dek

• Bolide


  Any extra-terrestrial object
• Bolide impacts happen less frequently and seem to be the least likely to occur, however they may pose one of the largest threats to the existence of humans
• Bolide impacts may be the reason for the demise of the dinosaurs during the K-Pg extinction
• Bolide Impact Examples


  • Chicxulub Crater in the Yucatan Peninsula, Mexico
  • Meteor Crater in Arizona, USA
• Past and Present Impact Events

  1. Chicxulub Crater in Yucatan Peninsula, Mexico - K-Pg extinction event 65 MYA

  2. Chelyabinsk Meteorite Impact - February 15, 2013

  3. Tunguska Event - Siberia in 1908
• Impact Crater


  The depression excavated by the impactor
• Factors influencing impact crater size

  • Size, velocity and angle approach of the impactor
• Impact


  The time lapse of what usually takes place during an impact event
• Types of Impactors

  • Asteroids
  • Comets
  • Meteoroids
  • Meteorites
  • Meteors
• Potential Effects of Large Impact Event

  • Drastic changes in the climatic conditions
  • Wildfires
  • Tsunamis
  • Acid Rain
• How to Prepare for an Impact

  1. NASA identifying and tracking near-earth objects (NEOs)

  2. Initiating a space mission to intercept a NEO

  3. Preparing supplies necessary for survival
• Landslide


  A downward movement of geological materials such as soil and rock
• Types of Landslides

  • Slumps
  • Rockfall and topples
  • Mudslides
  • Debris slides and flow
  • Creep
• Slumps


  Involve both soil and rock, travel short distances and vary from slow to very rapid
• Rockfall and topples


  Involve rocks, are very to extremely rapid and can travel great distances
• Mudslides


  Generally involve saturated soils moving at very to extremely rapid velocities and travel great distances
• Debris slides


  When debris from rockfalls and slumps mix with water, they can transform into debris slides that can travel great distances
• Creep


  Generally slow, involve soil, and travel short distances
• Sinkhole


  Depressions or openings in the ground surface, generally formed as the result of a collapse in the ceiling of an underground cavity or cavern
• Rocks prone to sinkholes

  • Limestone
  • Dolomite
  • Gypsum
  • Salt
• Types of Sinkholes


  • Dissolution sinkholes
  • Cover-subsidence sinkholes
  • Cover-collapse sinkholes
• Impending Signs of Landslides


  • Springs, seeps or saturated ground
  • New cracks or unusual bulges
  • Soil moving away from foundations
  • Sunken or down-dropped road beds
  • Rapid increase in creek water levels
  • Sudden decrease in creek water levels
  • Unusual sounds
• Areas prone to landslides


  • On existing old landslides
  • On or at the base of slopes
  • In or at the base of minor drainage hollows
  • At the base or top of an old fill slope
  • At the base or top of a steep cut slope
  • Developed hillsides where leach field septic systems are used
• Impending Signs of a Sinkhole


  • Trees or fence posts that tilt or fall
  • Foundations that slant
  • New small pond that appear after rain
  • Cracks in the ground
  • Sudden drainage of a pond
  • Rapid appearance of a hole in the ground
  • Dips, depressions, slopes that appear in a yard
  • Dead patches of grass or plants
  • Sinkholes in the neighborhood
• Precautionary and Safety Measures for Landslides

  • Stay tuned to local radio and TV for warnings
  • Listen for unusual sounds indicating moving debris
  • Be alert for sudden changes in water flow
  • Dial emergency number if landslide is occurring
  • Inform others nearby
  • Leave the area
  • After a landslide, stay away from the slide area, check for injured, direct rescuers, help people who require special assistance, check your building and surrounding land for damage
• Precautionary and Safety Measures for Sinkholes

  • Increase Knowledge, Determine Risk, Safeguard, Plan
  • Safety Basics, Evacuation, Shelter in Place
  • Get Disaster Relief, Clean-up
• Parts of Hazard Map

  • Title
  • Legend
  • Orientation Compass
  • Map Ruler /Bar Scale
  • Coordinates
• • Near-Earth Object Human Space Flight Accessible Targets Study (NHATS)– a program started in 2010 to identify NEOs that could potentially be accessed by future human space flight missions.
• International Academy of Astronautics (IAA) Working Group on Near-Earth Object Studies (WGNEOS) - A group established by the International Academy of Astronautics to promote research and collaboration on near-Earth object studies.
• Spaceguard Foundation - An international organization dedicated to identifying and tracking near-Earth objects and raising awareness about their potential impacts on Earth.
• Asteroids are rocky objects orbiting the Sun, ranging in size from tiny dust grains to large bodies like Ceres, Vesta, Pallas, Hygiea, and many more.
• Comets are celestial bodies made up of ice, gas, and dust, with long tails formed as they approach the sun.
• Asteroids


  Large stony and or metallic chunks which are confined in the region between Mars and Jupiter, asteroid belt and which orbits the sun just like other planets. They can be as big as 3km in average diameter but are mostly 100m to 1000m wide.
• Comets


  Combination of ice, rock fragments and dust which come either from Oort cloud which is 50,000AU away from the sun or from the Kuiper Belt of comets within the solar system that is 30-55AU away. They have a glowing tail formed by the solar wind and sun radiation pressure on the stream of gas and dust of the comet. The glowing tail does not indicate the direction of the travel but points away from the sun.
• Meteoroids


  Stony iron and stony-iron chunks, also from the asteroid belts that are still travelling in outer space.
• Meteorites


  Same as asteroids except that they have already hit the Earth's surface.
• Meteors


  These are still in flight in the Earth's atmosphere and give off a characteristic light streak.