AP Environmental Science Flashcards: The Hydrologic (Water) Cycle
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Review key ideas with interactive flashcards. This set includes 10 cards to help you master important concepts.
Based on the relative sizes of the reservoirs, where is the vast majority of Earth's water located?
The vast majority of Earth's water is located in the oceans, which are the primary reservoir.
Card 1 of 10
All Flashcards (10)
Based on the relative sizes of the reservoirs, where is the vast majority of Earth's water located?
The vast majority of Earth's water is located in the oceans, which are the primary reservoir.
If global temperatures rise, causing ice caps to melt, how does this affect reservoir interactions in the hydrologic cycle?
Melting ice caps would cause a transfer of water from the ice cap reservoir (solid phase) to the ocean reservoir (liquid phase).
What is the relationship between water 'sources' and 'sinks' in the hydrologic cycle?
Sources and sinks are the reservoirs between which water moves; for example, water moves from the ocean (a source) to the atmosphere (a sink).
Besides the oceans, name two other significant water reservoirs.
Ice caps and groundwater are two other significant, though much smaller, reservoirs of water.
What fundamental process does the hydrologic cycle describe?
It describes the continuous movement and interaction of water between different reservoirs on Earth, powered by the sun.
In what physical phases does water exist during the hydrologic cycle?
Water exists and moves in its solid, liquid, and gaseous phases throughout the cycle.
Define 'reservoir' in the context of the hydrologic cycle.
A reservoir is a location where water is stored, such as the oceans, ice caps, or groundwater.
What is the primary energy source for the hydrologic cycle?
The sun is the primary energy source that powers the hydrologic cycle.
What is the hydrologic cycle?
The hydrologic cycle is the movement of water in its various solid, liquid, and gaseous phases between sources and sinks.
What is the primary reservoir of water on Earth?
The oceans are the primary reservoir of water in the hydrologic cycle.