
prominent feature of the hydrosphere,
blanketing nearly ____ percent of Earth’s
surface to an average depth of about
______ meters. It accounts
for about ___ percent of Earth’s water.
71, 3800, 97
What is the average radius of the Earth?
6371 km
What is the equatorial circumference of the Earth?
approximately 40,075 km
A ________ can be any
size group of interacting parts that form a
complex whole.
system
An ________ is a common boundary where different parts of a system come in
contact and interact.
interface
What are the two sources of energy for the Earth system?
a) Sun and Earth’s Interior
b) Wind and Water
c) Moon and Stars
d) Fire and Ice
a) Sun and Earth’s Interior
The _______ is a unit for measuring
distances to stars.
light-year
What is the age of the oldest oceanic crust and where it can be found?
180 Ma, along the western and eastern borders of the north Atlantic Ocean and in the western Pacific Ocean
These are slices of ocean crust thrust onto continental margins and, provide evidence for the existence of Precambrian oceanic crust.
Ophiolites
What is the age of the oldest continental curst and where it can be found?
4.03 Ga, Northwest Territories of Canada
The mantle constitutes
__% of Earth ’ s total volume. The mantle is distinguished from the crust by being very rich in ___________ and, to a lesser extent, in ____. It contains an average of approximately ______% SiO2 which means it has an ultramafic composition.
∼83, MgO (30 – 40%), FeO, 40 – 45
Why does the Low-Velocity Zone (LVZ) exhibit anomalously low P-wave velocity?
a) High-pressure conditions
b) Intense seismic activity
c) Presence of partial melting in small amounts
d) Increased mineral density
c) Presence of partial melting in small amounts
According to Williams and Garnero (1996), what is the proposed explanation for sporadic Ultra Low Velocity Zones (ULVZs) in the lowermost mantle?
a) Increased seismic activity
b) Presence of dense minerals
c) Formation of deep mantle plumes
d) Elevated temperature gradients
c) Formation of deep mantle plumes
According to Hutko et al. (2006), what is suggested to be responsible for the anomalously fast velocities in the D″ layer?
a) Seismic activity
b) Subducted lithosphere
c) Enhanced mantle convection
d) Presence of ultra-dense minerals
b) Subducted lithosphere
What is Earth’s largest mountain range, covering approximately 20% of the planet’s surface?
a) The Andes
b) The Himalayas
c) The oceanic ridge system
d) The Alps
c) The oceanic ridge system
What is the length and average width of the oceanic ridge system?
> 65,000 km, 1,500 km
True or False: The Mid-Atlantic Ridge has gentler slopes than the East Pacific Rise.
True
