Geo Test 4

Which is true? Corals like cool water Corals like muddy water Corals partner with lichens. Corals live in a symbiotic relationship with algae, which photosynthesize and provide nutrition to the algae. Corals do not contribute anything to algae: they are parasitic

Corals live in a symbiotic relationship with algae, which photosynthesize and provide nutrition to the algae.

As a volcano subsides (submerges under water), coral reefs grow upward.

True

Changes in continental configuration, which change the pattern of ocean currents when they allow much more cold water to reach northern Europe.

True

Depositional coasts are often on the trailing edge of a continent, where there is gentle relief and sediments from many sources are available.

True

In general, oceanic carbon dioxide is higher during an ice age, while atmospheric carbon dioxide is lower.

True

It is possible that desert pavement is formed when windblown sediments are deposited between rocks, then washed downward, while the rocks are displaced upward.

True

Mountain-building events, such as the rise of the Tibetan Plateau, can change weather patterns and increase the amount of permanent snow on the planet.

True

Ripples form at right angles to the wind direction

True

Sediment gets from rivers to beaches through the work of the longshore current.

True

Three sources of sediment to beaches are streams, rocky landforms, and the seafloor.

True

Glaciers can transport rocks and sediments on their surface.

True,

A crevasse is a type of glacier.

False, A glacier can develop vertical cracks known as crevasses.

Dolphins herd fish to land to capture them.

Red note

Carolina bays: swarms of oval-shaped depressions in Georgia formed from deflation during the last ice age.

...

Lichens also release mild acids that can help decompose the rock

Red notes

Which is FALSE? Waves in shallow water are refracted, going slower than waves in deeper waters, making them run parallel to the coast. A current running parallel to the coast is called a tracking current Longshore drift is sand, gravel, sediment and debris that is moved by the longshore current and waves.

A current running parallel to the coast is called a tracking current(Longshore current makes this correct)

Which is FALSE? The accumulation area of a glacier ends at the snow line, which is where the winter snow and ice accumulation survive the summer. A glacier grows larger during dry, cold periods. A glacier retreats when the summer melt area occurs farther uphill

A glacier grows larger during dry, cold periods.

Which is TRUE about wave-cut platforms? They are composed of sand They are vertical benches at the base of some seacliffs A series of wave-cut platforms can form a stair-step pattern on emergent coasts due to subsidence They are eroded by animals, abrasion and salt crystallization

A series of wave-cut platforms can form a stair-step pattern on emergent coasts due to subsidence They are eroded by animals, abrasion and salt crystallization

Which is FALSE? When a glacier lurches forward, it is called a glacial surge. Glacial surges can occur when water builds up under the glacier Glacial surges can occur when soft beds develop under them A soft bed is a layer of saturated clay that is caused by a glacier crossing a river.

A soft bed is a layer of saturated clay that is caused by a glacier crossing a river.(soft bed - a muddy layer under the glacier - can form as water enters the dirt under a glacier, and the mud can enable the glacier to surge.)

Which are NOT the correct terms for the definitions given? Glacial drift: the general term for all glacial deposits Till: deposits that are not sorted or stratified by size in any way Erratics: Large rocks leaving behind large rocks, some of which are as large as a house, which are different in composition and origin from the ground on which they were deposited. Moraines: ridges of rock and sediment deposited by a glacier. Terminal moraine: the moraine that is dropped at the glacier's farthest extent. End moraines: moraines formed as a glacier retreated and paused long enough to deposit the moraine Till plain: a deposition of till (unstratified drift) that is spread across the surface as a broad plain that may hide the former landscape. Till plains often form behind an end moraine. Outwash plain: an expanse of glacial drift that is deposited beyond the end moraine by glacial meltwater. Esker: a curving, narrow ridge of coarse sand and gravel that forms along the channel of a meltwater stream that flows beneath the glacier, or in an ice tunnel at the base of the glacier. Kettle: a steep-sided hole that forms when a block of ice remains on the ground after the glacier retreats. The ice takes 20 or 30 years to melt, and as it does so, material accumulates around it, leaving the steep-sided hole.

