As if you didn’t have enough to worry about, here’s one more thing: We’re living in the middle of a volcano range.
Don’t worry, though. They’re not expected to erupt, like the one currently spewing up lava in Hawaii. No, really, the government says so. It’s even on the U.S. Geological Survey website: “Will extinct volcanoes on the East Coast of the U.S. erupt again? No.”
The spectacular eruption of Kilauea in Hawaii — well, spectacular from afar, a disaster if you happen to have owned a house that’s now incinerated under lava — is an opportunity for both a geology lesson and a political lesson. Yes, Virginia has — or at least had — volcanoes, and the forces that created them are still shaking our landscape today.
If you go back 750 million years, Virginia wouldn’t have been Virginia. Then, we were part of Rodinia, a supercontinent that took about 170 million years or so to pull apart.
As Rodinia separated into other continents we wouldn’t recognize, magma boiled up from deep in the Earth, and the future Virginia was as volcanically interesting as Hawaii is right now.
We know Mount Rogers as Virginia’s highest peak. Then, it was a volcano, although there was no one around to see it. Life then was only swimming around in the oceans. That’s why there are no postcards of the great Mount Rogers volcano eruption of 750 million years B.C.
Mount Rogers wasn’t the only volcano in Virginia; just the oldest. By 575 million years ago, the break-up of Rodinia was complete, but there was still magma bubbling up here and there. Some of it is on top of what today we know as the Blue Ridge Mountains.
How about now? Well, “now” is a relative term in geology. Geologists consider the Eocene Epoch a pretty recent event — and it was 56 million to 33.9 million years ago. By then, the Earth looked more like it does today. North America was pulling apart from Europe and Africa. Dinosaurs had come and gone, and mammals were starting to wander around. When the Earth pulls apart, volcanoes happen, so the Mid-Atlantic Range under the Atlantic was a hotspot. In Iceland, it still is.
But 48 million years ago, something completely unexpected happened. A volcano erupted in the future Virginia. Today, we know it as Mole Hill, just outside Bridgewater in Rockingham County. Then 35 million years ago, another volcano erupted just outside Monterey in Highland County — today’s Trimble Knob.
Geologists are at a loss to explain why these volcanoes happened when they did. Logically, their magma should have burst up out of the Earth’s surface in the geologically active Mid-Atlantic, not what was then the geologically sedate landscape of the future Virginia.
However they happened, Mole Hill and Trimble Knob are the youngest volcanoes on the East Coast. So, why are geologists so convinced they won’t erupt again?
The main reason is simply that they haven’t for a long, long time, no matter how languidly geologists measure that time. Scientific American quotes Elizabeth Johnson, a geology professor at James Madison University who has studied Virginia’s volcanoes: “If something hasn’t erupted for the last 47 million years, you can call it completely extinct.”
If you’re a pragmatist, that ought to be sufficiently reassuring. If you’re a worrier, well, you just never know, now do you? Virginia is no Hawaii but there’s clearly something going on underneath us. Something down there is keeping Hot Springs hot and Warm Springs warm and occasionally shaking our pretty modest earthquake zone.
Remember that 2011 earthquake that caused nearly $81 million of damage in Louisa County (mostly to schools) and closed the Washington Monument for three years? Scientific America traces that back to the two Virginia volcanoes, saying those eruptions weakened the fault lines.
The magazine goes on to write: “There’s no reason that more of the heavy roots of the Appalachians could not drop off at any time, spurring a recurrence of volcanism on the East Coast and an outbreak of lava in the most densely populated regions of the U.S.”
The journal Geology last year published research suggesting that “a rising mass of hot rock” is forming under New England and might someday erupt into a volcano. Perhaps that’s the migrating hotspot that some think might have caused Virginia’s volcanoes? Researchers at Rutgers University estimated an eruption might come in “millions of years,” so you’re probably safe to still book that trip to Fenway Park.
We promised a political question, so here it is:
Why doesn’t the government stop people from living near Kilauea? Well, we Americans don’t like the government telling us where we can and cannot live. Never have.
One of the many reasons why American colonists were mad at King George III is that in 1763 he forbade settlement west of a certain line through the Appalachian Mountains. He thought he was being practical. He didn’t want to have to pay for wars against the natives.
Some colonists, though, didn’t mind the risk, just as some people today don’t mind living in Florida, even though every so often a hurricane blows through and wreaks havoc. Or, in this case, living in Leilani Estates even though there’s a chance that a volcanic fissure might open up in the backyard.
Do we really want a government powerful enough to tell us we can’t live where we want?
Feel free to debate that until the cows come home, or Trimble Knob and Mole Hill erupt again. The odds are the cows will come first.