GED Science TestEarth and Space ScienceHard
A scientist is studying a rock sample collected from the Earth's mantle. What is the approximate range of temperatures and pressures that this rock would have experienced within the mantle?
- ATemperatures: 900-4000°C; Pressures: 20-136 GPa
- BTemperatures: 4000-6000°C; Pressures: 136-360 GPa
- CTemperatures: 200-500°C; Pressures: 1-10 GPa
- DTemperatures: 500-900°C; Pressures: 10-50 GPa
Show answer & explanationAnswer & explanation
Correct answer: A. Temperatures: 900-4000°C; Pressures: 20-136 GPa
The Earth's mantle extends from approximately 30 km to 2900 km depth. Temperatures generally range from about 900°C near the crust to around 4000°C near the core. Pressures increase from about 20 GPa at the top of the mantle to 136 GPa at the core-mantle boundary.
Why the other options are wrong
- B. These temperatures and pressures are characteristic of the Earth's outer and inner core, not the mantle.
- C. These temperatures and pressures are too low, corresponding more to the lower crust or very uppermost mantle.
- D. These temperatures are too low for the bulk of the mantle, and pressures are too low for the full range.
Earth's Mantle Conditions
The Earth's mantle is a thick, solid but ductile layer extending from the crust to the outer core, characterized by extremely high temperatures (900-4000°C) and pressures (20-136 GPa).
- Located between the crust and outer core.
- Comprises about 84% of Earth's volume.
- Solid but flows slowly over geological time scales.
Memory trick: Deep Down, Pressure and Heat Soar