Tides & Currents vocab

Diurnal Tide

1 high, 1 low

Semi-Diurnal Tide

2 highs, 2 lows

Mixed Semi-Diurnal

2 highs, 2 lows (different ranges)

Cause of tides

Gravitational pull of the moon and sun, rotating earth

What does MLLW stand for?

mean lower low water

Spring Tide

happens during fukl and new moons, causing the most extreme tides twice a month

Tidal Range

The difference between high and low tide in feet

Neap Tides

Occur during the 1st & 3rd quarters of the moon, least amount of tidal range

Declination

Angle above the horizon

Perihelion

The earths closest approach to the sun

Aphelion

The earths farthest distance from the sun

Perigee

Moon is closest to earth

Super moon leads to…

King tides

Negative Tide

When the water drops bellow the charted depth

Ocean Current cause

global currents caused by heating and cooling of the oceans by the earths atmosphere, winds, & coriolis affect

What are tidal durrents driven by?

high and low tides

Ebb current

Outgoing current

Flood current

Incoming current

Slack water

current is not moving

Rotary current

Occur offshore, not restricted, moves around the compass during each tidal cycle