Natural Disasters Week 6

Tsunamis

  • Tides: water getting pulled out by the moon

  • We experience two hide tides and two low tides every day

  • Tsunami = harbor wave

  • Regular waves occur because of wind

  • Fetch: the distance traveled by wind across open water

  • Surface waves:

    • Caused by friction of wind moving over the surface

    • Hawaii, Australia, east coast all has dangerous surface waves

  • Normal waves don’t pick up debris, rather than tsunami’s which keeps coming

  • Tsunamis are formed when a body of water is displaced

  • Tsunami’s have consistent waves coming closer together to get bigger

  • Long wavelengths allow for continued wave inundation

Energy

  • Energy: the ability to work

  • Potential energy

    • Stored energy ready to use

  • Kinetic energy

    • Energy in motion

  • Energy types:

    • Heat

    • Radiation

    • Nuclear

    • Elastic

    • Electrical

    • Chemical

    • Gravitational

  • Primary energy comes from the sun (99.9%)

  • Once light reaches earth, 30-40% energy is reflected

  • The sun still provides 4000X the energy flowing inside the Earth’s interior

  • Lots of this energy is absorbed by sea water

  • Ice in polar regions reflect more energy

Atmosphere

  • A thin layer of gas that surrounds the Earth

  • Troposphere: lots of mixing - windy, heated by earth surface

  • Composition

    • Constant gases, nitrogen, oxygen

  • Climate is long term like the seasons

  • Weather is day to day

  • Temp is a measure of how much kinetic energy of the particles, the higher the temp the higher the kinetic energy

  • Atmospheric pressure: force per unit area produced by a vertical column of air

  • Pressure decreases with higher elevation

  • Heating leads to expansion

  • Cooling leads to contraction

Density

  • Mass per given volume

  • Amount of stuff packed into the space