Plate Tectonics and Pangaea Overview

Pangaea

• Pangaea was a supercontinent that contained all land masses
• Was formed around 250 million years ago
• Broke up around 200 million years ago

Plate Tectonics

• Theory widely accepted since the 1960s
• Earth's outer layer is broken into several large slabs called plates
• Plates hold the continents and oceans
• Plates slowly and constantly move around the planet
• Supports the understanding that continents aren't fixed and have moved over time
• Explains how and why earthquakes, volcanoes, and other geologic events occur

Types of Crust

• Continental Crust is thicker than Oceanic Crust

Tectonic Plates

• North American Plate carries Canada, US/Central America, and the NW Atlantic Ocean
• Pacific Plate, Juan De Fuca Plate, and North American Plate boundaries are located on the BC west coast.

Plate Boundaries

• Convergent Boundaries are an area on Earth where two or more plates push toward each other.
• Divergent Boundaries are two tectonic plates moving away from each other
• Transform Boundaries happen when two tectonic plates slide against each other.

San Andreas Fault

• Is a famous transform boundary
• Located in California, USA

Divergent Boundaries

• Push up large amounts of land
• Cause land masses to rift/break apart
• Magma rises between the cracks of the plates
• Hardens/cools from cold ocean water.

Convection Currents in the Mantle

• Magma rises to the top, causing the earth to split apart
• When plates split apart, some collide, causing one of them to go underneath the earth
• When some of that rock is melted due to the intense heat, carbon dioxide is released and once enough pressure is built, volcanoes form and erupt.
• This cycle repeats as not all of the magma stays on the surface; some comes back down, and once reheated, comes back up.
• Inner core can have temperatures of up to 5500 degrees C
• Oceanic plates are found are oceans, and continental plates are found beneath large land masses

Fold Mountains

• Formed over millions of years when colliding tectonic plates cause the Earth's crust to warp and fold, a process known as orogeny.
• Typically found at convergent plate boundaries
• Primarily made of weaker sedimentary and metamorphic rocks
• More prone to folding due to compression forces.

Ocean Trenches

• Connected to divergent boundaries
• Mariana's Trench is the deepest ocean trench, located in the Pacific Ocean

Oceanic Crust

• Thinner than continental crust

Cascadia Subduction Zone

• The Juan De Fuca plate is in the process of subducting underneath the North American Plate

"The Big One"

• The earthquake that will occur when the Juan the Fuca plate hits the North American Plate.
• Magnitude 8 or above

Urban Infrastructure

• Buildings, roads, bridges, power lines, water supply systems
• Impact by "The Big One" will likely result in loss of power and water, damage to buildings and infrastructure.

Tsunami Evacuation Protocol

• Tsunami hazard zone/inundation area is at risk of being flooded by a tsunami
• Assembly areas/meeting spots are safe locations to gather after an earthquake
• Stay outside of tsunami hazard zones to avoid being affected by the tsunami
• Notification Zones are areas that are at risk of being affected by a tsunami.

DART

• Deep-Ocean Assessment and Reporting of Tsunamis
• Stations are located around the Pacific and Atlantic Oceans, as well as near earthquake zones
• Buoys stationed within earthquake zones measure wave heights
• Predicts the area of land that will be affected by a tsunami using the data the buoys obtain.
• Provides a high-quality tsunami forecast showing which areas will be inundated

Earthquake Preparedness

• Before, During, and After are the three recommended stages in earthquake preparedness
• Secure your stuff by securing heavy items and moving breakable items to lower shelves.
• Plan to be safe by creating an emergency plan, choosing a meeting spot after the earthquake and having a plan to communicate with family.
• Get emergency supplies such as water, food, and a first aid kit.

Explore the formation and breakup of Pangaea, the supercontinent that existed around 250 million years ago. Understand the theory of plate tectonics, including the types of crust and different plate boundaries, which explain the movement of Earth’s continents and the geological activities that occur. This quiz covers the fundamental aspects of Earth's geological processes.