1
00:00:02,040 --> 00:00:07,280
Speaker 1: Welcome to brain Stuff from How Stuff Works, Hi, brain Stuff,

2
00:00:07,360 --> 00:00:11,360
Speaker 1: Lauren Vogel bomb Here. It's a familiar cinematic situation. A

3
00:00:11,440 --> 00:00:14,680
Speaker 1: daring scientist arrives in town to study the local volcano,

4
00:00:14,800 --> 00:00:17,560
Speaker 1: which has been dormant for centuries but now seems dangerously

5
00:00:17,600 --> 00:00:20,960
Speaker 1: close to erupting. Despite the dire warnings of everyone around him,

6
00:00:20,960 --> 00:00:24,680
Speaker 1: the intrepid volcanologist, perhaps with a trusty and attractive assistant

7
00:00:24,680 --> 00:00:27,520
Speaker 1: in tow, insists on scaling the mountain to more closely

8
00:00:27,560 --> 00:00:30,400
Speaker 1: examine its condition. But just as the pair arrives at

9
00:00:30,400 --> 00:00:34,600
Speaker 1: the gaping crater, it blows, sending them running or possibly jeeping,

10
00:00:34,680 --> 00:00:37,479
Speaker 1: hand in hand down the slope, barely staying ahead of

11
00:00:37,479 --> 00:00:40,800
Speaker 1: the raging river of hot lava. Seeing any number of

12
00:00:40,840 --> 00:00:43,880
Speaker 1: these exhilarating scenes might leave you wondering what would happen

13
00:00:43,960 --> 00:00:46,639
Speaker 1: if I suddenly needed to escape from an erupting volcano.

14
00:00:46,840 --> 00:00:49,839
Speaker 1: Could I outrun the lava and make it to safety? Well,

15
00:00:50,240 --> 00:00:53,680
Speaker 1: technically yes, If lava were all you had to deal with,

16
00:00:53,720 --> 00:00:56,600
Speaker 1: ball scrambling down the side of a fiery mountain, you

17
00:00:56,720 --> 00:01:00,000
Speaker 1: might be in the clear. Most lava flows, especially those

18
00:01:00,120 --> 00:01:03,960
Speaker 1: from shield volcanoes, the less explosive type are pretty sluggish.

19
00:01:04,440 --> 00:01:06,440
Speaker 1: As long as the lava doesn't find its way into

20
00:01:06,480 --> 00:01:09,160
Speaker 1: a tube or shoot shaped valley, it will probably move

21
00:01:09,240 --> 00:01:12,400
Speaker 1: slower than a mile per hour. For example, the lava

22
00:01:12,400 --> 00:01:14,920
Speaker 1: flow from the Mauna Lower eruption of nineteen fifty was

23
00:01:14,959 --> 00:01:18,319
Speaker 1: clocked at six miles per hour. That's nine kilometers per hour.

24
00:01:18,560 --> 00:01:21,480
Speaker 1: You probably wouldn't have any trouble scurrying away from that.

25
00:01:22,160 --> 00:01:24,600
Speaker 1: There have been examples of fast moving lava, but there

26
00:01:24,600 --> 00:01:27,559
Speaker 1: are few and far between, like when the Democratic Republic

27
00:01:27,600 --> 00:01:30,759
Speaker 1: of Congo's mountainear A Congo erupted in nineteen seventy seven.

28
00:01:31,160 --> 00:01:33,640
Speaker 1: Its lava was measured going forty miles per hour that's

29
00:01:33,800 --> 00:01:36,880
Speaker 1: sixty four kilometers per hour, and at least two thousand

30
00:01:36,880 --> 00:01:40,240
Speaker 1: people lost their lives. The unfortunate truth, though, is that

31
00:01:40,319 --> 00:01:42,280
Speaker 1: lava will be the least of your worries if you're

32
00:01:42,319 --> 00:01:44,920
Speaker 1: close enough to an erupting volcano that you're thinking about

33
00:01:45,000 --> 00:01:48,080
Speaker 1: running for your life. Contrary to what we might see

34
00:01:48,080 --> 00:01:50,480
Speaker 1: in the movies, the dangers of a volcanic eruption are

35
00:01:50,520 --> 00:01:53,600
Speaker 1: not confined to burning hot lava. Even if you could

36
00:01:53,640 --> 00:01:56,800
Speaker 1: stay ahead of the lava, you'd never survived the pyroclastic

37
00:01:56,880 --> 00:02:00,480
Speaker 1: flow that's the accompanying burning hot, fast move in cloud

38
00:02:00,480 --> 00:02:04,600
Speaker 1: of ash, rock, gas, and debris. Pyroclastic flows are the

39
00:02:04,640 --> 00:02:08,600
Speaker 1: worst when they come from the more dramatically explosive composite volcanoes,

40
00:02:08,919 --> 00:02:11,480
Speaker 1: but they generally move at speeds greater than sixty miles

41
00:02:11,480 --> 00:02:14,360
Speaker 1: per hour a k a nine kilometers per hour and

42
00:02:14,440 --> 00:02:17,919
Speaker 1: reach temperatures between about two hundred and seven hundred degrees

43
00:02:17,960 --> 00:02:23,400
Speaker 1: celsius that's around four hundred dred degrees fahrenheit. By many estimates,

44
00:02:23,400 --> 00:02:26,440
Speaker 1: the pyroclastic flow from the infamous eruption of Mount Vesuvius

45
00:02:26,440 --> 00:02:30,040
Speaker 1: in seventy nine reached four hundred and fifty miles per

46
00:02:30,040 --> 00:02:33,480
Speaker 1: hour or seven hundred kilometers per hour. There's obviously no

47
00:02:33,560 --> 00:02:36,720
Speaker 1: way anyone's out running that. And if the pyroclastic flow

48
00:02:36,760 --> 00:02:39,600
Speaker 1: happens to melt snow or a glacier, this creates a

49
00:02:39,680 --> 00:02:44,840
Speaker 1: lahar and extra deadly concrete thick mud slide slash avalanche combo.

50
00:02:45,560 --> 00:02:48,160
Speaker 1: So if you one day find yourself flirting with danger

51
00:02:48,240 --> 00:02:50,720
Speaker 1: on the rim of an erupting volcano, we hate to

52
00:02:50,720 --> 00:02:59,000
Speaker 1: say it, but your toast. Today's episode was written by

53
00:02:59,040 --> 00:03:02,160
Speaker 1: Alison Cooper and produced by Tristan McNeil. For more on

54
00:03:02,160 --> 00:03:04,560
Speaker 1: this and lots of other myth busting topics, visit our

55
00:03:04,639 --> 00:03:17,959
Speaker 1: home planet as stuff works dot com