Earth and Space Science Flashcards

Which energy resource is renewable?

Answer: Hydroelectric power

Hydroelectricity uses flowing water replenished by the water cycle, and it is a major power source in Quebec and B.C.

Groundwater is stored in porous, permeable rock layers called:

Answer: Aquifers

An aquifer is an underground layer of rock or sediment that holds and transmits water.

A long ridge of unsorted sediment left at the edge of a melted glacier is called a:

Answer: Moraine

Moraines are deposits of till pushed or dropped by glaciers.

Which scenario best shows erosion rather than weathering?

Answer: A river carrying sand downstream to a delta

Erosion is the movement of weathered material by agents like water, wind, or ice.

Scientists use radiometric dating of rocks mainly to determine:

Answer: The absolute age of the rock in years

Measuring the decay of radioactive isotopes with known half-lives gives an absolute age.

A radioactive isotope has a half-life of 1,000 years. How much of a 100 g sample remains after 3,000 years?

Answer: 12.5 g

After three half-lives, 100 → 50 → 25 → 12.5 g remains.

Why are earthquakes and volcanoes common along British Columbia's coast?

Answer: The Juan de Fuca Plate is subducting beneath the North American Plate

The Cascadia subduction zone produces earthquakes and fuels volcanoes in the region.