D - Geophysical Hazard Adaptation Flashcards
What are predictions, forecasts, and warnings in the context of geophysical hazards?
They are statements about the time, place, and size of future events. Forecasts are general, often probabilistic, and effective warnings depend on science, technology, communications, and public interpretation.
Why are earthquakes particularly difficult to predict?
Although at‐risk areas are known, the complex precursors and sudden energy release make precise timing and magnitude forecasting challenging.
What are the main ways of preparing for earthquakes?
Improving forecasting and warning systems, enhancing building design and location, and establishing effective emergency procedures.
Name three measurements or indicators used in predicting earthquakes.
Small-scale ground surface changes (uplift/subsidence, tilt), micro-earthquake activity, and changes in rock stress (including radon gas concentration and magnetic field anomalies).
Which instrument is used to record micro-earthquakes?
Seismometers.
What is the purpose of using a magnetometer in earthquake monitoring?
To record changes in the Earth’s magnetic field that may indicate stress changes in rocks.
How does a vibroseis truck contribute to earthquake prediction?
It generates shear waves to probe the earthquake zone and assess subsurface conditions.
How are volcanic eruptions predicted differently from earthquakes?
Volcanic eruptions are predicted by monitoring seismic swarms, chemical changes (like increased sulphur levels), physical swelling (using lasers/GPS), ultrasound signals, and visual observations.
How do volcanoes at destructive plate boundaries differ from those at hotspots?
Plate-boundary volcanoes tend to produce more explosive eruptions, while hotspot volcanoes (like those in Hawaii) erupt more frequently but less explosively.
What is land-use zoning in geophysical hazard adaptation?
It is the planning practice of restricting certain developments (e.g., dense residential, hospitals, fire services) from high-risk areas to reduce potential hazard impacts.
How can building codes reduce the impacts of geophysical hazards?
By ensuring that buildings are constructed to withstand seismic forces or other hazards, thereby reducing damage and casualties.
What role does insurance play in hazard preparedness, and what are its limitations?
Insurance can help mitigate financial losses after an event, but it is often unavailable for ‘acts of God’ and may be unaffordable for low-income communities.
How is new technology utilized in hazard prediction and preparedness?
Technologies like laser survey equipment, mobile phones with GPS, and sensors that monitor volcano swelling or water chemistry help detect early signs of geophysical changes and improve communication of warnings.
Why is effective warning critical in reducing the impacts of geophysical hazards?
Because timely and accurate warnings allow for better preparedness, evacuation, and emergency response, thereby reducing loss of life and damage.
