glg ch 9
Terms
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- highest part of the wave above average water level
- crest
- valley between wave crests below average water level
- trough
- vertical distance between crest and trough
- height
- horizontal distance between two successive crests (troughs)
- wavelength
- time to move one wavelength
- wave period
- number of waves passing a fixed point/second
- wave frequency
- energy that causes waves to form
- disturbing force
- dominant force that returns the water surface to flatness
- restoring force
- disturbing forces
- wind earthquakes landslides colcanic eruptions gravitational force between moon, earth and sun
- restoring forces
- surface tension gravity
- types of waves
- wind waves seismic sea waves (tsunami) tides
- factors that impact wve height
- wind speed fetch duration of wind
- long-wavelength, shallow-water, progressive waves caused by rapid displacement of ocean water
- tsunami
- tsunami caused by the sudden vertical movement of earth along faults
- seismic sea waves
- Tsumani facts
- speed at which tsunamis travel depends on the ocean depth in less than 24 hours a tsunami can cross the entire pacific ocean Do not have seasons and do not occur regularly or frequently pose a major threat to the coastal populations of the Pacific adn other world oceans and seas
- -shallow earthquake along the seafloor -seafloor is "permanently" uplifted and down-dropped, pushing the entire water column up and down - the potential energy that results from pushing water above mean sea level is then tranferred to horizontal propaga
- Initiation
- -within min of earthquake, initial tsunami splits into two waves 1. distant Tsunami 2. Local tsunami -height above mean sea level is approximately half that of the original tsunami
- SPLIT
- -seveal things happen as Local Tsunami travels over the continental slope: 1. Amplitude increases 2. Wavelength decreases -result is wave steepening of the leading wave -deep tsunami will also experience amplification if it comes in contact with l
- Amplification
- -as the tsunami wave travels from teh deep-water, continental slope region to the near-shore region, tsunami runup occurs -Runup is measure of the height of the water onshore ovserved above a refernece sea level. Comes in much like very fast tide -much
- RUNUP
- Tsunami Warning Network
- established in 1948 international pacific ocean -seismically active -largest potential fetch