lesson 2: geological hazards

• Geological Hazards define as a large scale, complex natural events that happen of land.
• Tension pulls rocks apart resulting in normal faults
• Compression squeezes rock together resulting in reverse faults
• Shear stress causes rocks to slide past each other resulting in strike-slip faults
• Epicenter - the point in the earth's surface directly above the earthquake's origin
• Focus - the origin of the earthquake below the earth's surface
• Types of earthquakes:

  • tectonic
  • volcanic
  • collapse
  • explosion
• The strength of ground shaking depends on factors like the area's physical profile and the features of the fault rupture; strong vibrations
• When an earthquake happens, cracks appear on the surface as ground rupture
• Liquefaction takes place in water-saturated soil and sediments that an earthquake greatly disturbs.
• An earthquake may cause abrupt lowering or sinking of the ground surface called ground subsidence.
• The surface of the water that is rapidly displaced in a vertical direction generates large water waves referred to as tsunamis
• Magnitude refers to the quantity of seismic energy in an earthquake and measured by a seismograph
• Intensity is the rate of the damages observed during an earthquake and can vary as the affected area becomes farther from the epicenter
• Richter Scale is used to measure the strength of an earthquake
• Earthquakes are caused by sudden release of energy stored within rocks deep beneath the earth's crust due to tectonic plate movement