1 00:00:20,280 --> 00:00:23,880 Jane: This is But Why: A Podcast for Curious Kids from Vermont 2 00:00:23,880 --> 00:00:27,705 Public. I'm Jane Lindholm. On this show, we take questions 3 00:00:27,705 --> 00:00:32,325 from curious kids just like you, and we find answers. You know, 4 00:00:32,385 --> 00:00:37,005 it's been a big summer for volcanoes. You might have heard 5 00:00:37,005 --> 00:00:41,145 that back in July, a volcano erupted in Iceland, and then in 6 00:00:41,145 --> 00:00:44,325 August, a big earthquake struck off the coast of Russia, 7 00:00:44,325 --> 00:00:48,630 triggering multiple volcanic eruptions in the region. While 8 00:00:48,630 --> 00:00:51,810 the eruption in Iceland was related to a couple of years of 9 00:00:51,810 --> 00:00:55,410 ongoing volcanic activity in that region, the one in Russia 10 00:00:55,410 --> 00:01:00,630 had been dormant - inactive, quiet - for hundreds of years. 11 00:01:01,230 --> 00:01:04,410 And as we're putting this episode out in September of 12 00:01:04,470 --> 00:01:09,390 2025, an active volcano in Japan has been spewing ash into the 13 00:01:09,390 --> 00:01:13,695 air. The Smithsonian Institution's National Museum of 14 00:01:13,695 --> 00:01:17,535 Natural History in the United States keeps a list of all the 15 00:01:17,535 --> 00:01:21,795 active volcanoes and volcanic activity in the world, and says 16 00:01:21,795 --> 00:01:26,475 that at any given time there are typically 40 to 50 continuing 17 00:01:26,475 --> 00:01:30,675 eruptions, and out of those, generally around 20 will be 18 00:01:30,675 --> 00:01:35,280 actively erupting on any particular day. I did not 19 00:01:35,280 --> 00:01:39,240 realize there was that much volcanic activity all the time. 20 00:01:40,200 --> 00:01:43,020 You definitely don't want to be near a volcano while it's 21 00:01:43,020 --> 00:01:45,960 erupting, but if you ever get a chance to view it from a safe 22 00:01:45,960 --> 00:01:50,580 distance, volcanic eruptions are fascinating. You might see 23 00:01:50,580 --> 00:01:55,260 bright, hot, orange lava flowing down mountain slopes, making 24 00:01:55,260 --> 00:01:58,845 really cool patterns, and when you look up into the sky, you 25 00:01:58,845 --> 00:02:03,585 could see giant plumes of smoke filling the air. Melody, Joey 26 00:02:03,585 --> 00:02:07,245 and I were kind of hoping to get that safe viewpoint to watch an 27 00:02:07,245 --> 00:02:10,845 eruption while we were in Iceland earlier this summer. And 28 00:02:10,845 --> 00:02:15,585 it turns out we just missed one. It was only a couple weeks after 29 00:02:15,585 --> 00:02:19,050 we left that Iceland's Sundhnúkur Crater row erupted 30 00:02:19,050 --> 00:02:23,190 right near where we had been. If you don't live in an area with 31 00:02:23,190 --> 00:02:26,790 volcanoes, they can seem really mysterious. Why do they erupt 32 00:02:26,790 --> 00:02:30,270 and how? And how can we know in advance so we can make sure to 33 00:02:30,270 --> 00:02:34,230 stay safe? If you live in areas that are very volcanically 34 00:02:34,230 --> 00:02:37,230 active, you may already know a lot about volcanoes and how to 35 00:02:37,230 --> 00:02:40,470 stay safe around them. You've sent us a lot of volcano 36 00:02:40,470 --> 00:02:43,695 questions over the years, and since Iceland has so much 37 00:02:43,695 --> 00:02:47,775 ongoing volcanic activity, we figured while we were there, 38 00:02:47,835 --> 00:02:51,735 whether we could see a live eruption or not, we should find 39 00:02:51,735 --> 00:02:55,875 someone who studies volcanoes in Iceland who could answer all of 40 00:02:55,875 --> 00:02:56,835 your questions. 41 00:02:57,080 --> 00:03:00,260 Freysteinn Sigmundsson: My name is Freystein Sigmundsson. I work 42 00:03:00,260 --> 00:03:04,100 at University of Iceland. We do research to better understand 43 00:03:04,100 --> 00:03:07,640 how our planet is working. And I study volcanoes. 44 00:03:08,120 --> 00:03:10,160 Jane: Does that mean you're a volcanologist? 45 00:03:10,340 --> 00:03:12,560 Freysteinn Sigmundsson: Yes, volcanology is a very broad 46 00:03:12,560 --> 00:03:16,760 field. You can study the rocks on a volcano. What I try to do 47 00:03:16,760 --> 00:03:18,980 is to study what is inside the volcanoes. 