Shoreline Flashcards
a common boundary where different parts of a
system interact.
Interface
A group of interacting or interdependent parts that
form a complex whole
System
the area that extends between the lowest tide level
and the highest elevation on land that is affected by storm
waves
Shore
- the area exposed when the tide is out (low tide)
and submerged when the tide is in (high tide)
-region between mean high water and mean
low water marks of the tides
Foreshore
the area that extends inland from the shore as far as
ocean-related features can be found.
Coast
the area landward of the high-tide shoreline.
backshore
the line that marks the contact between land
and sea
Shoreline
– this marks the coast’s seaward edge, whereas
the inland boundary is not always obvious or easy to
determine
Coastline
the zone that lies between the low-tide
shoreline and the line where waves break at low tide
Nearshore Zone
the zone seaward of the nearshore zone.
Offshore Zone
is an accumulation of sediment found along the
landward margin of the ocean or a lake.
Beach
a ridge at the top of the beach that marks the
division between the foreshore and backshore area
Berm
wet sloping surface that extends from the
berm to he shoreline
Beach Face
the built up clasts that are washed up
the beach at the top of the foreshore, a back-beach gravel
ridge that is a distinctive feature of gravelly beaches
Beach Dune Ridge
– the low-lying areas adjacent to seas. They
are part of the continental environment where there are fluvial, alluvial or aeolian processes of sedimentation and pedogenic modification
Coastal Plain
the extensive area of beach deposits lies
directly adjacent to the coastal plain
Strand Plain
typically have relatively steep gradients where a lot of the wave energy is reflected back into the sea from
the shoreline, both bedrock and loose material may be removed from the coast and redistributed by wave, tide and current processes
Erosional Coastline or Reflective Coast
gradient is normally relatively gentle and a lot of the wave energy is dissipated in shallow water: provided that there is a supply of sediment, these dissipative coasts can be sites of accumulation of sediment
Depositional Coastline or Dissipative Coast
develop either because an area experiences uplift or as a result of a drop in sea level.
Emergent Coast
created when sea level rises or the land adjacent to the sea subsides
Submergent Coast
are energy traveling along the interface between ocean and atmosphere, often transferring energy from
a storm far out at sea over distances of several thousand kilometers
Ocean Waves
– the top of a wave.
Crest
separates two crests
Trough
halfway between crest and trough
Still Water Level
vertical distance between crest and trough
Wave Height
horizontal distance between successive crest
Wave Length
The time it takes one full wave (one wavelength) to pass a fixed position
Wave Period
when critical point is reached where waves grow
so tall that they topple over, forming ocean breakers
White Caps
waves that are lower in height and longer in length and may carry thestorm’s energy to distant shores
Swell
movement of waves as the water passes the energy
along by moving in circle
Circular Orbital Motion
depth equal to one half the wavelength measured from still water level
Wave Base
turbulent water created by breaking waves
Surf
when turbulent sheet of water from collapsing breaks moves up the slope of the beach.
Swash
when water flows back down the beach towards the surf zone when the energy of the swash has been expended
Backwash
the impact of waves as it crashes along the shorelines
Wave Impact
The sawing and grinding action of water armed with rock fragments
Abrasion
-net loss or addition of sand depends on the wave activity
-mostly done by the swash and backwash action of
waves
Movement Perpendicular to the Shoreline
bending of waves
-As most waves travel to shore at an angle, they are bent when they reach the shallow water of a smoothly sloping bottom and tends to move parallel to the shore.
Wave Refraction
when the movement of water transporting sediments is in a zigzag pattern along the beach face.
