This question tests 4th grade ability to observe erosion moving earth materials (NGSS 4-ESS2-1). Students must recognize evidence that materials are being transported from one location to another by erosion agents. Erosion is different from weathering: weathering breaks down rocks IN PLACE, erosion MOVES materials from place to place. Erosion agents transport materials: (1) Water - carries sand, silt, rocks downstream or along shore, evidence is muddy water or sediment deposits, (2) Wind - picks up and carries dust, sand, deposits in new locations, evidence is sand dunes or dust in air, (3) Ice - glaciers carry rocks frozen in ice, evidence is rocks far from source, (4) Gravity - materials slide or fall downhill, evidence is piles at slope base. Observable evidence of erosion: materials in motion (sand in water, dust in wind), depleted source areas (eroded hillsides), deposition sites (sandbars, dunes, deltas), material in transport medium (muddy water = sediment being carried). In this observation, heavy rain on a hillside causes soil to wash into a ditch, with visible muddy water and soil accumulation. The evidence of erosion includes muddy water flowing downhill and soil piles in the ditch. The erosion agent is water (rain), shown by the flowing runoff. Materials are moving from the hillside to the ditch, which we can observe by eroded bare spots uphill and deposits below. Choice A is correct because it identifies materials being moved (soil) and describes transport evidence (washed downhill in muddy water to collect in ditch). The observations support this: muddy water = sediment in transport, bare hillside = soil removed, ditch piles = materials arriving. This demonstrates understanding that erosion is visible through material movement and deposition. Choice B is incorrect because it confuses weathering or melting with erosion and denies movement by suggesting soil turns into a puddle without transport. This error occurs when students attribute changes to wrong causes or don't recognize transport evidence. Critical distinction: Weathering = breaking down in original location; Erosion = moving broken materials to new location. Both often occur together but are different processes. To help students observe erosion: Make it visible - create model erosion: (1) Water erosion: Pour water on sand/soil hill, watch it carve channels and carry material down, (2) Wind erosion: Use fan to blow sand, observe movement and dune formation. Observe real erosion: Stream after rain (brown/muddy = carrying sediment), beach after storm (sand moved), construction site (exposed soil washes away). Identify the three components: (1) Source (where material comes from - being eroded), (2) Transport (material in motion - being carried), (3) Deposition (where material settles - being deposited). Practice: For each observation, identify all three - 'Where did material start? How is it moving? Where is it going?' Compare weathering vs. erosion: Weathering makes small pieces (breaks down), Erosion moves the pieces away (transports). Often happen together: weathering breaks, erosion carries away. Key observations: Materials in motion (sediment in water, dust in air), depleted areas (where material removed), built-up areas (where material deposited).

This question tests 4th grade ability to observe erosion moving earth materials (NGSS 4-ESS2-1). Students must recognize evidence that materials are being transported from one location to another by erosion agents. Erosion is different from weathering: weathering breaks down rocks IN PLACE, erosion MOVES materials from place to place. Erosion agents transport materials: (1) Water - carries sand, silt, rocks downstream or along shore, evidence is muddy water or sediment deposits, (2) Wind - picks up and carries dust, sand, deposits in new locations, evidence is sand dunes or dust in air, (3) Ice - glaciers carry rocks frozen in ice, evidence is rocks far from source, (4) Gravity - materials slide or fall downhill, evidence is piles at slope base. Observable evidence of erosion: materials in motion (sand in water, dust in wind), depleted source areas (eroded hillsides), deposition sites (sandbars, dunes, deltas), material in transport medium (muddy water = sediment being carried). In this observation, wind is blowing sand on a beach, forming a dune behind driftwood. The evidence of erosion includes sand shifting from the flat beach into a piled dune. The erosion agent is wind, shown by the blowing action moving lightweight sand. Materials are moving from the flat beach to behind the driftwood, which we can observe by the forming dune and bare spots on the beach. Choice C is correct because it identifies materials being moved (sand) and describes the deposition site (dune piled behind driftwood). The observations support this: flat beach as source = sand removed, dune formation = materials arriving. This demonstrates understanding that erosion is visible through material movement and deposition. Choice A is incorrect because it confuses weathering with erosion by stating the material stayed in place and only broke down. This error occurs when students don't distinguish weathering (breaking) from erosion (moving) or fail to recognize transport evidence. Critical distinction: Weathering = breaking down in original location; Erosion = moving broken materials to new location. Both often occur together but are different processes. To help students observe erosion: Make it visible - create model erosion: (1) Water erosion: Pour water on sand/soil hill, watch it carve channels and carry material down, (2) Wind erosion: Use fan to blow sand, observe movement and dune formation. Observe real erosion: Stream after rain (brown/muddy = carrying sediment), beach after storm (sand moved), construction site (exposed soil washes away). Identify the three components: (1) Source (where material comes from - being eroded), (2) Transport (material in motion - being carried), (3) Deposition (where material settles - being deposited). Practice: For each observation, identify all three - 'Where did material start? How is it moving? Where is it going?' Compare weathering vs. erosion: Weathering makes small pieces (breaks down), Erosion moves the pieces away (transports). Often happen together: weathering breaks, erosion carries away. Key observations: Materials in motion (sediment in water, dust in air), depleted areas (where material removed), built-up areas (where material deposited).

