Power of the Planet Year 9 Flashcards
(15 cards)
Timeline of beginning of Earth
Big Bang-Sun forms-Earth forms-Moon forms-Earth surface cools-ocean forms-living cells appear
Timeline from bacteria to us
3.5 bya stromatolites release O2 to world, 550 mya bacteria in sea forms new plants and creatures, 475 mya life in ocean comes on land, 410 mya fish form teeth and more new plants grow, 395 mya fish develop into tetrapods and use fins as feet, 360 mya tetrapods come to land and creatures like milipedes grow, 248 mya ash from volcanoes blocks sun and 95% of Earth life dies, 230 million years ago survivors develop into dinosaurs, 200 mya the first mammals appear, 65 mya a meteorite hits Earth and kills dinosaurs, 2 mya creatures related to apes appear in African and walk, 200000 years ago humans appear
Name the periods of time
Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian, Triassic, Jurassic, Cretaceous, Paleogene, Neogene, Quaternary
In descending order, name layers of the Earth and their depth
Oceanic crust (5-10 km), continental crust(30-70 km), upper mantle(410 km), lower mantle(660 km), outer core(5150 km), inner core(5270km)
Composition of each layer
Oceanic crust-Igneous rocks, Continental crust-Light coloured rocks, Upper mantle-Silicate minerals, Lower mantle-Silicate minerals, Inner core-Iron and nickel, Outer core-Iron and nickel
What is a constructive/divergent plate boundary?
Where 2 tectonic plates move away from each other, allowing magma to rise through the gap
What is a transform/conservative plate?
Where 2 plates slide past each other, get stuck together and build pressure, jolt into new position upon release and release huge amount of energy (earthquake)
What is a convergent plate boundary?
Two tectonic plates collide, oceanic crust is heavier and sneaks under continental crust into mantle, plate melts and forms magma which forces it way through crust and creates volcanoes
Who are at most risk to tectonic hazards?
Those who live near active tectonic plate boundaries such as inhabitants of Japan, Nepal, Chile, Indonesia, Turkey, those who live in poorly built housing as they are more likely to collapse, those who live in countries near coasts such as inhabitants of Sri Lanka and Thailand, those who live in densely populated cities such as Jakarta or Kathmandu
What is the top speed and temperature of pyroclastic flows?
100 km/h, 1000 degrees
Name 4 volcanic hazards
Lava flowing from the volcano destroys everything in its path, pyroclastic flows, volcanic ash and rocks blasted into air can collapse roofs and pollute environment, toxic gases like sulfur dioxide can be released
What caused the 1997 Montserrat eruption?
Over time, magma accumulated beneath the volcano Soufriere Hills due to subduction at a convergent plate boundary and a large dome formed at the top of the lava, large dome collapsed in 1997 and triggered pyroclastic flows
What were the effects of the 1997 Montserrat eruption?
Killed 19, destroyed airport and port, buried capital Plymouth under ash, large parts of south became uninhabitable, homes and businesses and schools were destroyed
What was the response to the 1997 Montserrat eruption?
Residents of south were evacuated, shelters put up in north, millions of pounds and food, water and medical supply was given by UK as emergency aid (all short term), new capital Brades developed in north with help from hundreds of millions given by UK, exclusion zones created to keep people away from areas of danger, new infrastructure was built (long term)
