Flashcards in Lecture 12 Deck (18):
Define a compounded hazard.
Linked or sequential events, one event leading to another.
Earthquake ---> tsunami
Earthquake ---> fire
Define a risk?
Human or environmental vulnerabilities, exposed infrastructure, activities, economics
What are faults?
A break in the earths crust/ fractures in the lithosphere.
What happens if a fault suddenly occurs?
What is another name for a transform fault?
What is an indicator of a slip strike fault or transform fault?
Define a natural hazard?
Atmospheric, hydraulic or geologic process that affects humans society, infrastructure that impacts our lives
What is an earthquake?
Surface shaking produced by rapid release of strain from tectonic plates. It produces waves that radiate in all directions
What two waves are emitted by an earthquake?
P wave (primary)
S wave (secondary)
Describe a primary wave.
Push pull motion that can travel through any surface.
Describe a secondary wave.
Up down motion. This wave is absorbed by water and sediment but propagates well through solids
What is the measure of an earthquake
Intensity and magnitude and is logarithmic
What four factors are connected to an earthquakes destruction?
Magnitude and direction
Amplification of waves
What material do structures rest on
Design of structures
A surface liquefying due to seismic waves
What is a tsunami?
Seismic generated sea wave that starts low and fast offshore And surges up on shore standing up
True or false:
earthquakes can alter earths tilt
What is the epicentre?
The point directly above the focus on the earths surface indication the start of a an earthquake