Tectonics 3.1.3 Flashcards
what are the two types of seismic waves
body waves
surface waves
name and explain the two sections body waves splits into
body waves consists of 2 sections
1. p waves (primary) which are compression waves
2. s waves (secondary) which are transverse waves
name the two types of waves that ‘surface waves’ is split into
surface waves are split into
1. love waves
2. Rayleigh waves
name three characteristics of a p wave
p waves are the fastest waves
p waves are able to move through solid and liquid
p waves are compressional waves
name three characteristics of an s wave
s waves arrive directly after p waves, in the same direction
s waves only move through solids
s waves are transverse waves
explain two characteristics of surface waves (love and rayleigh)
- surface waves move slower than body waves ( p and s waves)
- surface waves speed depends on the density of the properties they pass through
explain how body waves move
body waves move in different ways but in the same direction
so p waves are compressional and s waves are transverse
both oscillate the ground, back and forth in the direction of the wave
describe which direction p waves move a house in contrast to s waves
p waves move it up and down as it is compressional but s waves move it side to side as the wave is transverse
which waves are most important for ground shaking
surface waves including love and rayleigh cause ground shaking, is the cause of what makes earthquakes most destructive
which waves are the slowest and which ones diminish less quickly in comparison to the others
Surface waves move the slowest in contrast to body waves, but surface waves remain with a high amplitude for longer than body waves, meaning that cause the most damage for longer
where are body waves released from
The focus
where are surface waves released from
The epicentre
name the primary hazards formed from earthquakes
the one primary hazard is that surface seismic waves are created
name the 3 secondary hazards formed from earthquakes
- Landslides
- Tsunami
- Liquefaction
Explain how Mt St Helen’s volcanic eruption was caused and what seismic secondary hazards occured
a 5.1 magnitude earthquake hit below the north slope, which caused the that part of the volcano to slide, creating one of the largest landslides recorded. This avalanche of debris slide into the Spirit lake, causing a 180 m high wave in the lake.
Name the 2 primary impacts of an earthquake and the 3 secondary impacts (this is different to primary Hazards)
Primary impacts
1. Social
2. Environmental
Secondary impacts
1. Economic
2. Social
3. Environmental
what are the main scale that primary hazards affect
Mainly primary hazards have a local affect, no primary impacts have a global scale impact
does the scale vary in the secondary impacts
The scale for secondary impacts is very even, lots of local and then some global and regional
name the secondary hazards that occur, which create primary impact and what scale is
- Landslides, Liquefaction and tsunamis are hazards that led to primary impacts socially and economically, all at a local scale
List some examples of primary impacts that happen after one of these secondary hazards occur, that you can mention in your essay
-Buildings collapse with people inside leading to death or injuries
- destruction of cars, infrastructure and airports
all at a local scale
List the hazards that occur due to secondary impacts of an earthquake
flooding, fires, disease
local/regional
Describe what secondary impacts could occur due to the primary impacts of the hazards and in what scale
Local scale secondary impacts
- Powercuts
- Homelessness / unemployment
- looting
Global scale of secondary impact
- loss of economic activity
- costs of repairs
explain 2 factors that affect the impact of a tectonic hazard
two major factors influence affect on humans is Risk and Vulnerability, because they contribute to whether a hazard becomes a disaster (more than 10 deaths)
Describe how the level of hazard risk can be measured (every time risk and vulnerability is mentioned in a title, think of this)
The risk equation
risk = hazard (freq/ magnitude) X level of vulnerability
over (divided)
coping capacity meaning resilience level
