Where’s the Earth-shattering kaboom?
You are looking at a volcano. It is the Kaiserstuhl, on the western side of the Rhine Rift Valley. I was standing on the eastern side, at the base of a ruined castle.
Look, Ma, no guardrails!
The Germans are firm believers in the idea that if you back off a cliff taking selfies, or wander along the edge and lose your balance, you should know better and it’s your fault. I heartily endorse this philosophy. But back to volcanoes.
The best known volcanic activity in what is now Germany is in the northern part of the Rhine Valley, in the Eifel. But there are other places with evidence of vulcanism, including the Kaiserstuhl. The Rhine remains tectonically active, with hot springs and the occasional earthquake just to keep people wary.
You didn’t want to be under the green swaths.
The source of the green swaths. The Laachersee.
The Laachersee was, and is, a major volcano in northwestern Germany, in the Eifel. It erupted enormous amounts of tephra and ash, enough to ruin a lot of critters days back 12,900 or so years ago. So pretty recently, although not as recently as the Puy de Dome in France. The volcano then collapsed in on itself, forming the lovely lake that you see today, which happens to be bubbling again. Just CO2, nothing really interesting…yet.
There are lovely, perfectly round lakes in the area near the Laacher See, called Maar. The term comes from the Latin “mare” meaning sea, and is a dialect term that has become official geology language. Maars are perfectly round little crater-remains, often with water in them but not always, that are the result of certain kinds of eruptions. The Eifel has the type-sites, and is a neat place to visit if you are into geology.
The Kaiserstuhl is a wee bit older, as in 16 or 19 million years old, and quite dormant. It was probably six thousand feet tall at its greatest, but has eroded since then. The name comes because Otto III held a meeting there. It is part of the Rhine Graben volcanic complex in the southern part of the valley, not far from the French and Swiss borders.
Today, only the Laacher See is considered dormant. The rest are either extinct or very extinct, although there are a few spots on the Czech border that might be questionable. I’d put my money on the western part of Germany if I were betting on vulcanism.
There is a really wonderful book about vulcanism in Germany, but it is entirely in German and assumes that you have some basic geology and geochemistry. Until you read something like that, you have no idea just how much geological excitement took place of the the years in the area that is now Germany. Granted, it wasn’t happening all at once (thanks be!), but northern Europe was a happening place for many thousand years.
The website below has more information about three of the volcanic regions in what is now Germany.
Cat Rotator's Quarterly 
There are some good examples of Maar in Oregon, not far from Crater Lake. đŸ˜‰ Just in case anyone finds themselves in the area with an overwhelming desire to look at large holes in the ground.
(They are actually seriously impressive. Magma can turn a water table to steam and cause an explosion of mind-boggling size if the conditions are right.)
Geological processes happen on a scale that most people never really think about, and some have a great deal of trouble accepting.
(As an extreme example, I’ve had someone standing on a basalt flow, looking at a cinder cone, in a place where “Lava” was literally in the name, tell me that there were no volcanoes anywhere around the location. He’d lived there his whole life, after all, and would know if mountains thereabouts exploded with showers of molten rock.)
Volcanoes do produce some interesting scenery – and hiking opportunities. Of those I have personal experience with, at the opposite ends of the spectrum are the picturesque Yellowstone Lake in the massive caldera of the supervolcano, and the tiny cinder cone of El Calderon in northwestern New Mexico. The former is well known to many, if only vicariously through TV specials and books, and offers a variety of hiking experiences. There are level hikes along pebble shores with spectacular views across the lake and out to the sides of the caldera. (NB – Maintain situational awareness. For example, you should scan the beach and look for bears and their tracks, rather than obliviously walking parallel to them for hundreds of feet.) There are strenuous hikes up impressive slopes to amazing vantage points. And there are more moderate hikes throughout.
El Calderon has a single easy-to-moderate hiking trail to, through, and up a small extinct volcano. It winds past partially-collapsed lava tubes, up through a gap in the cone through which lava once flowed, up the red lava rock of the cone itself to the rim. The lava rock, seen through much of the nation as merely a landscaping material, gives the natural scene a strange sense of being sculpted, of being landscaped. The views out from the rim stretch out nicely, while the view inwards at the tiny dry pit of the caldera are a striking contrast different from regular scenery.
Capulin in north eastern NM is another hikeable cinder come. Great views, but if the deer flies are biting… I set a new speed record on the rim trail.
Thanks. I’ll have to keep that one in mind for my next southwestern trip – a quick look shows it to be a lot larger than El Calderon, but without the hiking restrictions that Arizona’s Sunset Crater National Monument suffers from.
That reminds me of Rotorua in NZ. From vantage points, you see it as a small part of the caldera chain that covers much of the central North Island. Lake Taupo, just south, is larger and much deeper. Their saving grace is that the highly active volcano/ relief valve is White Island, some miles off the coast, but many volcanoes are active or not very dormant.
Yep, we need to be reminded the “Ring of Fire” is NOT the only set of volcanoes in the world… Mt. Etna is the most active in Europe right now, as far as I know.
Don’t forget that when Mt. St. Helens got feisty, the status of all the Cascade volcanos changed from “extinct” to “dormant.” Also note that the whole Snake River Plane across Southern Idaho is a volcanic remnant of the same “hot spot” currently under Yellowstone. No mountains, but lots and lots of basalt.