Earth Science 1421 Kirk (Quiz 12-14)
Subtropical deserts form generally when dry air descends from high in the atmosphere at about
20 degrees and 30 degrees latitude north, and 20 degrees and 30 degrees latitude south.
How many major Tectonic Plates are there?
7
Who argues forcefully for the idea of continental drift in the early part of the 20th century?
Alfred Wegener
Where is the world's largest ice sheet located today?
Antartica
What type of structural landscape is the state of Nevada, and parts of nearby states situated in?
Basin and Range
A sineous ridge composed of sand and gravel is ___; it is a deposit made by streams flowing within or beneath glacial ice.
Esker
T/F Alfred Wegener found that streams showed evidence of interruption or flow reversal to prove his theory of "continental drift"
F
T/F Aretes, horns, and U-shaped valleys are depositional features made of till.
F
T/F Glaciers exist only in the Northern Hemisphere
F
T/F Rock in the asthenosphere is mostly molten
F
T/F Steppes are the driest of the true desert lands.
F
Ephermal Streams
Flow in desert regions only after recent rainfall
A ____ is a thick, flowing ice mass that can occur in high mountain valleys
Glacier
Medial, Hanging, Lateral, and End. Which is not a variety of moraine?
Hanging
Thick deposits of windblown silt are known as
Loess
Basalt and granite are the most common rocks, respectively, of:
Oceanic crust and continental crust
Cross-bedding consists of many preserved _____ resulting from moving sand dunes
Slip faces
T/F Bajadas develop when multiple alluvial fans grow and merge along the fronts of mountain ranges in arid lands
T
T/F Glaciers are part of the hydrologic cycle
T
T/F In general, rocks of the continental crust are less dense than rocks of the oceanic crust
T
T/F Till is unsorted sediment deposited directly from the melting glacial ice; stream action is not invlolved
T
If accumulation exceeds ablation in a glacial budget, which of the following will happen?
The Terminus will move downhill ("advance")
3 facts about glaciers
They show evidence of flow They originate on land They form from the re-crystallization of snow
How do glaciers move?
They slide along their bottoms, over the bedrock beneath, due to basal slip. They flow internally under plastic flow.
What was finally (just recently) determined to be the mechanism by which the "slithering rocks" of Death Valley (California, not Clemson) moved across the playa?
Winds blowing across the playa at the same time thin ice sheets formed under and around the boulders, were actually pushing them around.
In an area of alpine glaciation, sharp-edged ridges called ____ and sharp, pyramid-like peaks called _____ are common features.
aretes; horns
Under typical conditions, glaciers flow
at a rate between 2 meters (6.5 feet) per year to 800 meters (2,500 feet) per year
The Correct order of the layers, based on composition, making up the Earth are, from outside to inside:
crust, mantle, outer core, inner core
The end result of deflation is
desert pavement
Boulders left behind by glaciers that are different from the underlaying bedrock, often found in till or scattered on the surface, are called
erratics
A rainshadow desert forms
in places where mountain ranges act as barriers to the movement of water vapor
The longest mountain range in the world is the
mid-oceanic ridge.
The mid-oceanic ridge was discovered and begn to be mapped by
submarines in WW2
Wegener's theory of continental drift
wan not accepted by the scientific community of the early 1900's