This question tests 4th grade ability to observe erosion moving earth materials (NGSS 4-ESS2-1). Students must recognize evidence that materials are being transported from one location to another by erosion agents. Erosion is different from weathering: weathering breaks down rocks IN PLACE, erosion MOVES materials from place to place. Erosion agents transport materials: (1) Water - carries sand, silt, rocks downstream or along shore, evidence is muddy water or sediment deposits, (2) Wind - picks up and carries dust, sand, deposits in new locations, evidence is sand dunes or dust in air, (3) Ice - glaciers carry rocks frozen in ice, evidence is rocks far from source, (4) Gravity - materials slide or fall downhill, evidence is piles at slope base. Observable evidence of erosion: materials in motion (sand in water, dust in wind), depleted source areas (eroded hillsides), deposition sites (sandbars, dunes, deltas), material in transport medium (muddy water = sediment being carried). In this observation, a dust storm lifts dirt from a dry field and deposits it on cars miles away. The evidence of erosion includes: dirt lifted into the air (material in transport) and dirt settling on distant cars (deposition). The erosion agent is wind, shown by the dust storm conditions. Materials are moving from the dry field to locations miles away, which we can observe by the dust in the air and coating on cars. Choice A is correct because it identifies dust and fine soil as the materials transported by wind from field to town. The observations support this: wind picks up lightweight particles (dust and fine soil), carries them through the air, and deposits them on surfaces miles away. This demonstrates understanding that erosion is visible through material movement and deposition. Choice B is incorrect because it claims wind rolls large boulders, which is impossible - wind can only move small, lightweight particles. This error occurs when students don't understand the relationship between particle size and erosion agent strength. Critical distinction: Different erosion agents can move different sized materials - wind moves dust and sand, water moves larger particles, ice moves biggest rocks. To help students observe erosion: Make it visible - create model erosion: (1) Water erosion: Pour water on sand/soil hill, watch it carve channels and carry material down, (2) Wind erosion: Use fan to blow sand, observe movement and dune formation. Observe real erosion: Stream after rain (brown/muddy = carrying sediment), beach after storm (sand moved), construction site (exposed soil washes away). Identify the three components: (1) Source (where material comes from - being eroded), (2) Transport (material in motion - being carried), (3) Deposition (where material settles - being deposited). Practice: For each observation, identify all three - 'Where did material start? How is it moving? Where is it going?' Compare weathering vs. erosion: Weathering makes small pieces (breaks down), Erosion moves the pieces away (transports). Often happen together: weathering breaks, erosion carries away. Key observations: Materials in motion (sediment in water, dust in air), depleted areas (where material removed), built-up areas (where material deposited).

