Earthquake early warning systems
A) are based on long-term predictions of earthquakes,allowing planners to schedule evacuations.
B) alert people just before an earthquake takes place,allowing them to evacuate buildings.
C) alert people when an earthquake has taken place,possibly giving them seconds to get to a safer place.
D) do not yet exist,but the technology is something seismologists are working on.

Question

Quizplus · Accepted Answer

Earthquake early warning systems are designed to detect and quickly alert people when an earthquake has taken place, possibly giving them a few seconds to seek safety before the shaking reaches their location. These systems work by detecting the initial, fast-moving P-waves of an earthquake and calculating the expected arrival time and the intensity of the shaking for the affected area.

Earthquake Early Warning Systems