Beach Drift
currents that flows parallel to the shore
Longshore Current
unconfined flow across the ocean bottom where backwash flows back to the open ocean
Sheet Flow
concentrated movements of water that flow in the opposite direction from breaking waves
Rip Current
cliffs formed due to the cutting action of the surf against the base of coastal land
Wave Cliffs
a relatively flat, bench like surface
Wave Platform
wave-cut platforms uplifted by tectonic forces
Marine Terrace
ridges separating the valleys remain above sea level and project into the sea
Headland
when two caves on opposite sides of a headland unite
Sea Arch
isolated remnants formed when sea arch falls in
Sea Stack
formed due to the further weathering of sea stack
Sea Stump
an elongated ridge of sand that projects from the land into the mouth of an adjacent bay
Spit
– sandbar that completely crosses a bay, sealing it off from
the open ocean
Baymouth Bar
ridge of sand that connects an island to the mainland or to another island
Tombolo
barrier of sediments that separates a lagoon from the open sea
Barrier
barrier that is partially attached to a land.
Barrier Spit
– barrier the is wholly attached to a land
Welded Barrier
isolated barrier
Barrier island
are daily changes in the elevation of the ocean
surface.
Tide
occurs when the sun and the moon are aligned causing larger tidal bulges (higher high tides) and deeper tidal troughs (lower low tides), thus, producing a large tidal range
Spring Tide
horizontal flow of water accompanying the rise and fall of the tide
Tidal Current
tidal currents that advance into the coastal
zone as the tide rises.
Flood Current
periods of little to no current
Slack Water
occurs when the gravitational pull of the sun and moon
acts upon earth at a right angle therefore they partially offsets the gravitational forces of each other
producing less tidal range
Neap Tide
tidal current generated by seaward-moving
water as the falls.
Ebb Current
area affected by alternating tidal currents
Tidal Flats
– formed at the landward inlet
Flood Delta
deltas created by tidal currents
Tidal Delta
formed at the seaward side of an inlet
Ebb Delta
wave action can maintain a barrier system that can be more or less continuous for tens of kilometres.
Microtidal
With the increased tidal range of _____ conditions, more exchange of water between the lagoon and the sea is required, resulting in more inlets forming, breaking up the barrier into a series of islands
Mesotidal
Coasts that have high tidal ranges do not develop barrier systems because the ebb and flood tidal currents are a stronger control on the distribution of sediment than wave action
Macrotidal
measure of the depth of water in oceans seas or lakes, the shape and depth of the sea floor
Bathymetry
Very level area of the deep ocean floor, usually lying at the foot of the continental rise
Abyssal Plain
ocean margins the transition from ocean crust to continental crust
Continental Rise
lower and upper parts of the bathymetric profile
from the deep ocean to the shelf. Relatively steep,
usually between about 2° and 7°
Continental Slope
- junction between the shelf and the slope
usually occurs at about 200m below sea level at present-day margins
Shelf Edge Break
large areas of continental crust that are covered by seawater, which are mainly bordered by land masses and connected by straits to the oceans
Epicontinental Seas (epeiric seas)
shelf area, down to 200m water depth
Neritic Zone
corresponds to the continental slope and extends from 200m to 2000m water depth
Bathyal Zone
ocean floor below 2000m. (can also be
applied to up to 5000m)
Abyssal Zone
deepest parts of the oceans
Hadal Zone
beach environment
Littoral Zone
defined as the region of the shelf between the low-tide mark depth to which waves normally affect the sea bottom.
Shoreface
depth to which waves normally affect the sea bottom
Fair Weather Wave Base
higher energy waves generated by storms that
affect the sea bed
Storm Weather Wave Base
deeper shelf area between the fair weather
and storm wave bases
Offshore Transition Zone
region below storm wave base and extends out to
the shelf-edge break at around 200m depth
Offshore Zone
water that is closest to the moon experiences the largest gravitational attraction and this creates a bulge of water
Tidal Bulge
any point on the surface the level of the water will rise and fall twice a day as the two bulges are passed in each rotation.
