Walt's Look Around: Is there a volcano under Jackson?

JACKSON, MS (Mississippi News Now) - People are still talking about last Saturday night's earthquake. It makes you wonder what's down below. Obviously something big enough to cause a small earthquake. But that's nothing compared to what the City of Jackson is sitting right on top of.

But today, it was awfully tranquil in south-central Madison County. Too calm for earthquake country. But quakes aren't caused by what's above, but what's below.

David Dockery with the Mississippi Department of Environmental Quality says he knows what's at fault that caused the quake. A small fault in the earth his department mapped about seven years ago.

"That fault is exactly where those two earthquakes are," said Dockery.

On the map, the green line is the fault. The 3.0 and the 3.2 arrows point to where the quakes happened. But that's nothing compared to what ELSE is down there.

Take a look at a cross section of this part of the country from say about Terry to Pickens along I-55. The fault is about three miles down.

But pull the map out wide and what your are looking at, that orange and red thing on the left that comes from way, way down and rises to about a half mile below the surface, that's a dormant volcano! VERY dormant.

Jackson sits on top of this huge volcano with the rim about a half-mile under where David and I are standing, at the Coliseum. But instead of being a liability, the volcano has been a huge asset over the last hundred or so years.

"Oil and gas drilling in the 1930s we found gas in Jackson on a reef on top of the old volcano," explained Dockery. "In fact it's credited with helping Mississippi get through the depression, the gas that was found at Jackson."

And even now there are all sorts of CO2 wells at work here down below the tree line. You can't see them, because of what the volcano left here a hundred million years ago.

"This structure at Jackson vented so much carbon dioxide in to the Jurassic strata, especially the Norfolk sandstone that we have maybe 10% of the national reserve in just two counties, Madison and Rankin County," added Dockery.

And David let me have a copy of this from the annual report from the Denbury Company that is drilling for the CO2 here, an artists rendering of what the volcano would have looked like when it was active. Jackson was an Island. We're all living at the seashore, but we're at least a half-mile or better above it.