natrual hazards

What are the three main internal layers of the Earth?

The crust (outer solid layer), mantle (semi-molten rock), and core (dense inner and outer nickel-iron core).

What causes earthquakes and volcanic eruptions?

Movement of tectonic plates driven by convection currents in the Earth's mantle at plate boundaries.

How do tectonic plates interact at constructive, destructive, and conservative plate boundaries?

Constructive: Plates move apart, forming new crust (volcanoes/earthquakes). Destructive: Plates collide, one subducts under the other (severe earthquakes/volcanoes). Conservative: Plates slide past each other (earthquakes only).

What does the Richter scale measure?

The magnitude or amount of seismic energy released by an earthquake on a logarithmic scale.

What conditions are necessary for the formation of a tropical cyclone?

Ocean surface temperature of at least 27 °C, ocean depth of at least 60 m, and location between 5° and 20° north or south of the Equator.

What are the main causes of river flooding?

Heavy or prolonged rainfall, rapid snowmelt, steep topography (land relief), saturated or compacted soil, deforestation, and urbanisation.

How do coastal storm surges, tsunamis, and sea-level rise cause flooding?

Storm surges push ocean water inland via low pressure/winds; tsunamis drive massive sea waves onshore; sea-level rise permanently floods low-lying coastal areas.

What causes severe meteorological drought?

Prolonged high atmospheric pressure preventing rain, oceanic shifts like El Niño/La Niña, and long-term climate change altering rainfall patterns.

What are the main impacts of tectonic events (earthquakes and volcanoes)?

Damage to buildings and infrastructure, fires, tsunamis, landslides, loss of farmland/habitats, water-related disease, loss of life, trauma, and financial losses.

What are the main impacts of tropical cyclones and flooding?

Loss of human and livestock life, crop destruction, habitat loss, severe infrastructure damage, drinking water contamination, water-related diseases, and high economic losses.

What are the primary impacts of severe drought?

Death of organisms, drying up of water sources, agricultural yield collapse, widespread starvation/famine, soil erosion, desertification, poor air quality, and wildfires.

How can tectonic hazard impacts be managed before, during, and after an event?

Before: Seismic monitoring, land-use zoning, earthquake-proof buildings, drills/emergency kits. During: Search and rescue. After: Evacuation, international aid, and rebuilding.

How can tropical cyclone impacts be managed before and after landfall?

Before: Satellite tracking, early warning systems, storm shelters, building reinforcements, and evacuation plans. After: Emergency relief, rebuilding infrastructure, and aid.

What role do storm hydrographs play in flood management?

They monitor river flow by tracking surface runoff, through-flow, and groundwater flow to predict when a river will peak and flood.

How can drought impacts be managed and mitigated?

Water rationing, building dams/reservoirs, tapping deep aquifers, water transfer schemes, rainwater harvesting, desalination plants, and emergency food/water aid.

What economic and agricultural opportunities are presented by volcanoes and flooding?

Volcanoes: Provide fertile volcanic soils, mineral deposits, and geothermal energy. Floods: Deposit nutrient-rich silt onto farmland, renewing soil fertility.