Speaker 1: Welcome to brain Stuff from How Stuff Works, Hi, brain Stuff,
Speaker 1: Lauren Vogel bomb Here. It's a familiar cinematic situation. A
Speaker 1: daring scientist arrives in town to study the local volcano,
Speaker 1: which has been dormant for centuries but now seems dangerously
Speaker 1: close to erupting. Despite the dire warnings of everyone around him,
Speaker 1: the intrepid volcanologist, perhaps with a trusty and attractive assistant
Speaker 1: in tow, insists on scaling the mountain to more closely
Speaker 1: examine its condition. But just as the pair arrives at
Speaker 1: the gaping crater, it blows, sending them running or possibly jeeping,
Speaker 1: hand in hand down the slope, barely staying ahead of
Speaker 1: the raging river of hot lava. Seeing any number of
Speaker 1: these exhilarating scenes might leave you wondering what would happen
Speaker 1: if I suddenly needed to escape from an erupting volcano.
Speaker 1: Could I outrun the lava and make it to safety? Well,
Speaker 1: technically yes, If lava were all you had to deal with,
Speaker 1: ball scrambling down the side of a fiery mountain, you
Speaker 1: might be in the clear. Most lava flows, especially those
Speaker 1: from shield volcanoes, the less explosive type are pretty sluggish.
Speaker 1: As long as the lava doesn't find its way into
Speaker 1: a tube or shoot shaped valley, it will probably move
Speaker 1: slower than a mile per hour. For example, the lava
Speaker 1: flow from the Mauna Lower eruption of nineteen fifty was
Speaker 1: clocked at six miles per hour. That's nine kilometers per hour.
Speaker 1: You probably wouldn't have any trouble scurrying away from that.
Speaker 1: There have been examples of fast moving lava, but there
Speaker 1: are few and far between, like when the Democratic Republic
Speaker 1: of Congo's mountainear A Congo erupted in nineteen seventy seven.
Speaker 1: Its lava was measured going forty miles per hour that's
Speaker 1: sixty four kilometers per hour, and at least two thousand
Speaker 1: people lost their lives. The unfortunate truth, though, is that
Speaker 1: lava will be the least of your worries if you're
Speaker 1: close enough to an erupting volcano that you're thinking about
Speaker 1: running for your life. Contrary to what we might see
Speaker 1: in the movies, the dangers of a volcanic eruption are
Speaker 1: not confined to burning hot lava. Even if you could
Speaker 1: stay ahead of the lava, you'd never survived the pyroclastic
Speaker 1: flow that's the accompanying burning hot, fast move in cloud
Speaker 1: of ash, rock, gas, and debris. Pyroclastic flows are the
Speaker 1: worst when they come from the more dramatically explosive composite volcanoes,
Speaker 1: but they generally move at speeds greater than sixty miles
Speaker 1: per hour a k a nine kilometers per hour and
Speaker 1: reach temperatures between about two hundred and seven hundred degrees
Speaker 1: celsius that's around four hundred dred degrees fahrenheit. By many estimates,
Speaker 1: the pyroclastic flow from the infamous eruption of Mount Vesuvius
Speaker 1: in seventy nine reached four hundred and fifty miles per
Speaker 1: hour or seven hundred kilometers per hour. There's obviously no
Speaker 1: way anyone's out running that. And if the pyroclastic flow
Speaker 1: happens to melt snow or a glacier, this creates a
Speaker 1: lahar and extra deadly concrete thick mud slide slash avalanche combo.
Speaker 1: So if you one day find yourself flirting with danger
Speaker 1: on the rim of an erupting volcano, we hate to
Speaker 1: say it, but your toast. Today's episode was written by
Speaker 1: Alison Cooper and produced by Tristan McNeil. For more on
Speaker 1: this and lots of other myth busting topics, visit our
Speaker 1: home planet as stuff works dot com