All Correct

Which is NOT correct?(All are correct) Barchan: crescent-shaped dune with horns pointed downwind. Parabolic: Open end faces upwind with u-shaped blowout and arms anchored by vegetation. Longitudinal: long, slightly sinuous, ridge-shaped dunes, aligned parallel with the wind direction; two slipfaces. All are correct

All are correct

Which is true? A sea arch occurs on the back side of a bay, and is formed when waves strike straight against the shore. An arch formed in a headland as waves wrap around the headland and form caves that eventually connect is called a sea arch. An isolated block of rock formed when a sea arch collapses is called a sea mount.

An arch formed in a headland as waves wrap around the headland and form caves that eventually connect is called a sea arch.

Which are TRUE? The Epoch commonly known as the Ice Ages is called the Pliocene. An ice age is the same thing as a glacial. An interglacial is the space that divides two large continental glaciers from one another. An ice age will have one or more glacials interrupted by interglacials Glacials typically last about 100,000 years, while Ice Ages can last several million. The most recent glaciation was called the Illinoisan in the US The most recent glaciation occurred roughly 200,000-50,000 years ago. Temperatures were about 50 degrees colder than they are today during the most recent glaciation. Here in the South, animals such as giant ground sloths, tapirs, mastodons, and saber-toothed cats roamed the landscape during the most recent glaciation. The vegetation in Atlanta was similar to today's during the most recent glaciation. The ice sheet extended down to Georgia during the most recent glaciation Sea levels were about 20 feet lower than they are today during the most recent glaciation.

An ice age will have one or more glacials interrupted by interglacials Glacials typically last about 100,000 years, while Ice Ages can last several million. Here in the South, animals such as giant ground sloths, tapirs, mastodons, and saber-toothed cats roamed the landscape during the most recent glaciation.

Which definition is matched with the correct term? Dunes: elongate sediment ridges that form at the entrance to bays when longshore sediment is deposited. Offshore bars: spits that link one headland or barrier island to the next and close off the intervening bay from the ocean. Barrier islands: long, narrow ridge of land that form parallel to, but separate from, the mainland coast. Gulfs: shallow, calm, bodies of water located behind obstacles that absorb wave energy directed toward the shoreline. Distributaries: narrow openings between barrier islands that focus the tidal currents that pass from the open ocean into the lagoon.

Barrier islands: long, narrow ridge of land that form parallel to, but separate from, the mainland coast.

Which is TRUE? Breaking waves arrive perpendicular to the beach Backwash flows down the beach at an angle. Beach drift refers to wind creating sanddunes Beach drift plus longshore drift = coastal drift Beach drift works in a zigzag motion.

Beach drift works in a zigzag motion.

Which is true? The lower stretch of river that is affected by tidal rhythms every day is called a yazoo tributary Salt marshes are devoid of life and fairly useless ecologically Because of the Georgia Bight - the concave shape of Georgia's coast, the state has a larger area of salt marsh than any other part of the eastern seaboard.

Because of the Georgia Bight - the concave shape of Georgia's coast, the state has a larger area of salt marsh than any other part of the eastern seaboard.

Which is FALSE? A continental glacier is a continuous mass of ice that is larger than 19,000 square miles. An ice sheet is the most extensive form of continental glacier Ice sheets are usually a couple of hundred feet thick. Dome-shaped glaciers less than 19000 square miles in size are called ice domes.

Dome-shaped glaciers less than 19000 square miles in size are called ice domes.(ICE Caps Makes this correct)

Which is TRUE? Erosional coasts typically have a gentle topography, and very little tectonic action. Erosional coasts are often on the leading edge of a tectonic plate. Erosional coasts occur when land is sinking due to the growth of glaciers. Areas where the land juts out to sea are called archipelagos Areas where there are recesses in the coastline are called concave coasts.

Erosional coasts are often on the leading edge of a tectonic plate.

The blasting of rocks by windblown sand particles is known as scrubbing.

