hazardous environments Flashcards
What is a natural event
Something happening in the physical environment such as a storm, volcanic eruption or earthquake.
What is a natural hazard
An event that threatens the well-being of people and their property.
Multi hazardous environment
A region where more than 1 hazard may occur.
Whats the focus of an earthquake
The point in the earths crust where the pressure is released.
Whats the epicenter of an earthquake
The area on the surface of the earth directly above the focus.
What are seismic waves
Waves of energy that travel through the earths layers released from an earthquake.
What is volcanic ash
Fragments of pulverised solid lava.
What are lahars
A violent mudflow or debris that flow down the volcano.
What are pyroclastic flows
Clouds of hot poisonous gasses mixed with ash that flow down the side of a volcano.
State one reason people decide to live in areas
at risk of a hazardous event
Living close to your family.
Energy from volcanos can be good for hot springs.
The soil is fertilised for certain plants.
How are hot spots formed
hot spots form in the middle of plates, these are
called interplate volcanos. Magma plumes are formed
in the mantle of the earth and melt off bits of the crust.
magmga pushes into the crust forming a volcano. Over time the plate will move and the volcano will disconnect
from the plume at which point another one will be formed. Important to note the plume does not move only
the plate.
Description of destructive plate boundary
Continental and Oceanic plate moving toward each-other. The Oceanic one is heavier and therefore moves under the continental plate. Magma melts of part of the plate and pushes into it forming a volcano.
Description of collision plate boundary
Two continental plates move toward each-other but
since they have the same weight the collide and form mountains. This also means no volcano is formed
Description of conservative plate boundary
Two plates move in the same direction or against each-other. This movement causes earthquakes but no fold mountains or volcanos.
Description of constructive plate boundary
Two oceanic plates move away from each-other thus creating land which causes violent earthquakes.
What scale is used to measure earthquakes
Richter scale or Mercalli scale
What is used to measure volcanos
The VEI (Volcano Explosivity Index) scale
What is used to measure the power of hurricanes/typhoons
Saffir-Simpson scale
