FLASHCARDS-2

Front

What is Continental Drift Theory?

Back

Continental Drift Theory, proposed by Alfred Wegener in 1912, suggests that Earth's continents have moved over geological time. According to Wegener, all continents were once part of a supercontinent called Pangaea. Over millions of years, this massive landmass broke apart, and the pieces drifted to their current positions.

Key points:

• Pangaea: The supercontinent that existed about 300 million years ago.

• Plate Tectonics: The mechanism driving the movement, involving Earth's lithospheric plates shifting on the semi-fluid asthenosphere beneath them.

• Evidence: Fossil records, geological formations, and the fit of South America and Africa's coastlines support this theory.

Front

Tectonic plates

Back

Large slabs of rocks that divide the Earth's crust that continuously moves to shape the Earth.

Front

What is mid-ocean ridges?

Back

A mid-ocean ridge is an underwater mountain range formed by plate tectonics. Some key points about mid-ocean ridges:

• Location: They are found in all of the world's oceans, with the most famous being the Mid-Atlantic Ridge.

• Formation: They form at divergent plate boundaries, where two tectonic plates are moving away from each other.

• Geological Activity: These areas are sites of frequent volcanic activity and earthquakes due to the movement and interaction of tectonic plates.

• Hydrothermal Vents: Mid-ocean ridges are home to hydrothermal vents, which spew superheated water rich in minerals, supporting unique ecosystems.

Front

Plate Boundary

Back

Plate boundaries are the edges or area where two tectonic plates meet, and they are classified into three main types based on their movements:

1. Divergent Boundaries

• Description: Plates move away from each other.

• Example: Mid-Atlantic Ridge.

• Result: Creation of new crust, leading to seafloor spreading and rift valleys.

2. Convergent Boundaries

• Description: Plates move towards each other.

• Example: Himalayas (continental-continental collision), Andes Mountains (oceanic-continental collision).

• Result: Subduction zones, mountain formation, and volcanic activity.

3. Transform Boundaries

• Description: Plates slide past each other horizontally.

• Example: San Andreas Fault in California.

• Result: Earthquakes due to the friction and stress buildup.

Front

Mid-ocean ridges

Back

product of divergent plate boundary

Front

What is convection current?

Back

Convection currents in the mantle drive plate tectonics or movements of the plates, leading to volcanic activity and earthquakes.

Front

Highest mountain in the world

Back

Mount Everest holds the crown, standing at a staggering 8,848 meters (29,029 feet) above sea level. Located in the Himalayas, on the border between Nepal and Tibet.

Front

Pressure

Back

Most important factor in the formation of magma

Front

Two types of tectonic plates

Back

Oceanic plates and Continental plates

Front

When Oceanic and continental plates collide...

Back

Continental plate floats, oceanic plates

sinks.