48 00:03:19,200 --> 00:03:23,340 Jane: Iceland has about 30 volcanic systems with about 130 49 00:03:23,340 --> 00:03:27,720 volcanoes within those systems. You can think of a volcanic 50 00:03:27,720 --> 00:03:31,740 system as a network of volcanoes. So it's a good place 51 00:03:31,740 --> 00:03:36,240 to be if you're a volcanologist. And living so close to so many 52 00:03:36,240 --> 00:03:39,420 volcanoes when he was youngmade Professor Sigmundsson really 53 00:03:39,420 --> 00:03:40,200 curious. 54 00:03:40,400 --> 00:03:42,460 Freysteinn Sigmundsson: When I was a young kid, there was a 55 00:03:42,460 --> 00:03:46,000 period of very high activity of eruptions here in Iceland. So I 56 00:03:46,480 --> 00:03:50,260 saw a lot of coverage of that, and I guess that pushed me into 57 00:03:50,440 --> 00:03:51,820 the study of volcanoes. 58 00:03:52,200 --> 00:03:55,260 Jane: I did not see volcanoes growing up in New England, the 59 00:03:55,260 --> 00:03:59,520 northeastern part of the US. And there's a reason for that. Most 60 00:03:59,520 --> 00:04:03,420 volcanoes form at the boundaries of Earth's tectonic plates, 61 00:04:03,660 --> 00:04:07,560 these large pieces of the outer shell, the lithosphere of the 62 00:04:07,560 --> 00:04:12,720 earth. Iceland sits right on top of the Mid-Atlantic Ridge, where 63 00:04:12,720 --> 00:04:16,545 the North American and Eurasian tectonic plates are slowly 64 00:04:16,545 --> 00:04:21,705 drifting apart. And Iceland is a hot spot, meaning the underlying 65 00:04:21,705 --> 00:04:25,485 ground is warmer than the surface area above. These 66 00:04:25,485 --> 00:04:29,805 factors make for a lot of volcanic activity. But to get 67 00:04:29,805 --> 00:04:33,525 volcanic activity, you have to have a volcano. And what's a 68 00:04:33,525 --> 00:04:34,125 volcano? 69 00:04:34,485 --> 00:04:37,005 Freysteinn Sigmundsson: A volcano is, in essence, a crater 70 00:04:37,050 --> 00:04:41,730 that has erupted a magma, and in most cases we would expect it to 71 00:04:41,730 --> 00:04:45,690 have erupted more than once, so it builds up some kind of a 72 00:04:45,690 --> 00:04:46,290 mountain. 73 00:04:46,350 --> 00:04:49,770 Jane: The crater is at the top of the volcanic mountain, but 74 00:04:49,770 --> 00:04:52,530 it'll look a little bit like somebody's taken a big scoop 75 00:04:52,530 --> 00:04:55,950 out, leaving a bowl-shaped, round hole right at the top. 76 00:04:55,950 --> 00:05:00,510 That's the crater. Do you know what magma is? I. Here's how 77 00:05:00,510 --> 00:05:02,550 Professor Sigmundsson explains it. 78 00:05:03,315 --> 00:05:06,195 Freysteinn Sigmundsson: What is inside volcanoes. We call it 79 00:05:06,195 --> 00:05:10,875 magma, molten rock. You can think of it as a human body. We 80 00:05:10,875 --> 00:05:15,975 have blood inside our human body. Volcanoes have magma. 81 00:05:16,035 --> 00:05:21,615 Jane: This molten rock, magma, is extremely hot. So hot that it 82 00:05:21,615 --> 00:05:25,860 has become liquefied. It gets that hot because the core of the 83 00:05:25,860 --> 00:05:30,900 Earth is really, really hot. An eruption happens when more and 84 00:05:30,900 --> 00:05:35,400 more magma accumulates under the surface, building pressure. The 85 00:05:35,400 --> 00:05:39,060 magma can move upwards through cracks or weakness in the 86 00:05:39,060 --> 00:05:42,660 material around it, making its way up and then breaking through 87 00:05:42,660 --> 00:05:46,920 the top layer of the Earth's surface, and boom! That liquid 88 00:05:46,920 --> 00:05:51,525 rock plus gas and ashes come out onto the surface in an eruption. 89 00:05:51,705 --> 00:05:55,245 Freysteinn Sigmundsson: We have basically two types of volcanic 90 00:05:55,245 --> 00:05:59,445 eruptions. In one type of eruption, magma comes out of 91 00:05:59,445 --> 00:06:03,585 volcano and flows on the surface of the Earth like a liquid. The 92 00:06:03,585 --> 00:06:08,145 magma changes into lava, and it just solidifies as black rock on 93 00:06:08,145 --> 00:06:12,630 the surface. The other type of eruption is explosive, and they 94 00:06:12,630 --> 00:06:15,870 are often more dangerous. Liquid that is inside the volcanoes, 95 00:06:15,870 --> 00:06:18,810 when it comes to the surface of the Earth, it explodes into tiny 96 00:06:18,810 --> 00:06:22,230 particles and goes up into the air. And it can stop air 97 00:06:22,230 --> 00:06:26,670 traffic. And there can be so much of this particles that it 98 00:06:26,670 --> 00:06:28,350 becomes completely dark. 99 00:06:28,720 --> 00:06:32,560 Fritz: My name is Fritz. I am five years old, and I live in 100 00:06:32,680 --> 00:06:37,300 Fairview Park, Ohio. What was the first ever volcano to 101 00:06:37,420 --> 00:06:39,520 explode and turn into magma? 