This question tests 4th grade ability to observe erosion moving earth materials (NGSS 4-ESS2-1). Students must recognize evidence that materials are being transported from one location to another by erosion agents. Erosion is different from weathering: weathering breaks down rocks IN PLACE, erosion MOVES materials from place to place. Erosion agents transport materials: (1) Water - carries sand, silt, rocks downstream or along shore, evidence is muddy water or sediment deposits, (2) Wind - picks up and carries dust, sand, deposits in new locations, evidence is sand dunes or dust in air, (3) Ice - glaciers carry rocks frozen in ice, evidence is rocks far from source, (4) Gravity - materials slide or fall downhill, evidence is piles at slope base. Observable evidence of erosion: materials in motion (sand in water, dust in wind), depleted source areas (eroded hillsides), deposition sites (sandbars, dunes, deltas), material in transport medium (muddy water = sediment being carried). In this observation, a river carries brown sediment and deposits it where the river meets a lake. The evidence of erosion includes: brown color showing sediment in transport and delta formation at the lake edge (deposition). The erosion agent is flowing river water, shown by the downstream transport direction. Materials are moving from upstream sources to the river-lake junction, which we can observe by sediment accumulation building the delta. Choice A is correct because it describes sediment transported downstream and deposited to build a delta at the lake edge. The observations support this: rivers carry sediment from upstream erosion, transport it in the water (brown color), and deposit it where flow slows at the lake, building a delta landform. This demonstrates understanding that erosion is visible through material movement and deposition. Choice B is incorrect because it states sediment moves upstream and removes the lake, which contradicts how water flows and how deltas form. This error occurs when students don't understand that water and its sediment load flow downhill/downstream. Critical distinction: Rivers flow from high to low elevation, carrying sediment downstream, and deposit it where flow slows (like at lakes or oceans). To help students observe erosion: Make it visible - create model erosion: (1) Water erosion: Pour water on sand/soil hill, watch it carve channels and carry material down, (2) Wind erosion: Use fan to blow sand, observe movement and dune formation. Observe real erosion: Stream after rain (brown/muddy = carrying sediment), beach after storm (sand moved), construction site (exposed soil washes away). Identify the three components: (1) Source (where material comes from - being eroded), (2) Transport (material in motion - being carried), (3) Deposition (where material settles - being deposited). Practice: For each observation, identify all three - 'Where did material start? How is it moving? Where is it going?' Compare weathering vs. erosion: Weathering makes small pieces (breaks down), Erosion moves the pieces away (transports). Often happen together: weathering breaks, erosion carries away. Key observations: Materials in motion (sediment in water, dust in air), depleted areas (where material removed), built-up areas (where material deposited).

This question tests 4th grade ability to observe erosion moving earth materials (NGSS 4-ESS2-1). Students must recognize evidence that materials are being transported from one location to another by erosion agents. Erosion is different from weathering: weathering breaks down rocks IN PLACE, erosion MOVES materials from place to place. Erosion agents transport materials: (1) Water - carries sand, silt, rocks downstream or along shore, evidence is muddy water or sediment deposits, (2) Wind - picks up and carries dust, sand, deposits in new locations, evidence is sand dunes or dust in air, (3) Ice - glaciers carry rocks frozen in ice, evidence is rocks far from source, (4) Gravity - materials slide or fall downhill, evidence is piles at slope base. Observable evidence of erosion: materials in motion (sand in water, dust in wind), depleted source areas (eroded hillsides), deposition sites (sandbars, dunes, deltas), material in transport medium (muddy water = sediment being carried). In this observation, wind in a dry area is lifting and carrying dust and soil. The evidence of erosion includes visible dust clouds and bare ground where material was removed. The erosion agent is wind, shown by the blowing action carrying fine particles. Materials are moving from dry ground to downwind locations, which we can observe by dust in the air and potential distant deposits. Choice A is correct because it identifies materials being moved (dust and fine soil) and describes transport evidence (lifted from dry ground and carried downwind). The observations support this: bare ground = material removed, dust in air = in transport. This demonstrates understanding that erosion is visible through material movement and deposition. Choice B is incorrect because it exaggerates wind's capability, suggesting it carries large boulders, which is not typical for wind erosion. This error occurs when students don't recognize wind's limitation to lightweight materials or confuse agents. Critical distinction: Weathering = breaking down in original location; Erosion = moving broken materials to new location. Both often occur together but are different processes. To help students observe erosion: Make it visible - create model erosion: (1) Water erosion: Pour water on sand/soil hill, watch it carve channels and carry material down, (2) Wind erosion: Use fan to blow sand, observe movement and dune formation. Observe real erosion: Stream after rain (brown/muddy = carrying sediment), beach after storm (sand moved), construction site (exposed soil washes away). Identify the three components: (1) Source (where material comes from - being eroded), (2) Transport (material in motion - being carried), (3) Deposition (where material settles - being deposited). Practice: For each observation, identify all three - 'Where did material start? How is it moving? Where is it going?' Compare weathering vs. erosion: Weathering makes small pieces (breaks down), Erosion moves the pieces away (transports). Often happen together: weathering breaks, erosion carries away. Key observations: Materials in motion (sediment in water, dust in air), depleted areas (where material removed), built-up areas (where material deposited).