Diurnal Tide
a point on the Earth will pass under one high bulge and a slightly lower bulge 12 hours or so later
Diurnal Tide Inequality
sun and moon are in line with the earth
Syzygy
during the four weeks of the moon’s orbit, it is twice in line and twice perpendicular
Near-Spring Tidal Cycles
occurring when the three bodies are in line. The highest tidal range; occurs near the times of the new and full moons.
Spring Tide
The lowest tidal range, occurring near the times of
the first and third quarters of the Moon
Neap Tide
- caused by the elliptical nature of the earth’s orbit
around the sun. At the spring (vernal) and autumn (Fall) equinoxes, the Earth is closest to the Sun and the
gravitational effect is strongest.
Annual Tidal Cycle
point of zero amplitude of one harmonic constituent of the tide
Amphidromic Cell
rotational pattern of the tidal wave within amphidromic cells results in a flow of water that follows a circular or elliptical pattern
Rotary Tide
seen in a single vertical section produced by alternating directions of migration of ripples or dunes under favourable circumstances.
• results from a tidal current flowing predominantly in one direction for a period of time, probably many years, followed by a change in the pattern of tidal flow that results in another period of opposite flow
Herringbone or Bipolar Cross Stratification
seen in a single vertical section produced by alternating directions of migration of ripples or dunes under favourable circumstances.
• results from a tidal current flowing predominantly in one direction for a period of time, probably many years, followed by a change in the pattern of tidal flow that results in another period of opposite flow
Mud Drapes
there is one dominant direction of tidal current the bedforms migrate in that direction producing unidirectional cross-stratification.
• bedforms can be modified by the reverse current, principally by the removal of the crest of a subaqueous dune.
• When the bedform recommences migration in the direction of the dominant flow the cross-strata build out from the eroded surface. This leaves a minor erosion
surface within the cross- stratification.
Reactivation Surface
associated strong surface winds, typically in excess
of 100km, and may affect both land and marine environments
Storm
Japanese for ‘harbour wave’ and refers to waves with periods of 103 to 104 seconds that are generated by
events such as subsea earthquakes, large volcanic eruptions and submarine landslides
Tsunami
currents that are driven by contrasts in temperature and/or salinity
Thermo Haline Current
wind-driven currents related to the global wind systems, which result from differences in air mass
temperatures combined with the Coriolis force
Geostrophic Current
a dark green mineral that is found quite commonly in
marine sediments. Potassium-rich mica
Glauconite
material made up of any of these distinctive, medium to
dark green minerals.
Glaucony
sedimentary rocks that are enriched in phosphorus to a level where the bulk composition is over 15% P2O5
Phosphorite
mudrock that typically contains 1–15% organic
carbon
Black Shale
are evidence of the activity of organism
Trace Fossil
tracks of walking animals, trails of worms, burrows of
molluscs and crustaceans
Ichnofauna
formed in
a. soft sediment
b. hard substrate
a. Burrows
b. Boring
smaller vertical tubes in sands
Skolithos
crawling trail produced by a multilimbed organism. Provides very strong evidence that trilobites formed these features.
Cruziana
Ichnofossil
a. resting traces
b. feeding traces
c. grazing traces
d. crawling, tracks and trails
e. dwelling structures, burrows
a. Cubichnia
b. Fodinichnia
c. Passichnia
d. Repichnia
e. Domichnia
formed by organisms moving up to the surface, are common in settings where there is rapid sedimentation
by storms or turbidity currents
Escape Burrows
Assemblages
a. Littoral Zone
b. Shelf
c. Bathyal Zone
d. Abyssal Zone
a. Skolithos
b. Cruziana
c. Zoophycos
d. Nereites
Evidence of organisms disturbing sediment
Biotur
Scale of Bioturbation Intensity
a. between 30% and 60%
b. a few discrete traces
c. less than 30%
d. over 90%
e. totally reworked
f. between 60% and 90%
a. Grade 3
b. Grade 1
c. Grade 2
d. Grade 4
e. Grade 6
f. Grade 5
(a) forms if the rate of sedimentation is relatively slow
and a firmground forms (b)
(c) forms at even slower rates of sedimentation complete lithification of the sea floor occurs (d)
a. Firmground
b. Glossifungites
c. Hardground
d. Trypanites
shallow region of high biogenic productivity
Carbonate Factory
fundamental controlling factor in the formation of evaporite deposits
Climate
if the platform is attached to a continental mass
Carbonate Shelf
formed above a subsiding volcano island
Carbonate Atoll
with gentle slope (<1⁰) down deep water with no break in slope
Carbonate Ramp
Flat-topped with a sharp change in slope at the edge forming a steep margin
Rimmed or Nonrimmed Shelf
are coastal bodies of water that have very limited connection to the open ocean only through a channel to the sea or via seepage through a barrier.
