Prediction Flashcards
What is prediction like for earthquakes?
Currently impossible to predict when an earthquake will happen
What clues can there be for an imminent earthquake?
Small tremors
Cracks appearing in rocks
Strange animal behaviour, e.g. rats abandoning nests
What can earthquake warning system predict and why?
P waves, but only after an earthquake has begun. These waves travel faster than other seismic waves and cause less damage so they can be used as a warning for stronger tremors
Give an example of an earthquake warning system
Japan’s Earthquake Early Warning system was set up in 2007 and warns people by TV and radio
What are the problems with earthquake warning systems?
The warnings may only arrive a few seconds before the strong tremors
How is it possible to predict where future earthquakes may happen?
Using data from past earthquakes
What is prediction like for volcanoes?
It’s possible to roughly predict when volcanic eruptions will happen
What signs show that a volcanic eruption is likely?
Tiny earthquakes
Changes in the shape of the volcano, e.g. bulges in the land where magma had built up under it
Give an example of when prediction allowed time for people to be evacuated before an eruption
60,000 people were evacuated from the area around Mt. Pinatubo in the Philippines before it erupted in 1991. Although 800 people died, this figure would have been much higher without the evacuation
Why can it be difficult to evacuate people?
People don’t want to abandon their homes or they don’t believe the eruption will really happen
How did tsunami warning systems work?
They rely on earthquake detection system. If an earthquake occurs in a place that’s likely to cause a tsunami, a warning is issued
Give examples of tsunami warning centres
The USA’s National Oceanic and Atmospheric Administration (NOAA) runs centres in Alaska and Hawaii
What is a problem with tsunami warning systems? 2
They rely on good communication systems. If people don’t receive the warning message they won’t evacuate.
In an earthquake happens very close to land, the tsunami will reach the coast very quickly and people won’t be warned early enough to evacuate