This question tests 4th grade ability to observe erosion moving earth materials (NGSS 4-ESS2-1). Students must recognize evidence that materials are being transported from one location to another by erosion agents. Erosion is different from weathering: weathering breaks down rocks IN PLACE, erosion MOVES materials from place to place. Erosion agents transport materials: (1) Water - carries sand, silt, rocks downstream or along shore, evidence is muddy water or sediment deposits, (2) Wind - picks up and carries dust, sand, deposits in new locations, evidence is sand dunes or dust in air, (3) Ice - glaciers carry rocks frozen in ice, evidence is rocks far from source, (4) Gravity - materials slide or fall downhill, evidence is piles at slope base. Observable evidence of erosion: materials in motion (sand in water, dust in wind), depleted source areas (eroded hillsides), deposition sites (sandbars, dunes, deltas), material in transport medium (muddy water = sediment being carried). In this observation, waves hit a rocky shore and sand disappears from the waterline but appears farther down the beach. The evidence of erosion includes: sand missing near the waterline (source depletion) and sand appearing farther down the beach (deposition). The erosion agent is waves (water), shown by wave action along the shore. Materials are moving from the waterline area to locations along the beach, which we can observe by the pattern of removal and deposition. Choice A is correct because it identifies waves moving sand along the shore from the waterline to a new beach area. The observations support this: waves pick up sand at the waterline, transport it along the shore (longshore drift), and deposit it farther down the beach. This demonstrates understanding that erosion is visible through material movement and deposition. Choice B is incorrect because it states gravity pulled sand upward, which is impossible as gravity only pulls downward. This error occurs when students don't understand that gravity cannot move materials upward. Critical distinction: Waves can move sand laterally along shores through longshore drift, while gravity only moves materials downward. To help students observe erosion: Make it visible - create model erosion: (1) Water erosion: Pour water on sand/soil hill, watch it carve channels and carry material down, (2) Wind erosion: Use fan to blow sand, observe movement and dune formation. Observe real erosion: Stream after rain (brown/muddy = carrying sediment), beach after storm (sand moved), construction site (exposed soil washes away). Identify the three components: (1) Source (where material comes from - being eroded), (2) Transport (material in motion - being carried), (3) Deposition (where material settles - being deposited). Practice: For each observation, identify all three - 'Where did material start? How is it moving? Where is it going?' Compare weathering vs. erosion: Weathering makes small pieces (breaks down), Erosion moves the pieces away (transports). Often happen together: weathering breaks, erosion carries away. Key observations: Materials in motion (sediment in water, dust in air), depleted areas (where material removed), built-up areas (where material deposited).

This question tests 4th grade ability to observe erosion moving earth materials (NGSS 4-ESS2-1). Students must recognize evidence that materials are being transported from one location to another by erosion agents. Erosion is different from weathering: weathering breaks down rocks IN PLACE, erosion MOVES materials from place to place. Erosion agents transport materials: (1) Water - carries sand, silt, rocks downstream or along shore, evidence is muddy water or sediment deposits, (2) Wind - picks up and carries dust, sand, deposits in new locations, evidence is sand dunes or dust in air, (3) Ice - glaciers carry rocks frozen in ice, evidence is rocks far from source, (4) Gravity - materials slide or fall downhill, evidence is piles at slope base. Observable evidence of erosion: materials in motion (sand in water, dust in wind), depleted source areas (eroded hillsides), deposition sites (sandbars, dunes, deltas), material in transport medium (muddy water = sediment being carried). In this observation, a glacier is melting, revealing rocks that were carried within the ice. The evidence of erosion includes rocks deposited in a pile at the glacier's end, far from their source. The erosion agent is ice (glacier), shown by the moving ice mass. Materials are moving from the mountain source to the glacier's terminus, which we can observe by rocks embedded in ice and final deposits. Choice B is correct because it identifies materials being moved (rocks) and describes transport evidence (moved with glacier and deposited in pile at end). The observations support this: rocks in ice = in transport, pile at end = materials arriving. This demonstrates understanding that erosion is visible through material movement and deposition. Choice C is incorrect because it confuses weathering with erosion by focusing on breaking in place without movement. This error occurs when students don't distinguish weathering (breaking) from erosion (moving) or fail to recognize transport by ice. Critical distinction: Weathering = breaking down in original location; Erosion = moving broken materials to new location. Both often occur together but are different processes. To help students observe erosion: Make it visible - create model erosion: (1) Water erosion: Pour water on sand/soil hill, watch it carve channels and carry material down, (2) Wind erosion: Use fan to blow sand, observe movement and dune formation. Observe real erosion: Stream after rain (brown/muddy = carrying sediment), beach after storm (sand moved), construction site (exposed soil washes away). Identify the three components: (1) Source (where material comes from - being eroded), (2) Transport (material in motion - being carried), (3) Deposition (where material settles - being deposited). Practice: For each observation, identify all three - 'Where did material start? How is it moving? Where is it going?' Compare weathering vs. erosion: Weathering makes small pieces (breaks down), Erosion moves the pieces away (transports). Often happen together: weathering breaks, erosion carries away. Key observations: Materials in motion (sediment in water, dust in air), depleted areas (where material removed), built-up areas (where material deposited).

