Guest Videos: When in Rome…


…check out the active volcanoes on the edge of town.

The public-domain image above, from Wikimedia, shows what they look like from Rome’s Aqueduct Park.

That shot of Italy’s Colli Albani (Alban Hills) volcanic complex reminds me of the view of Newberry Volcano from Bend, Oregon, only a little closer.

Just for the record, slightly more than 100,000 people live in Bend; roughly 4,300,000 live in the Rome metro area.

The video below is from a source I’m usually quite cautious about, but here their information generally matches that found at the volcanic complex’s GVP page, apart from the VEI, which GVP doesn’t list.

There are lots of academic papers on the Colli Albani, though, and one of those might have been the source. VEI 6 or 7 isn’t unreasonable, given the size of some of those ancient calderas and the complex regional tectonics.



However, the uncredited images used to illustrate various points are all from other volcanoes.


At highest risk are people around and near Lake Albano …



Unless you’re exercising on a treadmill or stationary bike, you might not want to watch the full hour-long video. It sure is pretty, though!


…and in between the lake and Rome, less than ten miles away.

Per the boffins (emphasis added):

Although controversy exists about the age of its most recent eruption (either 36 ka or <23 ka). Colli Albani volcano is unanimously considered to be quiescent and not exinct. During the Holocene. several lahars were generated by overflows from Albano crater lake up to the fourth century BCE. when the Romans excavated a drainage tunnel to keep the lake level below the crater rim. Such recent activity, together with the frequent occurrence of seismic swarms underneath the crater zone, the ongoing uplift of the volcanic edifice and the magmatic affinity of the emitted gas. indicate the presence of an active magma chamber. The most likely site for a new eruption is the deep crater hosted in the southern part of the Lake Albano. where the last eruptive events occurred. Any eruption would have a strong explosive character enhanced by the interaction of magma with the water of the lake and would endanger a densely inhabited area up to the outskirts of Rome. The hazard of a new overflow from Lake Albano is very low because of the present low level of the lake. There is instead a potential for CO2 release from the deep lake water following the occurrence of rollovers, which would threaten the lake shore, a site where thousands of people spend their vacations in the summer. However, the content of dissolved CO2 is presently far from saturation and no Nyos-type events will occur today. Presently, the main hazard is related to strong gas emissions (CO2· H2S and Rn) from fractured zones and gas blowouts from wells reaching shallow gas-pressurized aquifers.

I added that emphasis because Lake Albano is meromictic — gas leaking out of Colli Albani sometimes makes it explode.



Status:

Volcanologists report that Colli Albani is at its baseline level; it is monitored closely (both linked pages are in Italian).


Lagniappe:

Meanwhile, in Egypt…

…there are no active volcanoes now. But 35 million years ago:





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