Year 10 Natural Hazards and Tectonic Theory 1A Flashcards
natural hazard
natural event that has potential to cause damage or destruction or death
earthquake
a sudden violent movement in the Earth’s crust
tectonic hazards
caused by movement of tectonic plates
weather hazards
tropical storms, drought, floods
molten
hoy, liquid and melted rock
magma
molten rock when it’s underground
lava
molten rock when it’s over the ground
Why is urbanisation affecting hazard risk?
high population density means more people in area so more are affected
Why is poverty affecting hazard risk?
low development means weak buildings and less medical care so less help and more deaths
Why is climate change affecting hazard risk?
higher temperature means more things like tropical storms so more are affected
Why is farming affecting hazard risk?
low lying land is more at risk to flooding
What is the inner core?
solid made or iron and nickel and is 5000°C and under high pressure
What is the outer core?
liquid made of iron and nickel
What is the mantle?
semi molten rock that is 3800°C
What is continental crust?
thick (20-200km) and less dense, made of granite, old (3.8 billion years old)
What is the crust?
surface layer of the Earth and there are two types, oceanic and continental
What is oceanic crust?
thin (5-10km) and more dense, made of basalt, young (200 million years old)
tectonic plate
section/segment of crust
plate margins
where plates meet
constructive plate margin
two plates moving away from each other so rising magma fills the gap
destructive plate margin
two plates moving towards each other and the oceanic crust is subducted under the continental crust
conservative plate margin
two tectonic plates slide past each other or side by side at different speeds
convection
convection currents occur by magma being heated by the core so it rises and when it hits the crust it splits in two opposite directions pushing crust apart and moving the plates
ride push
molten magma rises in the gap created between a conservative plate margin and cools to form new land which pushes the original plates further apart