This question tests 4th grade ability to observe erosion moving earth materials (NGSS 4-ESS2-1). Students must recognize evidence that materials are being transported from one location to another by erosion agents. Erosion is different from weathering: weathering breaks down rocks IN PLACE, erosion MOVES materials from place to place. Erosion agents transport materials: (1) Water - carries sand, silt, rocks downstream or along shore, evidence is muddy water or sediment deposits, (2) Wind - picks up and carries dust, sand, deposits in new locations, evidence is sand dunes or dust in air, (3) Ice - glaciers carry rocks frozen in ice, evidence is rocks far from source, (4) Gravity - materials slide or fall downhill, evidence is piles at slope base. Observable evidence of erosion: materials in motion (sand in water, dust in wind), depleted source areas (eroded hillsides), deposition sites (sandbars, dunes, deltas), material in transport medium (muddy water = sediment being carried). In this observation, a slope shows signs of a mudslide, with a bare scar uphill and soil piled at the bottom. The evidence of erosion includes the fresh bare scar on the slope and a new pile of soil at the bottom. The erosion agent is gravity, shown by the downhill slide on the slope. Materials are moving from the upper slope to the base, which we can observe by the scar as source and pile as deposition. Choice A is correct because it identifies materials being moved (earth materials) and describes transport evidence (bare scar as removal and pile at bottom as arrival). The observations support this: bare scar = material removed, soil pile = materials arriving. This demonstrates understanding that erosion is visible through material movement and deposition. Choice D is incorrect because it wrongly suggests materials are added from the sky rather than moved downhill, denying erosion's transport. This error occurs when students attribute changes to wrong causes or don't recognize gravity's role in movement. Critical distinction: Weathering = breaking down in original location; Erosion = moving broken materials to new location. Both often occur together but are different processes. To help students observe erosion: Make it visible - create model erosion: (1) Water erosion: Pour water on sand/soil hill, watch it carve channels and carry material down, (2) Wind erosion: Use fan to blow sand, observe movement and dune formation. Observe real erosion: Stream after rain (brown/muddy = carrying sediment), beach after storm (sand moved), construction site (exposed soil washes away). Identify the three components: (1) Source (where material comes from - being eroded), (2) Transport (material in motion - being carried), (3) Deposition (where material settles - being deposited). Practice: For each observation, identify all three - 'Where did material start? How is it moving? Where is it going?' Compare weathering vs. erosion: Weathering makes small pieces (breaks down), Erosion moves the pieces away (transports). Often happen together: weathering breaks, erosion carries away. Key observations: Materials in motion (sediment in water, dust in air), depleted areas (where material removed), built-up areas (where material deposited).

