1 00:00:01,840 --> 00:00:07,440 Speaker 1: Welcome to brain Stuff, a production of iHeartRadio. Hey brain Stuff, 2 00:00:07,480 --> 00:00:10,959 Speaker 1: Lauren Vogel Bomb here with another classic from our podcast's archives. 3 00:00:11,680 --> 00:00:15,440 Speaker 1: This one covers a natural phenomenon that you probably don't 4 00:00:15,520 --> 00:00:22,800 Speaker 1: have to worry about, but that's nonetheless fascinatingly terrifying. Exploding lakes. 5 00:00:24,280 --> 00:00:27,400 Speaker 1: Hey brain Stuff, Lauren vogel Bomb Here. Today we're talking 6 00:00:27,440 --> 00:00:32,240 Speaker 1: about a rare but incredibly deadly natural phenomenon, exploding lakes 7 00:00:32,479 --> 00:00:36,800 Speaker 1: aka limnic eruptions. A limnic eruption is what happens when 8 00:00:36,840 --> 00:00:40,720 Speaker 1: deadly gases like carbon dioxide explode out of volcanic lakes. 9 00:00:41,360 --> 00:00:45,000 Speaker 1: Sometimes the carnage unfolds on multiple fronts. Just as lethal 10 00:00:45,040 --> 00:00:48,640 Speaker 1: clouds suffocate humans and animals, the abrupt displacement of water 11 00:00:48,720 --> 00:00:52,400 Speaker 1: is liable to create tsunamis. That exact combination of events 12 00:00:52,479 --> 00:00:55,639 Speaker 1: killed more than seventeen hundred people one grim summer day 13 00:00:55,680 --> 00:00:58,480 Speaker 1: in nineteen eighty six in the West African country of Cameroon. 14 00:00:59,160 --> 00:01:02,000 Speaker 1: And now sign up. Wonder if an even bigger limnic 15 00:01:02,120 --> 00:01:05,280 Speaker 1: eruption is in the making. But how does such an 16 00:01:05,280 --> 00:01:10,080 Speaker 1: explosion happen? Let's start with water pressure. Water pressure increases 17 00:01:10,120 --> 00:01:12,880 Speaker 1: with depth. That's why scuba divers can't venture too far 18 00:01:12,920 --> 00:01:15,960 Speaker 1: below the surface without the right equipment. The force that's 19 00:01:15,959 --> 00:01:18,800 Speaker 1: exerted upon a submerged object by the weight of all 20 00:01:18,880 --> 00:01:22,720 Speaker 1: the liquid above it is called hydrostatic pressure. Normally, this 21 00:01:22,760 --> 00:01:26,360 Speaker 1: pressure intensifies by fourteen point five pounds per square inch 22 00:01:26,640 --> 00:01:30,119 Speaker 1: or one hundred kilopaskels or one bar for every ten 23 00:01:30,200 --> 00:01:34,000 Speaker 1: meters of water depth. That's about thirty three feet. But 24 00:01:34,120 --> 00:01:38,440 Speaker 1: the key to limnic eruptions lies in temperature. Gases dissolve 25 00:01:38,520 --> 00:01:42,360 Speaker 1: more easily in cold, high pressure water. Limnic eruptions can 26 00:01:42,400 --> 00:01:44,880 Speaker 1: only occur in deep bodies of water with a lot 27 00:01:44,920 --> 00:01:48,080 Speaker 1: of hydrostatic pressure at the bottom. There must also be 28 00:01:48,120 --> 00:01:51,600 Speaker 1: a significant difference in both the pressure and temperature between 29 00:01:51,600 --> 00:01:54,360 Speaker 1: the surface water and the lower depths, with the lower 30 00:01:54,400 --> 00:01:59,120 Speaker 1: depths being much chillier. Stratification will act like a barrier, 31 00:01:59,480 --> 00:02:02,520 Speaker 1: keeping that dissolved gas confined to the lake bottom, where 32 00:02:02,520 --> 00:02:06,200 Speaker 1: it can't depressurize and escape out into the atmosphere. Because 33 00:02:06,200 --> 00:02:09,440 Speaker 1: it's trapped, the dissolved gas accumulates in massive and potentially 34 00:02:09,440 --> 00:02:13,359 Speaker 1: deadly quantities. Explosions are impossible in lakes whose lower and 35 00:02:13,440 --> 00:02:17,200 Speaker 