Name: ______

3rd Quarter Test Review

  1. What you need to know about erosion…

Erosion is the movement of sediment by wind, water, ice, or gravity from one location to another. Glaciers are considered the most erosive agents—they are able to carry the most stuff. Sudden erosion due to gravity is considered mass wasting.

  1. Define four major landforms left behind during the process of glacial erosion.

Aretes--steep knife-like ridges left when two adjacent glaciers erode parallel valleys. Horn--a pointed peak left behind from glacial erosion on all sides.

Cirque--bowl-shaped depression with very steep slopes

Fjord—long narrow inlet to a sea with steep sides or cliffs, created in a valley carved by glacial activity.

Hanging valley--a steep drop or cliff where a small valley glacier drains into a much larger (deeper) valley glacier.

Moraines--ridges or rows of sediment deposited on the sides and at the end of glacial movement.

  1. What is the name given to all sediment of glacial origin?

drift

  1. What is mass wasting? What are some examples?

Mass wasting is the transfer of rock material downslope under the influence of gravity. Examples include: debris flow, slump, earth flow, and rockslide.

  1. The best evidence for shifts in Earth’s magnetic poles throughout history is found where?

…lines of seafloor around mid-ocean trenches that have iron-rich basalt strips arranged in magnetically opposite directions.

  1. The ability for a substance to be magnetized has to do with how many unpaired ______it has. What lends itself to greater magnetic properties…more or less?

Electronsmore unpaired electrons means more ability to be magnetized

  1. What is one major piece of evidence that proves the earth’s magnetic poles have shifted before?

Strips of iron-rich basalt crust running parallel to the mid-Atlantic trench are arranged opposite of each other in magnetic polarity. This provides evidence the poles were arranged oppositely during these spans of crust-building.

  1. What is unique about superconductors? What are some uses of superconductors?

Superconductors are unique metals that, under certain low temperatures, provide virtually no resistance to electric current. Uses include Magnetic Levitation (high speed) trains, MRI machines, Particle colliders, and in efficient electrical wiring.

  1. What is the geodynamo that is believed to be the cause of the earth’s magnetic field?

The earth’s outer core appears to move in constant circular convection currents due to heating from the much hotter solid inner core. The liquid ferromagnetic iron and nickel in motion creates the magnetic field.

  1. What beneficial purpose does Earth’s magnetic field serve?

The magnetic field helps to block much of the sun’s harmful radiation including intense ion bombardment.

  1. Name a form of mechanicalweathering that is common to both wind force and glacier movement.

abrasion

  1. Briefly describe the methods of mechanical weathering.

Abrasion-water and wind (and ice) that scrape and carry rock particles away

Ice wedging-repeated melting and freezing of water in cracks through rock. Due to expansion when freezing.

Uploading-highly pressurized rock that emerges at surface begins to flake and peel when no longer under pressure

Organic activity-wearing or cracking of rock due to plant, animal, or human activity. Root wedging…

Gravitational impact-gravity pulling on rock or causing glaciers to do so. Ex: landslides, mass wasting, glacial abrasion with boulders after plucking.

  1. Briefly describe the methods of chemical weathering.

Oxidation-metals reacting with oxygen to form various kinds of rust

Hydrolysis-molecules being split into smaller ones by a water molecule in a chemical process

Dissolution-dissolving rock with slightly acidic water. Carbonic acid and Sulfuric acid are common agents.

Plant acids-some plants make weak acids that can dissolve certain minerals in some rock

Hydration-attachment of H+ and OH- ions to rock; increases volume, and the expansion creates stress.

  1. What 3 factors affect the rate of weathering?

Amount of exposed surface area

Mineral composition-certain minerals weather at different rates.

Climate-environmental temperature, avg rainfall. Higher temps and more water mean faster weathering.

  1. What 4 natural elements are responsible for erosion?

WaterWindIceGravity

  1. Ice wedging occurs when water seeps into cracks in rock and ______due to freezing. This causes the rock to fracture and open larger gaps in the rock. expands
  2. Carbonic acid and sulfuric acid are two agents involved in breaking down rock through a process known as:
  3. dissolution
  4. hydration
  5. mechanical weathering
  6. oxidation
  7. Which of these are not factors that influence the rate of weathering?
  8. Amount of surface area exposed to weathering
  9. The chemical composition of the rock or mineral
  10. Climate factors including temperature and water availability
  11. All of the above affect weathering rate.
  12. The only two Ice sheets on Earth can be found covering ______and ______. Greenland :: Antarctica
  13. A thin, knife-like ridge of rock left behind when two valley glaciers erode parallel U-shaped valleys is known as a(n):
  14. Cirque
  15. Arête
  16. Horn
  17. Fjord
  18. What kind of landform is created when a block of ice gets buried in drift then melts to form a lake?

kettle

  1. Which zone of a glacier involves the net loss of glacial snow and ice?

Zone of Ablation or Zone of Wasteage

  1. What is the difference between an ice sheet, an ice shelf, and an ice cap?

Ice sheets cover large areas of continental crust (more than 50,000 sq km)

Ice caps are miniature ice sheets (less than 50,000 sq km) usually form on relatively high & flat lands

Ice shelves are extensions of ice caps and ice sheets at the end of a glacial land mass and out over water

  1. In a glacier, what is plucking?

Loosening and lifting blocks of rock during glacial flow, and carrying them off in the ice.

  1. What is a hot spot?

An area where the crust is thin, or an area in earth’s crust where magma makes its way very close to the surface of the earth. These are the sites of enhanced volcanic activity.

  1. Know some landforms left by glaciers (i.e. question #2) and know how to diagram a glacier.

  1. Know the three types of plate boundaries and be able to identify them:

Divergent boundary ; Convergent boundary ; Transform Fault boundary