With the wildfires in California, you hear about “Why do people live in those areas?”
Of course people reply, “Why do people live in coastal areas, subject to hurricanes, or near rivers etc, etc.”
I was wondering what would be the biggest city near an active volcano. I know it’s impossible to predict when a volcano will go off (or maybe it isn’t) but I was wondering what the biggest urban area near an active volcano?
Not researched at all, but I’d think Honolulu or Seattle. Is Mount Fuji active?
Naples Italy. There are about 5 million people in the Naples Metro area.
Mount Fuji is currently dormant, but doing things to make vulcanologists nervous about its continued dormancy.
In the USA, I’d say Seattle. Mount Ranier is technically considered active, isn’t it? And even if not, Mount St. Helens is probably closer to it (and closer still to Portland, but Seattle’s definitely bigger) than any active volcano is to Honolulu.
Mount Fuji is considered to be active, but Tokyo is further from it than Ranier is from Seattle or St. Helens from Portland.
World-wide, Naples is practically a stone’s throw from Mount Vesuvius. Wikipedia has a volcano map of Indonesia which shows a few volcanoes looking like they’re practically on top of Jakarta, but it’s hard to tell exactly how close they get.
This is probably the best answer; Naples is less than ten miles from Vesuvius. For a looser definition of “near”, Popocatepetl is less than fifty miles from Mexico City, which is larger than Naples.
I guess when I said “near,” what I mean is close enough so if the volcano goes off it’d do major damage to the city or they’d have to evacuate the city
Nowhere near as large a population as Naples, but the city of Kagoshima in Japan is pretty spectacularly close to an active volcano. The volcano, Sakurajima, smokes most of the time and the city is almost permanently dusted in fine white ash, which sometimes falls like snow, and every so often there are eruptions of lava.
I think Mexico City would definitely be the biggest urban area near a volcano, with the city center being only about 40 miles or so from Popocatépetl and some of the suburbs going practically right up to the thing.
Popocatépetl and Vesuvius are both pretty puny little volcanoes, though. I think the Seattle/Tacoma area still has the prize of being the largest urban area seriously threatened by a volcano.
Vesuvius is not puny.
People live right up the slopes of the volcano. If and when it does decide to go bang, things would get rather interesting rather quickly.
When the Taupo Volcano decides to become active again, it could imperil most of New Zealand’s North Island (c. 3.25 million).
Whilst medium term predictions of volcanic activity are unreliable, it’s usually possible to give a warning of a few days, or at least several hours, for an impending eruption, provided monitoring systems are in place. Whilst there are false positives, many case studies show that meaningful alerts are possible, unlike with earthquakes, where no reliable indicators have been found.
How about Plymouth (the one on Montserrat). It’s not so much near a volcano, more like buried under one :eek:
You’re right. It’s now classified as active with a low risk of eruption. Weird. They were calling it dormant 20 years ago. I apologize for my out of date information.
Mount Hood is closer to Portland than Mount St. Helens.
Mt St Helens isn’t close to Seattle. Mt Rainier is closer to Tacoma than Seattle. All of the past eruptions from Rainier have had pyroclastic flows and lahars through the Tacoma area and to the south. Seattle is northwest of Rainier.
Darn, you beat me to it. To summarize the risks: if Rainier goes off in the worst-case scenario way, you’ll have 100,000 people buried under 20 feet of mud. (Unless they run really fast. Driving to safety isn’t an option, as anyone who’s experienced “normal” traffic around there can testify.)
But Naples has definitely got us beat.
Popocatepetl has produced some major plinian eruptions, too, though not since around 800 AD. That is, of course, no guarantee that it couldn’t produce another one.
Actually, if Rainier goes off in the worst-case scenario way, the volcano will take out Tacoma and the triggering and/or triggered earthquakes will upset the region while the Sound tsunamis into Seattle.
But still, fewer people than Naples.
When the supervolcano under Yellowstone blows again, a significant chunk of the continent is pretty well screwed.
Mount St. Helens is an insignificant threat compared to Mt. Rainier or Mt. Hood.
As already mentioned, volcanic activity on Mt. Rainier will trigger extremely large lahars and greatly endanger sizeable population areas in the Seattle-Tacoma corridor, irrespective of downwind ash clouds or lava. If I remember correctly, timing is everything with 30 minutes being the upper limit from the time the sirens go off until the lahars hit.
The topography around Mt. Hood directs lahars away from Portand in the west. Then again, a damming of the Columbia River to the north by a large lahar (and earthquakes) is always a possibility. At least it would offer the Army Corps an opportunity to create a drainage channel to prevent further disaster downstream as was done after the 1959 Hebgen Lake earthquake near Yellowstone.
While the OP is targetting populations endangered, the real danger is a critical disruption to communications, transportation and commerce with an eruption of either Mt. Rainer or Mt. Hood. A Mt. Rainer eruption will close the I-5/I-90 corridors and impact Puget Sound shipping. A Mt. Hood eruption with impact I-84 and the two rail lines along the Columbia River, not to mention the river itself. Those disruptions will have a much greater impact than the 3.5 million near Seattle or the one million near Portland.
Actually, when Yellowstone blows, it will be a world-wide event.
