Earth Video

What was the source of heat that keeps the interior of the Earth very hot?

Radioactivity and radio active decay

Where did most of the water on earth come from?

extra terrestrial water rich asteroids and commets. CO2 rocks cooled

how did the development of the ozone layer allow life to develop on land?

free life from the oceans, it acts as a UV shield and absorbs UV rays

What type of rock is found under the continents?

granite

What caused the dinosaurs to go extinct 65 million years ago? list both events

hit by an enormous meteor. 100 mi. crater. or from lava flows

How are mountains such as the alps formed?

mountains become squeezed higher and higher (Europe and Africa)

How did Alfred Wegner explain the same fossils found in areas separated by many miles of ocean?

proposed the continents were once joined together and then drifted apart.

what 2 countries were found in the heart of the supercontinent Rodenia?

Canada and the U.S.A.

How did the Earth form?

collisions of countless meteorites in the young solar system

When could the next ice age occur?

15 thousand years in the future

What is the rate at which North America and Europe are moving apart? (cm and in)

2.5 cm per year or one inch per year

What is the current accepted age for the earth?

4.5 Billion years

Which planet will Earth resemble when the core finally cools and plate tectonics stops?

Mars

what did stromatolites add to the atmosphere? What happened to the iron in the oceans when this compound was added?

Oxygen. oxygen combined with iron and made rust and the ocean turned from green to blue.

What evidence for the ice ages can be found in the granite of central park?

Parallel grooves in the granite rocks

what caused the greatest mass extinction 250 million years ago?

Volcanic eruptions (mantle plum eruption) occurred for 1 million years

Describe what happened to the earth 700 million years ago?

the polar regions froze and the temperature fell below -40 degrees. most species were driven to extinction

By what processes was the Grand Canyon formed?

the uplifting of the colorado plateau and erosion by the colorado river

describe what happens to rocks between two colliding continental plates..

they collide and form continental mountains

How is radioactivity used by scientists?

to accurately date the planet, make bombs and make energy