Answer:
D. They define geological periods because scientists use them as reference points for tracking the history of the earth.
Explanation:
Catastrophic events related to changes in geological timeline are very useful in defining geological periods.
These events have very significant appearance in the geological record and can be used to determine the history of the earth.
The catastrophic events usually culminates into extinction cycles or termination of some organisms from the earth surface.
Geologists use these events that are often wide spread to delineate geological periods.
Answer:
Tides
Explanation:
The intensity of the water from the rise and fall of tides is a sort of kinetic energy, and tidal energy is generated by the movement of our tides and seas. Gravitational hydropower, which uses the flow of water to drive a turbine to create energy, is surrounded by tidal power.
