Appendices A through M · Full Glossary · Selected Answers · Complete Index — the reference foundation for all 29 chapters and 7 parts of the textbook
The back matter of this textbook is designed to serve as a permanent reference companion to all 29 chapters and 7 parts of the course. It is organized so that a student can quickly locate a formula, a definition, a procedure, a worked principle, or a specific topic from any part of the book without having to page through individual chapters.
Use the appendices during study sessions to review skills and reference tables. Use the glossary when a term needs clarification. Use the selected answers to check your reasoning on practice problems. Use the index to locate any concept, process, landform, hazard, resource, or system discussed anywhere in the text.
Earth and environmental science depends on quantitative reasoning at every scale. This appendix reviews the mathematical skills used throughout the textbook. No calculus or advanced algebra is required, but fluency with ratios, rates, percentages, unit conversions, graph reading, and scale interpretation is essential.
A ratio compares two quantities of the same type. Example: a rock sample has 3 parts quartz and 1 part feldspar. The ratio of quartz to feldspar is 3:1, or 3/1 = 3. Ratios can compare any two related quantities.
A percentage expresses a part out of 100. If 42 of 200 water samples exceeded contamination limits, the percentage is: (42 ÷ 200) × 100 = 21%. To find a percentage change: [(new − old) ÷ old] × 100.
| Operation | Formula | Earth Science Example |
|---|---|---|
| Ratio | a : b or a/b | Land : ocean area on Earth ≈ 1 : 2.4 |
| Percentage of total | (part ÷ whole) × 100 | Freshwater = 2.5% of all Earth's water |
| Percentage change | [(new − old) ÷ old] × 100 | CO₂ increased from 280 ppm to 420 ppm: +50% |
| Finding a part | whole × (percent ÷ 100) | 97.5% of 1,386 million km³ = ocean volume |
Earth science routinely uses numbers that are either enormous (geologic time in years, distances in kilometers) or tiny (particle sizes, trace gas concentrations). Scientific notation writes any number as a coefficient between 1 and 10, multiplied by a power of 10.
| Standard Form | Scientific Notation | Context |
|---|---|---|
| 4,600,000,000 years | 4.6 × 10⁹ yr | Age of Earth |
| 1,386,000,000 km³ | 1.386 × 10⁹ km³ | Volume of all water on Earth |
| 0.0000001 m | 1 × 10⁻⁷ m | Fine clay particle diameter |
| 0.000420 | 4.20 × 10⁻⁴ | CO₂ concentration in atmosphere (volume fraction) |
Multiply by a conversion factor — a fraction equal to 1 — so the unwanted unit cancels. Example: convert 5 km to meters.
5 km × (1,000 m / 1 km) = 5,000 m
The km units cancel because they appear in both numerator and denominator.
| From | To | Multiply By |
|---|---|---|
| kilometers (km) | meters (m) | 1,000 |
| meters (m) | centimeters (cm) | 100 |
| kilograms (kg) | grams (g) | 1,000 |
| liters (L) | milliliters (mL) | 1,000 |
| miles | kilometers | 1.609 |
| feet | meters | 0.305 |
| °Celsius | °Fahrenheit | °F = (°C × 9/5) + 32 |
| °Fahrenheit | °Celsius | °C = (°F − 32) × 5/9 |
Rate = Change in quantity ÷ Change in time
Example: a glacier retreated 2.4 km in 30 years. Rate = 2.4 ÷ 30 = 0.08 km/yr = 80 m/yr.
Rates in Earth science: erosion rate (mm/yr), sea-level rise rate (mm/yr), plate velocity (cm/yr), temperature change (°C/decade).
Representative fraction (RF): 1 : 24,000 means 1 unit on the map = 24,000 units in reality.
Bar scale: A drawn segment labeled with real-world distance. Measure the segment, then proportion.
Formula: Real distance = Map distance × Denominator of RF
Example: 3.5 cm on a 1 : 50,000 map = 3.5 × 50,000 = 175,000 cm = 1.75 km.
| Graph Type | Best Used For | Key Reading Skills |
|---|---|---|
| Line graph | Change over time; trends | Slope direction, steepness, turning points |
| Bar graph | Comparing categories | Bar heights, relative differences, scale |
| Scatter plot | Relationships between two variables | Correlation direction, outliers, clusters |
| Pie chart | Parts of a whole | Sector size, percentage labels |
| Climate graph | Temperature and precipitation by month | Dual axes, seasonal patterns, range |
| Contour map | Elevation; topography | Contour interval, slope steepness, watershed |
Before reading a graph: (1) read the title, (2) read both axis labels and units, (3) note the scale on each axis, (4) look for trends before reading specific values. Never read a value from a graph without first checking the axis units.
Mean = Sum of all values ÷ Number of values
Example: Monthly precipitation (cm): 5, 8, 12, 18, 22, 25, 30, 28, 20, 14, 8, 4. Sum = 194. Mean = 194 ÷ 12 = 16.2 cm/month. Annual total = 194 cm.