102 00:06:40,060 --> 00:06:44,680 Luca: I'm Luca from Pasadena. How many years did volcano 103 00:06:44,740 --> 00:06:46,060 starting existed? 104 00:06:47,200 --> 00:06:51,100 Jane: Luca is wondering how many years ago did volcanoes start 105 00:06:51,100 --> 00:06:54,985 existing? And Fritz is wondering if we know what the first ever 106 00:06:54,985 --> 00:06:57,505 volcano to explode was. 107 00:06:57,780 --> 00:07:01,260 Freysteinn Sigmundsson: The existence and evolution of our 108 00:07:01,320 --> 00:07:06,300 planet is all about volcanoes. So the first volcanoes were 109 00:07:06,300 --> 00:07:10,020 really born when the planet was forming. We don't have a name 110 00:07:10,020 --> 00:07:13,020 for the first volcano, so we cannot say what was the first 111 00:07:13,020 --> 00:07:18,180 volcano, but we can ask other questions, like, if you are in 112 00:07:18,180 --> 00:07:22,845 some specific region, we can ask, when did the first 113 00:07:22,845 --> 00:07:28,665 volcanoes form in this region? And often the time scale, or the 114 00:07:28,665 --> 00:07:33,045 time for that is measured in millions of years. Like, I live 115 00:07:33,045 --> 00:07:38,805 in Iceland. Iceland is an island in the middle of the ocean, and 116 00:07:38,925 --> 00:07:44,145 the reason Iceland exists are volcanoes. And Iceland started 117 00:07:44,145 --> 00:07:50,370 to form as an island about 20 million years ago. That is when 118 00:07:50,370 --> 00:07:55,530 the first volcanoes appeared here. And typically a volcano 119 00:07:55,530 --> 00:08:01,950 here in Iceland is about half a million years. So mankind, we 120 00:08:01,950 --> 00:08:06,750 are very small in comparison to the lifetime of volcanoes. 121 00:08:07,020 --> 00:08:12,420 Navy: My name is Navy. I live in Meridian. How do volcanoes 122 00:08:12,480 --> 00:08:13,440 erupt? 123 00:08:13,800 --> 00:08:17,460 Boaz: My name is Boaz. I'm from Israel. I'm eight years old. 124 00:08:17,700 --> 00:08:21,120 What is the pressure that makes a volcano erupt? 125 00:08:21,240 --> 00:08:23,640 Oliver: My name is Oliver. I live in Watertown, 126 00:08:23,640 --> 00:08:27,900 Massachusetts, and I'm six years old. How do volcanoes erupt? 127 00:08:27,900 --> 00:08:31,605 Zoe: My name is Zoe. I'm seven years old, and I live in 128 00:08:31,605 --> 00:08:34,425 Singapore. How do volcanoes erupt? 129 00:08:34,425 --> 00:08:38,925 Rosemary: My name is Rosemary. I live in Canada. I'm six years 130 00:08:38,925 --> 00:08:41,805 old. Why do volcanoes form? 131 00:08:42,045 --> 00:08:45,885 Jane: How do volcanoes form? And how do they erupt? 132 00:08:46,080 --> 00:08:50,160 Freysteinn Sigmundsson: Volcanoes form because of this heat that 133 00:08:50,160 --> 00:08:54,120 needs to escape from the interior of the Earth. So there 134 00:08:54,120 --> 00:08:58,260 is somewhere rock is melted, there's a liquid inside the 135 00:08:58,260 --> 00:09:03,900 Earth. This liquid wants to rise up to the surface because it is 136 00:09:03,960 --> 00:09:07,020 buoyant. It is less dense. It is like if you jump into a swimming 137 00:09:07,020 --> 00:09:11,145 pool, you float up. The same is happening with the magma inside 138 00:09:11,145 --> 00:09:15,285 the Earth. And therefore they form because this liquid is 139 00:09:15,285 --> 00:09:20,985 coming towards the surface of the Earth. And often when there 140 00:09:20,985 --> 00:09:24,645 has been sort of one path for magma, it is utilized by more 141 00:09:24,645 --> 00:09:29,805 magma. So there are repeated outflow of this liquid and the 142 00:09:29,805 --> 00:09:34,470 eruptions, when do they occur, exactly? Well, pressure is 143 00:09:34,470 --> 00:09:39,510 building up inside where magma is accumulating in a very 144 00:09:39,510 --> 00:09:43,830 similar manner as what happens if you, if you have a balloon 145 00:09:43,890 --> 00:09:48,030 and you blow air into it, and you continue to blow, you see, 146 00:09:48,030 --> 00:09:50,970 it gets always more and more difficult. That's because there 147 00:09:50,970 --> 00:09:54,615 is more pressure inside the balloon. Same happens with 148 00:09:54,615 --> 00:09:58,935 volcanoes. More new liquid that flows into a volcano, the 149 00:09:58,935 --> 00:10:03,255 pressure increases. But if you continue very hard to blow into 150 00:10:03,255 --> 00:10:07,575 your balloon, it may explode. That is the same thing that 151 00:10:07,575 --> 00:10:10,455 happens for a volcano. The eruption starts when the 152 00:10:10,455 --> 00:10:15,795 pressure is too much inside the balloon that is collecting magma 153 00:10:15,855 --> 00:10:20,340 inside the volcano, and there we go. We have an eruption. 