1: upper water levels intermingle on the regular For build up 36 00:02:17,240 --> 00:02:20,320 Speaker 1: to occur. The water also needs a continuous supply of 37 00:02:20,360 --> 00:02:24,360 Speaker 1: some highly soluble gas, like carbon dioxide or methane, and 38 00:02:24,400 --> 00:02:28,440 Speaker 1: that's where volcanism comes in. At localities with active volcanoes, 39 00:02:28,560 --> 00:02:31,600 Speaker 1: buried magma is liable to send methane, CO two and 40 00:02:31,800 --> 00:02:35,040 Speaker 1: other gases seeping up through thin sections of Earth's crust. 41 00:02:35,600 --> 00:02:38,120 Speaker 1: If a lake is overhead, the gas may pass right 42 00:02:38,160 --> 00:02:41,400 Speaker 1: into the water, traveling by volcanic vents and other roots. 43 00:02:42,280 --> 00:02:44,800 Speaker 1: That brings us back to Cameroon and to its lakes. 44 00:02:44,880 --> 00:02:48,280 Speaker 1: NEOs and Monoun both are located in a volcanic field, 45 00:02:48,440 --> 00:02:52,040 Speaker 1: and both lake bottoms are oversaturated with carbon dioxide, which 46 00:02:52,120 --> 00:02:55,919 Speaker 1: underlying magma sends their way. On August fifteenth of nineteen 47 00:02:55,960 --> 00:02:58,320 Speaker 1: eighty four, some of the deep water in Monoun that 48 00:02:58,360 --> 00:03:00,800 Speaker 1: had been loaded up with the dissolved gas ascended to 49 00:03:00,800 --> 00:03:04,560 Speaker 1: the surface. No one knows why this happened. It's possible 50 00:03:04,560 --> 00:03:08,120 Speaker 1: that heavy rainfall and an earthquaker a landslide displaced some 51 00:03:08,160 --> 00:03:11,560 Speaker 1: of the lake bottom water. Regardless, as the water rose, 52 00:03:11,639 --> 00:03:15,200 Speaker 1: the dissolved carbon dioxide lurking inside it became depressurized and 53 00:03:15,280 --> 00:03:18,480 Speaker 1: formed bubbles. Those bubbles drove even more of the water 54 00:03:18,600 --> 00:03:21,000 Speaker 1: up to the top of the lake, resulting in a massive, 55 00:03:21,080 --> 00:03:25,040 Speaker 1: vowel smelling cloud of carbon dioxide gas. Under the wrong 56 00:03:25,080 --> 00:03:28,400 Speaker 1: set of circumstances, this gas is extremely dangerous to people. 57 00:03:28,919 --> 00:03:31,320 Speaker 1: Large quantities of CO two cling to the ground and 58 00:03:31,360 --> 00:03:34,720 Speaker 1: displaced oxygen, which can lead to death by suffocation. The 59 00:03:34,840 --> 00:03:38,040 Speaker 1: eruption killed at least thirty seven people, and two years later, 60 00:03:38,120 --> 00:03:41,400 Speaker 1: on August twenty first, nineteen eighty six, Lake NEOs experienced 61 00:03:41,400 --> 00:03:44,200 Speaker 1: a limit eruption of its own. Once again, there was 62 00:03:44,240 --> 00:03:47,880 Speaker 1: a sudden, mysterious upheaval of carbon dioxide laden water from 63 00:03:47,920 --> 00:03:51,640 Speaker 1: its frigid, high pressure depths, but this time the body 64 00:03:51,640 --> 00:03:54,640 Speaker 1: count was much higher. Carbon dioxide from the Lake Neo's 65 00:03:54,720 --> 00:03:58,160 Speaker 1: disaster killed approximately one thousand, seven hundred forty six people 66 00:03:58,360 --> 00:04:01,600 Speaker 1: and more than three thousand, five hundred demsic animals. Somewhere 67 00:04:01,640 --> 00:04:04,560 Speaker 1: from three hundred thousand to one point six million metric 68 00:04:04,640 --> 00:04:06,880 Speaker 1: tons of CO two gas burst out of the water 69 00:04:07,080 --> 00:04:09,400 Speaker 1: with enough force to set off a twenty meters tsunami 70 00:04:09,480 --> 00:04:13,200 Speaker 1: that's about sixty six feet tall. That was the last 71 00:04:13,200 --> 00:04:16,520 Speaker 1: recorded limnic eruption. If you're worried about a killer limnic 72 00:04:16,640 --> 00:04:19,360 Speaker 1: eruption coming to a lake, near you. University of Michigan 73 00:04:19,400 --> 00:04:23,320 Speaker 1: geoscience professor Yuxyu Jang says you probably shouldn't be. Lake 74 00:04:23,400 --> 00:04:26,160 Speaker 1: NEOs and Lake Monoon are located just above the equator, 75 00:04:26,200 --> 00:04:28,320 Speaker 1: where it tends to be warm all year round, and 76 00:04:28,440 --> 00:04:30,719 Speaker 1: there's just no way for a limnic eruption to happen 77 00:04:30,760 --> 00:04:34,080 Speaker 1: in a temperate body of water. In places where seasonal 78 00:04:34,080 --> 00:04:37,600 Speaker 1: temperatures vary widely, like in the Great Lakes, lake surfaces 79 00:04:37,680 --> 00:04:40,560 Speaker 1: often cool down, causing the water at that level to 80 00:04:40,680 --> 00:04:43,279 Speaker 1: sink and swap places with the layers of water beneath it. 81 00:04:43,880 --> 00:04:46,600 Speaker 1: Any gas is dissolved in there don't stay trapped. They're 82 00:04:46,600 --> 00:04:50,440 Speaker 1: released as they depressurize nearer to the surface. No gas accumulation, 83 00:04:50,680 --> 00:04:54,359 Speaker 1: no eruptions. However, Jiang and many of his colleagues have 84 00:04:54,400 --> 00:04:57,279 Speaker 1: taken a healthy interest in Lake Kivu, an up and 85 00:04:57,279 --> 00:05:00,200 Speaker 1: coming vacation destination on the border of Rwanda A the 86 00:05:00,240 --> 00:05:04,240 Speaker 1: Democratic Republic of the Congo. Why because it seems to 87 00:05:04,279 --> 00:05:08,320 Speaker 1: have all the necessary criteria for a truly colossal limnic eruption. 88 00:05:09,400 --> 00:05:12,479 Speaker 1: The lake contains about ten point five billion cubic feet 89 00:05:12,480 --> 00:05:15,640 Speaker 1: of carbon dioxide. That's about three hundred billion cubic meters 90 00:05:15,960 --> 00:05:18,799 Speaker 1: and two billion cubic feet of methane about sixty billion 91 00:05:18,839 --> 00:05:22,920 Speaker 1: cubic meters, all lurking near the bottom. For those gases 92 00:05:22,960 --> 00:05:25,839 Speaker 1: to explode from the lake's surface, the two million people 93 00:05:25,880 --> 00:05:29,880 Speaker 1: who live around Kivu might find themselves in jeopardy. One 94 00:05:30,040 --> 00:05:33,919 Speaker 1: possible solution, though, harvest those very gases as a possible 95 00:05:34,040 --> 00:05:37,680 Speaker 1: energy source by an extraction barge. Kivu Wat is a 96 00:05:37,680 --> 00:05:40,279 Speaker 1: one of a kind, two hundred million dollar facility that 97 00:05:40,400 --> 00:05:43,120 Speaker 1: uses an offshore barge to draw up water from the lake. 98 00:05:43,520 --> 00:05:45,680 Speaker 1: It then siphons off the methane and sends it to 99 00:05:45,720 --> 00:05:48,880 Speaker 1: a power plant, generating electricity for the area. When life 100 00:05:48,880 --> 00:05:59,839 Speaker 1: gives you lemons, turn it into electricity. Today's episode is 101 00:06:00,160 --> 00:06:03,279 Speaker 1: on the article what makes killer Lakes Explode on HowStuffWorks 102 00:06:03,279 --> 00:06:06,240 Speaker 1: dot com, written by Mark Mancini. Brainstuff is production of 103 00:06:06,240 --> 00:06:09,200 Speaker 1: iHeartRadio in partnership with HowStuffWorks dot Com and is produced 104 00:06:09,200 --> 00:06:11,960 Speaker 1: by Tyler Klang. For more podcasts from my heart Radio, 105 00:06:12,120 --> 00:06:15,080 Speaker 1: visit the iHeartRadio app, Apple Podcasts, or wherever you listen 106 00:06:15,160 --> 00:06:16,120 Speaker 1: to your favorite shows.