ESCI 111 Exam 4 Study Guide

Chapter 11: Earthquakes

Key Terms:

• Seismic wave: Energy waves in Earth's crust.

• Focus: Quake rupture point.

• Epicenter: Surface above focus.

• Foreshock: Smaller, before main quake.

• Aftershock: Smaller, after main quake (crust adjusts).

Essential Concepts:

• Risk USA: High: Pacific Coast (plate bnd.); Low: Cratonic interior (exc. N. Madrid).

• Wave Types:

  • Body Waves (Interior):

  • P-waves: Fast, compressional (push/pull). Thru S/L/G. First, less damage.

  • S-waves: Slower, shear (side-side). ONLY S. Second, more damage.

  • Surface Waves (Surface): Most destruction.

  • Love: Horiz. shear.

  • Rayleigh: Rolling (up-down, back-forth).

• Thru Liquids/Gases: Only P-waves. S-waves NO.

• Liquid Outer Core Evid. : S-wave shadow zone.

• Depth vs. Damage: Shallow focus = more intense local dmg (energy dissipates).

• Tsunamis: Seafloor disp. wave. Shallow H2O danger: speed $\downarrow$, height $\uparrow$ (shoaling).

• Destruction Factors: Mag, dist, geology, building qual, shake duration.

• Liquefaction: Saturated loose sediment $\rightarrow$ liquid during shaking $\implies$ sink/tilt.

• Scales Comparison:

  • Intensity (Mercalli): Observed effects. Subjective, varies, Roman ($I-XII$).

  • Magnitude (Richter, Moment $M<em>w$): Energy released. Objective, single value, Arabic ($M6.5$). $M</em>w$ better for large quakes.

Chapter 15: Landslides

Key Terms:

• Landslide: Mass movement down slope.

• Angle of repose: Steepest stable angle for loose material.

• Landslide scarp: Steep upslope surface at head.

Essential Concepts:

• Mass Mvmt Role: Shapes land, erosion, sediment transport.

• Mtns: Young vs. Old:

  • Young (Himalayas): Steep, rugged, active, rapid uplift/erosion $\implies$ frequent LS.

  • Old (Appalachians): Subdued, rounded, less active, weathering $\implies$ slower LS.

• LS Triggers:

  • Heavy rain/snowmelt ($\uparrow$ weight, $\uparrow$ pore H2O, $\downarrow$ shear strength).

  • Earthquakes (shaking).

  • Volcanic eruptions (lahars).

  • Human activity (constr, deforest etc.).

  • Slope undercutting.

• Rock Type/Layer Orient.: Weak/fractured/weathered (shale, clay) prone. Layers dipping parallel to slope, esp. weak layers, risky.

• USA Prone: Pacific Coast, Appalachians, Rockies (tectonics, steep, rain).

Chapter 18: Glaciers

Key Terms:

• Ice shelf: Floating ice platform (glacier to ocean).

• Grounded glacier: Base on land/seafloor.

• Iceberg: Broken off glacier/shelf, floating.

• Glacial calving: Ice breaks off glacier edge (major ice loss).

Essential Concepts:

• Glaciers/Snow-Ice Conv. : Ice mass moving slow. Snow $\rightarrow$ Firn (recryst/densify) $10s-100s$ yrs.

• Cont. vs. Alpine:

  • Continental (Ice Sheets): Vast, dome-shaped, covers land (Antarctica, Greenland). Outward flow.

  • Alpine (Valley): Smaller, mt valleys. U-shaped valleys.

• Cont. Glacier Distr.: Antarctica, Greenland.

• Valleys: Glacial vs. Stream:

  • Glacial: U-shaped (steep sides, flat bottom).

  • Stream: V-shaped.

• Glacial Features (Diagram):

  • Arête: Sharp ridge (between cirques/valleys).

  • Horn: Pyramid peak (3+ cirques).

  • Cirque: Bowl-shaped depression (valley head).

  • Moraines: Rock/sediment deposits (terminal, lateral, medial).

  • Fjord: Long, deep sea inlet in U-shaped valley.

• Erosion vs. Slope: More effective on steeper slopes ($\uparrow$ gravity).

• Shackleton Expedition (1914-1917): Endurance crushed by ice. All $28$ crew survived epic journey.

Lab 8: Earthquake Analysis

• Intraplate vs. Interplate:

  • Intraplate: Within plates (N. Madrid).

  • Interplate: At boundaries (San Andreas).

• N. Madrid 1811-1812 Impacts: $M7.0-8.0$ quakes. Destruction, Reelfoot Lake. Felt across E. NA (efficient wave prop).

• NMSZ Vulnerability: Ancient rifts/faults reactivated by compressional stress $\rightarrow$ intraplate seismicity.

• Liquefaction in NMSZ: shaking $\rightarrow$ H2O-sat alluvial sediments $\rightarrow$ liquid sludge.

• Seismic Wave E. vs. W. NA:

  • East: Older, colder, rigid crust. Waves more efficient, less attenuation. Felt over larger area.

  • West: Younger, warmer, fractured crust. Waves less efficient, more attenuation. Felt over smaller area.

