So the geologists were right. Now the Centre for Emergency Situations needs your help. They have to advise residents whether the ash cloud will affect them, whether they need to evacuate and if so, the safest way to do so.
It's midday. You're tasked with working out where the volcanic ash cloud could travel using the latest weather observations and some of the information you gathered in Activity 1.
You already know the height of the ash cloud, currently 5 km above the top of the volcano and you have a map of Green Island in your resources. To give you some more help, use the weather chart in your worksheet and watch this special forecast bulletin from TV News.
a) On the weather chart on page 3 of your worksheet, draw a line from the summit of FitzRoy's Peak in the direction you think the ash will travel in based on the current observations and forecast.
Hint: Wind blows anticlockwise around low pressure areas, clockwise around high pressure, roughly following the isobars (lines of equal atmospheric pressure)
b) Along the line, mark six dots indicating where the ash could reach over the next six hours. The wind speed today is roughly 20 km/h.
Hint: use the scale on the map combined with the wind speed to work out the distance the ash could travel each hour.
c) Now, using the graph you drew in Activity 1, can you calculate the approximate volume of the ash erupted? Fill in the value on page 1 of your worksheet.
d) Using the cut out ash cloud provided, cover the area on the ground that you think might be affected by the ash.
Last updated: 14 March 2013