154 00:10:21,300 --> 00:10:25,140 Theodore: My name is Theodore. How does the volcano rise up 155 00:10:25,320 --> 00:10:26,160 inside the sea? 156 00:10:26,160 --> 00:10:28,980 Jane: Can you talk a little bit about volcanoes that form 157 00:10:28,980 --> 00:10:29,580 underwater? 158 00:10:29,600 --> 00:10:33,800 Freysteinn Sigmundsson: Yes, we have super many volcanoes in the 159 00:10:33,800 --> 00:10:38,960 oceans, underwater. Lots of submarine volcanoes, underwater. 160 00:10:39,500 --> 00:10:43,760 What happens is, inside the volcano, the process is very 161 00:10:43,760 --> 00:10:48,320 similar, but the eruptions are different. Often we form both 162 00:10:48,320 --> 00:10:53,225 lava similar as on the surface, but the lava will be of a little 163 00:10:53,225 --> 00:10:57,245 different types. If the eruptions happen in shallow 164 00:10:57,245 --> 00:11:00,725 water or water depth of a few hundred meters, it becomes 165 00:11:00,725 --> 00:11:05,645 explosive. So what happens then is that the lava, when it comes 166 00:11:05,885 --> 00:11:09,725 into the ocean, it can explode into fine particles, similar as 167 00:11:09,725 --> 00:11:13,865 an explosive eruption, and then it can pile off. And eruptions 168 00:11:13,865 --> 00:11:18,530 can create mountains. And we have had new island created off 169 00:11:18,530 --> 00:11:23,810 the coast of Iceland in an eruption that was first under 170 00:11:23,810 --> 00:11:27,170 ocean water, and the volcano rose out of the sea. 171 00:11:27,660 --> 00:11:31,140 Calvin: My name is Calvin. I'm five years old. I live in New 172 00:11:31,140 --> 00:11:34,860 York City. Which one's hotter, the sun or a volcano? 173 00:11:35,220 --> 00:11:38,340 Freysteinn Sigmundsson: The red glow of this liquid that comes 174 00:11:38,340 --> 00:11:42,660 out of the volcano means it is very hot, 1,000 degrees Celsius. 175 00:11:42,720 --> 00:11:46,800 This is about 1,800 degrees Fahrenheit. So it is super hot. 176 00:11:47,280 --> 00:11:49,980 But inside the sun, it is much hotter. 177 00:11:50,565 --> 00:11:55,845 Jane: Scientists say the core of the Sun is as hot as 15 million 178 00:11:55,845 --> 00:12:01,185 degrees Celsius. That's 27 million degrees Fahrenheit. So 179 00:12:01,185 --> 00:12:04,845 the heat from underneath the earth is definitely hot. But if 180 00:12:04,845 --> 00:12:08,865 we're comparing about 1,000 degrees in a volcano to 15 181 00:12:08,865 --> 00:12:13,950 million degrees in the core of the Sun, the Sun is much, much 182 00:12:14,010 --> 00:12:19,350 hotter. Coming up, how do we know when a volcano is going to 183 00:12:19,350 --> 00:12:19,890 erupt? 184 00:12:20,790 --> 00:12:24,030 This is But Why. I'm Jane Lindholm, and today on the show, 185 00:12:24,030 --> 00:12:26,910 we're learning all about volcanoes with University of 186 00:12:26,910 --> 00:12:30,270 Iceland professor and volcanologist Freysteinn 187 00:12:30,270 --> 00:12:34,950 Sigmundsson. So as we just heard, when a volcano erupts, 188 00:12:34,950 --> 00:12:40,215 magma, or hot, molten rock, flows onto the Earth's surface. 189 00:12:40,635 --> 00:12:45,675 And at that point, we give it a new name: lava. We've got some 190 00:12:45,675 --> 00:12:48,015 questions about lava and how it forms. 191 00:12:48,075 --> 00:12:52,455 Alana: Hi, my name is Alana, and I'm eight years old, and I live 192 00:12:52,455 --> 00:12:58,515 in Norwalk, California. And my question is, why do volcanoes 193 00:12:58,515 --> 00:13:03,240 have lava in them, and how does the lava even get in there? 