hazards Flashcards
What are 3 types of hazards?
Hydrological
Geogphysical
Atmospheric
What is the Park Model?
a disaster/ response curve that shows the deterioration of quality of life after a hazard
What are the 4 stages of the Park Model?
Pre-disaster
Relief
Rehabilitation
Reconstruction
Advantages / Disadvantages of Park Model
A: useful to compare hazard events
shows recovery phase
deepness reflects scale of event
D: level of normality different for each country
some countries dont go back to normality
What are different perceptions of hazards
Adaptation, Domination and Fatalism
What are the 4 stages of hazard management cycle?
Preperation
Response
Recovery
Mitigation
What are the layers of the earth?
inner core
outer core
mantle
crust
Who introduced the continental drift?
Alfred Wegner
What is the theory of continental drift and its evidence?
All continents began as one big one called Pangea
jigsaw fit
fossil records
geology
What are convection currents?
Movements in molten rock in magma that acta as a conveyer belt for plates
What is ridge push?
magma rises, plates move apart
magma cools to form new plate material and causes plates to move apart from each other
What is sea floor spreading?
a process in which tectonic plates split apart from each other
What is the process of slab pull?
denser plate sinks back into mantle and rest of plate pulled with it
What is a hotspot?
A small volcano caused by a magma plume
What is a deep sea trench?
when denser oceanic plate subducts underneath less dense drust to form a ‘trench’
Island arc formation
partial melting of a plate at a subduction zone (destructive)
Young fold mountains formation
When two continental plates move towards each other accumulating sediment between them (destructive plate boundary)
Rift valleys formation
when tectonic plates beneath the Earth’s surface move away from one another in opposite directions, causing a small valley (conservative plate boundary)
Ocean ridge formation
When plates move away from each other, causing magma to move up and seperate these plates (conservative)
Deep sea trench formation
found on destructive plate boundary at the point where oceanic denser plate sinks into mantle (destructive)
Magma plumes and their relationship to plate movement
Magma plumes are areas of hot, upwelling mantle
As oceanic volcanoes move away from the hot spot of their tectonic plate, they cool and subside, producing older island chains.
What is positive feedback?
changes that take place amplifying impacts e.g enhanced greenhouse effect
What is negative feedback?
system counteracting change e.g leeves
What are the 3 types of magma?
Basaltic
Rhyolitic
Andesitic
Features of a shield volcano
-low viscosity
-high silica content
-lava flows far
-low height
Features of a composite volcano
-high viscosity
-low silica content
-ava flows short length
-high height
Describe information about the Mount Mayon eruption
13th Jan 2018
most active composite volcano in the Philippines
located in the Pacific Ring of Fire and on a destructive plate boundary
is surrounded by 9 towns
reached alert level 4
What are impacts and responses of the Mount Mayon eruption?
0 killed
64000 stayed in 58 evacuation centres
$3.4 million damage
10,000 farmers affected
Roads blocked due to landslides and ash fall
Some flights out of Legaspi were cancelled
Cash for work programme.
Hygiene packages for 50,000 families
Philippine Red Cross set up first-aid stations.
USAID gave $100,000. They constructed toilets, baths, hand washing stations.
Describe information about the Eyjafjallajökull eruption
erupted in 2010
located in Iceland
VEI 3
lies on Mid Atlantic Ridge
very fine ash and a persistent eruption lasting 39 days
What are impacts and responses of the Eyjafjallajökull eruption?
airlines lost £130m per day
Kenya lost $1.3 million due to loss of crops becauyse of ash
People had to wear masks and eye cover
fresh food imports stopped - especially in Europe
area around volcano was evacuated
European Red Cross helped with food packages and helping families mostly affected
EU integrated air traffic management
What is pyroclastic flow? Give a named example location.
the mixture of hot rock fragments and gases moving at high speeds in a large cloud
Pompeii - the stone people caused by pyroclastic flow
1980 - Mt. St. Helens caused 600km2 of forestry to be destroyed.
What is tephra? Give a named example location.
ash fall varying from fine ash to large volcanic bombs
2010 eruption of Eyjafjallajökull led to the cancellation of 100,000 flights. Tephra also causes breathing difficulties for people with respiratory problems.
What is a lahar? Give a named example location.
Mixture of water that has melted from snow on top of mountain and rock fragments/volcanic ash
Armero in Colombia was overwhelmed by lahars from the Nevado del Ruiz volcanic eruption. Although located more than 20km away from the volcano, over 22,000 people were killed in the 8m deep lahars.
What are tsunamis? Give a named example location.
huge sea waves formed when a large volume of water is suddenly displaced above the sea level by vertical movements of the continental shelf.
1883 - eruption of Krakatoa resulted in volcanic tsunamis. 35 metre high waves destroyed 300 villages and islands. More than 36,000 people died as a result.