False, Abrasion: the blasting of rocks by windblown sand particles. Abrasive action is restricted to the area immediately above the ground (up to six feet or so) because sand grains are lifted only a short distance. The rocks exposed to eolian abrasion usually appear pitted, fluted (grooved) or polished. They are usually aerodynamically shaped in a specific direction, according to prevailing effective winds.

An erg desert is one that consists of desert pavement.

False, An extensive area of dunes is an erg desert or sand sea. Only about 10% of desert areas are covered with sand.

Basins that are formed when wind removes sediments are called deflation basins.

False, Blowout depressions are formed whenever wind encounters loose sediments and removes enough sediment to form basins. The depressions range from small indentations less than a meter wide up to hundreds of meters wide and many meters deep. Chemical weathering is an important factor, because it removes the cemented materials between rock particles.

The removal and lifting of individual loose particles is called inflation.

False, Deflation is the removal and lifting of individual loose particles. Deflation blows away loose sediment. It can form desert pavement and blowout depressions.

A surface in the desert that resembles a cobblestone street is called deflation pavement.

False, Desert pavement is a surface that resembles a cobblestone street. One hypothesis for the formation of pavement states that deposition of windblown sediments is the formative agent. Windblown particles settle between rocks and pebbles and rain washes the dust downward, while the rocks and pebbles are gradually displaced

Dunes are always shaped by prevailing winds.

False, Dune fields tend to migrate in the direction of effective, sand-transporting winds. So stronger seasonal winds, or winds from a storm, may be more effective than average prevailing winds.

Crevasses are caused by a glacier melting and shrinking

False, Friction with valley walls, if it is a valley glacier Tension due to stretching as the glacier passes over convex slope Compression as the glacier passes over concave slope.

Glaciers can transport rocks and sediments on their surface, when debris or sediment fall or blow onto it, or embedded internally.

False, Glacial plucking occurs when ice melts at the bottom of the glacier, and then refreezes, thereby plucking and embedding rocks and sediments.

The windward side of a dune is its slipface side.

False, Leeward side is the slipface side

The smallest features shaped by individual saltating grains are ergs

False, Ripples: the smallest features shaped by individual saltating grains. Ripples form in crests and troughs, positioned at right angles to the wind direction.

Where sediment-heavy rivers are plentiful, the beaches are small.

False, So, where there are many sediment-heavy rivers entering the sea, beaches and dunes will be more plentiful.

The process by which saltating particles crash into other particles, knocking them forward is known as rebound transport.

False, Surface creep: where saltating particles crash into other particles, knocking them loose and forward.

When waves approach an irregular coast, the topography bends - reflects - them.

False, The topography refracts - bends - the approaching waves. The wave energy is focused around the headlands, and works to erode them.

Sandbars that connect sea stacks to the shore are called yardangs.

False, Tombolos are sandbars that connect sea stacks to the shore.

Rocks that show evidence of abrasion are called wind-blast formations.

False, Ventifacts are rocks that show evidence of abrasion are called ventifacts (literally, "artifacts of the wind").

The leeward side of a dune is long and gently sloping.

False, Windward side - usually long and _gently sloping.

Yardangs are a type of sand dune.

False, Yardgans are larger formations of bedrock or semi-consolidated material

Glaciers are simply large masses of snow

False, a glacier is a large mass of ice resting on land or floating as an ice shelf in the sea adjacent to land.

Gobi means dune.

False, desert pavements have many names: gobi in China, for example. Heavy recreational activity damages desert pavement, leading to more deflation.

Rocks exposed to eolian abrasion are typically very rough, not polished, and are ungrooved.

False, fluted (grooved) or polished.

Dunes migrate upwind.

False, in this way, a dune migrates downwind.

About 75% of desert areas are covered in sand.

False, only about 10% of desert areas are covered with sand.

The transport of grains, in which the grains are skipped and bounced close to the surface, is known as transport agitation.

False, saltation: the transport of grains, in which the grains are skipped and bounced close to the surface.

The lowest elevation where snow can survive year round is called the meltline.

False, the snowline is the lowest elevation where snow can survive year-round.

