Earth science glaciers

Glaciers cover _____% of the land surfaces near earth's poles

10

Where did the name alpine come from

Alps im the south central europe

What is the breakge process forming an iceberg called

Calving

A typical glacier moves most rapidly at its

Center and surface

What shape is a continentsl glacier

Circular

How can glaciers deposit material

Directly or indirectly

What gives clues about the past

Erosion and deposition left by glaciers

More snow ____ than ______ each year

Falls, melts

Low latitudes will have glaciers at

High altitudes (high in the mountains)

At the equator:

High elevations

Glaciers are found in

High mountains

Valley glaciers are a large river of

Ice and snow

Continental glacier

Large ice sheets that cover relatively flat ground. They flow putward from where the greatest amount of snow and ice accumulate

As it moves, it

Weathers and erodes materials

Moraine

When TILL builds up in linear deposits

Is outwash sorted and stratified

Yes

KETTLES:

are bowl-shaped hollows found in moraines and outwash plains. Kettles form where buried blocks of ice have been left behind by a retreating glacier. When the ice melts, it leaves a hole. When the hole fills with water, it is called a kettle lake.

END MORAINES:

are deposited where the glacier stopped for a long period of time. (Long Island has 2: Ronkonkoma Moraine and Harbor Hill Moraine)

Striations

are grooves in rock that help determine the glaciers direction of movement. They form when the glacier scratches the underlying land and rock. The scratches are caused by the massive ice above as well as the embedded sediment within the ice.

DRUMLINS:

are long smooth canoe shaped hills that are usually found in groups. Point in the direction of glacial movement.

Arête

divide between 2 cirques that formed next to each other on a peak.

OUTWASH PLAIN:

flat areas in front of large glaciers, that form from glacial meltwater.

Crevasses

form across the width of the glacier when the glacier comes to a steep downward slope. The cracks form because the ice near the surface of a glacier is rigid. The ice breaks. The crevasses rarely go deeper than 50 meters, since below that depth plastic flow is occurring.

LATERAL MORAINE:

form at the edges of the glacier.

TERMINAL MORAINE:

form at the point where the glacier had advanced the furthest.

GROUND MORAINE:

form when the sediments underneath the glacier are deposited.

MEDIAL MORAINE:

form where the lateral moraine of two tributary glaciers join together in the middle of a larger glacier

Hanging valley

forms where the main glacier cuts off a tributary glacier and creates a cliff. HANGING VALLEY WATERFALLS can be created.

Scientists know that

glaciers move and therefore study the rates of movement by stakes and satellites.

Horn

pyramid-shaped peak. Forms when three or more cirques cut into the same peak. (Matterhorn (Switzerland/Italy)

GLACIAL ERRATICS:

rocks carried by glacier that are deposited in a different location. These rocks do not match the surrounding bedrock.

Glaciers carve a ___ shaped valley due to its ________ ____

"U", massive side

What continent do valley glaciers exist on

Every continent excelt AUSTRALIA

Glacial erosion

Glaciers pick up and transport sediment in various ways. Glaciers have the ability to pick up tiny pieces of sediment to large boulders as big as a house.

Basal slip

Movement at the base of a glacier due to the partial melting and freezing of the ice at the base. Reduces fricition and allows for the glacier to slip at a faster rate. Responsible for movement at the base ONLY. In extremely cold areas, basal slip will not occur because it is too cold for the ice to melt

The glacier cuts through a valley and

widens the valleys and steepens the walls.

Where do continental glaciers form

Areas where all precipitation falls as snow (polar regions)

Alpine/valley glacier

Flow downhill through mountains long existing valleys. They move within balley walls

Solid ice that move extremely slowly along the land surface

Glaciers

What forms when the glacier reaches the sea ans a big chunk breaks off

Iceberg

Glacial till

If a glacier melts and directly deposits material, the material will be unsorted and unstratified and be in a big pile.

Outwash

If glaciers are deposited by glacial meltwater

Moraine sare named by their

Location relative to the glacier

How does meltwater from a glacier behave

Meltwater from a glacier behaves just the way a stream would deposit sediment. It drops the big sediment first, followed by smaller sediment.

If a mountain is covered in snow in the winter but without snow in the summer, it has

No snow line and no glacier either

Plastic flow

Occurs in the interior of the glacier. The grains of ice deform, change shape, and allow for the grains of ice to slip past each other to create forward movement

Alpine glaciers form in

Regions high enough to be in the coler part of the earth's atmosphere (high elevations)

High latitudes can have glacier at

Sea level

Friction between the ice and the valley floor/walls does what to movement

Slows movement

The lowest elevation at which the layer of permanent snow occurs in summer

Snow line

The weight of snow/ice along with gravity allow

Such a massive thing to move

How thick are continental glaciers and how long have they been forming

Thousands of meters thick and have been forming for thousands of years

Snow line fluctuates according to

Total yearly snowfall & amount of sun exposure

There are several moraines depending on

Where they are from

Move more rapidly after what

Winters of heavy snowfall, on steep slopes, and in summer

Plucking

occurs when a glacier picks up/plucks a rock from the land and embeds the rock in the ice and transports it to another location.

Cirque

semicircular basin found at the head of a glacial valley. The head is where the glacier began. When the ice melts, the hollow is left. When the basin fills with water, it is called a CIRQUE LAKE. Another name for this is TARN( small mountain lake).

Pater noster lakes

series of glacial lakes connected by a single stream. (Our Father: resembles a string of rosary beads)

KAMES:

small, cone shaped hills of stratified sand and gravel. Form when streams flowing across the top of a glacier deposit their sediments at the ice front. Deposited by water, not ice.

ESKER:

winding ridge of sand and gravel deposited under a glacier by a stream of meltwater.