Calif. geological hot spot defies explanation

[Zorro]

Our curious world...

<snip>

Scientists are puzzled by a mysterious Los Padres National Forest hot spot where 400-degree ground ignited a wildfire.

The hot spot was discovered by fire crews putting out a three-acre fire last summer in the forest's Dick Smith Wilderness. "They saw fissures in the ground where they could feel a lot of heat coming out," Los Padres geologist Allen King said. "It was not characteristic of a normal fire."

Fire investigators went back to the canyon days later and stuck a candy thermometer into the ground. It hit the top of the scale, at 400 degrees.

<snip>

More at: http://www.signonsandiego.com/uniontrib/20050716/news_1n16hotspot.html

[Teaser]

1. I wouldn't stand there for long.

Something may be about to pop open.

[lyberyl_prygryssyve]

2. Wasn't this the set-up for a Tommy Lee Jones movie?

"L.A. Volcano" or something.

[smirkymonkey]

3. This can't be good.

Could it be another caldera, previously unknown to geologists and about to blow?

[Pepperbelly]

4. You guys remember the old coal mines in ...

Appalachia that were on fire beneath the ground. The town had to be abandoned. I forget what state but it basically killed the town because the fire could not be extinguished.

[Emperor_Norton_II]

5. Yeah, but there's no coal seams in Los Padres.

Besides, a coal fire would also generate a lot more than just heat; smoke, fumes, ground collapse as the coal burned up... this is just plain weird.

[Pepperbelly]

7. Very weird ...

And of course, I was not suggesting that there was coal in LA to burn. Just noting something that happened that had a similar effect that was, IMO, pretty interesting.

I think that fire in Appalachia is still burning.

[sakabatou]

8. And one kid almost fell into the fire

There was a play last year on this. I forget what it was called.

[TreasonousBastard]

11. Centralia, PA...

about 50 miles NE of Harrisburg.

http://www.offroaders.com/album/centralia/centralia.htm

There are others, but that's the big one.

Campers know that if you don't build your fire right, you can start an underground fire in the loam. But, that doesn't look like what's happening here.

[Pepperbelly]

12. thanx ...

could not remember the name of the locale.

[bemildred]

6. We need a lot more information than this.

There are some thermal springs and such around there,
but that's pretty hot.

[Boomer]

9. It's obviously the Hellmouth

Where's Buffy when we need her?

[Boomer]

10. More details in this report

http://movermike.powerblogs.com/posts/1121383713.shtml

(snip)

Gradually, the scientists started narrowing down the possible causes. They found no oil and gas deposits or vents in the vicinity and no significant deposits of coal. The Geiger counter readings were normal for radioactivity, and there was no evidence of explosions or volcanic activity. Hot springs, a sign of geothermal activity, exist elsewhere in Los Padres, but nothing like that was happening here.

One possible explanation still under study is that an earthquake fault may be the source of the heat, Mr. King said, adding, "We can't rule out anything definitely yet."

But the likeliest theory, though still unproven, Mr. King said, is that when the landslide occurred, the slide broke apart the rock, creating a chemical reaction between oxygen in the air and minerals in the rock.

The rock, a type of shale, contains iron sulfides called pyrite and marcasite. When they are oxidized, the scientists theorize, the sulfides give off heat, burning the organic material in the shale — the remains of dead plants and animals that were deposited into the mud on the ocean floor, 45 million years ago.

(snip)

[Pepperbelly]

13. Maybe marcasite but probably not pyrite.

I know they are related but the phenomenon is observed far more substantially in marcasite than pyrite. There have been cases of it heating up the walls of some mines as well as the same reaction when held as specimans.

I don't know that the amount of heat indicated in the OP would be reached this way though.

[Boomer]

14. I wasn't persuaded

I'd want at least one other landslide-driven episode to lend support to this theory, and instead it seems to be the only occurrence, without any remarkable features to point to why this place only has turned into a hot spot.

Which leaves the question of what the heck is really going on. It's pretty obvious that this event has the geologists stumped and their groping around for answers.

[Pepperbelly]

15. they need more data before ...

even jumping to hypothesis.