HAZARDS & ELS Flashcards
EXAMINE HOW IMPACTS OF SEISMIC ACTIVITY ARE SEVERELY WORSENED BY THE WATER CYCLE
SEISMIC ACTIVITY = types & frequency of EQs in a particular area over a certain period of time. Caused by sudden release of energy to create seismic waves which are perceived as earthquakes.
POTENTIAL IMPACTS
Impacts are either primary/short term or secondary/ long-term. Impacts can be social, economic, environmental or political.
Caused by HAZARDS which include Ground shaking, tsunamis, surface faulting & landslides and liquification, Flooding, fires etc
WATER CYCLE
The continuous process by which water circulates between the earth’s oceans, atmosphere & land. Involves teh evaporation, condensation, precipitation and transpiration (inc run off & infiltration)
Seismic Activity –>interacts with water cycle
- Change to water Stores in Water Cycle
> Tsunamis
–> displacement of water from one store (ocean) to land. If water storage in oceans is high–> bigger Tsunamis (eg interglacial periods)
Eg Tohoku Earthquake Japan
–> extensive damage including Fukishima Nuclear Power Station (long-term imoacts n all areas) - Precipitation (especially if heavy and over long duration ) –> greater threat - exacerbates disaster
Eg Haiti - rainfall–> flooding–> over flow of sewers–> contamination –> disease
& hampered rescue - Groundstores of water (water saturated soils) can amplify Ground Shaking (make it worse)
–> building damage
–> landslides & avalanches
Eg Haiti–> landslides - Pressure in water between material pushes it apart –> Liquification.
Ground water is a necessary condition
Eg Christchurch New Zealand, 200,000 tonneees liquificated due to pressure of groundwater storage - ground water extraction
–> ground dehydration increase stress on rocks–> exacerbating impacts of earthquake.
Examine how volcanic eruptions influence the Carbon Cycle
Volcanic Eruptions = Release of energy–> expulsion of lava rocks and or gas through a volcano which is a vent in earth’s crust
Carbon Cycle = System via which carbon is exchanged between the atmosphere, oceans, soil and the biosphere. The main pathways between the stores include photosynthesis, respiration=, oxidation & weathering.
Eruptions influence in many ways:
- Release CO2
Eg E15 releases but some offset by grounding of flights
Sunlight blocked by ash–> less photosynthesis - Releases Carbon from deep onside earth’s core
- Impacts Climate Change
Release greenhouse gas CO2–> warming –> increase in photosynthesis & respiration affecting carbon cycle
Releases Co2–> cooling–> ash reflects sunlight –> affect on carbon processes eg Photosynthesis
Eg Mount Pinatubu in 1991 - cooling for 2-3 years
- Formation of Rocks
Volcanoes can release ash –> sediment–> sedimentary rocks –> carbon sequestration - Affect Carbon Cycle Processes eg Photosyntheiss
Volcanoes–> Sulfur dioxide–> acid rain–> kills plants –> less Photosytnthesis
Examine the Role Played by Tectonic activity in the carbon and water cycles
Tectonic Processes
Water & Carbon Cycle
Water
The processes that create and destroy the oceanic crust play significant roles in the global water cycle1234:
- Creation of Oceanic Crust: The creation of new oceanic crust at divergent plate boundaries (such as mid-ocean ridges) involves the upwelling of magma from the mantle.
Magma can carry with it water from the deep Earth.
When the magma reaches the seafloor and solidifies to form new crust, some of the water is released into the ocean.
(adds water - input) - Destruction of Oceanic Crust: The destruction or recycling of oceanic crust occurs at convergent plate boundaries, where one tectonic plate subducts another. As the oceanic crust is forced down into the mantle, it undergoes changes due to high and pressure temperature —> release water back into the mantle.
(removes water -output) - Tectonic Landforms eg fold mountains–> help determine path of water from one store to another – > land–> ocean
- Tectonic Processes–> climate change
Eg Change in earth currents & wind can affect evapotaranspiration and precipitation which impacts water cycle.
In summary, the creation and destruction of the oceanic crust are integral parts of the water cycle, helping to regulate the exchange of water between the Earth’s surface and its interior
Carbon Cycle
- Creation of Oceanic Crust: The creation of new oceanic crust at divergent plate boundaries (such as mid-ocean ridges) involves the upwelling of magma from the mantle.
