Q.Upward and downward movement of ocean water is known as the:
The upward and downward movement of ocean water is called a tide — it is the rhythmic rise and fall of sea level, driven mainly by the gravitational pull of the Moon and the Sun.
Ocean water is never still. It sways, slides, and surges in three distinct ways: waves, currents, and tides. Each is a different kind of motion, and each has a different cause. A wave is the up-and-down movement of water at the surface, usually whipped up by wind — think of the ripples that roll onto a beach. A current is the steady, horizontal flow of water, like a river within the ocean, driven by differences in temperature, salinity, or wind. But neither of these describes the slow, patient breathing of the sea itself — the way the water level climbs up the shore and then retreats, twice a day, like clockwork.
That rise and fall is the tide. It is not a sideways push of water, but a vertical one — the ocean surface literally lifts upward and then sinks downward. This happens because the Moon’s gravity tugs on Earth’s oceans, pulling water toward it on the side facing the Moon, and also flinging water outward on the opposite side due to inertia. The Sun adds its own weaker pull. As Earth rotates, different coastlines pass through these bulges of water, so most places experience two high tides and two low tides roughly every 24 hours and 50 minutes.
Tides are not caused by wind or earthquakes — those create waves and tsunamis respectively. Tides are a gravitational phenomenon, and they are so regular that sailors have used tide tables for centuries to plan harbour entries.
So when the question asks about the upward and downward movement of ocean water, it is pointing straight at the tide. Waves move up and down too, but they do so at the surface and in a localised, wind-driven way — they do not raise the entire sea level along a coast. Currents, by definition, flow horizontally. Only tides involve the whole body of water rising and falling vertically.
Remember the trio: waves = surface oscillation by wind, currents = horizontal flow, tides = vertical rise and fall by gravitational pull. The keyword “upward and downward” is the giveaway for tides.
In short, the upward and downward movement of ocean water is the tide — the periodic vertical rise and fall of sea level caused by the gravitational attraction of the Moon and the Sun. The correct option is (a) tide.
Unlock everything free for 14 days
- Full step-by-step solutions
- Concept-first explanations
- Methods, shortcuts & mistakes
- PYQ mapping + timed mock tests
Full access for 14 days. No credit card required.