Geology Chapter 1 - Lesson 2 Flashcards

Geologists study the Earth's interior using direct evidence from rock samples and indirect evidence from seismic waves.
Rock samples are obtained through drilling, providing insights into the Earth's structure and conditions at various depths.

Seismic waves generated by earthquakes are recorded and analyzed by geologists to infer information about the Earth’s layers.

The Earth is composed of three main layers: the crust, mantle, and core.
These layers differ significantly in size, composition, temperature, and pressure.

Pressure increases with depth due to the weight of overlying rock, leading to higher temperatures in the Earth's interior.

Crust: The Earth's outer skin made of solid rock, including land and ocean floor.
Ocean Crust: Found beneath oceans, primarily composed of basalt and ocean sediment.
Continental Crust: Forms continents and consists of diverse rock types, primarily granite.

Basalt: A dark, fine-grained volcanic rock that forms the ocean crust.
Granite: A light-colored, coarse-grained igneous rock that characterizes the continental crust.

The mantle, nearly 3,000 kilometers thick, is made of hot, solid rock divided into layers based on physical properties.
Lithosphere: The brittle uppermost part of the mantle combined with the crust, characterized by strong rock.
Asthenosphere: Located beneath the lithosphere, it is less rigid and hotter, under increased pressure.
Mesosphere: Below the asthenosphere, this layer is hot yet more rigid due to higher pressure, including the transition zone and the lower mantle.

Composed primarily of iron and nickel, divided into:
- Outer Core: A layer of molten metal surrounding the inner core, causing it to be liquid.
- Inner Core: A dense, solid metal ball where extreme pressure prevents iron and nickel from becoming liquid.