Q 01/05

What percentage of Earth's surface is covered by oceans?

A) About 71%

B) About 61%

C) About 51%

D) About 81%

Answer · why

A) About 71%

Oceans cover approximately 71% of Earth's surface, making our planet predominantly a water world when viewed from space.

Q 02/05

Which of the world's oceanic divisions is the largest by area?

A) Pacific Ocean

B) Indian Ocean

C) Atlantic Ocean

D) Arctic Ocean

Answer · why

A) Pacific Ocean

At about 165 million square kilometres it is bigger than all the planet's land put together.

Q 03/05

What is the deepest known spot on the seabed called?

A) Tonga Trench

B) Puerto Rico Trench

C) Challenger Deep

D) Java Trench

Answer · why

C) Challenger Deep

It reaches about 10,935 metres below sea level, deeper than Everest is tall, and is named for the HMS Challenger expedition that first sounded it in 1...

Q 04/05

What is the average depth of the world's oceans?

A) About 1,200 meters

B) About 3,688 meters

C) About 2,400 meters

D) About 5,500 meters

Answer · why

B) About 3,688 meters

The average depth of the world's oceans is approximately 3,688 meters (12,100 feet). This means if you could flatten Earth's surface, the entire plane...

Q 05/05

What is the average salinity of ocean water?

A) About 1.5%

B) About 3.5%

C) About 5.5%

D) About 7.5%

Answer · why

B) About 3.5%

Every kilogram of seawater carries roughly 35 grams of dissolved salts, enough that a swimmer floats noticeably higher than in a lake.