Natural Processes and Earthquakes

Natural Processes and Hazards

• Extreme natural events pose threats to life, property, and the environment.
• Tectonic plate movement causes geological phenomena like earthquakes, volcanic activity, and landslides.

Earthquakes

• Earthquakes are sudden, intense ground shaking from movements within Earth's crust.
• Seismic waves radiate outward from the source.
• Faults are fractures in Earth's crust where rocks move.
• The epicenter is above the focus (hypocenter); the focus is where the earthquake originates.

Earthquake Causes

• Earth's tectonic plates constantly move.
• Plate movement stresses Earth's crust.
• Stresses build up as plates become stuck, creating faults.
• Stress release causes the ground to shake.

Earthquake Hazards

• Ground Shaking: Movement from seismic activity.
  • Effects: Structural damage (cracking, collapse), interior damage (furniture movement, falls), and ground cracking affecting infrastructure.
• Ground Rupture: Movement on a fault breaking through the surface.
  • Effects: Damage to structures, land displacement (fault lines).
• Liquefaction: Shaking causes soil to turn into a fluid-like state.
  • Effects: Foundation failure (buildings sinking, tilting, collapsing), damage to underground utilities.
• Ground Subsidence: Gradual or sudden sinking of Earth's surface.
  • Effects: Structural damage, flooding, altered landscapes, transportation disruptions.
• Earthquake-Induced Landslides: Shaking triggers rock, soil, and debris sliding.
  • Effects: Buries infrastructure. Blocks roadways, disrupts communities, damages utilities, alters landscapes, and causes economic impacts.

Measuring Earthquakes

• Earthquakes are measured using the Richter scale (1-10).
• Seismometers measure the power of an earthquake.

Tsunamis

• Tsunamis are large, powerful ocean waves caused by underwater events (like earthquakes).
• Effects: Coastal flooding, Loss of ecosystems (beaches, coastal habitats), disruption of local economies (tourism, fishing), and human casualties, displaced communities, transportation disruption.
• Signs of an impending tsunami: Strong earthquake, sea receding, unusual waves, roaring sounds, alerts/warnings.

Human Activities and Landslides

• Human activities can speed up or trigger landslides(deforestation, mining, building on slopes, poor irrigation, debris disposal, etc.)

Mitigation and Coping Strategies

• Earthquakes: Emergency kits, secure furniture, safe spots, family plans, drills.
• Volcanic Eruptions: Evacuation, ash protection, medical supplies, stay away from low areas.
• Landslides: Recognizing signs, preventative measures (retaining walls), avoiding building on unstable slopes, planting vegetation, and hazard mapping.

PHIVOLCS Tsunami Alert Levels

• Alert Level 0: No tsunami threat to the Philippines.
• Alert Level 2: Non-destructive tsunami advisory.
• Alert Level 3: Destructive tsunami; evacuation recommended.

Explore the dynamics of extreme natural events, particularly earthquakes, and their impact on life and the environment. This quiz covers the causes of earthquakes, the mechanics involved in plate movements, and the hazards associated with seismic activity. Test your understanding of geological phenomena and their implications.