# EARTH SCIENCE LAB Volcanoes

### Fogo Volcano

Many of you may have read about or seen pictures of volcanic eruptions. Many of these eruptions are accompanied by large amounts of volcanic ash. Other eruptions are relatively small. This exercise will concentrate on the eruption of Fogo Volcano on the Azores island of Sao Miguel in 1563.

### Procedure

Answer the following questions, using the information from the isopach map.

### Questions

1. At which of the following points is the volcano located?
A, B, C, D, E, F, G, H, I

2. North is to the top of the image. Based on the pattern of the areas of greatest ashfall, what was the wind direction during the eruption, in the vicinity of the volcano? Wind is measured in the direction from which it is coming.
N, NNE, NE, ENE, E, ESE, SE, SSE
S, SSW, SW, WSW, W, WNW, NW, NNW

3. Based on the pattern of the areas of greatest ashfall, what was the wind direction during the eruption, in the vicinity of Point A? Wind is measured in the direction from which it is coming.
N, NNE, NE, ENE, E, ESE, SE, SSE
S, SSW, SW, WSW, W, WNW, NW, NNW

4. Which area received the largest amounts of ash?
A, B, C, D, E, F, G, H, I

5. Which area received the least amounts of ash?
A, B, C, D, E, F, G, H, I

6. How much ash fell in the area of Point G? (meters)
0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 5.0

The table below gives the sizes of the areas which received various amounts of ash from the 1563 eruption. Complete the two columns of the chart. In the second column convert meters to kilometers. Calculate the volume of ash for each isopach. (enter all decimal values less than one with a zero before the decimal - example 0.53, 0.32)

 Ash Thickness (m) Net Ash Thickness (m) Net Ash Thickness (km) Area (km2) Ash volume (km3) 1 0.5 113.0 2 1.0 81.0 3 2.0 30.5 4 4.0 8.7 5 8.0 2.3

What is the total area (km2) of the ash which fell on the Island of Sao Miguel during the 1563 eruption of Fogo? km2

What is the total volume (km3) of the ash which fell on the Island of Sao Miguel during the 1563 eruption of Fogo? (round answer to two decimal places) km3

The area receiving more than 0.5 meters of ash is (your answer from Question #7). The island of Sao Miguel has an area of 768.9 km2. What percent of the island received more than 0.5 meters of ash? (round to one decimal place) %

Illinois has an area of 144,120 km2. What percentage of Illinois would have been covered if the eruption had taken place here?(round to two decimal places) %