Range = maximum − minimum. Tells you how spread out the data are.
| Concept | Definition | Range |
|---|---|---|
| Latitude | Angular distance north or south of the equator | 0° (equator) to 90°N or 90°S (poles) |
| Longitude | Angular distance east or west of the prime meridian | 0° (prime meridian) to 180°E or 180°W |
| Parallel | Line of constant latitude; runs east–west | Every 1° latitude ≈ 111 km |
| Meridian | Line of constant longitude; runs north–south | Converge at poles |
| Prime meridian | 0° longitude; passes through Greenwich, England | Reference line for east/west |
| Coordinate format | Latitude first, then longitude | 40°N, 74°W = New York City |
| Projection | Preserves | Distorts | Best Used For |
|---|---|---|---|
| Mercator | Shape (conformal) | Area — high latitudes appear too large | Navigation; direction |
| Equal-area (e.g. Mollweide) | Area | Shape — countries stretched at edges | Comparing areas; climate zones |
| Robinson | Neither perfectly | Both slightly | General reference; world maps |
| Polar (azimuthal) | Direction from center | Shape and area at edges | Arctic/Antarctic; flight routes |
No flat map can perfectly represent a sphere. Every map projection involves tradeoffs. The Mercator projection, commonly used in classrooms, makes Greenland appear similar in size to Africa — but Africa is about 14 times larger. Always check what a projection preserves before using it to compare areas or distances.
| Category | What to Record |
|---|---|
| Location | GPS coordinates or described location; compass bearing; sketch map of site |
| Rock observations | Color, texture, grain size, layering, crystal size, fossils, weathering state |
| Soil observations | Horizon depth, color (Munsell notation if available), texture (sandy/silty/clayey), moisture, organic content |
| Water observations | Color, clarity, odor, flow direction, flow rate estimate, channel width and depth |
| Weather observations | Temperature, cloud cover, wind direction and speed, precipitation type, visibility |
| Biological context | Dominant plant species, evidence of animals, disturbance, land use nearby |
Always inform someone of your field location and expected return time. Wear appropriate footwear and weather protection. Be aware of cliff edges, unstable slopes, rising water, and lightning hazard in open terrain. Follow all rules of the field site.
| Property | Description | Testing Method |
|---|---|---|
| Color | Surface appearance; unreliable alone (impurities affect color) | Observe in good light |
| Streak | Color of powder on unglazed porcelain; more reliable than surface color | Rub on streak plate |
| Luster | Quality of light reflection: metallic or nonmetallic (vitreous, resinous, pearly, silky, adamantine) | Observe; compare to reference |
| Hardness | Resistance to scratching; compared to Mohs scale (1 = talc, 10 = diamond) | Scratch test with known minerals or fingernail/copper/steel |
| Cleavage | Tendency to break along flat planes parallel to crystal faces; described by number and angle of planes | Break or observe broken surfaces |
| Fracture | Irregular break pattern when cleavage is absent; types include conchoidal, fibrous, uneven | Observe break surface |
| Density / specific gravity | Mass per unit volume; ratio of mineral density to water density | Weigh in air and water |
| Special properties | Magnetism (magnetite), fizzes in acid (calcite), double refraction (calcite), fluorescence, taste (halite) | Test-specific |
| Hardness | Mineral | Field Test |
|---|---|---|
| 1 | Talc | Scratched by fingernail easily |
| 2 | Gypsum | Scratched by fingernail |
| 2.5 | — | Fingernail (hardness ~2.5) |
| 3 | Calcite | Scratched by copper coin |
| 3.5 | — | Copper coin (hardness ~3.5) |
| 4 | Fluorite | Easily scratched by steel knife |
| 5 | Apatite | Scratched by steel knife blade |
| 5.5 | — | Steel knife blade (~5.5) |
| 6 | Orthoclase feldspar | Scratches glass; scratched by steel file |
| 6.5 | — | Steel file (hardness ~6.5) |
| 7 | Quartz | Scratches glass and most minerals; scratched only by harder minerals |
| 8 | Topaz | Scratches quartz |
| 9 | Corundum | Scratches topaz |
| 10 | Diamond | Scratches all minerals; hardest natural substance |
| Mineral | Composition | Key Properties | Common Uses / Occurrences |
|---|---|---|---|
| Quartz | SiO₂ | Hardness 7; conchoidal fracture; vitreous luster; no cleavage | Sandstone, granite, sand; glass, electronics |
| Feldspar (orthoclase) | KAlSi₃O₈ | Hardness 6; two cleavage planes at 90°; pink or white | Most abundant mineral group in Earth's crust; granite, basalt |
| Feldspar (plagioclase) | NaAlSi₃O₈–CaAl₂Si₂O₈ | Hardness 6; striations on cleavage face | Granite, gabbro, basalt; ceramics |
| Mica (muscovite) | KAl₂(AlSi₃O₁₀)(OH)₂ | Perfect one-direction cleavage; transparent thin sheets | Granite, schist; electrical insulation |
| Mica (biotite) | K(Mg,Fe)₃(AlSi₃O₁₀)(OH)₂ | Perfect one-direction cleavage; black to brown | Granite, schist |
| Calcite | CaCO₃ | Hardness 3; fizzes in dilute HCl; rhombohedral cleavage; double refraction | Limestone, marble; cement, chalk |
| Dolomite | CaMg(CO₃)₂ | Hardness 3.5–4; fizzes in HCl when powdered | Dolostone; building stone, agriculture |
