GEOG 2051 Final (LSU, Namikas)

A term referring to all water that is temporarily frozen in polar ice caps, snow, permafrost, and glaciers.

cryosphere

Energy shifts around so that positive budgets don't burst into flames and negative budgets don't freeze the air.

global energy balance

For most of history, earth has been ______ than it is today.

warmer

What period melted Greenland?

Medieval Warm Period

What followed the medieval warm period?

Little Ice Age

The period of geological time from about 2.6 million years ago to the present. It is characterized by the appearance and development of humans and includes the Pleistocene and Holocene Epochs.

Quaternary Period

The current interglaciation period, extending from 10,000 years ago to the present on the geologic time scale; from the last ice age.

Holocene

Pertaining to glaciers; cold, ice, slow, unsympathetic.

glacial

Period of glacial retreat; temps are warmer, ice sheets are smaller, and sea level is higher.

interglacial

Temperatures were warmer over the Northern Hemisphere than during the subsequent "Little Ice Age," and also comparable to temperatures during the early 20th century

medieval warming

A century-long period of cool climate that began in the 1590s. Its ill effects on agriculture in northern Europe were notable. Significantly colder than today's temps.

Little Ice Age

Periodic changes in Earth's rotation and orbit around the sun; influences the earth's temperature with eccentricity, obliquity patterns.

Milankovitch Cycles

How much of the earth's surface is covered in glacial ice?

10%

Where are most of the glaciers located?

Antarctica and Greenland

The lowest elevation at which you can find snow at a given point in time. Mostly referring to mountains. The elevation at which snow can remain year round.

snowline

Above the snowline, where glacial ice is formed.

accumulation zone

At lower elevations, temps are warmer snow does not persist year-round. Zone where everything melts. Zone of outputs for the glaciers.

ablation zone

Partially compacted and refrozen snow which has yet to become a glacier.

firn

The difference between accumulation and ablation.

mass balance

What would happen if zones were connected?

Glacial ice would keep growing upwards.

A glacier where the edge moves back over time because more snow has melted than been added (negative budget).

retreating glacier

Glacier with a positive budget, so that accumulation results in the lower edges being pushed outward and downward.

advancing glacier

Balanced budget, the amount of ice in storage isn't changing over time. The same amount that is being lost is being replaced at the top, the glacier is staying in place.

stagnant glacier

Hard ice, fractures under forces, creates crevasses, on top of plastic zone.

brittle zone

Ice under lots of pressure, so it can't break, molecules stretch as glacier moves downhill.

plastic zone

Stretching of ice crystals in the plastic zone that carries overlying ice along with it.

internal deformation (flow)

Build up of melt water acts as a lubricant that allows for the glacier to slip along the surface or flow.

basal sliding or slip (flow)

The movement of glacial ice is very ________.

slow

A time of greatly accelerated flow in a glacier; commonly results in displacement of the glacier's terminus by several kilometers.

glacial surge (flow)

One of the two main mechanisms used to by glaciers to erode underlying material. Occurs in situations where glaciers flow overtop an outcrop of rock. As the ice flows over the rock, pressure increases, creating friction which creates heat and melt water. Once it gets over the rock, it becomes colder and the water can refreeze. Meltwater causes the glacier to not be smooth, have fingers, that can pluck up pieces of the rock, that then refreeze into the rock

Plucking

Chunks of rock(s) that freeze into the bottom of a glacier that then act as a "giant piece of sandpaper" as it scrapes upon the earth's surface.

abrasion

Sharp and jagged peak of a mountain (postglacial),

horn

Origin of mountain glaciers. Glacial ice created bowl-shaped depressions near the mountain peaks where previous snow accumulation and glacial position caused the bowl-shaped erosive depressions (postglacial),

cirque

Narrow and jagged, knife-like ridges that separate river valleys (postglacial).

arete

A small mountain lake

tarn

Chain of small lakes in a glacial trough.

paternoster lakes

A glacially carved tributary valley whose floor lies at a higher elevation than the floor of the trunk valley, waterfalls.

hanging valley

Glacial troughs as river valleys from the glacial ice erosion downwards and slightly side to side prior t melting.

hanging valley

ridges made of sediment and rock debris deposited by glacial activity.

morraines

The morraine formed by the glacier at the farthest point the glacier reached.

terminal morraines

Marks the pauses in the retreat of a glacier.

recessional morraine

Morraine that forms along the side of a glacier.

lateral moraine

Morraines that form from two glaciers merging and create a morraine within the central portion of the newly formed glacier.

medial morraines

Creates huge stones and boulders as well as fine-grain material. Material that was created underneath the glacier, and when it melts out it gets dumped into one place. Unsorted sediment; mixture of all different sizes of sediments of rocks.

till

Glacial sediment that has been laid down into a series of layers. Layers are sorted by the size of the material. Meltwater moves the material. The bigger sediment gets deposited first.

stratified drift

Area in front of a glacier in which melted water from the glacier has carried and deposited an abundance of sorted material.

outwash plain

A large, relatively flat plain composed of unsorted glacial deposits behind a terminal or end moraine. Covered in a thick layer of till deposited by mountain ice.

till plain

A ridge that winds back and forth; gently curves. Remains of a stream bed that was built up by deposited material from glaciers.

