BMST - Basic Math and Science Earth's Geological Cycles Questions and Answers 4 — Questions and Answers
Question 1: What drives the movement of tectonic plates according to the most widely accepted scientific explanation?
- Earth's rotation
- Convection currents in the mantle (Correct answer)
- Gravitational pull of the Moon
- Solar wind pressure
Correct answer: Convection currents in the mantle
Convection currents in the semi-molten mantle carry heat from Earth's interior and drag tectonic plates along with them.
Question 2: Which geological time scale unit is the longest?
- Era
- Period
- Eon (Correct answer)
- Epoch
Correct answer: Eon
An eon is the largest division of geological time; Earth's history is divided into four eons: Hadean, Archean, Proterozoic, and Phanerozoic.
Question 3: What percentage of Earth's water is freshwater?
- About 3% (Correct answer)
- About 10%
- About 25%
- About 50%
Correct answer: About 3%
Only about 3% of Earth's water is freshwater, and most of that is locked in glaciers and ice caps, leaving less than 1% accessible as liquid freshwater.
Question 4: What is the term for molten rock once it reaches Earth's surface through a volcanic eruption?
- Magma
- Lava (Correct answer)
- Pumice
- Basalt
Correct answer: Lava
Magma is called lava once it erupts onto Earth's surface; the terms refer to the same material at different locations.
Question 5: Which rock type can be transformed into metamorphic rock through heat and pressure?
- Only igneous rock
- Only sedimentary rock
- Only other metamorphic rock
- Any type of rock (Correct answer)
Correct answer: Any type of rock
Any pre-existing rock—igneous, sedimentary, or metamorphic—can be transformed into metamorphic rock when subjected to sufficient heat and pressure.
Question 6: In Earth's nitrogen cycle, what process converts nitrogen gas from the atmosphere into usable compounds?
- Denitrification
- Nitrification
- Nitrogen fixation (Correct answer)
- Ammonification
Correct answer: Nitrogen fixation
Nitrogen fixation, carried out by certain bacteria and lightning, converts atmospheric N₂ into ammonia or nitrates that plants can absorb.
Question 7: What evidence did Alfred Wegener use to support his theory of continental drift?
- Satellite images of moving continents
- Matching fossils and rock formations on opposite sides of the Atlantic (Correct answer)
- Measurements of ocean depth
- Volcanic eruption patterns
Correct answer: Matching fossils and rock formations on opposite sides of the Atlantic
Wegener noted that identical fossils and matching rock formations were found on coastlines of continents that are now separated by oceans, suggesting they were once joined.
BMST - Basic Math and Science Earth's Geological Cycles Questions and Answers 4
What drives the movement of tectonic plates according to the most widely accepted scientific explanation?