Ocean Topography

salinity

The measure of dissolved salts in a given amount of sea water.

SONAR (abbreviation)

SOund Navigation And Ranging

SONAR

The technology used by ocean scientists that uses sound waves to map the ocean floor. Based on the echo-ranging used by bats.

continental shelf

The part of the ocean floor that begins at the shoreline and slopes gently toward the open ocean.

You play on this when you go to the beach

continental shelf

continental slope

Tbe part of the ocean floor that begins at the edge of the continental shelf and drops sharply to the flattest part of the ocean.

abyssal plain

The flattest part of the deep ocean basin covered with sediments deposited by water sources like rivers and the remains of tiny marine organisms.

Before SONAR technology, scientists used to think that the whole ocean baasin resembled this

abyssal plain

seamount

An individual mountain of volcanic material below the ocean’s surface that rise through or between tectonic plates

If this builds up above sea level, it will become a volcanic island

seamount

Mid-ocean ridge

The longest mountain range on the Earth that forms at divergent plate boundaries.

In the ocean, this forms between the plates where a new sea floor is made

rift zone

ocean trench

Huge, deep cracks formed where tectonic plates converge and one oceanic plate subducts below another oceanic or continental plate.

density

Mass/Volume; The measure of the mass of a substance in a given volume.

What affects density in the ocean

salinity and temperature

rift valley

A long narrow valley that forms as tectonic plates separate / diverge.

continental rise

Gently sloping section of deposited sediments located between the continental slope and the abyssal plain.

As depth increases, salinity

decreases

As depth increases, pressure

increases; due to water pushing from above

As depth increases, temperature

decreases; due to lack of sunlight

As depth increases, marine life

decreases; due to oxygen levels