| Halite | NaCl | Hardness 2.5; cubic cleavage; salty taste; dissolves in water | Evaporite; table salt, food preservation, road salt |
| Gypsum | CaSO₄·2H₂O | Hardness 2; scratched by fingernail; sometimes transparent (selenite) | Evaporite; drywall, plaster, fertilizer |
| Pyrite | FeS₂ | Metallic luster; brass-yellow; cubic crystals; hardness 6–6.5; streak black | "Fool's gold"; sulfur source; not economically mined for gold |
| Magnetite | Fe₃O₄ | Metallic luster; black; strongly magnetic; hardness 5.5–6.5 | Iron ore; early compasses; beach sand |
| Hematite | Fe₂O₃ | Red-brown streak; metallic or earthy luster; hardness 5–6 | Iron ore; red pigment; Mars surface color |
| Olivine | (Mg,Fe)₂SiO₄ | Olive green; hardness 6.5–7; conchoidal fracture; glassy luster | Basalt, peridotite; upper mantle |
| Pyroxene (augite) | Complex silicate | Dark green–black; two cleavage planes at ~90°; hardness 5–6 | Basalt, gabbro |
| Amphibole (hornblende) | Complex silicate | Black; two cleavage planes at ~60°/120°; hardness 5–6 | Granite, diorite, schist |
| Garnet | Complex silicate | Red, brown, green; dodecahedral crystals; no cleavage; hardness 6.5–7.5 | Metamorphic rocks; abrasives; gems |
| Rock | Texture | Composition | Origin |
|---|---|---|---|
| Granite | Coarse-grained (intrusive) | Felsic: quartz, feldspar, mica | Slow cooling in magma chambers |
| Rhyolite | Fine-grained (extrusive) | Felsic: same as granite | Rapid cooling of silica-rich lava |
| Diorite | Coarse-grained (intrusive) | Intermediate: feldspar, hornblende | Intrusive; subduction zones |
| Andesite | Fine-grained (extrusive) | Intermediate: same as diorite | Composite volcano lava |
| Gabbro | Coarse-grained (intrusive) | Mafic: pyroxene, feldspar, olivine | Oceanic crust intrusions |
| Basalt | Fine-grained (extrusive) | Mafic: same as gabbro | Oceanic crust; shield volcano lava |
| Obsidian | Glassy (no crystals) | Felsic to intermediate | Very rapid cooling; volcanic glass |
| Pumice | Vesicular (glassy, frothy) | Felsic to intermediate | Gas-rich explosive eruption |
| Scoria | Vesicular (dark, coarser) | Mafic to intermediate | Gas-rich basaltic eruption |
| Porphyry | Porphyritic (large crystals in fine matrix) | Variable | Two-stage cooling history |
| Rock | Type | Grain / Composition | Environment |
|---|---|---|---|
| Conglomerate | Clastic | Rounded gravel-size or larger clasts | High-energy rivers, beaches |
| Breccia | Clastic | Angular gravel-size or larger clasts | Steep slopes; near-source deposition |
| Sandstone | Clastic | Sand-size grains (0.06–2 mm) | Beaches, dunes, rivers |
| Siltstone | Clastic | Silt-size grains (0.004–0.06 mm) | Floodplains, delta margins |
| Shale / Mudstone | Clastic | Clay-size grains (<0.004 mm) | Lakes, deep ocean, quiet water |
| Limestone | Chemical/Organic | CaCO₃; often fossil-rich | Warm shallow seas |
| Chalk | Organic | Fine CaCO₃ from microscopic organisms | Deep ocean (Cretaceous seas) |
| Chert | Chemical/Organic | SiO₂; very fine-grained | Deep ocean; some biochemical |
| Rock salt (halite) | Chemical (evaporite) | NaCl crystals | Evaporating inland seas or basins |
| Rock gypsum | Chemical (evaporite) | CaSO₄·2H₂O | Evaporating inland seas or basins |
| Coal | Organic | Compressed plant material (carbon-rich) | Swamps and peat bogs |
| Rock | Foliated? | Parent Rock | Grade / Setting |
|---|---|---|---|
| Slate | Yes (fine) | Shale | Low grade; regional metamorphism |
| Phyllite | Yes (silky sheen) | Slate / shale | Low–medium grade |
| Schist | Yes (coarse) | Shale, basalt | Medium grade; mica-rich |
| Gneiss | Yes (banded) | Granite or schist | High grade; light/dark bands |
| Marble | No | Limestone | Contact or regional; interlocking calcite |
| Quartzite | No | Sandstone (quartz) | Contact or regional; very hard |
| Hornfels | No | Shale or basalt | Contact metamorphism; fine-grained |
| Principle | Statement | What It Tells You |
|---|---|---|
| Superposition | In undisturbed horizontal layers, older layers are on the bottom, younger on top | Relative age of layers by position |
| Original horizontality | Sedimentary layers are deposited approximately horizontally; tilted or folded layers were disturbed after deposition | Deformation happened after deposition |
| Lateral continuity | Sedimentary layers extend laterally until they thin, change character, or are interrupted | Correlation of layers across a region |
| Cross-cutting relationships | A feature (fault, intrusion, erosion surface) that cuts across another feature is younger | Relative age of intrusions and faults |
| Inclusions | Fragments (inclusions) within a rock are older than the rock that contains them | Relative age of rock bodies |
| Faunal succession | Fossil assemblages follow a predictable sequence through time; index fossils identify geologic age | Age of rock by fossil content |
| Unconformities | Surfaces representing missing time due to erosion or non-deposition (angular unconformity, disconformity, nonconformity) | Gaps in the rock record |
A half-life is the time required for half of a radioactive parent isotope to decay into a stable daughter isotope. After one half-life, 50% parent remains. After two half-lives, 25% remains. After three, 12.5%. The ratio of parent to daughter in a rock sample, combined with the known half-life, gives the age of the rock.