Lagoons
an area of hypersaline shallow water that
precipitates evaporate minerals.
Saltern
are sites of fine-grained sedimentation forming
layers of carbonate mudstone and wackestone with
some grainstone and packstone beds deposited as
washovers near the beach barrier.
Carbonate lagoons
lies above the mean high water mark and is
only inundated by seawater under exceptional circumstances, such as very high tides and storm conditions
Supratidal Zone
Arid Coast
Subkha
are carbonate bodies built up mainly by framework- building benthic organisms such as corals
Reef
carbonate build-ups that form
a. dome-shaped reefs
b. tabular shaped reed
a. Bioherms
b. Biostromes
Low energy areas shelfward of the reef flat zone, where fine sediments winnowed from the reef settle out.
Back Reef
Very shallow-water surface immediately shelfward of the reef crest.
Reef Crest
Extends from the surf zone into deeper water (<100m) where growth of massive corals grades into sediments of the fore reef zone.
Reef Front
Little or no light penetration
Fore-Reef
are linear reef forms that parallel the shoreline, but lie at a distance of kilometres to tens of kilometres offshore: they create a back-reef lagoon area which is a
large area of shallow, low-energy sea
Barrier Reef
are built out directly from the shoreline and lack an
extensive back-reef lagoonal area
Fringing Reef
localised build-ups in shallow water areas such as
epicontinental seas, carbonate platforms and lagoons.
Patch Reef
is a sediment body consisting of structureless or crudely bedded fine
crystalline carbonate.
Carbonate Mud Mounds
are distinguished from lagoons in that they are basins
capable of accumulating hundreds of metres of evaporite sediment
Barred basin
setting exists where a basin is well below sea level
but is only partly filled with evaporating seawater, which is periodically replenished.
shallow-water to deep-basin
setting is one in which evaporites are deposited in salterns but continued subsidence of the basin allows a thick succession to be built up.
shallow-water to shallow-basin
is a basin filled with hypersaline water in which
evaporite sediments are formed at the shallow margins and are redeposited by gravity flows into deeper parts of the basin. Normally graded beds generated by turbidites and poorly sorted deposits resulting from debris flows are evidence of redeposition
deep-water to deep-basin setting
If the barred basin is completely enclosed the
water body will gradually shrink in volume and area. Most soluble salts in the basin center
Bullseye Pattern
- If equilibrium is reached between the inflow and the
evaporative loss then stable conditions will exist across the basin and tens to hundreds of metres of a single mineral can be deposited in one place
Teardrop Pattern
Poorly-sorted, clast-rich, muddy deposits, where the
clast are transported down slope.
- Rock types are matrix-rich conglomerates
Debris Flow Deposit
Are the most important process for transporting sand
to deep sea;
Turbidity Currents
This is fine-grained material derived from the
platform and resedimented by suspension into the
slope and basinal environment.
Hemipelagic Carbonate
Sediments is deposited by slow suspension of
material biochemically produced in surface waters
Pelagic Carbonate
These deposits can originate from the reef, reef wall, or lower on the slope
Slump Deposit
Sand is transported down steeps slopes by dispersive pressure.
- Grain-to-grain interaction
Grain Flow Deposit
