Geology Exam 4

A glacier is a _____ that forms over hundreds or thousands of years

thick ice mass

Which of the following locations does not currently have glaciers

scotland

when was the last glacial maximum

18,000 years ago

the Laurentide ice sheet is an example of _____ glaciation

continental

______ is an elevation point above which snow remains throughout the year

snowline

which crevasse will form perpendicular to the terminus as a glacier moves over a change in slope

transverse

why are the ice shelves off antarctica breaking off

global warming

arêtes, horns, and hanging valleys are evidence of ______ glaciation

alpine

_____ is an erosional method where meltwater penetrates fractures in subglacial bedrock and freezes

plucking

what shape do glacial troughs generally display

U

A _____ is a small, circular lake that occupies a cirque basin

tarn

a(n) ______ is a sharp, knife-edged ridge that forms between

arête

which part of a glacier is responsible for abrasion and plucking

basal sliding zone

how is "rock flour" formed

a glacier pulverizes rock

long narrow grooves gouged into the rock by glacial erosion are called _____

striations

_____ are stratified sands and gravels carried away from the glacial terminus by meltwater

outwash

______ is unsorted, unstratified, bimodal sediment directly deposited by the glacial ice

till

which moraine marks the furthest extent of glacial ice

terminal moraine

read the following exerpt from "The works of john playfair (1822). What glacial landform is being described?

"...For the moving of large masses of rock, the most powerful engines without doubt that nature employs are the glaciers....[Rock] fragments they gradually transport to their utmost boundaries, where a formidable wall ascertains the magnitude, and attests the force, of the great engine by which it was erected

moraine?????

lateral and medial moraines are found in connection with _____ glaciation

alpine

which of the following best explains the formation of a medial moraine on a glacier

a ridge of debris carried down the center of glacial ice

deposits of stratified sands and gravels transported from the glacial margin by meltwater are called a(n) ______ when adjacent to an ice sheet and a(n) ______ when adjacent to an alpine glacier

outwash plain; valley train

what bodies of water are formed when a stagnant block of glacial ice near the terminus becomes partly or completely buried in glacial sediments, eventually melting to create a lake

kettle lakes

which of the following scenarios can lead to the formation of a kame

sediment accumulates in a hole in the ice

which state would you not expect to contain drumlines, eskers, and kettle lakes

Tennessee

What name doe we give to large boulders that have been carried long distances by glacial ice

erratics

how does isostatic rebound affect a glacial landscape after the glacier is removed

a depressed crust rises after glacial retreat

what is a pluvial lake

a lake that fills in an arid/semiarid region due to increased precipitation in a cooler, wetter climate

which continent had the greatest area covered by glaciers at the height of the ice age

north america

which of the following is not part of the Milankovitch cycle

isostacy

traditionally, a region is defined as a desert if it receives less than _____ cm of rain per year

25

from a climatological perspective, a region is a desert if _____

yearly precipitation is less than evaporation

a true desert is defined by a lack of what substance

water

most dry lands exist between _____ degrees latitude on either side of the equator

20 and 30

which of the following statements about deserts is true

although rainfalls are infrequent, erosion and deposition related to water are more important than wind in deserts

which of the following areas is known for its rainshadow deserts

south America east of the Andes

within water-deficient regions, two climatic types are recognized. what are they

desert and steppe

deserts from in the subtropical regions as a result of _____

subsiding air masses

what is the definition of an ephemeral stream

an intermittent stream that only has water after specific episodes of rain

there are many names for ephemeral desert streams that remain empty for most of the year. which of the following is not another name for an ephemeral desert stream

playa

______ weathering is most common in a desert environment

mechanical

which of the following can contain large quantities of evaporite minerals such as borate and halite

playa

which desert location in the united states consists of alternating mountain ranges and flat-bottomed valleys as a result of fault-block mountains

basin and range province

why doesn't interior drainage, such as the drainage that develops in deserts, flow out of the desert

the water evaporates before the stream can exit the desert region

how was the salt pan at death valley created? what is the name of such a desert feature

evaporation; playa

a steep sided, flat topped desert hill is known as a(n) _____

butte

______ refers to the bouncing motion sands will display when transported by moving water or wind

saltation

which size(s) of sediment commonly make up most of winds suspended load

silt

which set of characteristics would best fit a geologically recent fault-block mountain uplift