| Isotope Pair | Half-Life | Materials Dated | Useful Age Range |
|---|---|---|---|
| Carbon-14 → Nitrogen-14 | 5,730 years | Organic material (wood, bone, charcoal) | Up to ~50,000 years |
| Potassium-40 → Argon-40 | 1.25 billion years | Volcanic rocks containing potassium | 100,000 years to billions of years |
| Uranium-238 → Lead-206 | 4.47 billion years | Zircon and other uranium-bearing minerals | Millions to billions of years |
| Rubidium-87 → Strontium-87 | 48.8 billion years | Granite, metamorphic rocks | Hundreds of millions to billions of years |
| Eon | Era | Period (selected) | Began (approx.) | Key Events |
|---|---|---|---|---|
| Phanerozoic (541 Ma–present) | Cenozoic | Quaternary | 2.6 Ma | Ice ages; human evolution; megafauna extinctions |
| Neogene / Paleogene | 66 Ma | Mammals diversify; grasslands spread; Himalayas rise | ||
| Mesozoic | Cretaceous, Jurassic, Triassic | 252 Ma | Dinosaurs; flowering plants; Pangea breakup; mass extinction at 66 Ma | |
| Paleozoic | Permian, Carboniferous, Devonian, Silurian, Ordovician, Cambrian | 541 Ma | Cambrian explosion; first land plants and animals; Pangea assembly; largest mass extinction at 252 Ma | |
| Proterozoic (2,500–541 Ma) | — | — | 2,500 Ma | First complex cells; snowball Earth glaciations; oxygen atmosphere develops |
| Archean (4,000–2,500 Ma) | — | — | 4,000 Ma | First continents; oldest known rocks; first life (microbial) |
| Hadean (4,600–4,000 Ma) | — | — | 4,600 Ma | Formation of Earth; heavy bombardment; formation of Moon; oceans begin forming |
For the Paleozoic periods oldest to youngest: Camels OSit Down Carefully, Perhaps Their Joints Creak — Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian, Triassic, Jurassic, Cretaceous.
| Layer | Depth | State | Composition | Key Facts |
|---|---|---|---|---|
| Continental crust | 0–70 km | Solid | Granite-like (felsic) | Thicker under mountains; less dense than oceanic |
| Oceanic crust | 0–10 km | Solid | Basalt (mafic) | Younger (max ~200 Ma); denser than continental |
| Upper mantle | 10–410 km | Solid (mostly) | Peridotite (ultramafic) | Includes rigid lithosphere and ductile asthenosphere |
| Transition zone | 410–660 km | Solid | Peridotite (high pressure) | Mineral phase transitions |
| Lower mantle | 660–2,900 km | Solid (high pressure) | Silicates and oxides | Very high pressure prevents melting despite temperature |
| Outer core | 2,900–5,150 km | Liquid | Iron–nickel alloy | Convection generates Earth's magnetic field |
| Inner core | 5,150–6,371 km | Solid | Iron–nickel alloy | Solid despite high temperature due to extreme pressure |
| Boundary Type | Plate Motion | Landforms | Hazards | Example |
|---|---|---|---|---|
| Divergent (oceanic) | Plates move apart | Mid-ocean ridge, rift valley, new ocean crust | Earthquakes (shallow), volcanic eruptions (basaltic) | Mid-Atlantic Ridge |
| Divergent (continental) | Plates move apart | Rift valley, eventually new ocean | Earthquakes, volcanism | East African Rift |
| Convergent (ocean–ocean) | One plate subducts | Oceanic trench, island arc volcanoes | Subduction earthquakes, tsunamis, volcanic eruptions | Mariana Trench; Japan arc |
| Convergent (ocean–continent) | Oceanic plate subducts | Trench, coastal mountain range, composite volcanoes | Megathrust earthquakes, tsunamis, explosive eruptions | Andes Mountains; Cascades |
| Convergent (continent–continent) | Both plates crumple | High mountain ranges, no volcanoes | Large earthquakes | Himalayas; Alps |
| Transform | Plates slide past horizontally | Strike-slip faults, offset stream channels | Shallow, strong earthquakes; no volcanism | San Andreas Fault |
| Fault Type | Stress Type | Motion | Setting |
|---|---|---|---|
| Normal fault | Tension (pulling apart) | Hanging wall drops relative to footwall | Divergent boundaries; rift zones |
| Reverse fault | Compression (pushing together) | Hanging wall rises relative to footwall | Convergent boundaries |
| Thrust fault | Compression (low angle) | Hanging wall rides over footwall at a low angle | Mountain building; convergent zones |
| Strike-slip fault | Shear (sideways) | Blocks move horizontally past each other | Transform boundaries |
| Type | Shape | Lava Viscosity | Eruption Style | Example |
|---|---|---|---|---|
| Shield volcano | Broad, gently sloping dome | Low (mafic, basaltic) | Effusive; flows freely; not highly explosive | Mauna Loa (Hawai'i) |
| Composite (stratovolcano) | Steep-sided cone | High (felsic to intermediate) | Explosive; pyroclastic flows; lahars | Mt. Fuji; Mt. St. Helens |
| Cinder cone | Small, steep, symmetrical | Low to intermediate | Short-lived; cinders and ash fall near vent | Paricutin (Mexico) |
| Caldera | Large collapse depression | Variable | Catastrophic collapse after magma chamber empties | Yellowstone; Crater Lake |
| Wave Type | Motion | Medium | Speed | Use |
|---|---|---|---|---|
| P-wave (primary) | Compression–expansion in direction of travel | Solid and liquid | Fastest; arrives first | Locating earthquakes; probing all layers |
| S-wave (secondary) | Perpendicular shaking to direction of travel | Solid only | Slower than P; arrives second | Confirms outer core is liquid (S-waves stop there) |
| Surface waves (Love, Rayleigh) | Complex rolling and shearing along surface | Surface of Earth | Slowest; arrives last | Cause most shaking damage in earthquakes |
| Process | Description | Driven By |
