Regents Earth Science 4 ā Questions and Answers
Question 1: A geologist measures the half-life of Carbon-14 as 5,730 years. If a sample contains 25% of its original C-14, how old is the sample?
- 5,730 years
- 11,460 years (Correct answer)
- 17,190 years
- 22,920 years
Correct answer: 11,460 years
After one half-life (5,730 yr), 50% remains; after two half-lives (11,460 yr), 25% remains.
Question 2: What term describes the bending of rock layers caused by compressional tectonic forces?
- Fault
- Fold (Correct answer)
- Joint
- Unconformity
Correct answer: Fold
Folds are bends in rock layers that result from compressional stress, forming structures like anticlines and synclines.
Question 3: Which ocean current transports warm water northward along the eastern coast of the United States?
- California Current
- Gulf Stream (Correct answer)
- Labrador Current
- Canary Current
Correct answer: Gulf Stream
The Gulf Stream is a powerful, warm Atlantic ocean current that flows northward along the U.S. East Coast and moderates climates of western Europe.
Question 4: Which factor most directly determines the climate of a region rather than its day-to-day weather?
- A single severe storm event
- Long-term average temperature and precipitation patterns (Correct answer)
- The pressure reading on one particular day
- The wind direction during one season
Correct answer: Long-term average temperature and precipitation patterns
Climate is defined as the long-term average of atmospheric conditions including temperature and precipitation, typically measured over 30 years.
Question 5: At a divergent plate boundary in the ocean, what type of feature typically forms?
- Deep ocean trench
- Mid-ocean ridge (Correct answer)
- Volcanic arc
- Fold mountain range
Correct answer: Mid-ocean ridge
At divergent oceanic boundaries, magma rises to fill the gap as plates separate, forming mid-ocean ridges.
Question 6: Which type of cloud is associated with continuous, widespread precipitation and forms in low horizontal sheets?
- Cumulus
- Cirrus
- Nimbostratus (Correct answer)
- Cumulonimbus
Correct answer: Nimbostratus
Nimbostratus clouds are dark, layered clouds that produce steady, widespread rain or snow over a large area for extended periods.
Question 7: What is the name of the boundary between Earth's crust and mantle?
- Gutenberg discontinuity
- Lehmann discontinuity
- MohoroviÄiÄ discontinuity (Correct answer)
- Conrad discontinuity
Correct answer: MohoroviÄiÄ discontinuity
The MohoroviÄiÄ discontinuity (Moho) marks the boundary between Earth's crust and upper mantle, identified by a sudden increase in seismic wave speed.
Regents Earth Science 4
A geologist measures the half-life of Carbon-14 as 5,730 years.
If a sample contains 25% of its original C-14, how old is the sample?