|

COURSE LECTURE NOTES:

| SCIENCE | MATTER | SOLAR SYSTEM | PLANETS | ATMOSPHERE | WIND and TEMPERATURE | HUMIDITY | WEATHERING | SOIL | SEASONS | MASS WASTING | SEASONS and CLIMATE | WIND WORK | STREAMS | LAND FORMS | GROUND WATER | CAVES/KARST | THE OCEAN | TIDES & ESTUARIES | WAVES | GLACIERS | GLACIAL LANDFORMS | VOLCANOES | VOLCANOES | CHON | PLATE TECHTONICS | EARTHQUAKES | ROCKS | CLIMATE CHANGE |

WAVES and WAVE WORK

Wave - the ocean in motion

Types of waves

1. Deep water


a. water must be deeper than 1/2 wave length
b. water moves up and down in a circular motion as the wave form for passes, no lateral movement.
c. created by wind action on water surface
d. size depends on:
1) wind speed - faster - stronger
2) duration of wind - longer - bigger
3) fetch (area covered by wind) -wider - bigger
e. no work done



2. Shallow water


a. wave work begins
b. water depth becomes less than 1/2 wave length
c. wave form touches bottom
d. toe/trough begins to drag and slow
e. top/crest speeds up and wave becomes taller and thiner
f. wave spills over - creats surf




e. classes of shallow water waves

1) spilling
2) breaking
3) plunging

3. rogue - Rogue waves, also known as freak waves, are relatively large and spontaneous ocean
surface waves which are a threat even to large ships and ocean liners.

Type of coast lines

1. submergent - water rises relative to land
Wave action tends to straighten a submergent coast line. 2. emergent - land rises relative to water, tends to resemble a straigntened
submergent coast line. Beach terrace - land form created by land rising relative to the water

Work done by surf/shallow water wave

1. erosion


a. direct lifting by water
b. abrasion
c. impact


erosional land forms created by waves - because of wave refraction, wave energy is concentrated
on any headlands that jut out from the shore.



i. wave-cut cliff- produced by wave action pounding away at base. Cliff recedes as upper portions fall away.
ii. sea cave - cave formed by wave attack along base of wave-cut cliff.
iii. sea arches - further wave action will eventualy cut through the cliff forming an arch.
iv. sea stacks - continued ersion and crumbling of an arch will produce a stack.




v. platform -





2. transportation


a. large stuff left on land, moved by beach drift.




b. smaller stuff carried into water and moved by off shore current

depositional landforms
a. barrier island - build up of sand off shore

long thin islands
parallel to shore
used to be sand dune
migrates toward shore
b. bay mouth bar - sand blocking off a bay




c. beach - build up of sand in protected area
d. lagoon - bay blocked off by bar
e. spit - sand building up at the mouth of a bay
f. tombolo - strip of sand conecting a barier island to the land



Result of building jetties out from shore



Home

Page Visits