SHORT - COASTAL SYSTEMS

Question 1

Tectonic Activity (TA) & Impact on Coastal Landscapes/ Landforms

Answer 1

1. TA can ALTER Physical Landscapes
   EQ 2004 Indian Ocean EQ & T –> coastal landshape reshaped Indonesian coastline.
   V - Mount St Helens - glacial melt–> river channels altered flows to sea
2. TA can CREATE Create unique Landforms
   Volcanic island Chains Eg Hawaii
   Lava Plateaus eg New Zealand
3. TA can CHANGE sea levels -
   -> emergent or submergent landscapes
   Eg Sea Floor Spreading & subduction trenches –> sea level rise and falls.
4. TH can ALTER sediment dynamics
   Sediment increase - Increase in erosional, transport & depositional processes
   Eg EQ Christchurch NZ –> liquification–> sediment–> sea
   Sediment patterns altered
   2011 Tohoku - EQ & T –> sediment displacement
5. TA can Change Coastal Vegetation
   EQ Uplift –> tidal range changes
   VE –> fertile soils and or veg destruction and or atmospheric changes
6. TA can CAUSE Socio Economic Changes
   Industries changed/destroyed/created
   Eg 2011 Tohoku Fishing & I
   New opportunities created
   eg Iceland Tourism “land of fire & ice”

Question 2

Tectonic Activity & Influences on Coastal Landscape SYSTEMS

Answer 2

COASTAL SYSTEM
INPUTS, OUTPUTS, FLOWS, STORES

1. Energy Inputs
   Thermal Energy increase –> VE lava & Hot gases -atmosphere & sea
   Wave energy increase eg eg Tsunami
   Kinetic Energy increase eg EQ & VI–> land slides & lahars
   Chemical Energy eg VI - gases & minerals
2. Sediment Input
   Weathering, Marine Material, Mass Movement
   VE & EQ –> changes to volume of material
3. Wave Energy Outputs
   Wave dissipation measures eg sea walls affect disspi;lation.
4. Erosion & evaporation changes
   Eg EQ –> mountain ranges affect precipitation patterns–> affect flows
5. Changes to Geomorphic Processes
   Wave Processes (Tsunamis, changed sea beds, currents, wave characteristis changed)
   River Processes (velocity shape, direction, sediment load)
   Aeolian Processes (increased erosion due to weathering of volcanic rock, ash)

Question 3

Role of Tectonic Activity on Formation of Emergent and Submergent Landcapes.

Answer 3

Formation of EMERGENT COASTLINE
Sea Level DROP caused by TA

Tectonic Uplift (all Plate Boundaries) –> more exposed surfaces–> cliffs and terraces
Rifting (divergent boundaries) –> Deeper oceans–> sea level drop
Subsidence- Volcanic rock eventually cools and contracts –> sea level drop
TA –> Changes in shape of Ocean basins –>change in levels
TA –> Climate Change–> Temp increase–> Glacial melt

Formation of SUBMERGENT COASTLINES
Sea level RISE caused by TA
TA –> Changes in shape of Ocean basins –>change in levels
Volcanism –> crust creation–> Displacement of water
TA causes land adjacent to isostatic uplift–> subsidence
TA –> Climate Change–> temp drop–> more ice stores

Formation of TSUNAMIS
—> flooding –> submerged landscapes
—> subsidence–_> submerged landscapes
—> coastal erosion –> exposed cliffs and raised beaches

Question 4

How does tectonic activity influence HUMAN ACTIVITY

Answer 4

1. COASTAL MANAGEMENT ACTIVITY
   TA —> sea level changes and increased energy in coastal landscape system & sediment movement.

–> Hard & Soft Engineering to Mitigate
Eg Sea Walls, groynes, riprap, beach nourishment

2. COASTAL URBANISATION
   –> Magnifies possible impacts of TA
3. ECONOMIC ACTIVITY
   TA–> can destroy or create industries
   VE & EQ
   eg fishing & tourism
4. TOURSIM $
   Increased number due to scenery
   Decreased number due to risk
5. RECREATIONAL ACTIVITY
   Landscape & coastal landforms - coasteering, diving, rock climbing, hiking

Question 5

How does Tectonic activity alter the coastal landscape

Answer 5

1. CREATE NEW COASTAL LANDFORMS
   VE –> Island chains and lava plateau
   Eg Hawaii (hotspot)
2. ALTER EXISITING LANDFORMS
   Uplift and subsidence–> emergent/submergent landforms
   Eg Alaska EQ 1964
3. CHANGE SEDIMENT SUPPLY
   Volcanic ash & rock and mass movement.
   Eg Tohoku 2011, Japan
4. SEA LEVEL CHANGES
   E & VE –> CO2 climate change
   VE–glacial melt, isostatic change
   Eg Pinatubu, 1991
5. PRODUCE TSUNAMIS
   Reshape coastline, alter sediment patterns
   eg Indian Ocean 2004
6. CHANGE OCEAN BASIN
   Sea level changes .
7. GEOLOGY
   VE–> discordant concordant coastlines
8. HUMAN MITIGATION ACTIVITIES
   Eg sea walls, groynes
   Eg Tohoku, Japan 20011