ENGEO 1

• Earthquake


  Sudden shaking of the ground caused by the release of energy in the Earth's crust, resulting in seismic waves that travel through the Earth's interior and radiate outward
• Epicenter


  • The point on the Earth's surface directly above the focus
• Plate


  Sections into which the lithosphere is cracked

  
• Plate Tectonics


  A scientific theory that explains how major landforms are created as a result of Earth's subterranean movements
• Pacific Ring of Fire

  Also referred to as the Circum-Pacific Belt, is a path along the Pacific Ocean characterized by active volcanoes and frequent earthquakes

  
• Types of plate boundaries

  • Divergent
  • Convergent
  • Transform

  
• Divergent boundary

  Occurs when two tectonic plates move AWAY from each other
• Convergent boundary


  Occurs when two tectonic plates move TOWARDS each other

  
• Transform boundary

  Occurs when two plates SLIDE PAST each other, horizontally
• Volcanic Activity

  Volcanic earthquakes and active volcanism are related. They frequently happen quite close to the surface and are typically weaker than tectonic earthquakes

  
• Induced Earthquakes


  Human activity, such as digging tunnels, filling reservoirs, and executing fracking or geothermal projects, causes of ...
• Collapse Earthquakes


  Can be triggered by such phenomena as cave-ins, mostly in karst areas or close to mining facilities, as a result of subsidence
• Explosion Earthquakes

  Earthquakes could also occur due to the force released when a nuclear or chemical device is tested/launched
• Types of seismic waves

  • Surface waves
  • Body waves
• Love wave


  Surface seismic waves that cause horizontal shifting of the Earth during an earthquake
• Rayleigh wave


  Surface seismic waves that cause circular motion of the Earth during an earthquake
• Primary Wave (P-Wave)


  Fastest waves that compress and expand rocks in the direction of wave propagation
• Secondary Wave (S-Wave)


  Slower waves that shake the ground perpendicular to their direction of travel
• Charles F. Richter


  American seismologist who revolutionized the measurement of earthquake magnitude and made significant contributions to our understanding of seismic activity

  
• Richter Scale


  Quantifies the magnitude of earthquakes based on the amplitude of seismic waves recorded by seismographs

  
• Seismologists


  Scientists who specialize in the study of earthquakes and seismic waves

  
• Contributions of Seismologists

  • Earthquake Detection and Monitoring
  • Seismic Hazard Assessment
  • Earthquake Early Warning Systems
  • Seismic Imaging and Tomography
  • Understanding Earthquake Mechanisms
  • Tsunami Warning Systems
  • Seismic Risk Assessment and Mitigation
  • Public Outreach and Education
• Seismometer


  The internal part of the seismograph, which may be a pendulum or a mass mounted on a spring; however, it is often used synonymously with "seismograph"
• Seismograph


  An instrument used to record and measure the motion of the ground during an earthquake. It consists of a stationary base and a suspended weight that remains stationary during an earthquake but records the motion of the ground
• Seismogram


  Recording of the ground shaking at the specific location of the instrument
• Intensity


  The measure of the earthquake's effects at a particular location which considers effects on people, man-made structures, and the landscape
• Focus


  The point where the earthquake started

  
• Epicenter


  The point on the surface that is directly above the focus
• Aftershock


  Any one of a number of smaller earthquakes that occur after a larger earthquake's primary shock
• Magnitude


  The size of the earthquake
• Continental Drift Theory


  The movement of the Earth's continents relative to each other, appearing to "drift" across the ocean bed. It is also Alfred Wegener's hypothesis in which he proposed that the continents were once united into a single supercontinent named Pangaea, meaning all earth in ancient Greek

  
• Wegener's Evidences for Continental Drift

  • Topographic Evidence
  • Fossil Evidence
  • Rock layers and Mountain Ranges
  • Glacial Evidence

  
• Effects of Earthquakes

  • Ground Shaking
  • Ground Rupture
  • Landslide
  • Tsunamis
  • Fire
• Things to do during an earthquake

  1. DROP

  2. COVER

  3. HOLD
• Surface Waves - a mechanical wave that can occur along the boundary of any two media
• Seismic waves - are caused by the sudden movement of materials within the Earth, such as slip along a fault during an earthquake
• Ground shaking - well-known effects of earthquakes, caused by seismic waves traveling through the ground.
• Ground Rupture - a significant effect of earthquakes where movement along a fault causes the Earth's surface to break.
• Landslide - triggered by earthquake through direct rupture or sustained shaking of unstable slopes.
• Tsunamis - series of water waves generated by vertical movement of the seafloor during an earthquake.