|---|---|---|
| Evaporation | Liquid water converts to water vapor at the surface | Solar energy |
| Transpiration | Water vapor released through plant leaves | Solar energy; plant biology |
| Evapotranspiration | Combined evaporation and transpiration from land surfaces | Solar energy; vegetation |
| Condensation | Water vapor cools and converts to liquid droplets; cloud formation | Cooling of rising air |
| Precipitation | Water falls from clouds as rain, snow, sleet, or hail | Cloud droplet growth |
| Infiltration | Water soaks into the soil and rock | Gravity; soil porosity |
| Runoff | Water flows across the surface into streams and rivers | Gravity; slope; saturation |
| Groundwater flow | Water moves slowly through pores and fractures in rock and sediment | Gravity; pressure gradients |
| Sublimation | Ice converts directly to water vapor without melting first | Solar energy; dry conditions |
| Term | Definition |
|---|---|
| Aquifer | A permeable rock or sediment layer that stores and transmits groundwater |
| Unconfined aquifer | An aquifer with a permeable layer above it; recharged from directly above |
| Confined aquifer | An aquifer bounded above and below by impermeable layers (aquitards) |
| Water table | The upper surface of the saturated zone in an unconfined aquifer |
| Porosity | The percentage of void space in a rock or sediment |
| Permeability | The ability of water to flow through a porous material |
| Recharge zone | The area where precipitation or surface water infiltrates and replenishes an aquifer |
| Artesian well | A well in a confined aquifer where water rises on its own due to pressure |
| Spring | A natural discharge of groundwater at the surface |
| Term | Definition |
|---|---|
| Watershed (drainage basin) | The total land area that drains to a common outlet (stream, river, lake, or ocean) |
| Divide | The ridge or high ground separating adjacent watersheds |
| Tributary | A stream or river that flows into a larger stream or river |
| Discharge | The volume of water flowing past a point per unit time (m³/s or cfs) |
| Floodplain | The flat land adjacent to a river channel that floods periodically |
| 100-year flood | A flood with a 1% probability of occurring in any given year (not literally once per 100 years) |
| Erosion | Picking up and carrying away of sediment by flowing water |
| Deposition | Settling of sediment when flow energy decreases |
| Channel | The physical pathway carved by a river or stream |
| Concept | Description |
|---|---|
| Salinity | Average ocean salinity is about 3.5% (35 g dissolved salts per 1,000 g seawater); dominated by sodium and chloride |
| Thermocline | A zone of rapid temperature decrease with depth, separating warm surface water from cold deep water |
| Surface currents | Wind-driven currents in the upper 200 m; form large circular gyres in each ocean basin |
| Thermohaline circulation | Deep ocean circulation driven by density differences caused by temperature and salinity; global conveyor belt |
| Upwelling | Rising of cold, nutrient-rich deep water to the surface; supports productive fisheries |
| Wave | Energy moving through water; orbital motion of water molecules; breaks when water depth ≈ half wavelength |
| Tides | Periodic rise and fall of sea level caused by gravitational pull of Moon and Sun; spring tides when aligned, neap tides when at 90° |
| Longshore drift | Transport of sediment along a coastline by waves approaching at an angle |
| Layer | Altitude | Temperature Trend | Key Feature |
|---|---|---|---|
| Troposphere | 0–12 km (avg) | Decreases with altitude | Weather occurs here; contains 75% of atmospheric mass |
| Stratosphere | 12–50 km | Increases with altitude | Ozone layer absorbs UV; stable; jet aircraft fly here |
| Mesosphere | 50–80 km | Decreases with altitude | Coldest layer; meteors burn up here |
| Thermosphere | 80–600 km | Increases greatly with altitude | Aurora borealis/australis; very low density; ISS orbit |
| Exosphere | >600 km | — | Outer fringe; merges with space; satellite orbits |
| Instrument | Measures | Units |
|---|---|---|
| Thermometer | Air temperature | °C or °F |
| Barometer | Air pressure (atmospheric pressure) | mb (millibars), hPa, inHg |
| Hygrometer / psychrometer | Relative humidity | Percent (%) |
| Anemometer | Wind speed | km/h, mph, knots, m/s |
| Wind vane | Wind direction | Compass bearing; wind direction is where it comes FROM |
| Rain gauge | Precipitation amount | mm or inches |
| Radiosonde (weather balloon) | Temperature, humidity, pressure, wind aloft | Multiple |
| Doppler radar | Precipitation location, intensity, and motion | dBZ (reflectivity); m/s (velocity) |
| Air Mass Code | Source Region | Temperature | Moisture |
|---|---|---|---|
| cP (continental polar) | Canada, Siberia | Cold | Dry |
| cA (continental arctic) | Arctic regions | Very cold | Very dry |
| mP (maritime polar) | North Pacific/Atlantic | Cool | Moist |
| cT (continental tropical) | Desert Southwest, Mexico | Hot | Dry |
| mT (maritime tropical) | Gulf of Mexico, subtropical ocean | Warm | Moist |
| Front Type | Symbol (on map) | Weather Ahead | Weather After Passage |
|---|---|---|---|
| Cold front | Blue triangles pointing in direction of movement | Cumulonimbus clouds; heavy rain; thunderstorms | Temperature drops; pressure rises; winds shift; clearing skies |