194 00:13:03,360 --> 00:13:07,020 Landis: My name is Landis. I'm seven years old. I live in San 195 00:13:07,020 --> 00:13:10,740 Antonio, Texas. Where do volcanoes get their lava from? 196 00:13:10,740 --> 00:13:14,580 Charlie: My name is Charlie. I live in New Zealand. I am six 197 00:13:14,580 --> 00:13:17,160 years old. What is lava made out of? 198 00:13:17,600 --> 00:13:22,100 Freysteinn Sigmundsson: Lava is made out of rock that has become 199 00:13:22,100 --> 00:13:26,840 so hot that it melts. And you'll see many of the features of 200 00:13:26,840 --> 00:13:30,320 volcanoes can be explained by this heat. So the volcano 201 00:13:30,320 --> 00:13:34,700 scattered magma initially, that is when the lava is inside the 202 00:13:34,700 --> 00:13:39,860 volcano. Because of heat, the rock started to melt and form 203 00:13:39,860 --> 00:13:45,065 liquid. So the liquid inside the volcano comes to the surface, 204 00:13:45,185 --> 00:13:50,705 and then we call it lava. So it is a hot liquid. And many 205 00:13:50,705 --> 00:13:54,725 volcanoes have a lot of hot liquid inside them, and that's 206 00:13:54,725 --> 00:13:57,485 when we have an eruption. This liquid comes to the surface and 207 00:13:57,485 --> 00:14:00,665 we have lava. So that's the story, basically, of the lava. 208 00:14:00,725 --> 00:14:05,090 It's all about the Earth trying to release heat from its 209 00:14:05,060 --> 00:14:11,180 Trixie: My name is Trixie. I'm four. I live in Virginia. Why 210 00:14:05,090 --> 00:14:05,510 interior. 211 00:14:11,540 --> 00:14:15,980 are volcano lava is orange? 212 00:14:16,040 --> 00:14:17,600 Jane: Why is lava orange? 213 00:14:17,600 --> 00:14:21,440 Freysteinn Sigmundsson: Yeah, similar reasons the sun is 214 00:14:21,440 --> 00:14:26,900 yellow. It is transmitting energy. It is so hot that it 215 00:14:26,900 --> 00:14:33,245 starts to radiate energy. The sun is radiating energy that is 216 00:14:33,605 --> 00:14:38,585 still hotter than the lava that is yellow. The orange color is 217 00:14:38,585 --> 00:14:41,525 simply radiation from a different temperature. 218 00:14:41,960 --> 00:14:44,780 Jane: When melody, Joey and I were in Iceland, we didn't see 219 00:14:44,780 --> 00:14:49,160 an eruption, but we did visit a solidified lava field from 220 00:14:49,160 --> 00:14:52,100 volcanoes that had already erupted just a few years ago. 221 00:14:52,820 --> 00:14:55,880 The lava there was no longer bright orange because it had 222 00:14:55,880 --> 00:14:59,720 cooled and hardened back into rock. But I could see the 223 00:14:59,720 --> 00:15:03,380 different textures and patterns of the lava as it had flowed 224 00:15:03,380 --> 00:15:06,725 across the surface. And I was really surprised to see that 225 00:15:06,725 --> 00:15:10,145 there was still smoke coming out of the solidified lava field, 226 00:15:10,445 --> 00:15:13,025 even though it had been more than a year since the last 227 00:15:13,025 --> 00:15:17,465 eruption. We even saw signs warning people not to walk on it 228 00:15:17,465 --> 00:15:21,785 because it might still be very hot underneath. So I asked 229 00:15:21,785 --> 00:15:25,625 Professor Sigmundsson how long can it be hot underneath that 230 00:15:25,865 --> 00:15:30,170 hard surface, and how long can a lava field be dangerous after an 231 00:15:30,170 --> 00:15:30,770 eruption. 232 00:15:30,950 --> 00:15:34,790 Freysteinn Sigmundsson: For... for years. Because it takes a 233 00:15:34,790 --> 00:15:39,050 long time to cool a lava field. It depends, of course, how thick 234 00:15:39,050 --> 00:15:44,030 it is, but if it is like few meters... 235 00:15:44,150 --> 00:15:45,350 Jane: As tall as an adult. 236 00:15:45,350 --> 00:15:48,650 Freysteinn Sigmundsson: Yes, or twice or three times that. That 237 00:15:48,650 --> 00:15:53,975 is maybe typical for lava fields here in Iceland, they can have 238 00:15:54,575 --> 00:15:59,675 really liquid magma inside them for possibly for months or 239 00:15:59,675 --> 00:16:03,695 years. But there is also another danger simply related to the 240 00:16:03,695 --> 00:16:08,315 rocks. You know, it is liquid that is transforming into rock 241 00:16:08,315 --> 00:16:13,295 again on the surface of the Earth. And the structure of lava 242 00:16:13,295 --> 00:16:16,340 fields is very intriguing. Many of the lava fields here in 243 00:16:16,400 --> 00:16:19,400 Iceland are very irregular on the surface. So you also have 244 00:16:19,400 --> 00:16:26,240 the danger of just falling. So they are dangerous, yes. So you 245 00:16:26,240 --> 00:16:27,560 need to be aware of that. 246 00:16:28,940 --> 00:16:32,780 Harper: My name is Harper, and I am five years old, and I live in 247 00:16:32,780 --> 00:16:37,280 Scottsdale, Arizona. Why can't we live on volcanoes? 