The angle of the slipface of a dune is typically much steeper than the sand's angle of repose.

False, the steepest angle at which loose material is stable: its angle of repose.

Tombolos form when the water refracting around a headland erodes the sea floor.

False, they form when longshore currents converge from two directions and deposit sediment.

Abrasion commonly occurs to heights of 30 feet above the ground.

False, up to six feet or so

Eolian is the term used for the work of water.

False, wind makes it correct

Wind-sculpted accumulations of sand are called ventifacts.

False,Dunes are wind-sculpted accumulations of sand. An extensive area of dunes is an erg desert or sand sea. Only about 10% of desert areas are covered with sand.

What is FALSE about the effects of rising sea level on barrier islands? Wave energy focuses farther inland More of the beach submerges at high tide Each centimeter of sea-level rise commonly causes more than 1.5 meters of shoreline retreat. Barrier islands migrate landward as storms erode the seaward facing beach The beach sediment gets washed across the island and into the landward lagoon. Geologists know that islands migrate because there is no mud underneath the current islands

Geologists know that islands migrate because there is no mud underneath the current islands

Which is not the correct term? Hanging (platforms of coral rock that occur sporadically around a sea mount/volcano, which rises high above the water) Barrier reefs (reefs that enclose lagoons; the volcano is lower) Atolls (circular, ring-shaped reefs, where the volcano is nearly or totally submerged).

Hanging (platforms of coral rock that occur sporadically around a sea mount/volcano, which rises high above the water)Fringing would make this correct.

Which is true? High tide only affects the lagoon behind barrier islands - it does not impact the delta area farther upstream High tide brings with it sediments and nutrients Tidal flats are exposed at high tide.

High tide brings with it sediments and nutrients

Which is true? When coral reefs turn white, the phenomenon is called peroxiding. Coral reefs turn white by creating a unique chemical Increased sea ocean temperature is a cause of coral bleaching; pollution may also contribute.

Increased sea ocean temperature is a cause of coral bleaching; pollution may also contribute.

Which definition is matched with the correct term? Joists: walls built perpendicular to the shoreline. Jetties: longer versions of groins built adjacent to an inlet. Sea cliffs: walls or stacked stones built on the beach to prevent wave erosion. Beach replacement: sand is imported from elsewhere and deposited on the beach.

Jetties: longer versions of groins built adjacent to an inlet.

Which are FALSE? The shape of earth's orbit varies by more than 11 million miles during a 100,000 year cycle. Earth's axis wobbles through a 26,000 year cycle Earth's axial tilt varies from roughly 22 to 24.5 degrees during a 41,000 year period. Milankovitch calculated that cycles in the orbit, axis, and axial tilt would lead to a 150,000 year climate cycle. A 100,000 year climate cycle that is driving glaciations is called the Pakchar cycle.

Milankovitch calculated that cycles in the orbit, axis, and axial tilt would lead to a 150,000 year climate cycle.(100,000 to make correct) A 100,000 year climate cycle that is driving glaciations is called the Pakchar cycle.(Milankovitch makes this correct).

Which are NOT the correct terms for the definition given? Cirque: a bowl-shaped recess at the head of a valley, which is carved and widened by a glacier. Aretes: (means knife-edge in French) - sharp ridges around the edge of a cirque that form as the glacier erodes the sides of the cirque. The arêtes often separate one cirque from another Col: a saddle-like depression that forms when two eroding cirques erode the arête that separates them. Point: a sharp peak that forms when several cirque glaciers gouge an individual mountain summit from all sides. U-shaped valley: a river valley that used to be V shaped, but is widened and rounded by the erosion of a glacier growing and passing through it. Tarn: a small mountain lake that forms in a cirque Paternoster lakes: A string of small, circular stair-stepped lakes that are most likely formed by differing resistance in the bedrock, or damming by glacial deposits. Hanging valley: A valley carved by a tributary glacier that is left stranded high above the valley floor. Often the sites of spectacular water falls. Fjord: a steep-sided valley that leads to the sea, and was widened by a glacierand is flooded with sea water after the glacier retreats.