| Warm front | Red semicircles pointing in direction of movement | Stratiform clouds; steady rain or snow over wide area | Temperature rises; pressure steadies; skies may clear slowly |
| Stationary front | Alternating blue triangles and red semicircles | Extended clouds and precipitation in the area | Little change until front moves |
| Occluded front | Purple with both symbols | Complex clouds; precipitation | Temperature change depends on type |
| Storm Type | Formation | Key Hazards | Scale / Wind Speed |
|---|---|---|---|
| Thunderstorm | Unstable air; strong updraft; cumulonimbus cloud | Lightning, hail, downbursts, flash flooding, tornadoes | Local to regional; updrafts to 160+ km/h |
| Tornado | Rotating supercell thunderstorm; wind shear | Extreme winds; structural destruction | EF0 (65 km/h) to EF5 (>322 km/h) on Enhanced Fujita Scale |
| Hurricane (tropical cyclone) | Warm ocean ≥26°C; Coriolis effect; organized rotation | Storm surge, flooding, extreme winds, tornadoes | Categories 1–5 on Saffir-Simpson; >119 km/h sustained |
| Nor'easter | Mid-latitude cyclone along US East Coast | Heavy snow/rain; coastal flooding; strong winds | Regional |
| Blizzard | Winter storm with heavy snow and strong winds | Whiteout; dangerous wind chill; travel disruption | Requires >56 km/h winds; visibility <0.4 km for 3+ hours |
| Climate Zone | Location | Temperature | Precipitation |
|---|---|---|---|
| Tropical / Equatorial | Near equator (0–15°) | Hot year-round; little seasonal variation | High; wet and dry seasons in some areas |
| Subtropical desert | Near 30° latitude | Hot summers; mild to cool winters | Very low; dominated by descending dry air |
| Mediterranean | West coasts ~30–45° | Warm, dry summers; mild, wet winters | Seasonal; rain concentrated in winter |
| Temperate / Mid-latitude | Middle latitudes 30–60° | Four distinct seasons | Moderate; year-round in many areas |
| Subarctic / Boreal | High latitudes 55–70° | Long cold winters; short mild summers | Low; mostly snow |
| Polar / Tundra | Near poles >70° | Very cold; permafrost; no warm season | Very low; mostly snow |
| Highland | Mountain regions | Cooler with altitude; highly variable | Variable by aspect and elevation |
Solar radiation (mostly visible light) passes through the atmosphere and warms Earth's surface. Earth's surface radiates energy back as infrared (heat) radiation. Greenhouse gases — water vapor, CO₂, methane, nitrous oxide — absorb infrared radiation and re-emit it in all directions, including back toward the surface. This keeps Earth ~33°C warmer than it would be without an atmosphere. The greenhouse effect is natural and essential for life.
| Greenhouse Gas | Natural Sources | Human Sources | Relative Warming Potential |
|---|---|---|---|
| Water vapor (H₂O) | Evaporation | Indirect (amplifies warming) | Most abundant; largest greenhouse gas |
| Carbon dioxide (CO₂) | Respiration; volcanic outgassing; ocean exchange | Fossil fuel combustion; deforestation | GWP = 1 (reference) |
| Methane (CH₄) | Wetlands; digestion by ruminants | Livestock; landfills; natural gas leaks | GWP ≈ 80 over 20 years |
| Nitrous oxide (N₂O) | Soil bacteria; ocean | Fertilizers; combustion | GWP ≈ 270 over 100 years |
| Biome | Climate | Dominant Vegetation | Example Regions |
|---|---|---|---|
| Tropical rainforest | Hot; high year-round rainfall | Tall broadleaf evergreens; high canopy | Amazon; Congo; Southeast Asia |
| Tropical savanna | Hot; distinct wet/dry seasons | Grasses; scattered trees | East Africa; Brazilian cerrado; northern Australia |
| Desert | Very low precipitation; extreme temperature swings | Cacti; succulents; sparse shrubs | Sahara; Atacama; Mojave; Arabian |
| Mediterranean shrubland (chaparral) | Mild wet winters; hot dry summers | Drought-resistant shrubs; fire-adapted | California; Mediterranean coast; central Chile |
| Temperate grassland | Moderate; seasonal; low rainfall | Grasses; few trees | Great Plains; Pampas; Eurasian steppe |
| Temperate deciduous forest | Four seasons; moderate precipitation | Oaks; maples; beeches (shed leaves seasonally) | Eastern US; Western Europe; East Asia |
| Temperate rainforest | Mild; very high rainfall | Conifers; ferns; mosses | Pacific Northwest; southern Chile; New Zealand |
| Boreal forest (taiga) | Cold; moderate precipitation (mostly snow) | Spruce; fir; pine | Northern Canada; Russia; Scandinavia |
| Tundra | Very cold; very low precipitation; permafrost | Mosses; sedges; low shrubs | Arctic; high alpine areas |
| Trophic Level | Role | Examples |
|---|---|---|
| Producers (Level 1) | Convert sunlight to chemical energy via photosynthesis | Plants; algae; phytoplankton |
| Primary consumers (Level 2) | Eat producers (herbivores) | Insects; rabbits; zooplankton; elk |
| Secondary consumers (Level 3) | Eat primary consumers | Frogs; small fish; foxes; weasels |
| Tertiary consumers (Level 4) | Eat secondary consumers | Hawks; large predatory fish; wolves |
| Decomposers | Break down dead organic matter; return nutrients to soil and water | Bacteria; fungi; some insects and worms |
On average, only about 10% of the energy stored at one trophic level is transferred to the next. The remaining 90% is lost as heat, used for metabolism, or not consumed. This is why food chains rarely have more than four or five levels, and why it takes much more land and resources to produce animal protein than plant protein.
