Comparing the Mauna Ulu and Puu Oo Eruptions (Grades 9-12)
Prior to the ongoing eruption of Kilauea, the most longest-lived and
voluminous rift eruption in historic time was at Mauna Ulu from
1969-1974. Activity 10. compares the early episodes of these two
eruptions. The line graph shows the cumulative eruption volume for the
first 20 episodes of the Puu Oo eruption. A similar graph is shown for
Mauna Ulu eruption. The graphs can be used to answer the questions
provided in the activity.
- For the time intervals shown, which eruption produced the greatest
volume of lava? Puu Oo.
- What are the volumes for each eruption? Mauna Ulu erupted 70 million
m3. Puu Oo erupted 235 million m3.
- Calculate the rate of each eruption in m3/month and m3/hr.
Eruption rate is volume in m3 per unit of time. Mauna Ulu erupted 70
million m3 in about 7 months for an average eruption rate of 10 million
m3/month or about 14,000 m3/hr. Puu Oo erupted 235 million m3 in about
17.5 months for an eruption rate of 13 million m3/month or about 18,000
m3/hr. Swanson (1972) used the three longest eruptions of Kilauea since
1952 to estimate a lava production rate of 9 million m3/month. He
considered this estimate to represent the rate of magma supply from the
- Are the actual eruption rates higher or lower than those
question 3? The actual eruption rates are much higher. For example,
Oo eruptions were relatively brief compared to the repose periods between
eruptions. The calculated rates are averages over a several-month period
that includes both eruptions and repose periods.
- Estimate the total erupted volume of the ongoing eruption of Kilauea
Volcano. List all assumptions.
Assuming a constant eruption rate of 13 million m3/month for 120 months,
the volume of material erupted is about 1.5 billion m3. This also
assumes that he eruption rate of the first 20 episodes is representative
of the entire eruption.
for a handout for Activity 10.