other geological hazards

• ASTEROID

  • large
  • stony or metallic
  • larger than meteoroid
• METEOROID

  • smaller than asteroid
  • stony
  • irony
• COMET

  • smallest
  • ice, dust, rock frag
  • usually it has a tail
• BOLIDE IMPACTS : Acid rains
• GROUND SUBSIDENCE

  • it is the relative lowering of the earth’s surface with  respect to the mean sea level.
• COASTAL EROSION

  • It is a natural process which shapes shorelines by the wearing away of coastal land or beaches, mainly by the impact of waves along the shoreline.
• CAUSES of ground subsidence

  • Carbonate dissolution and collapse
  • Excessive groundwater withdrawal
  • Extraction of oil and natural gas
  • Earthquakes
  • Underground mining methods
  • Isostatic rebound
  • Change in season
• EFFECTS of ground subsidence

  • Sudden ground collapse events
  • Slow subsidence
  • SINKHOLE FORMATION
• NATURAL CAUSES of coastal erosion

  • Waves
  • Currents
  • Tides
  • Wind-driven water
  • Ice
  • Rainwater
  • Groundwater
  • Wind
• MAN-MADE CAUSES of coastal erosion

  • Removal of vegetation 
  • Concentration of drainage water flow into the sea 
  • Construction of structure along the shore
  • Building activities that damage natural protective features
  • Shipping and boating activities