# Which of the following is the result of aeolian deflation? a)desert pavement b)ventifact c)loess d)yardang e)dune.

## Presentation on theme: "Which of the following is the result of aeolian deflation? a)desert pavement b)ventifact c)loess d)yardang e)dune."— Presentation transcript:

Which of the following is the result of aeolian deflation? a)desert pavement b)ventifact c)loess d)yardang e)dune

Which of the following is the result of aeolian deflation? a)desert pavement b)ventifact c)loess d)yardang e)dune

The skipping and bouncing of particles transported by the wind is called _____. a)sedimentation b)compaction c)surface creep d)saltation e)infiltration

The skipping and bouncing of particles transported by the wind is called _____. a)sedimentation b)compaction c)surface creep d)saltation e)infiltration

a)underneath the dune. b)at the crest. c)on the leeward side. d)on the windward side. e)several feet in front of the windward side. The location of the slip face of a dune is best described as

a)underneath the dune. b)at the crest. c)on the leeward side. d)on the windward side. e)several feet in front of the windward side. 12.04 The location of the slip face of a dune is best described as

Choose the best description of a barchan dune. a)long, sinuous ridge-shaped dune aligned parallel with the wind b)pyramidal or star-shaped dune with three or more arms extending outward c)crescent-shaped dune with horns pointing downwind d)circular or elliptical mound with no slipface e)crescent-shaped dune with open end facing upwind

Choose the best description of a barchan dune. a)long, sinuous ridge-shaped dune aligned parallel with the wind b)pyramidal or star-shaped dune with three or more arms extending outward c)crescent-shaped dune with horns pointing downwind d)circular or elliptical mound with no slipface e)crescent-shaped dune with open end facing upwind

Choose the best description of a longitudinal dune. a)long, sinuous ridge-shaped dune aligned parallel with the wind b)pyramidal or star-shaped dune with three or more arms extending outward c)crescent-shaped dune with horns pointing downwind d)circular or elliptical mound with no slipface e)crescent-shaped dune with open end facing upwind

Choose the best description of a longitudinal dune. a)long, sinuous ridge-shaped dune aligned parallel with the wind b)pyramidal or star-shaped dune with three or more arms extending outward c)crescent-shaped dune with horns pointing downwind d)circular or elliptical mound with no slipface e)crescent-shaped dune with open end facing upwind

Oceans

Ocean Topography

Physical Structure of the Ocean

Littoral Zone

Wave Formation

Wavelength Distance from one wave crest to the next Wave height The distance between trough and crest Wave period The time taken for two crests to pass a given point (remains almost constant) = V * P The wavelength,, is the product of its velocity and period.

Wave Properties The energy source for both coastal erosion and sediment transport are the ocean waves generated by the frictional effect of the winds incident on the ocean surface (1) Kinetic Energy: The motion of the water within the wave. (2) Potential Energy: Due to the position of water above the wave trough. Wave energy increases with wind speed and fetch

Wave motion (a)Ocean depth > ½ wavelength - waves not affected by ocean floor (b) Ocean depth < ½ wavelength - wave height increases and wavelength decreases The wave becomes more peaked “Breakers” form Breaking of waves: conversion of potential to kinetic energy Work done on the shoreline

Transport of Sediments by Wave Action Rock particles are eroded from one area and deposited elsewhere. Wave refraction affects this process. Beach Drift: Swash and backwash rarely occur in exactly opposite directions Upward movement occurs at some oblique angle Backward movement occurs at right angles to the beach. This creates lateral movement of particles (beach drift)

Decrease in wavelength as waves approach a shoreline

Wave Refraction Straight shoreline -drag exerted by the ocean floor causes waves to break parallel with the shoreline. The direction of travel of a wave varies as it approaches an indented coast. Crests approaching the headlands experience the drag of the ocean floor first, which causes: 1.Increase in wave height 2.Decrease in wavelength 3.Decrease in velocity

Longshore Current and Beach Drift

Longshore Currents

Rip currents form when waves are pushed over sandbars. The weight of excess water near the shore can ‘rip’ an opening in the sandbar, causing water to rush seaward. Rip Currents Source: NOAA

Rip Current

Tidal forces Tides enhanced during full Moon and new Moon Sun-Moon-Earth closely aligned

Influence of Perigee, Apogee, Perihelion and Aphelion on the Earth’s Tides Stronger for perigee and perihelion

Annapolis Tidal Power Generating Station

Hopewell Rocks, New Brunswick “flower pot rocks”

Coastal Processes and Landforms Erosional and depositional landforms of coastal areas are the result of the action of ocean waves. Erosional LandformsDepositional landforms Sea CliffsBeaches Wave-cut NotchesBarrier Spit CavesBaymouth Bar Sea stacksLagoon Sea archesTombolo

Erosional Coastal Landforms Along rugged, high-relief, tectonically-active coastlines Sea cliffs A tall, steep rock face, formed by the undercutting action of the sea Wave-cut notches A rock recess at the foot of a sea cliff where the energy of waves is concentrated Sea Caves Caves form in more erosive sediment when the rock does not fully collapse in a deeply-notched environment

Wave-cut platform Horizontal benches in the tidal zone extending from the sea cliff out into the sea If the sea level relative to the land changes over time (becoming lower with respect to the land due to uplift), multiple wave cut platforms (terraces) result 1 3 2 5 4 6 http://www.rgs.edu.sg/events/geotrip/cliff.html

