Ocean Basics
What percentage of Earth's surface is covered by oceans?
71%
What is the gently sloping area that extends from the shore?
Continental shelf
What are underwater mountain chains caused by magma and plate movement?
Mid-ocean ridges
What zone is between high and low tides?
Intertidal zone
What is the salinity of average seawater?
3.5%
Which element makes seawater salty?
Sodium chloride
What steep area leads to the deep ocean floor?
Continental slope
What underwater volcanoes rise at least 1 km from the ocean floor?
Seamounts
What zone stretches from the low tide mark to the edge of the continental shelf?
Littoral zone
What is the formula for density?
Mass รท Volume
What is the term for a mix of freshwater and saltwater, often near river mouths?
Brackish water
What lies at the bottom of the continental slope, formed by settling sediments?
Continental rise
What chain of islands forms near ocean trenches from rising magma?
Island arc
What deep ocean zone has no light, high pressure, and cold temperatures?
Abyssal zone
What is the process where sunlight helps produce oxygen in the ocean?
Photosynthesis
What is the term for the ancient ocean believed to exist before today's oceans (old-earth view)?
Panthalassa
What are flat muddy parts of the ocean floor called?
Abyssal plain
What is a deep underwater valley formed by subduction?
Trench
What is the term for organisms that live attached to or on the ocean floor?
Benthic
What is the name of the process where bacteria make nitrogen usable?
Nitrogen fixation
According to young-earth creationists, what two events shaped the ocean?
Creation and the global flood
What is the deepest known point in the ocean?
Challenger Deep (in the Mariana Trench)
What process at tectonic ridges forms new ocean crust?
Magma rising and forming rock (seafloor spreading)
What is the name for marine organisms that can produce their own light in dark zones?
Bioluminescent organisms
What harmful event can happen when fertilizer runoff causes too much algae to grow?
Algae bloom / Dead zone