sci sci Flashcards
Who proposed the theory of continental drift?
Alfred Wegener, a German geophysicist.
What is Pangea?
A supercontinent that existed 250 million years ago.
What are the four key observations to prove Pangea?
- Continental shelves fit together like a puzzle.
- Matching fossils are found on different modern continents.
- Matching mountain ranges are found on different modern continents.
- Same rocks found on different modern continents.
What are fossils?
Traces or remains of organisms that lived long ago, found in sedimentary rocks.
What is a continental shelf?
The edge of a continent that is underwater.
What are divergent plate boundaries?
Two plates moving away from each other.
What is a rift valley?
A place where two plates are pulling apart. Example: Great Rift Valley in East Africa.
What is a linear sea?
When the rift valley gets wider and fills with salt water.
What is an ocean basin?
When a linear sea gets so big, it becomes an ocean.
What is a mid-ocean ridge?
An underwater mountain/volcano range.
Example: Mid-Atlantic Ridge.
How was the Atlantic Ocean formed?
It formed when South America and Africa split into two continents millions of years ago.
What is a convergent plate boundary?
Two plates come together.
What is an ocean-ocean convergent boundary?
An example is Japan.
What is subduction?
The older, basalt ocean floor sinks down into the asthenosphere and liquifies.
What is a trench?
The deepest part of the ocean where subduction occurs.
What is an ocean-continental convergent boundary?
An example is the Andes Mountains, where the ocean floor subducts, creating volcanoes.
What is a continental-continental convergent boundary?
An example is the Himalayan Mountains.
What is a transform fault boundary?
Two plates slide past each other.
Example: San Andreas Fault in California.
What are the Aleutian Islands?
Convergent, ocean-ocean volcanic islands with a trench, composed of extrusive igneous rock.
What is the San Andreas Fault?
A transform fault in California known for earthquakes.
What are the Andes Mountains?
A convergent, ocean-land region with volcanoes and a trench, located in South America.
What is the Mid-Atlantic Ridge?
Underwater volcanoes in the middle of the Atlantic Ocean, representing a divergent plate boundary.
What is the Great African Rift Valley?
A divergent plate boundary that causes deep cracks in the soil.
What are the Himalayan Mountains?
A convergent, land-land region, home to Mt. Everest.
What is Japan’s geological feature?
Volcanic islands with a trench, located at a convergent plate boundary (ocean-ocean).
What is the Earth’s crust?
The top layer of Earth with land and oceans.
What is the mantle?
Comprises 84% of Earth, where convection occurs that moves the tectonic plates.
What is convection?
The circulation of liquids due to uneven heating (from crust to inner core).
What is the outer core?
A liquid layer of the Earth that contributes to the planet’s magnetic field.
What is the inner core?
A solid layer of the Earth that is very hot and under lots of pressure.
