Tides Flashcards
What are tides?
periodic, short-term changes in the height of the ocean surface at a particular place
longest waves
what causes tides?
combination of the gravitational force of the moon and sun, the motion of the Earth, and the inertia of water
what is inertia?
an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
Why are tides forced waves and not free waves?
they are never free from the forces that caused them
What is the equilibrium theory?
the moon’s gravity attracts ocean the ocean surface toward it
2 tidal bulges produced (one pulled by the moon (lunar), the other formed by the earths motion (solar))
What are tractive forces?
the combined forces of inertia and gravity
What happens when lunar and solar tides combine?
form spring and neap tides
What is apogee
greatest distance from moon and earth
what is perigee
moon and earth at closest
what is aphelion
greatest distance between earth and sun
what is perihelion
earth and sun at closest
What is dynamic theory of tides?
tides are actually shallow-water waves
continents also get in the way
basin shape also influence patterns and heights of tides
influenced by coreolis effect
What is a node (amphidromic point)?
no tide point
circle that wave (or tide) travels in because of the combination of the coreolis effect and the interaction with the water on the shoreline
what is tidal range is influenced by?
Basin size and shape
What is a tidal bore?
when a tide wave flows into a confined inlet or stream channel (true tidal wave)