This magma can carry with it carbon dioxide (CO2) and other gases from the deep Earth. When the magma reaches the seafloor and solidifies to form new crust, some of the CO2 is released into the ocean and eventually into the atmosphere.
(Adds Carbon - Input) - Destruction of Oceanic Crust: The destruction or recycling of oceanic crust occurs at convergent plate boundaries, where one tectonic plate subducts another. As the oceanic crust is forced down into the mantle, it undergoes changes due to high pressure and temperature.
This process can release CO2 and other gases back into the atmosphere through volcanic eruptions.
(adds Carbon - Input) - Carbon Sequestration: The oceanic crust also plays a role in the long-term sequestration (or storage) of carbon. Carbonate minerals formed from CO2 dissolved in seawater can become part of the oceanic crust. When this crust is subducted, it carries the carbon down into the mantle.
(removes Carbon - Output) - Tectonic activity eg volcanoes & tectonic uplift/downthrist –> Climate Change
Cooling–> affects precesses eg photosynthesis
Warming–> affects processes eg photosyntheis & increased weathering of rocks
Uplift–> increased weathering
Downthrust = increased wave erosion
In summary, the processes that create and destroy the oceanic crust are integral to the cycling of carbon on our planet, helping to regulate the amount of CO2 in the atmosphere and playing a key role in Earth’s long-term climate stability
Vegetation related tectonic activity and links to carbon and water cycles
Carbon Cycle
Tectonic activity —> affects marine vegetation
Gases from lava from underwater eruptions –>So2 and Co2 release into sea water –> can make sea more acidic —> less favourable for marine vegetation eg algae and seaweed. Less carbon used for photosynthesis.
Tectonic Uplift–> weathering of rocks–> soil
Change to carbon store
Soil can support vegetation which sequests carbon
Tectonic Activity eg volcanoes can destroy vegetation –> less carbon sequestraton & less CO2 use for photosynthesis.
Eg Mount St Helens
Tectonic activity eg Volcanic activity
–> fertile soils–> increased NPP–> increased use of carbon
Tectonic Activity releases CO2.
CO2 a limiting factor for photosynthesis __> so increase in atmospheric CO2–> increase in rate –> Plants absorb increased levels of CO2–> reducing atmospheric carbon stores
Tectonic activity eg volcanic eruptions –> ash –> reduced sunlight –> reduces sunlight intensity
Light is a limiting factor so affects rate of photosynthesis –> reduced CO2 use–> reduced carbon sequestration.
Tectonic activity eg oceanic plate subduction –> marine vegetation subducted into mantle
Water Store
tectonic activity —> changes in vegetation
Eg Volcanic Eruptions–> mineral rich ash–> soil –> very fertile —> increased NPP
eg Mount Etna –> increased evapotranspiration –> increased precipitation –> increased water stores
Volcanic Activity
Can destroy vegetation reducing evapotranspiration eg Munt St Helens lost forestry –> tourism so less evapotranspiration
Water subducted into mantle –> reduced store
How does Tectonic Activity affect long term changes in carbon and water cycles
Water CYcle
Plate tectonics –> collision boundary–> creation of fold mountains
eg Himalayas - PB = Continental Plates x 2 (Indian & Eruasian)
Himalayas have effect on water cycle as –> precipitation and impacts monsoon pattern in SE Asia.
Precipitation changes caused by Tectonic activity —> unequal distribution of water
Subduction between two oceanic plates–> older denser plate subducts–> magma rises & cools –> island arcs
–> displacement of water
Subduction –> Ocean Trenches -
Deepening of ocean–> reduced water levels–> emergent landforms eg raised beaches, terraces
Carbon
Subduction –> Ocean Trenches - plates pulled down and recycled back into mantle taking with it vast quantitities of water
Carbon
Divergent Plate Boundaries –> new ocean crust
–> releases Co2 but also more space for vegetation
Carbon
Tectonic activity –> volcanic eruptions –> release of CO2 increasing atmospheric stores
Long term effects of climate change eg sea level change
Carbon
Tectonic activity eg volcanoes –> weathering
Weathering–> absorption of cO2
Eg weathering –> Erosion –> release of Carbon especially in sedimentary rock
Carbon
Subduction –> Ocean Trenches - plates pulled down and recycled back into mantle sequestering carbon
