Flashcards in natural hazards Deck (12)
Loading flashcards...
1
how can prediction reduce the effects of tectonic hazards?
- earthquakes - cannot be reliably predicted, but scientists can forecast where they may occur by monitoring the movement of tectonic plates
- volcanic eruptions - can be predicted if scientists monitor volcanos closely
2
how can monitoring reduce the effects of tectonic hazards?
- earthquakes - seismometers and lasers monitor earth movements, can be used to give a vital amount of warning before a large earthquake
- volcanic eruption - scientists can monitor the tell-tale signs that come before an eruption. ex. escaping gas, change in shape of volcano
3
how can protection reduce the effects of tectonic hazards?
- earthquakes - new buildings can use reinforced concrete that absorbs an earthquake's energy
- existing bridges and buildings can be strengthened with steel frames so they're less likely to collapse
- automatic shut-off switches can turn off gas and electricity supplies to prevent fires
- volcanoes - buildings strengthened - less likely to collapse under weight of ash
4
how can planning reduce the effects of tectonic hazards?
- future developments can avoid high-risk areas
- emergency services can prepare
- people can be educated to know what to do in the event of a hazard
- governments can plan evacuation routes
- emergency supplies can be stockpiled
5
how can earthquakes occur at constructive margins?
tension builds along the cracks in the plates as they move away from each other
6
how can earthquakes occur at destructive margins?
tension builds up when one plate gets stuck as it moves past the other
7
how do earthquakes occur at conservative margins?
tension builds up when plates that are grinding past each other get stuck
8
how does an earthquake happen at all the margins?
- plates eventually jerk past each other - sending out shockwaves
- these vibrations are the earthquake
9
what are constructive margins?
- where two plates are moving away from each other
- magma rises from the mantle to fill the gap and cools creating new crust
10
what is used to measure an earthquake?
- the moment magnitude scale
- logarithmic scale
11
why do volcanoes occur at constructive margins?
magma rises from the gap created by the plates moving apart - forming a volcano
12
