Step 1: Start with a shaped place
Begin with a coastline, reef, or shelf in the map so students can notice that ocean processes help shape Earth’s surface.
Ocean Literacy Principle 2
The ocean and life in the ocean shape Earth
The ocean is not separate from the solid Earth. Ocean water, waves, sediments, sea-level change, tectonic activity, and marine life all help shape rocks, coasts, shelves, and landforms over time.
Guiding question: How do living things help shape ocean environments and Earth systems?
What this principle means
Ocean materials and rocks
Ocean water, sediments, and marine life help build Earth materials and leave long-lasting records in the rock cycle.
Many Earth materials and geochemical cycles originate in the ocean.
The ocean is a major source of sediments, minerals, and chemical processes that shape Earth over long timescales. Many important Earth materials and geochemical cycles are linked to ocean water and life in the ocean.
Many sedimentary rocks now found on land were formed in the ocean.
A large part of the rock record began in marine environments. Over time, the remains of organisms and layers of marine sediments formed rocks that are now exposed on land.
Ocean life has helped build siliceous and carbonate rocks.
Marine organisms have contributed enormous amounts of biological material to Earth’s crust. Over long periods of time, shells, skeletons, and other hard parts helped form major deposits of carbonate and siliceous rock.
Coasts, shelves, and sediments change over time
Shorelines are not fixed. Sea level, erosion, and sediment transport constantly reshape the boundary between land and ocean.
Sea level changes over time reshape shelves, seas, and land.
When sea level rises or falls, shorelines shift. Continental shelves expand or contract, inland seas can appear or disappear, and the shape of land near the coast changes over time.
Erosion shapes coastal areas.
Wind, waves, rivers, and ocean currents wear away and move rock, soil, and sediments. This erosion constantly reshapes beaches, cliffs, estuaries, and coastal landforms.
Sand comes from many sources and is always being moved.
Sand is made of tiny bits of rock, minerals, plants, and animals. Much of it comes from land and is carried by rivers, but some also comes from coastal and marine sources. Waves and currents keep redistributing sand along the shore.
Ocean and Earth processes work together
Marine environments are shaped by both ocean movement and deeper Earth forces, so coastlines and shelves reflect interacting systems rather than a single cause.
Tectonics, sea level, and waves help shape coasts.
The form of the coastline is influenced by several forces at once. Tectonic activity, changing sea level, and the power of waves all affect coastal structure and landforms.
Key ideas
- Many Earth materials and geochemical cycles originate in the ocean.
- Many sedimentary rocks now found on land were formed in the ocean.
- Ocean life has helped build siliceous and carbonate rocks.
- Sea level changes over time reshape shelves, seas, and land.
- Erosion shapes coastal areas.
- Sand comes from many sources and is always being moved.
- Tectonics, sea level, and waves help shape coasts.
Teach this principle
Step 2: Compare processes
Compare one marine structure, one sediment process, or one coastal example to show how water, life, and geology interact over time.
Step 3: Ask what is shaping it
Ask students whether waves, erosion, sediments, marine organisms, tectonics, or sea-level change are shaping the place they see.
Why this matters
This principle helps students understand that the ocean helps shape the planet itself. Coasts, sediments, shelves, reefs, and many rocks on land are connected to marine processes and life in the ocean.
What students should take away
Students often think of the ocean as water next to land. This principle helps them see that the ocean is also part of how Earth’s surface is built, worn away, changed, and rebuilt over time. That makes later topics easier to teach, including coasts, erosion, sea-level change, tectonics, reefs, sediments, and the long-term role of marine life in shaping Earth.
Classroom prompt: Choose one coastal or marine feature on this page. How might waves, sediments, sea-level change, tectonics, or marine life have helped shape it?
Teach with Blue Biome
Explore this principle with the platform
WebGIS
Compare reefs, coasts, shelves, and tectonically active marine regions to see how ocean processes shape Earth.
Knowledge Graph
Trace links among marine life, sediments, coastal change, tectonics, and other Earth-shaping processes.
Cards
Use cards to discuss thermal vents, storm surge, and other examples where ocean and Earth systems interact.
Start here
Ecoregion
1. Start with a marine structure that shapes Earth
Use the Great Barrier Reef to show that marine organisms can help build large physical structures that become part of Earth’s surface.
Ecoregion
2. Compare a coastline shaped by tectonics and sea level
The Red Sea helps students see how tectonic activity, coastlines, and marine processes work together to shape Earth features.
Opportunity
3. Explore how Earth’s interior meets the ocean
Thermal vents show that the ocean is connected to geological processes below the seafloor as well as to life above it.
Tool
4. Use the map to compare coastal and marine landforms
Open WebGIS so students can compare shelves, reefs, coasts, and marine regions shaped by waves, sediments, and tectonics.
Featured examples
Featured Species
No featured species added yet.
Featured Ecoregions
Ecoregion
Great Barrier Reef
Distinctive: This reef is a large biological structure built by marine organisms over long periods of time.
Connected to the global system: It shows that ocean life can become part of Earth’s physical surface by shaping habitat, rock, and coastal structure.
Ecoregion
Mesoamerican Reef
Distinctive: This reef system is built from accumulated biological material in a marine setting.
Connected to the global system: It helps explain how marine life contributes to the long-term building of coastal and carbonate structures.
Ecoregion
Red Sea
Distinctive: This region reflects a coastline shaped by tectonic activity, basin structure, and marine conditions.
Connected to the global system: It shows how tectonics, sea level, and the ocean work together to shape Earth features.
Featured Cards
Opportunity
Thermal Vents
Thermal vents illustrate the principle by showing that the ocean connects directly to geological processes below the seafloor.
Threat
Storm Surge
Storm surge illustrates the principle by showing how ocean forces can rapidly reshape coasts and affect the boundary between sea and land.