Earth's Geological Cycles Flashcards

What is the primary mechanism by which heat from Earth's interior reaches the surface through the mantle?

Answer: Convection

Convection currents in the mantle transfer heat from Earth's hot interior upward toward the crust, driving plate tectonics.

In the phosphorus cycle, where is most of Earth's phosphorus stored?

Answer: Rocks and sediments

Unlike carbon and nitrogen, phosphorus has no atmospheric phase — the vast majority is stored in rocks and sediments.

Which type of seismic wave travels only along Earth's surface and causes the most damage during an earthquake?

Answer: Surface waves

Surface waves travel along the ground surface and have a rolling or shaking motion that causes the greatest structural damage in earthquakes.

What geological time scale feature is used to identify boundaries between major periods based on mass extinctions?

Answer: Fossil assemblages

Changes in fossil assemblages — particularly mass extinctions — are the primary markers used to define boundaries between geological periods.

How does the infiltration of rainwater contribute to the geological cycle?

Answer: It weathers rocks and dissolves minerals, eventually reaching groundwater

Infiltrating rainwater chemically weathers rocks, dissolves minerals, and carries them into groundwater systems as part of the hydrological and rock cycles.

What term describes the slow, large-scale movement of Earth's lithospheric plates over geological time?

Answer: Plate tectonics

Plate tectonics is the theory describing the large-scale movement of Earth's lithospheric plates, explaining earthquakes, volcanoes, and mountain building.

Which process returns nitrogen from dead organisms back to the soil in a usable form?

Answer: Decomposition and ammonification

Decomposers break down dead organisms through ammonification, converting organic nitrogen into ammonia that can be used by plants and other organisms.