HAZARDOUS ENVIRONMENTS Flashcards
(25 cards)
What causes volcanoes and earthquakes?
The movement of tectonic plates at their boundaries causes volcanoes and earthquakes.
What happens at a destructive plate margin?
Plates move together, causing denser oceanic crust to sink below continental crust, leading to stratovolcanoes and earthquakes.
What occurs at a constructive plate margin?
Plates move apart, allowing magma to rise and form shield volcanoes, often causing gentle earthquakes.
What characterizes a conservative plate margin?
Plates slide past each other, building pressure until they jerk past each other, causing earthquakes.
What are faults?
Weaknesses in the crust where earthquakes occur.
What is the focus of an earthquake?
The point underground where the earthquake starts.
What is the epicenter of an earthquake?
The place on the surface directly above the focus.
What is magma?
Melted mantle rock that rises to the surface.
What are hotspots?
Areas in the middle of tectonic plates where a mantle plume of melted magma rises, forming island chains like Hawaii.
What is the Saffir-Simpson scale used for?
Measuring the intensity of hurricanes.
What is the Moment Magnitude Scale?
A scale that measures the shaking caused by earthquakes.
What are the four main earthquake hazards?
- Building collapse due to shaking. 2. Landslides from loosened rocks and soil. 3. Tsunamis from undersea movements. 4. Liquefaction of wet soils.
What are the short-term impacts of Mount Merapi’s eruption?
353 deaths, 278,000 displaced, crops destroyed, and roads closed.
What are the long-term impacts of Hurricane Helene?
Homelessness, economic downturn, and significant cost of damage.
Why do people live near active volcanoes?
Fertile land from volcanic ash, tourism, geothermal energy, and minerals in lava.
What are physical reasons for vulnerability to earthquakes?
Living close to plate boundaries, active volcanoes, steep slopes, and coastlines.
What are social reasons for vulnerability to earthquakes?
Poor education, lack of awareness about hazards, and dense populations.
What are economic reasons for vulnerability to earthquakes?
Richer countries can afford better building materials and emergency services.
What is a pyroclastic flow?
Fast-moving ash, gas, and rocks from a volcano.
What is a lahar?
Fast-moving mudflows caused by volcanic activity.
What is the Seismic Gap Theory?
A prediction method indicating sections of plate boundaries that may experience earthquakes due to inactivity.
What is the purpose of hazard mapping?
To identify areas at risk of flooding from tsunamis and guide evacuation and planning.
What are the immediate responses to an earthquake?
Issuing warnings, search and rescue operations, medical treatment, and provision of essentials.
What are the long-term responses to an earthquake?
Rebuilding properties, restoring infrastructure, enhancing building regulations, and economic recovery.