248 00:16:38,020 --> 00:16:40,000 Freysteinn Sigmundsson: Lots of people live on volcanoes, and 249 00:16:40,000 --> 00:16:43,060 lots of people live close to volcanoes. Here in Iceland, we 250 00:16:43,060 --> 00:16:47,380 live quite close to volcanoes. I mean, the capital of Iceland, 251 00:16:47,380 --> 00:16:51,100 Reykjavik, is not far from volcanoes. Here in Iceland, 252 00:16:51,100 --> 00:16:55,420 there are two villages that are practically on a volcano. But 253 00:16:55,420 --> 00:16:59,620 worldwide, there are many people that live on volcanoes. And the 254 00:16:59,620 --> 00:17:03,865 reason people live on volcanoes, like in Indonesia, is because 255 00:17:03,865 --> 00:17:10,525 the the soil on a volcano can be very fertile, and you can grow 256 00:17:10,525 --> 00:17:11,425 crops there. 257 00:17:11,545 --> 00:17:14,545 Jane: Professor Sigmundsson says living close to volcanoes can 258 00:17:14,545 --> 00:17:17,425 come with other great benefits. In Iceland, for example, 259 00:17:17,485 --> 00:17:21,205 geothermal energy powers about 70% of the country. 260 00:17:21,325 --> 00:17:24,430 Freysteinn Sigmundsson: We have cold winters, but we heat most 261 00:17:24,430 --> 00:17:28,510 of the houses in Iceland by water that comes from the 262 00:17:28,510 --> 00:17:32,350 volcanoes, hot water, and it just goes into a radiator 263 00:17:32,410 --> 00:17:35,170 directly from volcano and heats our houses. We have very hot 264 00:17:35,170 --> 00:17:37,330 houses here in Iceland, even if the winters are cold 265 00:17:37,690 --> 00:17:40,210 Jane: And many volcanoes stay dormant, which means they're 266 00:17:40,210 --> 00:17:43,870 inactive, kind of asleep for hundreds or even thousands of 267 00:17:43,870 --> 00:17:47,995 years. So it's entirely possible for someone to live close to an 268 00:17:48,055 --> 00:17:51,475 inactive volcano their whole life and not experience an 269 00:17:51,475 --> 00:17:55,015 eruption. The tricky thing, though, is that volcanoes don't 270 00:17:55,015 --> 00:17:57,235 always stay asleep. 271 00:17:57,300 --> 00:17:59,280 Freysteinn Sigmundsson: If they can talk about the volcanoes as 272 00:17:59,400 --> 00:18:03,300 a living creature, in their lifetime, most of the time they 273 00:18:03,300 --> 00:18:08,640 are sleeping. So they only wake up occasionally. Some of the 274 00:18:08,640 --> 00:18:11,940 work I do is try to understand what happens when a volcano is 275 00:18:11,940 --> 00:18:16,440 trying to wake up. And yeah, it is difficult to forecast. For 276 00:18:16,440 --> 00:18:20,340 example, if you're sick, if you do not feel very well in your 277 00:18:20,340 --> 00:18:24,825 stomach, you may need to throw up occasionally. And forecasting 278 00:18:24,885 --> 00:18:28,245 when you will throw up if you have a stomach disease may be 279 00:18:28,245 --> 00:18:33,045 difficult. You almost throw up, but then suddenly it comes, and 280 00:18:33,045 --> 00:18:38,145 maybe we are not prepared. The same is with volcanoes. It is 281 00:18:38,145 --> 00:18:39,945 difficult to forecast when they throw up. 282 00:18:41,040 --> 00:18:43,920 Jane: I like that way of thinking about it. And yes, in 283 00:18:43,920 --> 00:18:47,640 my experience, sometimes you think: Oh, I don't feel good. Oh 284 00:18:47,640 --> 00:18:50,820 my gosh, now I'm throwing up. It can be a very surprising thing. 285 00:18:51,060 --> 00:18:53,700 Freysteinn Sigmundsson: Same for volcanoes. What volcanologists 286 00:18:53,700 --> 00:18:58,860 are trying to do, some of our work is to forecast the activity 287 00:18:59,040 --> 00:19:04,125 and better prepare society. That you're listening to this podcast 288 00:19:04,125 --> 00:19:07,545 is very good, because we need to more people that understand what 289 00:19:07,545 --> 00:19:08,385 volcanoes are doing. 290 00:19:08,660 --> 00:19:11,780 Soleil: Hello. My name is Soleil and I live in Hamden, 291 00:19:11,780 --> 00:19:15,200 Connecticut, and I'm five years old and about to be 60, 292 00:19:15,200 --> 00:19:17,120 volcanoes erupt in the winter? 293 00:19:17,480 --> 00:19:19,640 Freysteinn Sigmundsson: What you know about volcanoes is that 294 00:19:19,640 --> 00:19:24,740 they are very irregular. They can erupt any time of the year. 295 00:19:24,980 --> 00:19:26,480 Volcanoes are not like a clock. 296 00:19:26,540 --> 00:19:29,240 Jennifer: My name is Jennifer, and seven years old. I'm from 297 00:19:29,240 --> 00:19:33,425 Ohio. How do volcanologists know a volcano is going to erupt? 