[Kryptid (OP)]

I have looked up the amount of energy released in volcanic eruptions. In one of my school books, the energy released by the eruption at Mt. St. Helens is listed as being 425 megatons. However, I have read on MULTIPLE websites that the energy released was actually 24 megatons, which is nearly 20 times less.

Likewise, several websites have listed the Krakatau eruption at 100 megatons, whereas other websites list values as high as 5,000 megatons.

I realize that it must be difficult to measure a volcano's power, but I would at least expect the measured values to be close to one another. Why are there such a huge differences in these values?

[qpan]

Not entirely sure, but my guess is that some of the figures are purely for the actual eruption and lava flow, whereas others are including the nearby earthquakes which triggered the eruption.

Only a guess though... as the figures are very different indeed...

"I have great faith in fools; self-confidence my friends call it."
-Edgar Allan Poe

[gsmollin]

I don't have a figure for energy release, but it's way more than 24 megatons. That's a pop gun. Several cubic miles of the mountain were blown half way to Portland.

Similarly, the Krakatoa explosion blew cubic miles into the stratosphere, and generated tsunamis that encircled the globe twice. 100 megatons is a joke. It had to be 5000 megatons to even get started.

[qpan]

Not entirely sure, but my guess is that some of the figures are purely for the actual eruption and lava flow, whereas others are including the nearby earthquakes which triggered the eruption.

Only a guess though... as the figures are very different indeed...

"I have great faith in fools; self-confidence my friends call it."
-Edgar Allan Poe

[gsmollin]

I don't have a figure for energy release, but it's way more than 24 megatons. That's a pop gun. Several cubic miles of the mountain were blown half way to Portland.

Similarly, the Krakatoa explosion blew cubic miles into the stratosphere, and generated tsunamis that encircled the globe twice. 100 megatons is a joke. It had to be 5000 megatons to even get started.