Volcanoes at Yellowstone

OK, so most volcanoes occur in the Ring of Fire, along tectonic plates edges esp. in the Pacific. Those are also earthquake prone areas.

But plates must be formed and destroyed somehow, yes?

Well we have a super-volcano waiting to burst forth like a giant zit … (nevermind, we have a lot of volcanic activity at Yellowstone). There was a huge earthquake at New Madrid Missouri not too long ago.

**Is a new fault line developing in the center of the US, along the Mississippi River line? Or is an old fault line closing up? **

Neither. If I’m getting it right, the faults in Missouri, and the entire Mississippi is due to a plate that failed to form, but the land was damaged enough to form faults.

Yellowstone is the site of a plume: a huge welling of magma that comes up through a plate. The Hawaii and Galapagos Islands were also formed at the site of a plume. You can actually see the sequence over time: the plate shifts and the plume stays in one place, so it’s like an assembly line: volcano gets formed, breaks the surface, makes an island, shifts over. New volcano gets formed, new island, gets shifted and so on and so forth.

There is a theory of “hot spots” and “mantle plumes” associated with Hawaii and Yellowstone. The Wiki article names other sites plus identifies “island arcs” that spring up in colliding plate zones. http://en.wikipedia.org/wiki/Hotspot_(geology)

Generally speaking, the Ring of Fire is where plates are butting up against each other, with the loser being destroyed. In the Pacific Northwest, it’s called the Cascadia Subduction Zone. But if there is destruction going on there, there has to be something creating the plate. The mid-ocean ridges are where the plates are forming and growing.

As previously mentioned, there are mantle plumes in the middle of plates. Yellowstone and the Hawaiian Islands are just two examples of plumes. The New Madrid Seismic Zone is an intraplate area of faults and earthquake activity. Current theory the area is a plate breakup that never occurred, resulting in a weak area. This December is the 200th anniversary of the New Madrid earthquakes.

The New Madrid quake was an example of an intraplate earthquake, which could be on a ‘fault’ but doesn’t necessarily mean a new plate is forming. We don’t have a well-developed understanding of all the factors that cause earthquakes yet, especially intraplate ones.

Ah, New Madrid. I think 20 years ago they were saying it was due to let loose again anytime. the longer it goes, the worse it may be. I doubt much of the mid west is prepared.

If Wikipedia is correct, major quake sequences are separated by 5 or 6 centuries.

The Yellowstone plume used to be located where Craters of the Moon National Monument in Idaho now sits (according to the signage there). Apparently, these plumes move about over the millenia. As you can see from the photos, when it decides to come to the surface, it pretty much destroys everything that’s there. That’s one bleak area.

It’s not the plume that moved; the North American plate has been moving roughly westward over the plume.

Ah, right. I translated “The plume is now under Yellowstone Park” to mean “The plume has moved under Yellowstone Park”. Makes much more sense that the plate has moved.

I should mention in the interest of fairness that there is a growing “faction” of geologists that either reject mantle plumes entirely or think they’re not as common. Basically, they argue the mantle plume has become a catch-all explanation for any volcanism not explained by classical plate tectonics and that other explanations exist for all or most things currently attributed to mantle plumes. Here’s their website if you’re interested in perusing, although a lot of it is fairly technical: http://www.mantleplumes.org/

Technically speaking, Yellowstone is a caldera that is part of a volcanic field that was formed about 16.5 million years ago in the area near the Oregon-Idaho-Nevada border. It landed in it’s current location about 4 million years ago and the Yellowstone caldera was formed in the last eruption about 640,000 years ago. Parts of the original walls are still visible in the NW part of the park.

Wikipedia is a good tool but until the Master elects to participate in this thread, you are better served by checking with the USGS, which runs the Yellowstone Volcano Observatory. :smiley:

From http://www.scchealth.org/docs/ems/docs/prepare/newMadrid.html

''A DAMAGING EARTHQUAKE in this AREA, 6.0 or greater, occur about every 80 years (the last one in 1895). The results would cause serious damage to schools and masonry buildings from Memphis to St Louis.

A MAJOR EARTHQUAKE in this AREA, 7.5 or greater, happens every 200- 300 years (the last one in 1812). There is a 25% chance by 2040. A New Madrid Fault rupture this size would be felt throughout half the United States and damage 20 states or more. Missouri alone could anticipate losses of at least $6 billion from such an event.’’

http://www.lewrockwell.com/rep/new-madrid-fault.html

Regardless of what Wikipedia has to say, there were predictions of damaging earthquakes in the 80’s as I said.