| Resource Type | Examples | Replenishment Time |
|---|---|---|
| Renewable (flow resources) | Solar, wind, hydropower, geothermal, timber, soils, freshwater (if managed) | Human-relevant timescales |
| Nonrenewable (stock resources) | Coal, oil, natural gas, most metal ores | Millions of years (effectively finite) |
| Perpetual (continuous) | Solar radiation, wind, tides | Effectively unlimited on human timescales |
| Pathway | Description | Example |
|---|---|---|
| Point source | Pollution from a specific, identifiable location | Factory discharge pipe into a river |
| Nonpoint source | Pollution from diffuse, spread-out sources | Agricultural runoff carrying fertilizers; stormwater |
| Atmospheric deposition | Pollutants from the air settle onto land or water | Acid rain; particulate fallout |
| Bioaccumulation | Pollutant builds up in an organism's tissues over time | Mercury in fish tissue |
| Biomagnification | Pollutant concentration increases at each trophic level | DDT in eagles and ospreys reaching dangerous levels |
| Leaching | Pollutant moves downward through soil into groundwater | Nitrates from fertilizer entering wells |
| Term | Definition | Example |
|---|---|---|
| Hazard | A natural event or process with the potential to cause harm | A hurricane; an earthquake; a volcanic eruption |
| Exposure | The degree to which people, property, or ecosystems are located in areas affected by a hazard | Cities built near active faults or in floodplains |
| Vulnerability | The characteristics that make people or systems susceptible to harm from a hazard | Poorly built structures; lack of warning systems; limited evacuation options |
| Risk | The probability that harm will result from a hazard, given exposure and vulnerability; Risk = Hazard × Exposure × Vulnerability | A densely populated, poorly built city near an active fault has high earthquake risk |
| Mitigation | Actions taken in advance to reduce the impact of a hazard | Building codes; seawalls; fire-resistant building materials |
| Preparedness | Planning, training, and stockpiling resources before a hazard occurs | Evacuation plans; emergency supply kits; early warning drills |
| Response | Actions taken during and immediately after a hazard event | Search and rescue; emergency shelter; medical aid |
| Recovery | The long-term process of rebuilding and restoring after a disaster | Reconstruction; economic recovery; community counseling |
| Resilience | The ability of a community or system to absorb a hazard impact and recover | Communities with diverse economies, strong social networks, and good infrastructure |
| Hazard | Primary Cause | Key Secondary Hazards | Warning / Monitoring |
|---|---|---|---|
| Earthquake | Sudden slip along a fault | Aftershocks; tsunamis; liquefaction; landslides; fires | Seismographs; GPS ground deformation (no reliable short-term prediction) |
| Volcanic eruption | Magma reaching surface | Pyroclastic flows; lahars; ashfall; lava flows; climate effects (large eruptions) | Seismographs; gas sensors; ground deformation; tiltmeters |
| Tsunami | Submarine earthquake; landslide; volcanic collapse | Coastal flooding; erosion; saltwater intrusion | Seismic alerts; ocean buoys; tide gauges; warning sirens |
| Flood | Heavy precipitation; rapid snowmelt; dam failure; storm surge | Erosion; contamination; infrastructure damage | Stream gauges; weather forecasting; flood maps |
| Hurricane | Warm ocean water; atmospheric disturbance; Coriolis effect | Storm surge; flooding; tornadoes; erosion | Satellite imagery; reconnaissance aircraft; hurricane hunter aircraft; National Hurricane Center |
| Tornado | Rotating supercell thunderstorm; wind shear | Flying debris; structural collapse | Doppler radar; storm spotters; NWS watches and warnings |
| Wildfire | Dry fuel; spark; wind; drought conditions | Air quality; erosion; debris flows after rainfall on burned slopes | Fire weather forecasts; satellite detection; red flag warnings |
| Landslide | Slope failure due to water saturation; earthquakes; undercutting | Blocking rivers (temporary dams); burial of infrastructure | Slope monitoring; rainfall thresholds; geologic hazard maps |
| Drought | Extended below-normal precipitation; high evapotranspiration | Crop failure; wildfire; water shortage; economic impacts | Drought monitor indices (PDSI, SPI); streamflow and reservoir levels |
Earth and environmental science vocabulary is built from Greek and Latin roots. Recognizing these roots allows you to decode unfamiliar terms and remember definitions more reliably. This appendix presents the most common roots, prefixes, and suffixes used throughout the textbook.
