Chapter 2 Sections 2, 3, and 4 Landforms and Water; Internal and External Forces Shaping the Earth

Bodies of Water Hydrologic cycle – the cycle of precipitation, evaporation, and condensation Hydrologic cycle – the cycle of precipitation, evaporation, and condensation Aquifer – supply of water between permeable and impermeable rock that can be welled for community water supply Aquifer – supply of water between permeable and impermeable rock that can be welled for community water supply

Landforms Relief – difference in elevation of a landform from lowest point to highest point Relief – difference in elevation of a landform from lowest point to highest point Mountains Mountains Hills Hills Plains Plains Plateaus Plateaus

INTERNAL FORCES

Plate Tectonics Tectonic plates – enormous pieces of earth’s crust, float on top of molten magma Tectonic plates – enormous pieces of earth’s crust, float on top of molten magma Plates move by spreading (moving apart), subduction (diving under another plate), collision (crashing into one another), and sliding past each other in a shearing motion Plates move by spreading (moving apart), subduction (diving under another plate), collision (crashing into one another), and sliding past each other in a shearing motion Folds – occur where 2 plates meet and cause bending and cracking of the rock Folds – occur where 2 plates meet and cause bending and cracking of the rock Faults – occur where 2 plates meet, cause a fracture in the earth’s crust, and move past each other Faults – occur where 2 plates meet, cause a fracture in the earth’s crust, and move past each other

Earthquakes Caused by grinding and slipping of plates along a fault Caused by grinding and slipping of plates along a fault Most earthquakes occur along plate boundaries Most earthquakes occur along plate boundaries Side effects – landslides, displacement of land, fires, collapsed buildings, tsunamis Side effects – landslides, displacement of land, fires, collapsed buildings, tsunamis Seismograph detects earthquake presence only Seismograph detects earthquake presence only Richter Scale is used to process data from seismograph to determine the relative strength of an earthquake Richter Scale is used to process data from seismograph to determine the relative strength of an earthquake

Volcanoes Eruptions – hot lava, gases, ash, dust and rocks explode out of vents in the earth’s crust, often creating a hill or a mountain Eruptions – hot lava, gases, ash, dust and rocks explode out of vents in the earth’s crust, often creating a hill or a mountain Majority of active volcanoes, earthquakes and tsunamis – Ring of Fire in Pacific rim (8 major plates) Majority of active volcanoes, earthquakes and tsunamis – Ring of Fire in Pacific rim (8 major plates) Hot spots – where the crust is thin and allows liquid, hot magma to melt through Hot spots – where the crust is thin and allows liquid, hot magma to melt through

EXTERNAL FORCES

Weathering Refers to physical and chemical processes that change the characteristics of rock on or near the earth’s surface Refers to physical and chemical processes that change the characteristics of rock on or near the earth’s surface Mechanical weathering – ice, plant growth, human activities break rock into smaller pieces Mechanical weathering – ice, plant growth, human activities break rock into smaller pieces Chemical weathering – elements in the air or water combine with minerals in the rock to create new substances (ex: rust) Chemical weathering – elements in the air or water combine with minerals in the rock to create new substances (ex: rust)

Erosion Occurs when weathered material is moved by water, wind, ice or gravity Occurs when weathered material is moved by water, wind, ice or gravity Water – widens and deepens streams, form deltas Water – widens and deepens streams, form deltas Waves reduce beaches and build sandbars/islands Waves reduce beaches and build sandbars/islands Wind – produces sand dunes, sculpted rock, loess Wind – produces sand dunes, sculpted rock, loess Glaciers – slice out valleys, form moraines (hills), leave eskers (ridges), and create kettles (depressions) Glaciers – slice out valleys, form moraines (hills), leave eskers (ridges), and create kettles (depressions)

Building Soil Soil – loose mixture of weathered rock, organic matter, air and water Soil – loose mixture of weathered rock, organic matter, air and water Humus – composed of only organic material Humus – composed of only organic material Fertility – depends on texture and the amounts of humus, air and water Fertility – depends on texture and the amounts of humus, air and water Geographers look at parent material, relief, organisms, climate and time when studying soil Geographers look at parent material, relief, organisms, climate and time when studying soil Type of soil in a location is important because it influences vegetation and agricultural potential Type of soil in a location is important because it influences vegetation and agricultural potential