Please enable JavaScript.
Coggle requires JavaScript to display documents.
hazards associated with earthquakes - Coggle Diagram
hazards associated with earthquakes
ground shaking
destroys ecosystems (natural systems)
ruptures oil and chemical factories, polluting land and water
fractures and uproot trees, causing widespread tree injury and death and damaging wildlife habitats
destroys properties and infrastructure (human system)
weakens buildings, bridges, roads and railways, causing them to collapse, making it difficult to rescue people or supply emergency aid
disrupt services (human services)
snaps water and gas pipes, resulting in water shortages and disruptions to gas supply
electricity and communication cables break, affecting important communication services such as tsunami warnings and television broadcasts
causes injuries and fatalities (human systems)
people may get trapped under collapsed buildings and infranstructure
examples:
2010 Haiti earthquake
2010 Christchurch, New Zealand earthquake
soil liquefaction
destroys ecosystem
trees on liquefied soil sink in and tip over, damaging wildlife habitats, causing forest and biodiversity loss
liquefied soil may enter rivers and smother aquatic plants, causing them to die
sewage pipes may be broken and untreated waste materials may pollute rivers, killing aquatic species
destroy properties and infrastructure
buildings and other infrastructure can sink in and tip over, and the damage makes it difficult to rescue people or supply emergency aid
disrupt services
electricity and communication cables, and water and gas pipes can sink in and snap, disrupting supply of these services
roads and railways above liquefied soil can sink in and get damaged, making it difficult to rescue people or supply emergency aid
causes injuries and fatalities
people can get trapped under collapsed buildings and infranstructure
examples:
2010 - 2011 Christchurch, New Zealand earthquakes:
-triggered severe liquefaction, as city lies on a former swamp area where soils are loose and saturated
more than 60,000 residential buildings and infrastructure covering about one-third of the city area were damaged
liquefied soil entered rivers and untreated sewage from broken pipes polluted rivers. resulting in the reduction of some species such as the caddisflies
soil liquefaction occurs when the violent ground shaking causes saturated loose soil to lose its soil structure and transform into a thick fluid
landslides
occurs as the violent vibrations form cracks on steep slopes, loosening the rocks and soil, and trigger the loose rocks and soil to move downslope
destroy ecosystems
fast-moving debris can bury huge areas of forest and wetlands
rivers can be polluted with debris, killing aquatic life
rivers can be blocked, causing floods that can damage nearby ecosystems and properties
destroy properties and infrastructure
debris can bury villages and farms, destroying properties and infrastructure
disrupts services
debris can snap electricity and communication cables, and water and gas pipes, disrupting supply of these services
road and railways can be blocked by debris, making it difficult to rescue people or supply emergency aid
causes injuries and fatalities
debris can bury people or hit them, causing injuries and loss of lives
debris can block rivers, resulting in floods which can drown people
examples:
2018 Papua New Guinea earthquake (Mw 7.5):
-triggered landslides that caused huge amounts of debris to enter the rivers
caused flooding
destroyed forests
polluted waters and killed fish
-2008 Great Sichuan, China Earthquake (Mw 7.9):
triggered more than 15000 landslides
-destroyed many buildings and infrastructure
-caused nearly 20,000 deaths
tsunamis
tsunamis are a series of ocean waves which can be caused by underseas earthquakes
tsunamis can travel over thousands of kilometers and devastate huge areas of coastlines
tsunamis occurs when:
-an undersea earthquake causes the seabed to be displaced
-a large volume of water is lifted, formed waves of great wavelength and how height of less than 1 metre
-the waves travel toward land at high speeds around 800km/h
on approaching the coast, greater friction with the shallower seabed slows the waves down
the waves get closer together and increase in height. waves can reach up to a height of 15m or more, travel at a speed of 30 -50 km/h and devastate shorelines the waves hit.
-before a tsunami occurs, the sea may recede from the shore because the sea water fills in the void caused by displacement of the seabed
destroys ecosystems
the seawater can flood huge areas of coastal wetlands and forests, damaging habitats
large amounts of debris carried in by the waves can pollute these areas, damaging ecosystems and killing wildlife
destroys properties and infrastructure
fast moving waters and the large amounts of debris carried in by the waves can sweep away buildings and infrastructure, destroying them
disrupt services
fast moving waters and the large amount of debris carried in by the waves can snap electricity and communication cables, disrupting supply of these services
fast moving water can sweep away roads and railways, making it difficult to rescue people or supply emergency
causes injuries and fatalities
sweeping water can drown people
large amounts of debris carried in by the waves can hit and kill people
examples:
2004 Indian ocean tsunami:
triggered by a 9.1 Mw undersea earthquake near Sumatra, Indonesia.
Tsunami waves slammed into the coast of 11 countries Indian Ocean countrie, from Indonesia to Somalia in Africa
More than 230,000 people were killed and entire coastlines and habitats were destroyed
2011 Tohoku, Japan earthquake (Mw 9.0)
triggered a tsunami up to 40m in height
waves destroyed homes and infrastructure
tsunami waves carried debris inland, flooding and polluting large areas of land
coastal city of Sendai suffered extensive damage and half its pop. was killed
In Iwate, 70,000 pine trees were knocked down, resulting in forest and biodiversity loss
The tsunami hit the Pacific islands, devastating the ecosystems
entire bird nesting sites were lost, and more than 100,000 Layson Albatross Chicks were killed, and thousands of fish were washed ashore where they suffocated