tectonic hazards and processes

Micro approach to improving protection from earthquakes
Quake- proof buildings
1 of 69
Four types of plate boundary
Convergent, divergent, conservative, transform
2 of 69
Two plate boundaries where most powerful earthquakes occur
Convergent, conservative
3 of 69
Two plate boundaries where most volcanoes occur
Divergent, convergent
4 of 69
How do hotspot volcanoes occur?
Crust above magma plume is weak, magma leaks through
5 of 69
Example of hotspot volcanoes
Hawiann islands
6 of 69
Characteristics of oceanic plate
Thin, light, made of basalt
7 of 69
Characteristics of continental plate
Thick, heavy, made of granite
8 of 69
Cause of plate movements
Convection currents in mantle causing slab pull
9 of 69
Three processes at work on destructive plate boundary
Subduction, mountain building, volcanic & seismic activity
10 of 69
What paleo-magnetism is
When cooling magma locks into earths polarity
11 of 69
How paleo-magnetism helps study of tectonics
Can work out; when there were large tectonic activity in geological history, directions and speeds of past and current plate movements
12 of 69
Example of a locked fault causing a tectonic hazard
2004 Indian Ocean tsunami
13 of 69
Why locked faults occur
The friction along the plate is greater than the stress across it
14 of 69
What the Benioff zone is
Oceanic plate subducted under continental plate > stress=earthquakes > within this zone oceanic plate is melted
15 of 69
Hypocentre
Origin
16 of 69
Epicentre
Manifestation, directly above hypocentre
17 of 69
Magnitude of earthquake
Amount of displacement of crust & amount of energy released
18 of 69
Intensity of earthquake
Amount of ground shaking
19 of 69
Three types of seismic waves
(1)P-waves: vibrations caused by compression, spread quickly, (2)S-waves: vibrations at right angles to direction of movement, slower, (3)L-waves: surface waves with high amplitude
20 of 69
Secondary hazards of earthquakes
Tsunamis, landslides, liquefaction
21 of 69
Liquefaction definition
Where sands, silts, and clays loose their load bearing capacities
22 of 69
Primary volcanic hazards
Lava flows, tephra, ash clouds
23 of 69
Jokulhaups
Glacial outburst floods caused by volcanic eruption occurring under ice sheet/ glacier
24 of 69
Key areas of globe affected by tsunamis
Pacific basin, Japan - Taiwan island arc, South America, Aleutian islands
25 of 69
Hazard risk equation
(hazard x vulnerability) / manageability
26 of 69
What vulnerability means in regards to hazards
The likelihood of a community being unable to recover from the affects of a hazard
27 of 69
What resilience means in context of hazards
How well a community can deal with the affects of a hazard
28 of 69
What makes a hazard into a disaster
When a hazard causes significant damage and destruction to a vulnerable population
29 of 69
The two pressures on the Pressure and Release model
Natural hazard event & vulnerability of people experiencing hazard
30 of 69
Scales used to measure earthquakes
Richter, Mercalli, MMS (moment magnitude scale)
31 of 69
Rickter
Measures amplitude of eathquakes shock waves
32 of 69
What VEI measures
Volcanic Explosivity Index measures volume of material ejected, height of eruption cloud, and other qualitative observations
33 of 69
Six characteristics in hazard profile
1)speed of onset, 2)magnitude, 3) areal extent of damage, 4)duration, 5)freqency, 6)predictability
34 of 69
Value of hazard profiles
Comparisons can be made, informs decision making in hazard planning to identify factors such as level or risk and scale/ impacts.
35 of 69
Inequalities causing low income communities to be affected worse
Less money to recover, access to services inequality; education, health care, policing etc. Political inequality, social status inequality
36 of 69
How poor governance increases vulnerability
People uneducated on response, lack of investment in infrastructure, inadequate transport links, inadequate mitigation strategies.
37 of 69
Why disaster statistics aren't altogether reliable
(1) Governments lying = more aid (2) Commercial bias = downplayed in tourist areas (3) Disasters unrecorded due to remoteness
38 of 69
Characteristics of mega disasters
(1) Huge damage to infrastructure/ loss of life, (2) Large economic impacts, (3) Likely to need international support, (4) High impact, low probability
39 of 69
Example of tectonic mega disaster
Asian 2004 tsunami
40 of 69
Why there is concern over world's rapidly growing mega cities
Located in hazard prone/ multiple hazard zones , Sheer population size and density = severe impacts
41 of 69
Four stages of hazard management cycle
