Quiz Maker

QUIZ: Tides & Currents

Test your tides and currents knowledge with this quiz!

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1. During which pair of Moon phases would you generally expect the smallest tidal ranges?

New Moon and full Moon

First quarter and third quarter

New Moon and first quarter

Full Moon and third quarter

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2. High water is predicted for 10:30. What does that tell you about the timing of slack water at the same location?

It must occur at 10:30

It must occur halfway to the next low water

It must occur exactly one hour later

It cannot be established from that information alone

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3. Two high tides of noticeably different heights, followed by two unequal low tides: which tidal pattern is this?

Mixed semidiurnal

Diurnal

Regular semidiurnal

Non-tidal

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4. What makes a spring tide 'perigean'?

It occurs nearest the spring equinox

Earth is at its closest point to the Sun

The Moon is near its closest point to Earth

The Moon is directly above the equator

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5. Why can two stretches of coastline experience very different tidal ranges despite being at similar latitudes?

The Moon’s gravity acts only on shallow water

Basin shape, water depth and resonance modify the tides

Tidal forces disappear beyond continental shelves

Coastal tides are controlled entirely by local winds

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6. Complete the pairing: wind primarily drives large-scale surface circulation; differences in _____ drive thermohaline circulation.

Wave height

Day length

Atmospheric oxygen

Seawater density

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7. Which change would make a parcel of seawater denser, assuming other conditions remain the same?

Cooling it and increasing its salinity

Warming it and reducing its salinity

Warming it without changing its salinity

Adding freshwater without changing its temperature

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8. Which effect, caused by Earth’s rotation, deflects moving ocean water to the right in the Northern Hemisphere and to the left in the Southern Hemisphere?

Tidal resonance

The Coriolis effect

Thermohaline circulation

Gravitational attraction from the Moon

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