Shore & Shelf

Question 1

_______ are elongate sandy islands or peninsulas that parallel the shoreline and are spearated from it by lagoons or marshes..

Answer 1

Barrier islands

Question 2

What is wave base?

Answer 2

The depth to which a passing wave will cause water motion. It is 1/2 the wave length.

Question 3

Where on a typical beach profile is the backshore?

Answer 3

The area closest to the land.

Question 4

Where on a typical beach profile is offshore?

Answer 4

The area of the shore line farthest from land (towards the open sea).

Question 5

Where in a typical beach profile might you find aeolian deposits?

Answer 5

Backshore

Question 6

Between the backshore and the shoreface, you can find the _____-shore.

Answer 6

fore

Question 7

As you go past the shoreface, in a beach profile, and before you are in the offshore area, you pass the ________________ zone.

Answer 7

Offshore transition

Question 8

Where does the storm wave base begin?

Answer 8

Offshore

Question 9

Which area of a beach profile is the wave reworking dominant?

Answer 9

shoreface

Question 10

What kind of ripples do you find in the low shoreface?

Answer 10

lenticular (mud dominant) truncated wave ripples

Question 11

Which rarely preserved bedform do you find in the foreshore?

Answer 11

swash cross-stratification, fine laminations deposited as thin flows of water run up then return down the beachface

Question 12

In the offshore transition area of a beach profile, you find wave ripples on top of what kind of base?

Answer 12

mudstone

Question 13

What kind of mudstones do you find in the offshore environment?

Answer 13

massive to laminated mudstones

Question 14

Study this tertiary diagram showing the hydrolic regimes.

Answer 14

Question 15

Describe microtidal shorelines

Answer 15

A lot of wave action. Tidal influence small. The back bay is connected to the ocean. The sand body is dominant. A barrier island like NY

Question 16

Describe a mesotidal coastline

Answer 16

Moderate tidal range. There is a marsh, small barrier islands, ebb deltas, tidal inlets. Wave action playing a significant role

Question 17

Describe a macrotidal coastline

Answer 17

Tidal dominant. Low wave energy. Lots of mud and marshes. Tidal flats, salt marshes.

Question 18

T/F: Barrier islands migrate landward and seaward with changes in sea level.

Answer 18

T

Question 19

The top of the foreshore is marked by a sandy terrace, called a ______, whose crest is just above the high water level.

Answer 19

berm

Question 20

During hurrican-force storms, the dune crest is breached in many places and waves that overtop the barrier deposit lobes or sheets of sand into the lagoon. These are called ___________________.

Answer 20

washover deposits.

They are dominated by landward dipping horizontal strata from storm washover episodes. Each layer is usually thin, forming lobate sheet.

Question 21

What are the wave dominated facies for tidal inlets?

Answer 21

sub-aerial spit, spit platform, and shallow channel

Question 22

What are the tide dominated facies for tidal inlets?

Answer 22

deep channel

Question 23

Describe the sub-aerial spit facies for tidal inlets

Answer 23

wave induced parallel lamination, dipping gently seawards or landwards

Question 24

Describe the spit platform facies for tidal inlets

Answer 24

steeply dipping avalanche foresets (30-35 degrees) underlain by ebb-oriented ripple laminations and overlain by floor-oriented ripple formations

Question 25

Describe the shallow channel for tidal inlets

Answer 25

parallel laminated sands, lo angle cross-bedding and ripple laminations

Question 26

Describe the deep channel facies for tidal inlets

Answer 26

sets of steeply-dipping (15-25 degrees) ebb-oriented planar cross beds produced by sandwave migration. Reactivation surfaces at the top of sets are occasionally overlain by smaller scale, flood-oriented cross-bedding

Question 27

Describe the channel floor facies for tidal inlets

Answer 27

gravel lag of shells and pebbles

Question 28

What is normal wave base?

Answer 28

The normal wave base, in the context of ocean waves, refers to the depth below the surface where the orbital motion of water particles caused by waves is negligible. It's essentially the depth where wave energy has little to no effect. The wave base is generally considered to be about half the wavelength of the wave.

Question 29

________ wave base refers to the depth below the surface where storm-driven waves no longer cause wave motion. It's typically deeper than fair-weather wave base, which is the depth below average daily waves. It is an important boundary in geology and sedimentology, marking the transition zone where storm-driven waves interact with the seafloor.

Answer 29

Storm

Question 30

Sediment moved landward by flood currents is deposited in a horseshoe-shaped shoal inside the inlet called a __________.

Answer 30

flood-tidal delta

Question 31

An ___________ is a sand deposit, fan-shaped and submerged, found at the seaward mouth of a tidal inlet. It forms as outflowing tides carry sediment outward and drop it, with waves also playing a role in shaping it. These features are common in areas with strong tidal currents and are dynamic, with their locations and shapes changing over time.

Answer 31

ebb-tidal delta

Question 32

What is Littoral drift?

Answer 32

Also known as longshore drift, is the movement of sediment (like sand and pebbles) along a coastline due to wave action. This process is primarily driven by waves approaching the shore at an angle, causing a zigzag movement of material along the beach

Question 33

__________ retreat refers to the landward movement of the ___________, which is the nearshore area of a coastline where sediments are actively moved by waves and currents. This retreat can occur due to various factors, including rising sea levels, coastal erosion, and changes in wave patterns.

Answer 33

Shoreface, shoreface