298 00:19:33,480 --> 00:19:35,640 Freysteinn Sigmundsson: That is my job, part of my job, to 299 00:19:35,640 --> 00:19:39,840 understand what happens before this, yeah. So we need to 300 00:19:39,840 --> 00:19:45,420 measure their activity, and we can measure what is happening 301 00:19:45,420 --> 00:19:48,780 inside the volcano with different techniques, mainly 302 00:19:48,780 --> 00:19:53,700 three techniques. We can study earthquakes, how the ground is 303 00:19:53,700 --> 00:19:58,725 shaking in a volcano, because the waves from earthquakes come 304 00:19:58,725 --> 00:20:01,005 to the surface. And we can measure the waves and then 305 00:20:01,005 --> 00:20:05,205 figure out what is happening inside. Or we can measure how 306 00:20:05,205 --> 00:20:10,305 the ground of a volcano is moving, and thereby, maybe, try 307 00:20:10,305 --> 00:20:13,785 to understand how the pressure is building up, like in a 308 00:20:13,785 --> 00:20:18,945 balloon. Or we can measure what we can call volcanic gas. That 309 00:20:18,945 --> 00:20:23,670 is like if you smell something is burning in your stove, then 310 00:20:24,150 --> 00:20:28,410 something serious may happen unless you stop the process. 311 00:20:28,710 --> 00:20:33,450 It's basically the same thing we can try to sense or sniff, in a 312 00:20:33,450 --> 00:20:37,410 sense, what the gas that is coming out of a volcano. 313 00:20:37,770 --> 00:20:41,190 Jane: When something is burning in your stove, that's a very 314 00:20:41,190 --> 00:20:43,815 familiar smell. Like I can picture the smell of burning 315 00:20:43,815 --> 00:20:49,515 toast. The smell of a volcano that is getting active, what is 316 00:20:49,515 --> 00:20:52,515 that smell? Is that a sulfuric smell, which sometimes people 317 00:20:52,515 --> 00:20:54,735 describe as kind of like rotten eggs? 318 00:20:55,455 --> 00:20:58,095 Freysteinn Sigmundsson: It can be increased in that. It can 319 00:20:58,095 --> 00:21:02,955 also be increase in gas types that has no smell that we need 320 00:21:02,955 --> 00:21:07,860 special instruments to measure. So we need some technology. 321 00:21:07,920 --> 00:21:11,160 Normally, we cannot use our nose for it. 322 00:21:11,400 --> 00:21:13,920 Jane: Are there things that you can look at? If I was looking at 323 00:21:13,920 --> 00:21:16,500 a volcano, and say, oh, something is happening? Or do 324 00:21:16,500 --> 00:21:20,580 you need special tools and special maybe even computer 325 00:21:20,580 --> 00:21:22,980 models to be able to understand what's happening? 326 00:21:23,320 --> 00:21:26,980 Freysteinn Sigmundsson: Sometimes we can see it with our eyes. For 327 00:21:26,980 --> 00:21:31,780 example, if there is new, hot liquid coming into a volcano, 328 00:21:31,840 --> 00:21:38,140 the heat of the rock around it can increase, and we can start 329 00:21:38,140 --> 00:21:41,860 to have more geothermal activity, or basically steaming 330 00:21:41,860 --> 00:21:45,925 from a volcano. So we can get visual steam from a volcano, 331 00:21:45,985 --> 00:21:51,205 basically meaning it is hotter. But we typically need equipment. 332 00:21:51,385 --> 00:21:54,805 We need to study the earthquakes. We need to see how 333 00:21:54,805 --> 00:21:59,185 the ground is moving, or we need to measure the gases that come 334 00:21:59,185 --> 00:22:03,625 out. And typically, to understand how volcanoes behave, 335 00:22:03,625 --> 00:22:07,825 both in this time period before an eruption and during eruption, 336 00:22:07,885 --> 00:22:13,510 we need this monitoring data, and we take it all together and 337 00:22:13,510 --> 00:22:17,170 try to understand what is happening inside the volcano 338 00:22:17,170 --> 00:22:21,550 during an eruption. And often we need a computer model for that. 339 00:22:21,910 --> 00:22:25,210 So even if I'm a volcanologist, most of the time I'm in front of 340 00:22:25,210 --> 00:22:25,750 a computer. 