Sand dunes & Coasts

Question 1

Barchan

Answer 1

Crescent shaped dune - horns point downwind

Question 2

Crescentic dune

Answer 2

Crescent shaped dune

Question 3

Deflation

Answer 3

Erosion of finer materials leaving coarser deposit

Question 4

Deflation hollow

Answer 4

Area subject to deflation, blowout, landscape depression feature

Question 5

Desert pavement

Answer 5

Large rocks left from deflation and the encrusted

Question 6

Foredune

Answer 6

Active dune developing on coast bordering present shoreline

Question 7

Gibber plain

Answer 7

A deflated hardpan surface

Question 8

Loess

Answer 8

Fine aeolian sediment sourced from glacial outwash

Question 9

Longitudinal dune

Answer 9

Linear dune forms parallel to the prevailing wind direction

Question 10

Lunette

Answer 10

Dune on fossil lake basin

Question 11

Parabolic dune

Answer 11

Crescent shaped dune, horns left upwind

Question 12

Saltation

Answer 12

Grains in intermittent contact with the ground surface

Question 13

Slip face

Answer 13

SLope of accumulation at 30-40 degrees, steeply-dipping sand beds

Question 14

Surface creep

Answer 14

Coarser grains slide/roll along the ground

Question 15

Ventifact

Answer 15

Wind-facetted rocks

Question 16

Barrier islands

Answer 16

Offshore beach parrael to shore, larger than barrier beach, vegetated and sometimes populated

Question 17

Bay barrier

Answer 17

Sand or shingle barrier across a bay, formed by littoral drift, weak currents

Question 18

Beach drift

Answer 18

Littoral drift by swash of waves running obliquely up beach and moving particles diagonal to shoreline

Question 19

Berm

Answer 19

Dry sand level of beach above high tide mark

Question 20

Geos

Answer 20

Zawns and gulches, a deeper or precipitous cleft

Question 21

Longshore drift

Answer 21

Waves arriving oblique to beach causing movement of sediment along the beach to downwind direction

Question 22

Macrotidal

Answer 22

Tidal range greater than 4 metres

Question 23

Mangroves

Answer 23

Inter tidal forest wetland of lower latitudes, equivalent habitat to intertidal salt marshes at higher latitudes

Question 24

Mean sea level

Answer 24

Average elevation between high tide and low tide

Question 25

Notches

Answer 25

Identation cut at mean sea level by hydraulic or biotic action on rock

Question 26

Plunging breaker

Answer 26

Tubular wavebreak favored by surfers, usually where offshore sea angle is steep

Question 27

Plunging steep cliffs

Answer 27

Vertical rock cliff that continues down below sea level

Question 28

Pocket beaches

Answer 28

Small beaches between bedrock outcrops

Question 29

Progrdation

Answer 29

Beach accumulation owing to good sediment supply or decreased erosive processes

Question 30

Relative sea level

Answer 30

Sea level height on a coast owing to factors such as volume of ocean water or tectonic land movement

Question 31

Retrgradation

Answer 31

Beach erosion owing to reduced sediment supply or increased erosive processes

Question 32

Rip current

Answer 32

Beach backwash focused into undertow offshore heading water movement

Question 33

Swash

Answer 33

Wave moving up the beach, onshore, while backwash is water heading back down the beach after swash

Question 34

Tombolo

Answer 34

Sand beach connection between island and mainland, caused by reduction of wave energy in lee of island

Question 35

Tsunami

Answer 35

Very long wavelength wave caused by earthquakes or undersea landslides, not related to tides or wind processes

Question 36

Wave period

Answer 36

Time interval between passage of two successive crests past a fixed point

Question 37

Wave refraction

Answer 37

Friction to wave movement causing preferential slowing of part of wave, causing change of orientation

Question 38

Wave train

Answer 38

Friction to wave movement from land causing preferential slowing of part wave, causing change of orenintation