yes Flashcards
Who proposed the theory of continental drift?
Alfred Wegener, a German geologist and meteorologist, proposed the theory in 1912.
What is continental drift?
The concept that Earth’s continents were once part of a large supercontinent but split apart and moved to their present locations.
What does Pangaea mean and what was it?
Pangaea means ‘all lands’ in Greek and was a supercontinent that existed millions of years ago.
What is Gondwana?
The southern part of Pangaea that eventually broke into South America, Africa, India, Australia, and Antarctica.
What is Laurasia?
The northern part of Pangaea that eventually broke into North America and Eurasia.
What are some predictions for continental movement in 50 million years?
Continents will move further north, Central America and the Caribbean may be submerged, Australia will move closer to the equator, and coastlines will shrink due to rising sea levels.
What are the four proofs of continental drift?
- Puzzle Pieces – Continents fit together like a puzzle (e.g., South America and Africa).
- Similar Fossils and Rocks – Matching rock types and fossils found on continents now far apart.
- Mountain Locations – Similar mountains on both sides of the Atlantic.
- Ice Sheets – Evidence of glaciers in areas that are now warm.
What was an issue with Wegener’s theory?
He could not explain what force was strong enough to move continents.
What modern proof supports continental drift?
Satellites (Lageos I & II) show continents drifting about 2.5 cm per year.
Who developed the modern Plate Tectonics theory?
John Tuzo Wilson, a Canadian geophysicist, developed the theory in the late 1960s.
What is the Plate Tectonics theory?
The theory that Earth’s outer shell consists of 20 moving plates, causing earthquakes, volcanoes, and mountains.
What are convection currents?
Circular movements in the mantle caused by heat, driving plate movement.
What is a divergent boundary?
Where plates move apart, forming new crust (e.g., Mid-Atlantic Ridge, East African Rift Valley).
What is a convergent boundary?
Where plates collide, forming mountains or subduction zones (e.g., Himalayas, Pacific Ring of Fire).
What is a transform boundary?
Where plates slide past each other, causing earthquakes (e.g., San Andreas Fault, Alpine Fault in New Zealand).
What is the Ring of Fire?
A Pacific Ocean region with 75% of Earth’s volcanoes and 90% of its earthquakes.
What is a tsunami?
A series of ocean waves caused by underwater earthquakes, volcanic eruptions, or landslides.
What is a seismograph?
An instrument used to measure earthquake vibrations.
What is the Richter scale?
A scale used to measure the magnitude of earthquakes.
What is the largest earthquake recorded?
A 9.5 magnitude earthquake in Chile in 1960.
What is a volcano?
An opening in the Earth’s crust where magma, ash, and gases escape.
Where are Canadian volcanoes mainly found?
In British Columbia and Yukon.
What is a glacier?
A slowly moving mass of ice formed by accumulated and compacted snow.
What is an alpine glacier?
A glacier found in mountains, moving through valleys.