341 00:22:26,020 --> 00:22:28,900 Jane: Scientists have been studying volcanic activity for a 342 00:22:28,900 --> 00:22:32,140 long time, but there's still a lot we don't know about how they 343 00:22:32,140 --> 00:22:35,860 work. For Professor Sigmundsson, he says his goals are to keep 344 00:22:35,860 --> 00:22:39,580 learning more about what's inside volcanoes and how that 345 00:22:39,580 --> 00:22:43,000 might help him understand better the warning signs volcanoes are 346 00:22:43,000 --> 00:22:46,960 giving. That way, people could be informed before a volcano 347 00:22:46,960 --> 00:22:49,945 erupts. That's especially important for people who live 348 00:22:49,945 --> 00:22:54,385 close by, of course. Volcanic eruptions are a forceful release 349 00:22:54,385 --> 00:22:58,705 of extreme heat and energy. They can destroy homes, they can make 350 00:22:58,705 --> 00:23:03,265 nearby towns unsafe, require residents to evacuate, or leave. 351 00:23:03,745 --> 00:23:07,645 Sometimes, all the ash from an eruption gets high up into the 352 00:23:07,645 --> 00:23:11,125 atmosphere and causes problems like planes needing to find new 353 00:23:11,125 --> 00:23:14,590 routes or not being able to fly at all. And remember our recent 354 00:23:14,590 --> 00:23:18,790 episode about smoke traveling from forest fires. Ash from 355 00:23:18,790 --> 00:23:22,930 volcanoes can, of course, also get into the atmosphere and go 356 00:23:22,930 --> 00:23:26,470 very, very far from where the volcano has originally erupted. 357 00:23:27,190 --> 00:23:30,070 Given all of that, it makes sense that we often think of 358 00:23:30,070 --> 00:23:33,970 volcanoes as something kind of scary and unpredictable and 359 00:23:33,970 --> 00:23:38,275 dangerous and bad. But Professor Sigmundsson says it's important 360 00:23:38,275 --> 00:23:41,155 to be respectful of the power and destruction of volcanic 361 00:23:41,155 --> 00:23:44,635 activity, but to also recognize the beauty. 362 00:23:45,475 --> 00:23:48,175 Freysteinn Sigmundsson: If you look at some photographs or 363 00:23:48,175 --> 00:23:52,675 videos of volcanoes, it's a beautiful thing to see a small 364 00:23:52,675 --> 00:23:58,840 eruption. You sese some nice red magma being thrown up into the 365 00:23:58,840 --> 00:24:02,860 air and flowing. So, so I was a young kid that had the 366 00:24:02,860 --> 00:24:07,960 opportunity to see eruptions and hear about them. They caught my 367 00:24:07,960 --> 00:24:13,060 interest. They are beautiful, spectacular, and if you stare at 368 00:24:13,060 --> 00:24:18,100 them for a long time, stare into the red glow, you can be 369 00:24:18,220 --> 00:24:18,700 charmed. 370 00:24:19,500 --> 00:24:22,920 Jane: And volcanoes are also very important. Not only did 371 00:24:22,920 --> 00:24:26,160 they shape the landscape we know today on Earth, but they 372 00:24:26,160 --> 00:24:30,900 continue to do that. New islands and new terrain is constantly 373 00:24:30,900 --> 00:24:34,680 being formed by volcanic eruptions. Plus, volcanoes are 374 00:24:34,680 --> 00:24:38,340 important for things like geothermal energy, how we can 375 00:24:38,340 --> 00:24:42,840 heat and cool our homes and buildings. And they can create 376 00:24:42,885 --> 00:24:46,485 very fertile soils, meaning it's easier to grow things like 377 00:24:46,485 --> 00:24:50,145 fruits and vegetables. So volcanoes are all of those 378 00:24:50,145 --> 00:24:53,625 things at once: a little bit mysterious, maybe scary 379 00:24:53,625 --> 00:24:57,645 sometimes, occasionally dangerous, but also beautiful, 380 00:24:57,945 --> 00:25:02,385 interesting and important. Thanks to Professor Freysteinn 381 00:25:02,385 --> 00:25:05,310 Sigmundsson at the University of Iceland for speaking with us 382 00:25:05,310 --> 00:25:08,910 about volcanoes and answering your question. As always, if you 383 00:25:08,910 --> 00:25:12,330 have a question about anything, have an adult record you asking 384 00:25:12,330 --> 00:25:15,330 it on a smartphone. You can use an app like voice memos or 385 00:25:15,330 --> 00:25:18,270 recorder. Then have your adult email the file to 386 00:25:18,930 --> 00:25:22,890 questions@butwhykids.org. But Why is produced by Melody 387 00:25:22,890 --> 00:25:26,790 Bodette, Sarah Baik and me Jane Lindholm at Vermont Public and 388 00:25:26,790 --> 00:25:31,215 distributed by PRX. Our video producer is Joey Palumbo, and 389 00:25:31,215 --> 00:25:34,215 our theme music is by Luke Reynolds. If you like our show, 390 00:25:34,395 --> 00:25:37,635 please have your adults help you give us a thumbs up or a review 391 00:25:37,635 --> 00:25:41,355 on whatever podcast platform you use. It helps other kids and 392 00:25:41,355 --> 00:25:45,195 families find us. We'll be back in two weeks with an all new 393 00:25:45,195 --> 00:25:48,795 episode. Until then, stay curious.