Geoscience Reference
In-Depth Information
6.
How do the concepts of carrying capacity and sustain-
ability relate to the issue of water use and population in
Las Vegas?
11.
Describe the general history of oil supply and demand in
the 20th century. What factors influenced gas prices, and
how has oil been traditionally extracted from the ground?
12.
Discuss the unconventional oil deposits in North Ameri-
ca. Where are they located, and how is oil extracted from
the ground at these sites? What are the various environ-
mental implications of oil recovery in these areas?
7.
Describe the process of soil salinization and how it can
occur naturally.
8.
How can agricultural practices cause soil salinization to
occur? What impact does increased soil salinity have
on crops?
13.
Describe the nature of the giant panda habitat, and how
and/or why its geographical distribution has changed
over time.
9.
In the context of soil salinization, how are the San Joa-
quin Valley and ancient Sumeria similar? Why are these
places particularly susceptible to soil salinization?
14.
What do studies of land-cover change in the late 20th
century indicate about panda habitat at the Wolong
Nature Reserve? How have these findings influenced
Chinese environmental policy?
10.
In the context of carrying capacity, why is soil saliniza-
tion in Australia an important environmental issue?
Answers to VisuAl ConCept CheCks
V i s u a l C o n C e p t C h e C k 2 0 . 1
Water in this fountain is most likely derived from Lake Mead, which is a reservoir upstream of Hoover
Dam on the Colorado River. Water in Lake Mead originates mostly as runoff from melting snow in the
Rocky Mountains, which are the headwaters of the Colorado River.
V i s u a l C o n C e p t C h e C k 2 0 . 2
The salt crust in the San Joaquin Valley formed because water tables in the basin have increased in the
past few decades from irrigation. As a result, water and salts have moved to the surface by wicking.
After the water evaporates, salts are left behind on the surface.
V i s u a l C o n C e p t C h e C k 2 0 . 3
The material shown in the photograph is bitumen, which is a semi-solid form of petroleum. It occurs
in sandy deposits, known as the Athabasca oil sands, in central Canada. Bitumen can be extracted
directly from the ground in blobs like this in open-pit mines. It can also be converted to liquid oil at
depth by injecting steam into the well.
