Science 8 Water Systems Unit Exam

Salt Water

97% of the planet’s water is found in oceans and seas.

Fresh Water

Makes up 3% of Earth’s water, with 77% locked in polar ice caps and 22% as groundwater.

Potable Water

Only 0.03% of Earth’s water is safe for human consumption.

Hard Water

Contains magnesium and calcium that prevent soap from producing bubbles.

Water Contaminants

Includes bad taste, odor, turbidity, bacteria (like E. coli), acidic or basic pH levels, dissolved oxygen, suspended solids, and dissolved solids.

Water Purification Methods

Methods to clean water, like distillation and reverse osmosis.

When Tides Happen

Two high tides and two low tides occur every 24 hours and 50 minutes, caused by the moon’s gravitational pull.

Deltas

Landforms formed from sediment where rivers meet larger bodies of water.

Meandering Rivers

Rivers that curve and wind due to erosion and sediment deposits. The water accumulates sediment through the outer banks (faster moving waters) and deposits it into the inner banks (slow moving waters), causing the water to bend like snakes

What do waves cause

Weathering, erosion, and deposits of sediment

What causes waves

Wind and earth movements are the primary causes. Happen when the wind transfers energy into the water making it ripple stronger and stronger, and earth movements such as underwater earthquakes, volcanic eruptions, and landslides make it ripple more violently

Watershed

Where all of the rain that falls and snow that melts stream down into a river, stream, lake, or ocean

Continental Divide

When a big geographical ridge like a mountain makes it so that if it rains on one side of the mountain, the water flows in a different direction and to a different ocean than if it rained on the other side.

Plate Tectonics

The theory that the Earth’s plates move, creating deep ocean trenches or mountains.

Subduction

Primary cause of earthquakes and volcanoes. When a oceanic plate goes underneath another tectonic plate, causing deep ocean trenches, volcanic arcs, and earthquakes.

Glaciers

Forms from large snowfall that compacts and turns into solid ice. They flow slowly downhill under gravity, carving out valleys and shape landscapes as they move. They make landforms such as eskers, drumlins, moraines, kettle lakes, erratics, calving

Eskers

Landform made from glaciers. A long winding ridge of sand and gravel deposits formed by melted water.

Erratics

Landform made from glaciers. Big rock that is picked up by a glacier and dropped off in a random location

Calving

Landform made from glaciers. Big chunks of ice that breaks off from a glacier and forms icebergs in the ocean.

Drumlins

Landform made from glaciers. Smooth, oval-shaped hills formed beneath moving ice

Moraines

Landform made from glaciers. Accumulation of debris carried and deposited into a huge buildups, forming lateral medial and terminal moraines.

Kettle Lakes

Landform made form glaciers. Depressions formed by melting ice blocks, that melt into small circular ponds

Heat Capacity

The ability of water retain heat better than land, affecting regional climate

Gulf Stream

Warm ocean current in the North Atlantic Ocean that flows from the Gulf of Mexico towards Europe that regulates the climate of Western Europe.

Thermohaline Circulation

a global system of deep ocean currents that transports heat and nutrients around the world, that are driven by the differences in water temperature and salt concentration.

Fresh Water Zones

Upper, Middle, and Lower Zones, each with different organisms and unique adaptations

Salt Water Zones

Estuary, Intertidal, Continental Shelf, and Oceanic, each of these zones requiring organisms to adapt to varying temperatures, salinity, light and pressure

Population Changes

Refers seasonal, short-term, and long-term shifts affecting ecosystems

Phosphate Pollution

Phosphate in water that forms algal blooms, which reduce sunlight through water, killing plants due to lack of sunlight, which ends up depleting oxygen resulting in fish die-offs.

Benefits of Building Large Dams

• Hydroelectric Power Generation: Dams harness the potential energy of stored water to generate electricity, providing a renewable energy source.

• Water Supply and Irrigation: They play a crucial role in supplying water for domestic use and agriculture, especially in arid regions.

• Flood Control: By regulating river flow, dams help prevent flooding in downstream areas.

• Recreation: Reservoirs created by dams offer recreational opportunities like boating and fishing.

Drawbacks of Building Large Dams

• Ecosystem Disruption: The construction of dams can lead to significant changes in local ecosystems, affecting fish migration patterns and altering habitats.

• Sedimentation: Over time, sediment can accumulate in reservoirs, reducing their capacity and affecting water quality.

• Community Displacement: Building large dams often requires relocating communities, leading to social and economic challenges for displaced populations.

• High Construction Costs: Building large dams is capital-intensive, with costs often exceeding initial estimates due to technical challenges and delays.