Volcanic Explosivity Index (VEI)

Geology News ^ | June 8, 2014 | Hobart King

[JimSEA]

Measuring the size or strength of natural events has always been a challenge for natural scientists. They developed the Richter Magnitude scale to estimate the amount of energy released by an earthquake, the Saffir-Simpson scale to estimate a hurricane's potential, and the Fujita scale for rating the intensity of hurricanes. These scales are valuable for comparing different events and for understanding the amount of damage that events of different size can cause.

Measuring the strength of a volcanic eruption is more challenging than collecting wind speed data or measuring ground motion with an instrument. Volcanic eruptions produce different types of products, have different durations and develop in different ways. There is also a problem that some eruptions are explosive (rock materials are blasted from the vent), while other eruptions are effusive (molten rock flows from the vent).

[JimSEA]

This is a pretty readable article on a severity index for volcanic eruptions. With all the interest in Yellowstone, I thought a few might find this interesting. It could get a lot worse than the most recent Yellowstone super volcanic eruption.

[JRandomFreeper]

Thought this might be about one of my ex-wives... I'll mosey on along... ;)

/johnny

[UCANSEE2]

The surface of the Earth is peppered with volcanoes. There are massive magma movements beneath a resilient semi-solid crust that is constantly on the move. One might compare it to the surface of a pizza in the oven. There are more volcanoes below the surface of the oceans than there are on land. We don’t necessarily even know when some of them explode. However, they change the landscape radically.

Yellowstone could go off, and the land contours of the continent would change.

All true, are they not ?

So... I wonder why scientists are trying to convince us that the oceans are rising or falling (I guess that depends on where you take your measurements)?

[JimSEA]

The place I’m watching just now is the Great African Rift, Afar region where some 500 cu. miles of magma is quite neat the surface. We knew very little about this until recently. For obvious reasons, this is a difficult area to study. The human remains folk go in with armed guards to protect a small area.

[JRandomFreeper]

That area is still pretty hot. I understand that some of the tribes there actually condense the steam coming out of the ground for water for their cattle.

That place is a wonder, biologically speaking. Tectonically, too, to make the biology so weird and wonderful.

/johnny

[JimSEA]

Absolutely!! That is really spooky to me anyhow. I’d love to go there for a look (a brief one that is).

[JRandomFreeper]

Because of the different levels across the Rift... there are trapped areas. One where the lion population that got trapped is so small that interbreeding is causing some serious problems when things like distemper get in.

Another area is basically a crater cone with a plateau in the center, surrounded by a river... really weird geography, and it affects the animals and people that live there.

Boundary areas are bizarre.

Rift valley in Africa is strange and wonderful.

Russia has similar topography, including semi-active areas where steam and poisonous gas still vent.

We live in a wonderful, complex world.

God must have known that we would be curious.

/johnny

[JimSEA]

There’s enough to keep me looking for several lifetimes.

[JRandomFreeper]

Not me. I eat a critter cooked in most of the traditional ways, and I'm ready to move on to new ground. Cooks are like that... ;)

/johnny

[Catmom]

It could also be a rating scale for heartburn inducing meals.