science

• Fault - a fracture or zone of fracture between two blocks of rocks.
• Epicenter - the point on the earth's surface vertically above the focus of an earthquake.
• Focus - point inside the earth where the earthquake started
• Seismic wave - just like a wave that transports energy from one place to another
• How to know if there is a fault?

  • There must be a movement between two blocks
  • Ex. The layers of sand and starch moved along with the cut/fracture/crack which represents fault.
• • A fault is a fault when there is a cut/fracture/crack on the surface which allows movement of the blocks of rocks.
• Fault Plane - Surface that the movement has taken place within the fault 

  • The plane that represents a fault's fracture surface.
• Hanging Wall - The rock mass resting on the fault plane

  • the upper or overhanging wall of a vein, fault, or other geologic feature.
  • opposed to footwall.
• Footwall - The mass of rock below the fault plane

  • the rocks beneath a fault plane that is inclined
  • Where we walk
• Normal Fault

  • The hanging wall moves down relative to the footwall
  • Younger rocks are displaced above older blocks
  • Fault displaced caused by tension/extension/ pulling apart.
• Reverse Fault 

  • Hanging walls moves up relative to the footwall
  • Older rocks are displaced above younger blocks
  • Fault displacement caused by contraction or pushing together
• Strike - slip fault

  • The plane of displacement is HORIZONTAL
  • Displacement occurs laterally, parallel to the strike of the fault, rather than up or down (parallel to each other)
  • Displacement caused by shearing or sliding past each other
• Active Fault 

  • a fault that is likely to have another earthquake sometime in the future.
  • Earthquake within 10k years
• Inactive Fault

  • No record in 10k years
  • Can still be active
  • Structures that we can identify, but which do not have earthquakes. These faults do not show any signs.
• Tensional Stress - When rocks are pushed away from each other
• Compressional Stress - Towards each other created on the Earth’s surface
• Shear Stress - Pushed perpendicular to the axis
• • Tsunamis are giant waves caused by earthquakes or volcanic eruptions under the sea.
• • A tsunami is a series of waves. You may experience flood waters if this occurs. Walking or driving in floodwaters can be risky.
• tsunami is caused by a large and sudden movement of the ocean
• • Tsunamis are usually triggered by huge earthquakes on the earth's surface, which cause slabs of rock to rapidly shift past each other and rise upward, resulting in a tsunami.
• • Reverse fault generates the strongest tsunami
• • Tsunami gets weaker as it reaches the shore
• intensity is the strength of the earthquake to the observer
• intensity Can be used to express the damage caused by an earthquake
• • Intensity can be determined from the shaking and the damage caused by an earthquake.
• The severity of an earthquake can be determined using a Mercalli Intensity Scale.
• Intensity varies depending on how close or far the location is from the epicenter of the earthquake, The closer it is to the epicenter the higher the intensity. The farther it is from the epicenter the lesser the intensity.
• intensity is Qualitative (describable)
• magnitude is Quantitative (measurable)
• magnitude Does NOT vary with the distance from the epicenter of the earthquake 
• • Magnitude values are calculated right after an earthquake
• Can be recorded using an instrument called seismograph
• The strength of an earthquake can be determined using the Ritcher’s Magnitude Scale
• magnitude It describes the total amount of energy that is released by an earthquake
• magnitude Cannot properly describe large scale of earthquakes
• Body Wave

  • Traveling through the interior of the earth
  • Arrive before the surface waves
  • Higher Frequency
• P-Waves or Primary Waves

  • Fastest kind of seismic wave
  • 1ST to arrive at a seismic station
  • Can pass through solid and liquid layers of the Earth’s interior
  • They are longitudinal waves they compress and Expand like a spring in the direction of the wave propagation