Chapters 1-3: Ocean, Islands of Oceania, and Tropical Pacific Weather and Climate - Vocabulary

Vocabulary flashcards covering key terms from Chapters 1-3 notes.

Ocean

A large body of salt water.

Challenger Deep

The deepest point of all oceans, about seven miles deep, located in the Mariana Trench.

Volcano

A geological landform that begins as a long, narrow crack in the Earth’s crust.

Ring of Fire

A ring of volcanoes that surrounds the Pacific Ocean.

Active volcano

A volcano that continues to pour out lava, gases, or ash.

Dormant volcano

A volcano that has not erupted for a long time but could still erupt.

Extinct volcano

A volcano that no longer has openings connecting to the Earth’s mantle, located below the Earth’s surface.

Mantle

The hot, flexible interior layer of the Earth.

Core

The layer below the mantle; also hot and flexible.

Tectonic plates

Floating plates that make up the crust of the Earth’s surface.

Subduction

The process in which an ocean plate moves under a continental plate, usually at a rate of a few inches per year.

Continent

A large land mass.

Continental drift

An early theory about Earth’s movement; states that the Earth’s original land mass was a single supercontinent that eventually broke apart and drifted over 200 million years or more.

Plate tectonics

A theory suggesting that the Earth’s surface is broken into several huge, rigid plates, each about 50 miles thick.

island

A relatively small piece of land surrounded entirely by water.

continental island

A large high island separated from a continent; may be connected by a continental shelf (e.g., New Guinea, New Caledonia).

continental shelf

Underwater edge of a continent; can connect to islands or drop off into deep ocean.

volcanic islands

Islands formed by volcanoes rising from the sea floor (e.g., Guam, CNMI, Tonga).

seamount

A volcano that rises from the sea floor but does not reach above the water.

hot spot

A place deep in the Earth where magma rises, forming islands like Hawaii.

ocean ridge

Underwater mountain range (e.g., Hawaiian Ridge).

coral polyp

Small coral animal with outside skin, tentacles, cavity, and skeletal cup.

plankton

Tiny floating plants and animals eaten by coral.

hermaphrodite

An organism that can produce both sperm and eggs.

larvae

Early swimming stage of coral that eventually attaches to a surface to form new colonies.

budding

Asexual reproduction where polyps divide to make new polyps, enlarging the colony.

sexual reproduction

Produces larvae to start new coral colonies.

asexual reproduction

Polyps divide or bud to enlarge the colony.

calcium

Mineral coral takes from water to build skeletons.

algae

Plant-like organisms that live with coral and provide nutrients.

symbiosis

A relationship where both organisms benefit.

fringing reef

Coral reef growing around the edge of a volcanic island.

barrier reef

Reef separated from the sinking island, forming a lagoon in between.

lagoon

Shallow water between a barrier reef and a sinking island.

patch reef

Small reef growing on underwater hills inside a lagoon.

atoll

Ring-shaped reef with a central lagoon, formed after the volcano sinks.

reef island

Land formed on reefs by sand and debris; can support plants if high enough.

phosphate

Mineral found on some coral islands, used to make fertilizer.

raised coral island

Atolls that have been lifted above sea level, forming cliffs and dry land (e.g., Niue).

weather

Short-term state of temperature, wind, humidity, cloudiness, and precipitation.

climate

Long-term average of weather over 30–50 years.

tropics

Zone of land and water between Tropic of Cancer (23.5° N) and Tropic of Capricorn (23.5° S).

equator

Line around the middle of the Earth at 0° latitude.

summer solstice

Sun is directly overhead at Tropic of Cancer (~June 21–22).

winter solstice

Sun is directly overhead at Tropic of Capricorn (~Dec 21–22).

season

One of the four natural periods of the year.

dry season

Tropical season with less rainfall.

rainy season

Tropical season with frequent rainfall.

atmospheric

Related to the air surrounding Earth.

humidity

Moisture in the air.

evaporate

When water changes from a liquid to a gas.

condense

When water vapor cools back into liquid.

trade winds

Steady winds blowing toward the equator; northeast in the northern hemisphere, southeast in the southern.

doldrums

Calm, low-pressure area near the equator with very little wind.

Inter Tropical Convergence Zone (ITCZ)

Belt near the equator where warm, moist air rises, causing heavy rainfall.

Coriolis effect

The effect of Earth’s rotation on the direction of winds and storms.

El Niño

Warming of Pacific Ocean currents off South America causing wet or dry conditions.

tropical cyclone

Storm over tropical or subtropical waters with strong winds and heavy rain.

hurricane

Tropical cyclone in the Northeast Pacific Ocean.

typhoon

Tropical cyclone in the Northwest Pacific Ocean.

greenhouse effect

Natural process where gases trap heat near Earth’s surface.

global warming

Long-term increase in Earth’s average atmospheric temperature due to trapped heat.