Mitigation - Preparedness - Response - Recovery -
42 of 69
What the risk disk model attempts to explain
Decline in disaster deaths in terms of preparedness, mitigation, response & recovery
43 of 69
Role of scientists in dealing with tectonic hazard
Seismologists - Predict WHERE and when earthquake could occur , Volcanologists - Predict WHERE and WHEN eruption could occur
44 of 69
Human factors affecting response
Education, quality of emergency services, quality of infrastructure/ transport links, population density
45 of 69
The four stages of Park's model
Pre-disaster - Relief - Rehabilitation - Reconstruction
46 of 69
How Park's model helps study of tectonic disasters
Compares two or more curves, Better understanding of their relative resilience, Help plan and understand risk, Places at risk to better prepare
47 of 69
Micro approach to improving protection from volcanoes
Spraying water on lava flows
48 of 69
Macro approach to protection from tsunamis
Tsunami wall, land use zoning, coastal buffers (mangroves)
49 of 69
Role of planners in managing impacts of tectonic hazards
Modifying potential impacts of event (land use zoning, improving prediction/ early warning systems) Improving preparedness (emergency action plans, education)
50 of 69
Role of insurers in managing impacts of tectonic hazards
Reduce financial burden - only for those who can afford insurance premium - no use to poor
51 of 69
Role of non-governmental organisations in managing impacts of tectonic hazards
Most active during emergency phase - providing various forms of aid. Educating about hazard risks & response
52 of 69
Four approaches to hazard management
1) Modify loss 2) Modify vulnerability 3) Modify the event 4) Modify the cause
53 of 69
How to modify loss
Aid and insurance
54 of 69
How to modify vulnerability
Improve prediction, preparedness, educate public on response
55 of 69
How to modify the event
Land use zoning, construct hazard resistant buildings, strengthen defences
56 of 69
How to modify cause
Not really possible, only on small scale hazards such as landslides
57 of 69
How to evaluate approaches to hazard management
1) Feasibility 2) Cost 3) Effectiveness 4) Type of hazard
58 of 69
japan earthqauke/tsunami 2011
>magnitude of 9.0 >paciifc plate sliding underneath North american plate
59 of 69
effects and responses of japan earthqauke/tsunami 2011
EFFECTS=16,000 killed, 12 countries effected, 230,000 people who lost their homes , Ports and airports in Sendai were damaged and closed. RESPONSES= seawall bulilt but the tsunami was too powerful and went past it,tsunami warning system put in place
60 of 69
Indian ocean (2004
subduction of the Indo-Australian plate(oceanic) under the Eurasian plate(continental)
61 of 69
effects and responses of Indian ocean (2004) earthquake/tsunami
EFFECTS=220,000 people killed,1.7M people displaced, countries such as india.maldives and thailand effetced RESPONSES=warning system, action aid>£13M
62 of 69
Haiti earthquake
the North American Plate sliding past the Caribbean Plate at a conservative plate margin
63 of 69
effects and responses of haiti earthquake
EFFECTS=316,000 people died, 3M affected, 4,000 prisoners escaped, hospitals & schools damaged RESPONSES=810,000 people in aid camps, water and saniations given to 1.7M people
64 of 69
mt st helens
near to a destructive plate boundary where the small Juan de Fuca Plate is being sub ducted underneath the North American Plate.
65 of 69
effects and responses of mt st helens eruption
EFFECTS=15cm ash fall leading to trafic chaos, mudflows choking up rivers and killing sea life, 7000 animals dead, less tourism, 57 people dead RESPONSES=aid protection, providing shelters, medical supplies
66 of 69
mt pinatubo
located at the plate boundary between to the Eurasian and Philippine Plate.
67 of 69
effects and responses of mt pinatbo
EFFECTS=847 died,300 killed by collapsing roofs and 100 by lahars,1.2m people lost their homes RESPONSES=barriers,diversions of lava flow, 58,000 evacuated
68 of 69
other case studies
hawaii islands, mt etna, phillipines, Eyjafjallajokull Eruption - 2010,
69 of 69

Other cards in this set

Card 2

Front

Four types of plate boundary

Back

Convergent, divergent, conservative, transform

Card 3

Front

Two plate boundaries where most powerful earthquakes occur

Back

Preview of the front of card 3

Card 4

Front

Two plate boundaries where most volcanoes occur

Back

Preview of the front of card 4

Card 5

Front

How do hotspot volcanoes occur?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Geography resources:

See all Geography resources »See all Natural hazards resources »