Exam 4 Flashcards
The ice age that started 2 million years ago is the
Pleistocene
All are factors in the Milankovitch theory except
The speed of Earths rotation
The last glacial maximum occurred
20,000 years ago
Many deserts lie at 30o S and N latitude because
Sinking air warms up and the ground is dry because of high evaporation.
Rain shadow deserts
Form on the leeward side
Desert stream bed that is dry most of the year
Wash
Salt deposits are found on desert lakes because
Dissolved ions precipitate during evaporation
Desert pavement forms because
Wind selectively removes sand and silt and leaves large particles behind.
During the last glaciation
Sea level dropped by 130m
Dune can be found at
Beaches, deserts, and glacial environments.
Loess is
silt that has been transported and deposited by wind.
Human mismanagement can cause the conversion of semiarid land to arid land in the process called
desertification
Oceanic crust is - than continental crust and therefore - isostatically.
denser, sinks
The abyssal plains of the ocean basins are about - deep
5 km
a magnetometer could be used to
determine the orientation of the Earth’s magnetic field at the time the rock cooled.
Moving away from the mid ocean ridges, oceanic crust
becomes older, sinks, and forms the abyssal plains.
During times of very fast sea floor spreading,
high volume spreading ridges cause sea level rise.
Hydrothermal vents at mid ocean ridge systems, where metal and sulfide rich water escapes
black smokers
If a series of island arcs collide with a continent over a long period of time they add to a continent as
Accreted terranes
An oceanic island
is a volcano that rises above sea level
Ocean floor sediment thickness
is minimal at the mid ocean ridge system
Most of the sediment deposited in the deep ocean environment consists of
Oozes and pelagic clay
The area labeled X is the
continental slope
An active continental margin commonly has a much narrower continental shelf and a considerably steeper continental slope than does a passive margin because
the subducting plate pulls down the continental plate, forming a steep-sided trench.
the world’s largest and deepest ocean is the - Ocean
Pacific
Surface salinity at the equator is
lower than average
The halocline
the zone of the ocean where salinity drops rapidly with depth
warm water is - than cold water, and salty water is - than less salty water
less dense, denser
A neap tide is
smaller tide formed from when the sun and moon are 90 out of alignment
The size of wind generated waves depends on
wind speed, length of time the wind has been blowing, fetch.
The wave height is
the vertical distance between the crest and the trough of a wave.
Ocean currents
Are continuous flows of water in a particular direction.
Due to the Coriolis effect,
currents tin the Southern Hemisphere are deflected to the Left.
If waves strike shore at an angle, they - and create a - current that flows parallel to the beach.
refract, longshore
The first organisms producing oxygen through photosynthesis were
cyanobacteria
Banded iron formations formed by
precipitation of iron oxides out of ocean water due to an increase in oxygen levels in the water
The earth’s modern atmosphere
contains 78% nitrogen
Standard pressure at sea level is
1013 mbar
Which of the following orders of the layers of the atmosphere is correct?
troposphere, stratosphere, mesosphere, thermosphere
Smog is produced
when sunlight reacts with automobile exhaust
