HTEWM Video Flashcards
What was Earth like:
4.5 BYA
World of Fire: Earth entirely molten, ~8,000º F, lots of meteor impacts, very little atmosphere
What was Earth like:
4.0 BYA
Water World: Surface rocks have cooled, small volcanic islands, 90% ocean, iron rich green oceans, CO2 rich red atmosphere, ~200+º F
What was Earth like:
3.4 BYA
Granite Planet: New granite forming the first cratons and continents, shallow water along edges of new land, lots of stromatolites, O2 being added to air
What was Earth like:
1.5 BYA
Blue Planet: Continents growing larger, lots of stromatolites, more oxygen in atmosphere, skies turning blue, iron in oceans “rusting” and sinking, oceans turning blue
What was Earth like:
1.0 BYA
Supercontinent Rodinia: Continental collisons, land is barren and lifeless, land blocks warm ocean currents, temperature dropping, poles freezing over
What was Earth like:
700 MYA
Snowball Earth: Polar ice moving towards equater becasue warm ocean currents are blocked, entire planet under 1 mile of ice, -40º F, mass extinction in oceans
What was Earth like:
650-550 MYA
Breakup of Rodinia: CO2 levels increase, temps rising, high oxygen levels, ozone layer starts forming, ocean basins widening, explosion of marine life
What was Earth like:
300 MYA
World of Tropical Swamps: Continents converging, Earth hot and humid, large plants, jungles and swamps, giant insects, amphibians and reptiles, oceans full of life
What was Earth like:
300-200 MYA
Supercontinent Pangea: N/S America, Africa, Europe and Antartica all connected, time of huge volcanic eruptions, mass extinction event and rise of dinausours, O2 and CO2 levels rising
What was Earth like:
200-100 MYA
Breakup of Pangea: Intense global warming, highest levels of O2 and CO2, hot and humid, tropical forests with dinausours, overactive volcanoes
What is Earth like:
Present Day
Earth Today: 71% ocean, 29% land, 7 continents, atmosphere 78% nitrogen, 21% oxygen, .9% argon, planet getting warmer, experiencing global climate change
Rocks at Siccar Point, Scotland
What does this evidence prove?
Evidence that the Earth is very old
Modern day volcanic activity
What does this evidence prove?
Evidence that Earth started out entriely molten
Radioactive elements such as uranium and potassium
What does this evidence prove?
Provides evidence via radiocative decay that Earth formed 4.5 BYA
Ancient pillow lavas dating 3.5 BYA
What does this evidence prove?
Provides evidence that Earth was covered by deep oceans 3.5 BYA
Ancient zircon crystals dating back 4.4 BYA
What does this evidence prove?
Provides evidence that Earth’s surface had water on it 4..4 BYA
Meteorites that have fallen to Earth
What does this evidence prove?
Provides evidence that most of Earth’s water arrived on meteors
Ancient granite cratons dating back 3.4 BYA
What does this evidence prove?
Provides evidence that the first continents on Earth were forming 3.4 BYA
Living and fossilized stromatolites
What does this evidence prove?
Provides evidence that early life on Earth changed the atmosphere by creating and releasing oxygen through photosynthesis
Banded iron formations dating back 1.5 - 2.5 BYA
What does this evidence prove?
Provides evidence that Earth’s atmosphere contained oxygen starting 2.5 BYA. This change caused the iron dissolved in ocean water to rust and sink, eventually creating rock
Fossilized trilobites being discovered on both sides of the Atlantic
What does this evidence prove?
Provides evidence that the Atlantic Ocean didn’t always exist and Earth’s continents were connected
Matching coastlines of Africa and South America
Provides evidence that Earth’s continents used to be connected
WWII sonar maps of undersea terrain
Provides evidence that Earth’s crust is separated into large plates that move, recycle and the seafloor
Volcanic fissures and fissure eruptions in Iceland
Provides evidence that Earth’s crust is separated into large plates that move as seafloor is created and recycled
