quiz 10 Flashcards
The desertification of the Sahel region in Africa was the result of
removal of grasses and plants from the soil
stalagmites
are composed of limestone precipitated out of cave water.
A relatively impermeable layer of rock or sediment is termed a(n) .. in hydrogeologic contexts
aquitard
Compared with humid climates, the rates of chemical weathering in deserts are …
much slower
A periodic explosive eruption of steam and water from within the ground up through the surface is termed a(n)
geyser
Hard water results from relatively high concentrations of dissolved
calcium and magnesium
Pumping vast quantities of water locally
lowers the local water table, forming a cone-shaped depression
If a material is porous. it
may be permeable or impermeable
Any place where groundwater naturally flows out of Earth’s surface is termed a(n)
spring
Physical weathering produces piles of broken rocks called …
talus or skree
A well that flows without pumping is called a(n) … well
artesian
The deserts found in the western United States are primarily the result of being located …
within rain-shadows of mountain ranges
You are performing a dye trace study in which you add some dye to a recharge area of the Norton Aquifer and monitor various wells drilled into the aquifer to watch for the dye to appear. You have determined that the effective velocity of groundwater in the Norton Aquifer is 7.5 × 10-7 m/s, and you are monitoring wells at distances of 0.5 m (Well A), 2 m (Well B), and 100 m (Well C) from the recharge area. When do you expect the dye to appear at each well site?
Well A = ~7 days, Well B = ~30 days, and Well C = ~4 years.
The water table surface mimics the topography in an area if …
groundwater flow rates are low
Mesas, buttes, and chimneys are all the result of …
cliff retreat
Material through which water readily flows is termed
permeable
Imagine you are digging a hole when the hole suddenly starts to fill with water. What have you found?
water table
An apron-shaped pile of alluvium that forms at the mouth of a canyon is known as
a(n)
alluvial fan
Which desert is the result of air masses that dry out as they cross over land?
Gobi desert
Desert climate associated with a rain-shadow is found
on the leeward side of mountain ranges
Groundwater contaminants
such as sulfur, iron, calcium carbonate, and methane may originate within rock,
sediments or mine tailings through which groundwater flows.
Hot groundwater is mineralized because
the hot water dissolves minerals
Iron-rich, well-oxidized strata will typically be
dark red
The majority of large cave and karst systems have resulted from … etching into …
carbonic acid: limestone
The Dust Bowl event in 1933 in the central US resulted from which natural event?
long-term drought
Deserts do not need to be in hot regions; they only need to be … , for example deserts can form in cold, dry … regions
arid; polar
Which of the following human activities can cause desertification?
addition of fertilizer to soil
overirrigating an area
building a city in an area
diversion of water from an area
diversion of water from an area
Why do deserts form in polar regions?
Cold air does not hold much moisture.
