Which ocean is the largest on Earth by surface area and covers roughly about one third of the planet's total surface, making it the biggest single ocean basin?

Introduction / Context:
Knowing the relative sizes of the world's oceans is a basic part of physical geography. Examinations often ask which ocean is the largest or which covers the greatest portion of Earth's surface. This question focuses on identifying the single biggest ocean basin by area.

Given Data / Assumptions:

• The question asks which ocean takes up about half of the surface of the Earth in a broad sense, meaning it is the largest.
• Options include the Southern, Pacific, Atlantic, and Indian Oceans.
• We interpret this as asking for the ocean that dominates the global map by surface coverage.

Concept / Approach:
The Pacific Ocean is the largest and deepest ocean on Earth. It extends from the Arctic in the north to the Southern Ocean in the south and from Asia and Australia in the west to the Americas in the east. It covers more area than all the landmasses of the world combined and occupies roughly one third of Earth's total surface area. Although the question loosely says about half, standard exam convention still expects the Pacific as the correct response when asked to choose the largest ocean.

Step-by-Step Solution:
Step 1: Recall that there are five major oceans: Pacific, Atlantic, Indian, Southern, and Arctic.Step 2: Remember that the Pacific Ocean appears as an immense basin on any world map, especially when centred on the Pacific.Step 3: Compare the Pacific with the Atlantic and Indian Oceans, which are significantly smaller in area.Step 4: Note that the Southern Ocean encircles Antarctica but does not exceed the Pacific in area.Step 5: Conclude that the Pacific Ocean is the largest and therefore best fits the description in the question.

Verification / Alternative check:
Basic reference figures show that the Pacific Ocean covers about 165 million square kilometres, while the Atlantic covers around 106 million square kilometres and the Indian about 70 million square kilometres. These numbers confirm that the Pacific is clearly the largest ocean basin by a wide margin, supporting it as the correct answer.

Why Other Options Are Wrong:
The Atlantic Ocean, though large, is smaller than the Pacific by tens of millions of square kilometres. The Indian Ocean is smaller still and mainly lies between Africa, Asia, and Australia. The Southern Ocean surrounds Antarctica and has a significant area but does not surpass the Pacific. None of these match the scale of the Pacific Ocean.

Common Pitfalls:
Some candidates may be misled by the phrase about half of the surface and assume the data must be exact. In exam settings, however, the intention is usually to highlight that the Pacific is by far the largest ocean. Remembering that the Pacific clearly dominates global ocean area will help you choose correctly even if the wording is approximate.

Final Answer:
The ocean that is largest by surface area and covers roughly one third of Earth's surface is the Pacific Ocean.