Erosional Features

Depositional Coastal Features

Littoral Drift

Barrier Spit Material transported by littoral drift deposited along ridge, extending outward from a coast in an area with weak offshore currents If the spit grows to completely block an embayment, it is called a bay barrier or baymouth bar A lagoon is a body of water behind the barrier

Puget Sound, WA

Bay Barrier

Near Eureka, CA

Coastal Straightening Figure 13.8 Copyright © 2010 Pearson Education, Inc.Christopherson, Elemental Geosystems, Sixth Edition

Frost Island, WA

A tombolo occurs when sediment deposits connect the shoreline with an offshore sea stack or island

Rebounding Coast isostatic rebound

Barrier Islands

Chandeleur Islands

Coral Reefs Coral: Marine animal in symbiotic relationship with algae Saclike body called a polyp Biodiverse, but bleaching a problem due to pollution, sedimentation, warming, and variable salinity. Figure 13.17

Coral Reef Formation and Forms

Coral Reef Formations

Coastal Salt Marsh

Mangroves

Which of the following is NOT a coastal feature that is the direct result of the erosion of waves? a)wave-cut platform b)notched cliff c)barrier spit d)sea arch e)sea cave

Which of the following is NOT a coastal feature that is the direct result of the erosion of waves? a)wave-cut platform b)notched cliff c)barrier spit d)sea arch e)sea cave

Which of the following is NOT a depositional coastal feature? a)bay barrier b)beach c)barrier spit d)sea stack e)tombolo

Which of the following is NOT a depositional coastal feature? a)bay barrier b)beach c)barrier spit d)sea stack e)tombolo

Which of the following statements about the chemical composition of seawater is false? a)Seawater that is less saline than average is called brackish. b)Seawater that is more saline than average is called brine. c)Seawater in equatorial regions is slightly higher in salinity than average. d)Seawater is generally lower in salinity near continents. e)The average salinity is 35 parts per thousand.

Which of the following statements about the chemical composition of seawater is false? a)Seawater that is less saline than average is called brackish. b)Seawater that is more saline than average is called brine. c)Seawater in equatorial regions is slightly higher in salinity than average. d)Seawater is generally lower in salinity near continents. e)The average salinity is 35 parts per thousand.

The physical structure of the ocean includes a)a warm surface zone that extends to a depth of 2.5 kilometers. b)a frozen zone that lies about 5 kilometers deep in tropical regions. c)a frozen zone that may be only 0.5 kilometers deep in polar regions. d)a zone of mixed water temperatures that extends from the surface to the ocean floor. e)a thermocline transition zone, which is a region of decreasing temperature gradient.

The physical structure of the ocean includes a)a warm surface zone that extends to a depth of 2.5 kilometers. b)a frozen zone that lies about 5 kilometers deep in tropical regions. c)a frozen zone that may be only 0.5 kilometers deep in polar regions. d)a zone of mixed water temperatures that extends from the surface to the ocean floor. e)a thermocline transition zone, which is a region of decreasing temperature gradient.

In the littoral zone, the beach (shore) zone includes a)the offshore zone. b)cliffs. c)the backshore. d)offshore bars. e)the foreshore.

In the littoral zone, the beach (shore) zone includes a)the offshore zone. b)cliffs. c)the backshore. d)offshore bars. e)the foreshore.

Spring tides occur under which of the following circumstances? a)Meltwater from snowfields lowers the salinity in estuaries. b)All latitudes experience equal day and night. c)The Sun, Moon, and Earth are positioned in a straight line. d)The Sun’s rays are directly overhead at the equator. e)The Moon is positioned 90° to Earth and the Sun.

Spring tides occur under which of the following circumstances? a)Meltwater from snowfields lowers the salinity in estuaries. b)All latitudes experience equal day and night. c)The Sun, Moon, and Earth are positioned in a straight line. d)The Sun’s rays are directly overhead at the equator. e)The Moon is positioned 90° to Earth and the Sun.

Which is responsible for concentrating wave action onto headlands? a)wave refraction b)neap tides c)rip currents d)longshore currents e)waves of transition

Which is responsible for concentrating wave action onto headlands? a)wave refraction b)neap tides c)rip currents d)longshore currents e)waves of transition

The net transport of water parallel to the shoreline that is the result of breakers striking at an angle to the beach is(are) _____. a)longshore current b)deflation c)spring tides d)waves of translation e)interference

The net transport of water parallel to the shoreline that is the result of breakers striking at an angle to the beach is(are) _____. a)longshore current b)deflation c)spring tides d)waves of translation e)interference

Coral bleaching may be the result of _____. a)the warming of sea-surface temperatures b)dumping of chemicals and pollutants on fringing reefs c)increased human recreation in coral reef areas d)the erosive action of tsunamis e)increased wave action on fringing reefs

Coral bleaching may be the result of _____. a)the warming of sea-surface temperatures b)dumping of chemicals and pollutants on fringing reefs c)increased human recreation in coral reef areas d)the erosive action of tsunamis e)increased wave action on fringing reefs

Which of the following tend to form along coastlines north of 30º N latitude in the Northern Hemisphere? a)mangrove swamps b)salt marshes c)coral reefs d)tombolos e)atolls

Which of the following tend to form along coastlines north of 30º N latitude in the Northern Hemisphere? a)mangrove swamps b)salt marshes c)coral reefs d)tombolos e)atolls

Download ppt "Which of the following is the result of aeolian deflation? a)desert pavement b)ventifact c)loess d)yardang e)dune."

Similar presentations