Prediction and Prevention of Natural Disasters

Question 1

Volcanoes
- Three-dimensional imaging

Answer 1

• Satellite radar informs scientists of active volcanoes and impending eruptions by measuring ground movement as volcanoes swell and change shape, indicating the build up of pressure or magma filling the volcanic chamber.
• Three-dimensional imaging is effective in predicting volcanic eruptions as it shows the volcano swelling and changing shape.

Question 2

Volcanoes
- Seismic data

Answer 2

• Seismic data involves the use of seismometers and probes to detect small earthquakes and tremors, which occur before a volcano erupts
• Seismic data is effective in predicting volcanic eruptions as it allows earthquakes, near a volcano, to be compared and determines whether the earthquake is severe enough to trigger an eruption; however, it is best used in combination with other technologies

Question 3

Volcanoes
- Early warning systems

Answer 3

• Early warning systems combine several technologies into a computer model; satellite radars are used for remote sensing, seismometers for ground vibration, gas spectrometers for gas pressure and GPS for ground deformation
• Early warning systems are effective in predicting volcanic eruptions as the computer model is constantly monitored and updated to provide accurate predictions of an imminent eruption

Question 4

Volcanoes
- Ground- movement data

Answer 4

• Tilt meters are highly sensitive instruments that measure ground tilt near fault slips and volcanoes, with precision of less than 1 part per billion
• Ground-movement data is somewhat effective in predicting volcanic eruptions, as it provides an accurate estimate of the volcano’s physical changes. However, strain and tilt meters may be impacted by external sources and cannot be used independently for predictions

Question 5

East coast lows
- Temperature

Answer 5

The BOM measures sea temperatures with temperature probes, in an effort to predict east coast lows. A liquid-in-glass thermometer measures temperature with alcohol or mercury, which rises or falls depending on the external temperature. Differences in sea surface temperature and subsurface temperature can drive large variations of heavy rainfall and atmospheric circulation patterns. The BOM gathers marine temperatures in many ways. Some come from board ships and other comes from equipment on sea such as buoys. SSTs are therefore often strongly related to the development of severe weather.

Judgement: The Bureau of Meterlogy states “in general, studies have found that ECL’s are not strongly influenced by SSTS, therefore rending these technologies ineffective in predicting ECLs but can be used with other technologies to create an early-warning system

Question 6

East coast lows
- Pressure systems

Answer 6

However, SST have some influence on their severe weather (eg location of rainfall), and are therefore of some value to in predicting locations of heavy rainfall during an ECL. Since ECL are a low pressure weather system, the BOM can predict the location by analysing MSL (mean sea level) with a barometer at weather stations which is a metal box that compresses as pressure increases and expands as pressure decreases,
indicating changes in pressure. With the pressure observations, they create an MSL chart, which shows where the low is situated. They then use computer models to predict the development of an ECL but only up to a week in advance. The severity of the ECL can not be estimated using pressure measurements.

Judgement: the use of barometers are effective in locating the ESL and computer modelling is effective in finding the path of an ECL. However, this is restricted to a one week prediction. Forecast accuracy is increased when both temperature and pressure data is used in conjunction.

Question 7

Predicting natural weather events

Answer 7

The Bureau of Meteorology in Australia uses the ACCESS system to collect and analyse weather and climate data. ACCESS is a climate model that gathers information from satellites and radars. Satellites take frequent atmospheric photos to track cyclones and thunderstorms, while radars create images of rainfall intensity.

Cyclone forecasting has improved by 30%, Flooding detection is four times better, with warnings three times more accurate. In March 2011, ACCESS predicted a major flood, allowing time for preparations and resource deployment to minimise damage.