Chapter 11: Earthquakes

Key Terms:

• Seismic wave: Energy waves in Earth's crust.

• Focus: Quake rupture point.

• Epicenter: Surface above focus.

• Foreshock: Smaller, before main quake.

• Aftershock: Smaller, after main quake (crust adjusts).

Essential Concepts:

• Risk USA: High: Pacific Coast (plate bnd.); Low: Cratonic interior (exc. N. Madrid).

• Wave Types:

  • Body Waves (Interior):

  • P-waves: Fast, compressional (push/pull). Thru S/L/G. First, less damage.

  • S-waves: Slower, shear (side-side). ONLY S. Second, more damage.

  • Surface Waves (Surface): Most destruction.

  • Love: Horiz. shear.

  • Rayleigh: Rolling (up-down, back-forth).

• Thru Liquids/Gases: Only P-waves. S-waves NO.

• Liquid Outer Core Evid. : S-wave shadow zone.

• Depth vs. Damage: Shallow focus = more intense local dmg (energy dissipates).

• Tsunamis: Seafloor disp. wave. Shallow H2O danger: speed $\downarrow$, height $\uparrow$ (shoaling).

• Destruction Factors: Mag, dist, geology, building qual, shake duration.

• Liquefaction: Saturated loose sediment $\rightarrow$ liquid during shaking $\implies$ sink/tilt.

• Scales Comparison:

  • Intensity (Mercalli): Observed effects. Subjective, varies, Roman ($I-XII$).

  • Magnitude (Richter, Moment $M<em>w$): Energy released. Objective, single value, Arabic ($M6.5$). $M</em>w$ better for large quakes.

Chapter 15: Landslides

Key Terms:

• Landslide: Mass movement down slope.

• Angle of repose: Steepest stable angle for loose material.

• Landslide scarp: Steep upslope surface at head.

Essential Concepts:

• Mass Mvmt Role: Shapes land, erosion, sediment transport.

• Mtns: Young vs. Old:

  • Young (Himalayas): Steep, rugged, active, rapid uplift/erosion $\implies$ frequent LS.

  • Old (Appalachians): Subdued, rounded, less active, weathering $\implies$ slower LS.

• LS Triggers:

  • Heavy rain/snowmelt ($\uparrow$ weight, $\uparrow$ pore H2O, $\downarrow$ shear strength).

  • Earthquakes (shaking).

  • Volcanic eruptions (lahars).

  • Human activity (constr, deforest etc.).

  • Slope undercutting.

• Rock Type/Layer Orient.: Weak/fractured/weathered (shale, clay) prone. Layers dipping parallel to slope, esp. weak layers, risky.

• USA Prone: Pacific Coast, Appalachians, Rockies (tectonics, steep, rain).

Chapter 18: Glaciers

Key Terms:

• Ice shelf: Floating ice platform (glacier to ocean).

• Grounded glacier: Base on land/seafloor.

• Iceberg: Broken off glacier/shelf, floating.

• Glacial calving: Ice breaks off glacier edge (major ice loss).

Essential Concepts:

• Glaciers/Snow-Ice Conv. : Ice mass moving slow. Snow $\rightarrow$ Firn (recryst/densify) $10s-100s$ yrs.

• Cont. vs. Alpine:

  • Continental (Ice Sheets): Vast, dome-shaped, covers land (Antarctica, Greenland). Outward flow.

  • Alpine (Valley): Smaller, mt valleys. U-shaped valleys.

• Cont. Glacier Distr.: Antarctica, Greenland.

• Valleys: Glacial vs. Stream:

  • Glacial: U-shaped (steep sides, flat bottom).

  • Stream: V-shaped.

• Glacial Features (Diagram):

  • Arête: Sharp ridge (between cirques/valleys).

  • Horn: Pyramid peak (3+ cirques).

  • Cirque: Bowl-shaped depression (valley head).

  • Moraines: Rock/sediment deposits (terminal, lateral, medial).

  • Fjord: Long, deep sea inlet in U-shaped valley.

• Erosion vs. Slope: More effective on steeper slopes ($\uparrow$ gravity).

• Shackleton Expedition (1914-1917): Endurance crushed by ice. All $28$ crew survived epic journey.

Lab 8: Earthquake Analysis

• Intraplate vs. Interplate:

  • Intraplate: Within plates (N. Madrid).

  • Interplate: At boundaries (San Andreas).

• N. Madrid 1811-1812 Impacts: $M7.0-8.0$ quakes. Destruction, Reelfoot Lake. Felt across E. NA (efficient wave prop).

• NMSZ Vulnerability: Ancient rifts/faults reactivated by compressional stress $\rightarrow$ intraplate seismicity.

• Liquefaction in NMSZ: shaking $\rightarrow$ H2O-sat alluvial sediments $\rightarrow$ liquid sludge.

• Seismic Wave E. vs. W. NA:

  • East: Older, colder, rigid crust. Waves more efficient, less attenuation. Felt over larger area.

  • West: Younger, warmer, fractured crust. Waves less efficient, more attenuation. Felt over smaller area.