| Root | Meaning | Origin | Examples from This Textbook |
|---|---|---|---|
| geo- | Earth | Greek: gē | geosphere, geology, geologic, geothermal, geomorphology |
| hydr- | water | Greek: hydōr | hydrosphere, hydrology, hydropower, groundwater, hydrograph |
| atmo- | vapor, air | Greek: atmos | atmosphere, atmospheric, ATM |
| bio- | life | Greek: bios | biosphere, biodiversity, biomass, biomagnification, biome |
| litho- | rock, stone | Greek: lithos | lithosphere, lithology, monolith, batholith |
| asthen- | weak | Greek: asthenes | asthenosphere (the "weak" layer that flows) |
| seismo- | shake, earthquake | Greek: seismos | seismograph, seismology, seismic, seismometer |
| volcan- | fire, volcanic | Latin: Vulcanus (Roman god of fire) | volcano, volcanic, volcanism |
| tecto- | builder, carpenter | Greek: tektōn | tectonics, plate tectonics |
| strat- | layer | Latin: stratum | stratigraphy, stratosphere, stratovolcano, sedimentary strata |
| ero- | to wear away | Latin: erodere | erosion, erode |
| sed- | to settle, sit | Latin: sedimentum | sediment, sedimentary, sedimentation |
| meta- | change, beyond | Greek: meta | metamorphic, metamorphism, metasomatism |
| morph- | form, shape | Greek: morphē | metamorphic, geomorphology, landform |
| aqui- | water | Latin: aqua | aquifer, aquatic, aqueduct |
| clim- | slope, region (of Earth) | Greek: klima | climate, climatology |
| meteor- | high in the air | Greek: meteōros | meteorology, meteorologist, meteor |
| therm- | heat | Greek: thermē | thermosphere, thermohaline, geothermal, thermocline |
| halo- | salt | Greek: halos | thermohaline, halite, halogen |
| eco- | house, environment | Greek: oikos | ecosystem, ecology, ecosphere |
| fossil- | dug up | Latin: fossilis | fossil fuel, fossilization |
| radio- | ray, radiation | Latin: radius | radioactive, radiometric dating, radiosonde |
| iso- | equal, same | Greek: isos | isostasy, isobar, isotherm, isotope |
| mafic- | magnesium + ferric (iron) | Modern blend | mafic rock (basalt, gabbro); contrast with felsic |
| felsic- | feldspar + silica | Modern blend | felsic rock (granite, rhyolite) |
| conti- | hold together, continuous | Latin: continere | continent, continental, continuum |
| pluvio- | rain | Latin: pluvia | pluvial (referring to rainy periods) |
| evapo- | to emit vapor | Latin: evaporare | evaporation, evapotranspiration, evaporite |
| precip- | to fall headlong | Latin: praecipitare | precipitation, precipitate |
| Prefix | Meaning | Examples |
|---|---|---|
| a- / an- | without, not | anoxic (without oxygen); asymmetric |
| anti- | against, opposite | anticyclone; anticlinal |
| con- / com- | together, with | convergent; compaction; condensation |
| di- / dis- | apart, away | divergent; dissolution |
| sub- | under, below | subduction; submarine; subsidence; subtropical |
| trans- | across, through | transform fault; transpiration; transmission |
| ultra- | beyond, extreme | ultramafic (very iron/magnesium rich) |
| inter- | between, among | interglacial; intertropical convergence zone |
| intra- | within | intraplate volcano; intraplate seismicity |
| micro- | very small | microclimate; microplastic; microorganism |
| macro- | large | macrofossil; macronutrient |
When you encounter an unfamiliar Earth science word, break it into its root parts. Example: thermohaline = thermo (heat) + haline (salt) → driven by temperature and salt. Example: asthenosphere = astheno (weak) + sphere (layer of Earth) → the weak, ductile layer beneath the rigid lithosphere. This strategy works for most technical vocabulary in Earth and environmental science.
This glossary defines key terms used throughout the 29 chapters of the textbook. Terms appear in the chapter where they are introduced and are collected here for quick reference. Definitions are written in student-friendly language and remain scientifically accurate. Chapter references (e.g., Ch. 6) indicate where each concept is developed in full.
Selected answers are provided for representative practice problems from each chapter. These are intended to help you check your reasoning and verify that you are using correct procedures — not to replace working through the problems yourself. Where a problem requires explanation, interpretation, or systems thinking, a model response is described rather than a single number.
Check your answer only after completing a problem. If your answer differs, work backward from the correct answer to find where your reasoning diverged. Many Earth science problems have more than one valid approach — if your method is sound and your answer is equivalent, it is correct even if phrased differently.
This index lists major topics, concepts, processes, landforms, systems, hazards, resources, and applications covered in the 29 chapters of the textbook. Chapter numbers appear after each entry. Bolded page references indicate primary discussions.