Earth's Structure and Depths

Overview

Crust Depths:
- Earth’s crust may seem deep; perspective changes with depth.
- Example depths:
  - Swimming pool depth: 2.5 m (8 ft)
  - Derinkuyu (Turkey): 85 m (280 ft)
  - Great Pyramid of Giza: 137 m (450 ft)
  - Burj Khalifa: 828 m (2,717 ft)
  - Lake Baikal (deepest lake): 1,642 m (5,387 ft)
  - Average ocean floor: 3,897 m (12,785 ft)
  - Deepest hydrothermal vents: ~5,000 m (16,400 ft)
  - Mount Everest (if underground): 8,848 m (29,029 ft)
  - Deepwater Horizon drilling: 9,100 m (30,000 ft)
  - Kola Superdeep Borehole: 12,262 m (40,230 ft)
  - Z-44 Chayvo Well (deepest well): 12,345 m (40,502 ft)

Types of Crust:
- Oceanic Crust:
  - Depth: ~6-7 km (3-4 miles)
  - Composed of basalt rock (formed by cooling lava)
- Continental Crust:
  - Depth: ~38 km (25 miles)
  - Composed of granite (most common rock)

Layers of the Mantle:
- Upper Mantle:
  - Lower pressure, cooler temperatures (1,400 to 3,000 °C)
  - Composed of hard rock and soft rock that bends and flows.
- Lower Mantle:
  - Temp: up to 3,700 °C (6,700 °F)
  - Stays solid due to high pressure.
Overall depth of mantle: ~2,900 km (1,800 miles)
Analogy: Mantle compared to a sandwich cookie:
- Top cookie: Upper mantle hard rock
- Cream: Soft bendy rock (bottom upper mantle)
- Bottom cookie: Lower mantle

Outer Core:
- Liquid layer, composed of iron and nickel.
- Generates Earth’s magnetic field.
- Extends to a depth of 5,150 km (3,200 miles).
- Temperature can reach 5,000 °C (9,000 °F).
Inner Core:
- Solid metal ball, primarily nickel and iron.
- Diameter: ~2,500 km (1,550 miles).
- Temperature can reach up to 6,000 °C (11,000 °F).
- Remains solid due to immense pressure.

Total travel distance from the crust to the inner core: ~6,000 km (4,000 miles).

Geological study methods:
- Analyzing rock samples (young and old).
- Using mathematical models to track energy wave travel through Earth layers.