ways to monitor natural hazrads (earthquakes and volcanic eruptions) Flashcards
laser beams - earthquakes
these can detect plate movement by directing the beam across the fault line
animal behaviours -earthquakes and volcanoes
animals can often sense and react to the earthquake before humans do
tilt meter-earthquakes
these show ground deformation leading to an earthquake.
these however have been replaced by modern ranging satellites
seismometers- earthquakes
earthquakes also use some technology used to monitor volcanoes
seismometers measure seismic waves and it is often that we get smaller earthquakes after the huge main one
this happen to Japanese tsunami (mag 9.0) which was preceded by a massive mag 7.2 earthquake
what is monitoring and predicting?
the human race cannot fully predict exactly when or how a volcano eruption or an earthquake is going to happen however we have technology that can monitor tectonic actions that allow us to predict more accurately when an hazard is going to happen
volcanoes seismic waves and seismometers
before volcanic eruption happens it gives up seismic waves this can be measure on a seismometers that allow us to know when an earthquake is going to happen
monitoring gas emmisions
before an eruption magma rises and magma chambers escapes. this contains sulphur dioxide. If amounts of this escapes it could warn people of a volcanic eruption
mount Pinatubo sulphar dioxide increased by 10x times within 2 weeks before eruption
ground deformation
magma movement within crust can deform land above the swelling signals that magma is being collected near the surface.
scientist monitoring an active volcano will measure the slopes tilts and track changes of rates of swelling
Yellowstone at Yellowstone lakes
mount st . helens suffered from same symptoms
satellite images and remote sensing
remote sensing uses satellites to detect the earth's movement this can be used to check thermal activity sulphur dioxide emissions by gas sensing swelling on land before and after images of the land
