Ocean Chemistry and Geological Features

The video explores the mystery of ocean salinity, initially attributed to rivers. However, the discovery of black smokers in 1979 revealed that ocean water cycles through the Earth's crust every six to eight million years, exchanging chemicals and maintaining its unique chemistry. This process occurs along the mid-ocean ridge, which spans the globe.

What was the initial assumption about the source of the ocean's salinity?

• Volcanic eruptions

• Rivers

• Underwater vents

• Rainfall

What significant discovery was made in 1979 regarding ocean chemistry?

• The impact of climate change on oceans

• The presence of black smokers

• The existence of underwater volcanoes

• The role of rivers in ocean salinity

What are black smokers?

• Large oceanic fish

• Deep-sea plants

• Micro crystals of minerals

• Volcanic eruptions

How often does the entire volume of the world's oceans cycle through the Earth?

• Every 3-4 million years

• Every 10-12 million years

• Every 1-2 million years

• Every 6-8 million years

What happens to the chemicals in ocean water during its cycle through the Earth?

• They are diluted

• They are completely removed

• They are exchanged for new chemicals

• They remain unchanged

What geological feature stretches around the planet like the seam of a baseball?

• The Mariana Trench

• The continental shelf

• The Great Barrier Reef

• The mid-ocean ridge

What is found along the mid-ocean ridge that contributes to ocean chemistry?

• Coral reefs

• Sand dunes

• Icebergs

• Magma chambers