This question tests 4th grade ability to observe erosion moving earth materials (NGSS 4-ESS2-1). Students must recognize evidence that materials are being transported from one location to another by erosion agents. Erosion is different from weathering: weathering breaks down rocks IN PLACE, erosion MOVES materials from place to place. Erosion agents transport materials: (1) Water - carries sand, silt, rocks downstream or along shore, evidence is muddy water or sediment deposits, (2) Wind - picks up and carries dust, sand, deposits in new locations, evidence is sand dunes or dust in air, (3) Ice - glaciers carry rocks frozen in ice, evidence is rocks far from source, (4) Gravity - materials slide or fall downhill, evidence is piles at slope base. Observable evidence of erosion: materials in motion (sand in water, dust in wind), depleted source areas (eroded hillsides), deposition sites (sandbars, dunes, deltas), material in transport medium (muddy water = sediment being carried). In this observation, a stream shows flowing water carrying sediment downstream, with visible sand and pebbles moving along the bottom or in the current. The evidence of erosion includes muddy water showing sediment being carried and pebbles tumbling along the streambed. The erosion agent is water, shown by the flowing stream present. Materials are moving from the stream bank to downstream locations, which we can observe by the sediment in motion and bare spots on the bank. Choice B is correct because it identifies materials being moved (sand and pebbles) and correctly names the erosion agent (flowing water) while describing transport evidence (from the bank to downstream). The observations support this: muddy water = sediment in transport, bare bank = soil removed, and potential deposits downstream = materials arriving. This demonstrates understanding that erosion is visible through material movement and deposition. Choice A is incorrect because it confuses the erosion agent with ice instead of water and wrongly suggests movement to the riverbank rather than downstream. This error occurs when students don't distinguish the correct agent based on the visible flowing water or misidentify the direction of transport. Critical distinction: Weathering = breaking down in original location; Erosion = moving broken materials to new location. Both often occur together but are different processes. To help students observe erosion: Make it visible - create model erosion: (1) Water erosion: Pour water on sand/soil hill, watch it carve channels and carry material down, (2) Wind erosion: Use fan to blow sand, observe movement and dune formation. Observe real erosion: Stream after rain (brown/muddy = carrying sediment), beach after storm (sand moved), construction site (exposed soil washes away). Identify the three components: (1) Source (where material comes from - being eroded), (2) Transport (material in motion - being carried), (3) Deposition (where material settles - being deposited). Practice: For each observation, identify all three - 'Where did material start? How is it moving? Where is it going?' Compare weathering vs. erosion: Weathering makes small pieces (breaks down), Erosion moves the pieces away (transports). Often happen together: weathering breaks, erosion carries away. Key observations: Materials in motion (sediment in water, dust in air), depleted areas (where material removed), built-up areas (where material deposited).

This question tests 4th grade ability to observe erosion moving earth materials (NGSS 4-ESS2-1). Students must recognize evidence that materials are being transported from one location to another by erosion agents. Erosion is different from weathering: weathering breaks down rocks IN PLACE, erosion MOVES materials from place to place. Erosion agents transport materials: (1) Water - carries sand, silt, rocks downstream or along shore, evidence is muddy water or sediment deposits, (2) Wind - picks up and carries dust, sand, deposits in new locations, evidence is sand dunes or dust in air, (3) Ice - glaciers carry rocks frozen in ice, evidence is rocks far from source, (4) Gravity - materials slide or fall downhill, evidence is piles at slope base. Observable evidence of erosion: materials in motion (sand in water, dust in wind), depleted source areas (eroded hillsides), deposition sites (sandbars, dunes, deltas), material in transport medium (muddy water = sediment being carried). In this observation, a river enters a lake, forming a delta with sediment buildup. The evidence of erosion includes sediment-laden water depositing material where the flow slows. The erosion agent is water (river), shown by the flowing current carrying sediment. Materials are moving from upstream sources to the lake delta, which we can observe by muddy river water and growing delta deposits. Choice A is correct because it identifies materials being moved (sediment) and describes transport evidence (carried from upstream and deposited where water slows). The observations support this: upstream erosion = source, sediment in river = transport, delta buildup = materials arriving. This demonstrates understanding that erosion is visible through material movement and deposition. Choice C is incorrect because it confuses weathering with erosion by stating rocks break in place without movement. This error occurs when students don't distinguish weathering (breaking) from erosion (moving) or deny transport. Critical distinction: Weathering = breaking down in original location; Erosion = moving broken materials to new location. Both often occur together but are different processes. To help students observe erosion: Make it visible - create model erosion: (1) Water erosion: Pour water on sand/soil hill, watch it carve channels and carry material down, (2) Wind erosion: Use fan to blow sand, observe movement and dune formation. Observe real erosion: Stream after rain (brown/muddy = carrying sediment), beach after storm (sand moved), construction site (exposed soil washes away). Identify the three components: (1) Source (where material comes from - being eroded), (2) Transport (material in motion - being carried), (3) Deposition (where material settles - being deposited). Practice: For each observation, identify all three - 'Where did material start? How is it moving? Where is it going?' Compare weathering vs. erosion: Weathering makes small pieces (breaks down), Erosion moves the pieces away (transports). Often happen together: weathering breaks, erosion carries away. Key observations: Materials in motion (sediment in water, dust in air), depleted areas (where material removed), built-up areas (where material deposited).