EMES101 Study Questions for Lesson 3: Plate Tectonics

These flashcards cover key concepts from the lecture notes on Plate Tectonics, including Alfred Wegener's contributions, plate boundaries, and the processes involved in plate tectonics.

What key evidence did Alfred Wegener provide to support the theory of Pangaea?

He used fossils, geological formations, climatic evidence, and the fit of the continents to support his hypothesis.

Why was Alfred Wegener's theory of plate tectonics initially rejected?

The scientific community rejected his ideas due to lack of a mechanism explaining how continents moved.

What is the difference between seafloor spreading and continental drift?

Seafloor spreading is the process of new oceanic crust forming at mid-ocean ridges, while continental drift describes the movement of continents over geological time.

What occurs at mid-ocean ridges, and what is their significance to plate tectonics?

Mid-ocean ridges are underwater mountain ranges created by seafloor spreading, marking the boundaries where tectonic plates move apart.

What is a magnetic reversal?

A magnetic reversal is a change in Earth's magnetic field such that the positions of magnetic north and magnetic south are switched.

List the three main types of plate boundaries and one feature of each.

Divergent (mid-ocean ridges), Convergent (trenches), Transform (fault lines).

How do continental rift zones evolve to become spreading ridges?

Continental rift zones develop as a result of diverging plates, eventually leading to the formation of an ocean basin and creating a mid-ocean ridge.

What is isostasy and how does it relate to ocean basins and plate tectonics?

Isostasy is the equilibrium between the Earth's crust and mantle, affecting the distribution of ocean basins based on density and thickness of the crust.

What processes occur at transform plate boundaries?

At transform plate boundaries, plates slide laterally past one another, causing earthquakes and creating fault lines.

Why does oceanic crust subduct at a subduction zone?

Oceanic crust is denser than continental crust, causing it to sink into the mantle when they converge.