Point: a sharp peak that forms when several cirque glaciers gouge an individual mountain summit from all sides.(Horn makes this right)

Why weren't there Ice Ages before?

Reasons include major changes in continental configuration and topography.

Hawaii: White sand comes from coral; black sand comes from basalt rock; green sand comes from ultramafic rock.

Red Note

Georgia has ancient river dunes in the middle of the state(not at the beach) deposited by winds blowing over rivers during the ice ages.

Red Notes

Which is FALSE? Cliffs along the shoreline and headlands are called sea cliffs Sea cliffs erode away as notches formed at water level deepen, causing the cliff above to collapse Sea caves form in areas that are more resistant to erosion.

Sea caves form in areas that are more resistant to erosion.

Which is FALSE? A snowfield is a glacier's accumulation zone. Snow becomes glacial ice in about a year. Firn is the transitional stage between glacial ice and snow

Snow becomes glacial ice in about a year.(Snow and ice are transformed under pressure and recrystallized to form glacial ice. The main input to a glacier is snow falling in a snowfield, which is the glacier's accumulation zone. Initially, the snow becomes firn, which is a transitional stage to glacial ice, and has a compact, granular texture. In Antarctica, glacial ice formation may take 1000 years because of the dryness of the climate (minimal snow input), whereas in wet climates, the time is only a several years because of rapid, constant snow input to the system.)

Which is TRUE? Spits are attached to land on the upcurrent side of a bay. Spits often have a hook at the end because of the beach backwash Lagoons are located on the side of an obstacle that is receiving the full force of wave action

Spits are attached to land on the upcurrent side of a bay.

What was the culprit for bleaching according to this video?(red notes)

Temperature extremes caused by global warming

Which is FALSE about the impact of each of the following beach protection measures? Scouring occurs under sea walls The sand that is used in beach nourishment is usually identical to the original beach sand. Jetties tend to starve the islands upcurrent from them o sediment. Groins tend to cause the beach downstream of them to erode.

The sand that is used in beach nourishment is usually identical to the original beach sand. Jetties tend to starve the islands upcurrent from them o sediment.

Which is TRUE about beaches? The sediment tends to stay in one place The sediment is being deposited and transported by waves and currents. The flatter, upper part of the beach is called the beach terrace. Most beaches are dominated by calcium carbonate. Quartz is not very weathering resistant, so it is rare on the planet. Black sands are most common in areas where there are no volcanoes Black sands are formed from quartz. Beach sediments are sharp-edged due to lack of weathering and erosion.

The sediment is being deposited and transported by waves and currents.

Which is TRUE about loess? Mostly made up of sand Forms a kind of karst topography The source of the clays and silts can be glacial outwash or deserts Very weak, and falls apart easily Formed by particles deposited by water

The source of the clays and silts can be glacial outwash or deserts

Which is TRUE? Glaciers are rigid blocks that simply slide downhill. The weight and pressure of a glacier causes it to move. The degree of slope below a glacier is not a factor in its movement. The greatest movement of a glacier is in the rigid surface layer. When the base of the glacier slides along, the process is called basal creep.

The weight and pressure of a glacier causes it to move.

What is true about coastal sand dunes? They are formed by deposition by the longshore current. They are perpendicular to the shoreline. They form when shore vegetation traps sand blown by the wind off of the beach Wrack is a combination of seashells, rocks, and mud that builds on a beach Sea oats germinate in salt marshes The dunes closest to the shore are called Initial Dunes. Secondary dunes are those that occur behind primary dunes.

They form when shore vegetation traps sand blown by the wind off of the beach Secondary dunes are those that occur behind primary dunes.

Which is FALSE about barrier islands? They consist of sediment rather than rock. They tend to form on steep, sharply breaking continental shelves. In one model, they form when sediment deposited on the continental shelf during the recent glaciation was reworked and molded. In barriers with low sand supply, the landform will have low relief, and will lie only a yard or two above sea level. Where there is an abundant sand supply, dunes form and create a higher landscape.

They tend to form on steep, sharply breaking continental shelves.