Esker

A hole in the ground that has been formed by material getting deposited around it.

Kettle (kettle lake when filled with water)

Small irregularly shaped hills. Started as a depression, but then was filled and built up with sediment from meltwater.

kames

Depositional feature, streamlined hills formed by glacial ice depositing sediments into these stream-line shapes.

drumlin

Streamline shape, blunt nose. Product of erosion. Carved into bedrock outcropping by glaciers.

roche moutonee

Distinguished by the fact that they are covered in permafrost.

periglacial environments

At high latitudes, can be up to 400 meters thick. Further south, only a few meters thick. The active layer thaws on an annual basis.

permafrost

Permafrost that occurs in scattered patches.

discontinuous permafrost

Permafrost layer that thaws out on an annual basis.

active layer

Under lakes, they are produced by the insulating effect of the water even when the water is around 32 degrees. Because the water won't freeze, the ground won't either.

taliks

Land is frozen for a large part of the year, but thaws as summer grows nearer. Produces rock fields. Responsible for shaping environments.

frost action

Area of land covered in stones or boulders.

block field

Type of ground ice. Wedge of ice that has been formed inside the ground. Active layer thaws out, water seeps into the cracks and freezes there next freeze/ A series of freeze-thaw cycle will add water to it, leading to a massive ice wedge. It can push the rock out of the ay as it grows.

ice wedge

Mixing of soil as a result of the freeze-thaw cycle. When it freezes, it moves some sediment upwards, when it thaws gravity moves it all back down, but not where it was originally. Pushes larger material up to the surface.

cryoturbation

Irregularly shaped bodies formed by an ice wedge moving the rocks.

patterned ground

Dome-shaped hill formed in a permafrost area when the pressure of freezing groundwater pushes up a layer of frozen ground.

pingo

The rigid outer part of the earth, consisting of the crust and upper mantle.

lithosphere

All the waters on the earth's surface, such as lakes and seas, and sometimes including water over the earth's surface, such as clouds.

hydrosphere

Part of earth in which life exists including land, water, and air.

biosphere

The envelope of gases surrounding the earth or another planet.

atmosphere

Method of building new knowledge. Allows us to fill gaps in our knowledge.

scientific method

A possible explanation of something that requires variation.

hypothesis

General body of knowledge, something you commonly believe, well-accepted knowledge.

theory

Testing your hypothesis

verification

A set of objects and their attributes that are linked together by closed matter-energy.

systems

The exchange is between the system and environment.

open system

Has no environment, everything happens inside the system.

closed system

Matter and energy cannot be created nor destroyed, it can only be changed into other forms.

law of conservation of matter and energy

Inputs>outputs _______ storage. Inputs

increases; decreases

Inputs=outputs

equilibrium

System responses to change in environmental inputs that influence that change.

system feedbacks

Enhance the change

positive feedback

Work to reduce and eliminate the change.

negative feedback

Set of points directly between the north and south poles. 0-90 degrees N and S. Parallels.

latitude

Meridians. 0-180 degrees E and W.

longitude

The innermost layer, where the inner core is solid iron and the outer core is molten iron.

core

80% of earth's volume involving the asthenosphere that is plastic molten and the uppermost mantle which is rigid; the plastic asthenosphere is what allows for plate tectonics.

mantle

The surface of the Earth with the lowest density and temperatures.

crust

Crust + uppermost mantle; floats on the asthenosphere and shifts with the currents; trends: temperature and density increase with depth from the surface to the core.

lithosphere

Layer of rigid, solid rock that floats on top of the aesthenosphere.

uppermost mantle

The soft, plastic, layer of the mantle on which the lithosphere floats.

asthenosphere

The series of processes that change on type of rock into another type of rock.

rock cycle

A type of rock that forms from the cooling of molten rock at or below the surface.

igneous rock

A rock that forms from compressed or cemented layers of sediment.

sedimentary rock

Rock that has been changed by heat and pressure.

metamorphic rock

Large scale vertical movements of the earth's crust.

isostasy

A theory stating that the earth's surface is broken into plates that move. Discovered by the idea that the continents were once together.

plate tectonics

The process by which molten material adds new oceanic crust to the ocean floor.

sea-floor spreading

The process by which oceanic crust sinks beneath a deep-ocean trench and back into the mantle at a convergent plate boundary.

subduction

Plates moving away from each other (sea floor spreading).

divergent boundary

Plates slipping past each other, moving in opposite directions (san andreas fault).

transform boundary

Plates moving towards each other (subduction zones).

convergent boundary

A supercontinent containing all of earth's land that existed about 225 million years ago.

pangea