Test 2

The Hydrologic Cycle

  • **Stages: **
    • A: Evaporation
    • B: Runoff
    • C: Reservoir
    • D: Precipitation
    • E: Infiltration
    • F: Groundwater
    • G: Reservoir

How Rivers Flow Downhill

  • Contour Lines:
    • Use contour lines to determine direction of river flow.
    • Upstream: Where the river originates.
    • Downstream: Where the river flows towards.
    • The Vs in contour shapes point upstream.
    • Water exits the river at the mouth of the V.

Basic Vocabulary

  • Headwaters:
    • The source area of a stream or river.
  • Mouth:
    • The end of a stream where it enters a sea, lake, or larger stream.
  • Gradient:
    • The slope of a stream bed.
    • Example: A gradient of 5 ext{ ft/mi} corresponds to a vertical drop of 5 feet for every 1 horizontal mile.
  • Floodplain:
    • A broad flat area adjacent to a river, made of sediment deposits; susceptible to flooding based on river levels.
  • Stream Channel:
    • A narrow pathway through which a stream flows.

River Meanders

  • Oxbow Lake:
    • A lake formed when a meander is cut off due to erosion.
  • Meander Scar:
    • Remnants of a meander which may fill with sediment.
  • Cutbank:
    • Area where the stream flows fastest, causing erosion.
  • Point Bar:
    • Region where the stream flows slowest, leading to sediment deposition.
  • Sinuosity:
    • A description of how bendy a stream is.

Groundwater

  • Definition:
    • Water located underground in cracks and spaces within soil, sand, and rock.
  • Aquifers:
    • Geologic formations that contain and allow water movement.
  • Travel Time:
    • Groundwater can take from days to millions of years to move through aquifers.
  • Usage:
    • Provides approximately 38% of drinking water in the US and about 50% worldwide.
  • Zone of Saturation:
    • The area of underground soil or rock that is fully saturated with water.

Groundwater Flow

  • Water Table Elevation:
    • Water table contours indicate the underground elevation.
    • Flow lines show the direction of groundwater flow and intersect water table contours at 90°.
    • Lakes and wells demonstrate groundwater elevation.

Glaciers

  • Definition:
    • A body of ice and snow that moves downslope or outward due to gravity.
  • Formation:
    • Develops when snow accumulates more than it melts.
  • Erosion:
    • Glaciers cause erosion as they move.

Moraines

  • Types:
    • Lateral: At the sides of a glacier.
    • Median: In the middle, formed from converging lateral moraines.
    • Terminal: At the glacier's furthest point of advance.

Glacial Landforms - Plains

  • Outwash Plain:
    • A slightly sloped area made by sand and gravel from streams flowing away from the glacier.
  • Drumlin:
    • An elongated hill parallel to the direction of ice movement.
  • Kettle:
    • A depression formed when ice blocks melt in deposited glacial materials; often filled with water to form lakes.
  • Esker:
    • A long, winding ridge of sediment left by meltwater.
  • Glacial Drift:
    • All materials transported and deposited by glaciers (may include till).

Glacial Landforms - Mountains

  • Arête:
    • A sharp ridge formed between two glacial valleys.
  • Horn:
    • A pyramid-shaped peak formed by glacial erosion from multiple sides.
  • Cirque:
    • A bowl-shaped depression with steep sides.
  • Tarn:
    • A small lake in a cirque formed by melted glacial ice.

U-Shaped Valleys

  • Definition:
    • Valley with a broad flat floor and steep sides, shaped by a glacier.
  • Hanging Valley:
    • A smaller valley carved by a tributary glacier, found upstream of a cliff.