Waves, Tides, and Tsunamis

Waves

• Formation: Generated by wind blowing over the ocean surface. The stronger the wind and the longer it blows, the larger the waves.
• Characteristics:
  • Crest: The highest point of a wave.
  • Trough: The lowest point of a wave.
  • Wavelength: The horizontal distance between two successive crests or troughs.
  • Wave Height: The vertical distance between the crest and the trough.
  • Wave Period: The time it takes for two successive crests to pass a fixed point.  
• Types:
  • Wind Waves: Generated by wind.
  • Tsunamis: Large waves caused by underwater earthquakes, volcanic eruptions, or landslides.
  • Tides: Periodic rise and fall of sea level caused by the gravitational pull of the Moon and Sun.

Tides

• Formation: Primarily caused by the gravitational pull of the Moon and, to a lesser extent, the Sun.
• Types:
  • Spring Tides: Occur when the Sun, Moon, and Earth are aligned, resulting in higher high tides and lower low tides.
  • Neap Tides: Occur when the Sun and Moon are at right angles to each other, resulting in smaller tidal ranges.  
• Importance: Tides influence coastal ecosystems, navigation, and fishing.

Tsunamis

• Formation: Triggered by large underwater earthquakes, volcanic eruptions, or landslides.
• Characteristics:
  • Long wavelengths and long periods.
  • In deep water, they are barely noticeable.
  • As they approach shallow water, they slow down and increase in height, becoming destructive waves.
• Impact: Tsunamis can cause widespread devastation, including flooding, erosion, and loss of life.

Key Differences:

Feature	Waves	Tides	Tsunamis
Cause	Wind	Gravitational pull of Moon and Sun	Underwater earthquakes, volcanic eruptions, landslides
Wavelength	Relatively short	Long	Very long
Height	Varies depending on wind strength	Predictable, moderate changes	Can be extremely high
Period	Short	12-24 hours	Long periods
Impact	Primarily erosion and shaping coastlines	Influences coastal ecosystems and navigation	Can cause widespread destruction