eps sci Lecture 5- Planetary Surfaces

Oceanic crust

The thinner section of Earth's crust, primarily made of basalt, and typically 7-10 km thick.

Continental crust

The thicker section of Earth's crust, consisting of various rock types including granite, and measuring 25-70 km in thickness.

Plate tectonics

A theory that explains geological processes through the movement of tectonic plates on the Earth's surface.

Volcanism

The geological process involving the eruption of magma from below the Earth's crust, leading to the formation of volcanic landforms.

Erosion

The process of wearing down high places and filling in low places on a planetary surface, driven by gravity, atmospheric pressure, and temperature.

Impact craters

Circular depressions on planetary surfaces formed by the collision of asteroids or comets.

Lithosphere

The rigid outer layer of the Earth, consisting of the crust and the upper mantle.

Asthenosphere

The partially molten layer beneath the lithosphere that allows for the movement of tectonic plates.

Divergent boundaries

Plate boundaries where tectonic plates move apart, creating new oceanic crust at mid-ocean ridges.

Convergent boundaries

Plate boundaries where tectonic plates move toward each other, leading to subduction zones and mountain formation.

Transform boundaries

Plate boundaries where tectonic plates slide past one another, often causing earthquakes.

Hot spots

Areas where mantle plumes create volcanic activity independent of plate boundaries, such as the Hawaiian Islands.

Rifting

The process in which continental lithosphere stretches and breaks apart, forming rift valleys and new ocean basins.

Caloris basin

A large impact structure on Mercury, characterized by evidence of volcanic activity and lava-flooded craters.

Tectonism

The geological process involving movements of the Earth's lithosphere, leading to earthquakes and the formation of landforms.

Convective currents

The currents within the mantle that drive the movement of tectonic plates.

Maria

Dark, smooth plains on the Moon formed from cooled lava that filled ancient impact basins.

Highlands (Moon)

Bright, heavily cratered elevated regions of the Moon's surface, distinguished from the darker maria.

Magma

Molten rock beneath the Earth's surface that can erupt as lava during volcanic activity.

Volcanic landforms

Landforms created by volcanic activity, including volcanoes, lava flows, and volcanic plains.

Mass wasting

The downslope movement of rocks and debris due to gravity, contributing to erosion.