flat upland surface, steep slopes, and small alluvial fans

which mechanical weathering process is most common in an arid environment

abrasion

what makes up the bulk of the wind-transported suspended load

silt

what process creates desert blowouts

deflation by wind

there is no one maximum depth for desert blowouts. they vary in depth depending on conditions present at the location. what controls the depth of all blowouts

elevation of water table

a(n) ______ is a smooth, polished rock that has been abraded by the wind

ventifact

what is a yardang

a wind-sculpted landform oriented parallel to the prevailing wind, often narrow at the base

the _____ was a period of drought in the 1930s in the united states that resulted in significant dust storms blowing fine sediment for hundreds of miles

dust bowl

_____ are mounds and ridges of and that are deposited by the wind

dunes

deposits of silt carried by blowing winds are referred to as _____

loess

the central united states is covered with extensive deposits of loess. where did this loess come from

weathering and erosion of western mountains

long ridges of sand that form more or less parallel to the prevailing wind where sand supplies are moderate are called ______ dunes

longitudinal

the _____ is the line that marks the contact between land and sea

shoreline

what is the fetch

a large area of open water over which wind blows to generate waves

under which conditions will a wave be considered a deepwater wave

water depth > 1/2 wavelength

when will a deepwater wave change to shallow water wave as it approaches shore

wavelength = 2 times water depth

what is the wave base

water depth equal to 1/2 the distance between successive waves

if the distance from one wave crest to the next is 10 ft., what will the depth to the wave base be

5 ft

as the quantity of energy transferred to the wave increases, what will happen to the height and the steepness of the wave

both the wave height and steepness increase

defined by breaking waves in the surf zone, which two terms describe the directions of water movement associated with a wave breaking on the beach

swash and backwash

circular orbital motion in waves will occur in ____ water

deep

which circumstance will force a wave displaying circular orbital motion to slow down at the base, which allows the wave to break

the wave feels bottom with shallower depth

abrasion will be greatest in which part of the beach environment

surf zone

what term describes the bending of waves

refraction

_____ form when waves that approach the beach at an angle and produce a net current direction that is parallel to the shore, resulting in beach drift

longshore currents

______ is a strong current formed by backwash concentrated into small channels and flows rapidly away from the beach

rip currents

which of the following will not occur as the result of longshore currents

refraction of waves

which of the following scenarios is not related to wave refraction

large quantities of sand are carried from estuaries and deposited on the seacoast side of a barrier island system

if you happen to be caught in a rip current, what is the best way to get to safety

swim parallel to the shore

why does hawaii have black sands on some beaches

the source rock being weathered is nearby basalt

a _____ is hard shoreline stabilization feature, detached from the shoreline, that protects shorelines from the pounding of waves by creating an area of quiet water behind it

breakwater

which of the following deposition/erosion scenarios will develop when a groin is constructed on the beach

deposition on upcurrent side and erosion on downcurrent side

which of the following is an artificial coastal feature

jetty

a ridge of sand that connects an island to the mainland or to another island is known as a ______

tombolo

a(n) _____ coast will be created when sea level rises or the land subsides

submergent

a(n) ______ coast will be created when sea level falls or the land is uplifted

emergent

what system of measurement is used to categorize the strength of a hurricane

saffir-simpson scale

hurricanes get their energy from _____ water

warm

what prevents hurricanes from developing in the band five degrees on either side of the equator

the Coriolis effect is too weak

the erosional retreat of a coastal cliff will lead to the enlargement of a ______

wave-cut platform

during the last glaciation, a large tongue of glacial ice occupied lake Michigan for thousands of years. Now, several thousand years after the retreat of the ice, an emergent coastline is developing along part of the lake. What geologic process is creating an emergent coastline in lake Michigan

lake levels are falling

what generates tides on the earth

gravitational attraction of the moon

The _____ explains the formation of the solar system by describing how the sun and planets formed from a rotating cloud of interstellar gases

nebular theory

an estimated 99.85% of the mass in the solar system is concentrated in ______

the sun

what is a planetesimal

rocky material accreted through repeated collisions

_____ is the speed required for an object to escape a planets gravitational force

escape velocity

orbital periods of jovian planets range from ____ to _____ years

12; 165

mercury is very hot on one side and very cold on the other side. Why might that be the case

long rotation cycle

which of the following processes created the lunar maria

large impact craters were then filled with basaltic lava flows

what is the age of the moon

4.5 billion years

the major bombardment period that shaped much of the surface of the moon ended _______

3.8 billion years ago

because of the low relative mass, the gravitational attraction on the moon is _____ that of the earth

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