1 00:00:00,000 --> 00:00:04,162 WWW.MY-SUBS.CO 1 00:00:02,489 --> 00:00:05,892 >> Earth, a unique planet, 2 00:00:05,969 --> 00:00:09,705 restless and dynamic. Continents 3 00:00:09,773 --> 00:00:13,576 shift and clash. Volcanoes 4 00:00:13,610 --> 00:00:17,847 erupt. Glaciers grow and recede, 5 00:00:17,881 --> 00:00:19,381 titanic forces that are 6 00:00:19,416 --> 00:00:22,251 constantly at work, leaving a 7 00:00:22,319 --> 00:00:24,286 trail of geological mysteries 8 00:00:24,321 --> 00:00:27,790 behind. Among Earth's many 9 00:00:27,858 --> 00:00:29,391 geological wonders, there's 10 00:00:29,426 --> 00:00:31,327 nowhere more dangerous than 11 00:00:31,394 --> 00:00:36,398 Mount Vesuvius. It's a volcano 12 00:00:36,466 --> 00:00:43,239 well-known for its violent past. 13 00:00:43,306 --> 00:00:44,673 As witnessed by the remains of 14 00:00:44,774 --> 00:00:47,376 its victims, frozen in time for 15 00:00:47,410 --> 00:00:53,215 nearly 2,000 years. But Vesuvius 16 00:00:53,283 --> 00:00:55,417 is still very much alive, and 17 00:00:55,485 --> 00:00:57,553 only now are its mysteries being 18 00:00:57,587 --> 00:01:00,589 revealed. A new discovery of a 19 00:01:00,657 --> 00:01:02,191 vast magma chamber of 20 00:01:02,225 --> 00:01:04,126 boiling-hot rock beneath 21 00:01:04,227 --> 00:01:06,862 Vesuvius: Just one of many 22 00:01:06,963 --> 00:01:08,864 startling new clues to how the 23 00:01:08,965 --> 00:01:11,033 volcano could threaten one of 24 00:01:11,101 --> 00:01:14,503 Europe's most crowded cities 25 00:01:14,571 --> 00:01:17,506 with a fiery rain of death and 26 00:01:17,574 --> 00:01:20,142 destruction. Unlocking the 27 00:01:20,210 --> 00:01:22,678 secrets of Vesuvius exposes the 28 00:01:22,746 --> 00:01:24,780 awesome forces behind "How the 29 00:01:24,848 --> 00:01:28,483 Earth was made." S02x02 Vesuvius Original Air Date on December 1, 2009 30 00:01:28,519 --> 00:01:31,320 -- Sync, corrected by 00:01:32,821 The next eruption at Vesuvius 32 00:01:32,856 --> 00:01:34,590 could kill more people than any 33 00:01:34,658 --> 00:01:37,092 other volcano in history. 34 00:01:37,160 --> 00:01:40,763 3 million lives are at risk. 35 00:01:40,797 --> 00:01:42,431 On the west coast of Italy 36 00:01:42,532 --> 00:01:44,333 towering 4,000 feet over the 37 00:01:44,401 --> 00:01:47,069 city of Naples stands Mount 38 00:01:47,137 --> 00:01:50,706 Vesuvius. 39 00:01:50,774 --> 00:01:52,141 >> The death toll will be big, 40 00:01:52,209 --> 00:01:53,409 running into the millions. 41 00:01:53,410 --> 00:01:54,977 So it really is the catastrophic 42 00:01:55,045 --> 00:01:56,779 nightmare scenario that we all 43 00:01:56,846 --> 00:01:58,247 fear. 44 00:01:58,248 --> 00:01:59,515 >> The challenge for geologists 45 00:01:59,616 --> 00:02:00,983 is to figure out what could 46 00:02:01,051 --> 00:02:03,686 trigger Vesuvius' next eruption 47 00:02:03,787 --> 00:02:05,221 and assess how such a potential 48 00:02:05,255 --> 00:02:08,591 horror would unfold. The first 49 00:02:08,692 --> 00:02:10,392 catastrophic explosion would 50 00:02:10,427 --> 00:02:12,661 burst from the ground here, from 51 00:02:12,696 --> 00:02:14,230 yhe depths of the volcano's 52 00:02:14,297 --> 00:02:18,133 2,000-foot-wide crater. 53 00:02:23,840 --> 00:02:25,140 >> Within seconds the whole 54 00:02:25,208 --> 00:02:28,777 thing would be ripped apart. 55 00:02:28,845 --> 00:02:30,479 >> It's the nightmare scenario 56 00:02:30,513 --> 00:02:35,884 that everyone fears. A cloud of 57 00:02:35,952 --> 00:02:37,886 fiery volcanic debris would 58 00:02:37,954 --> 00:02:39,321 blast down the steep sides of 59 00:02:39,422 --> 00:02:41,857 the volcano at 450 miles per 60 00:02:41,958 --> 00:02:43,959 hour, twice as fast as a 61 00:02:44,060 --> 00:02:48,430 formula 1 racing car. Anyone 62 00:02:48,498 --> 00:02:50,232 within 10 miles of the crater 63 00:02:50,300 --> 00:02:51,500 would be caught in the 64 00:02:51,568 --> 00:02:53,869 eruption's death zone. Nothing 65 00:02:53,937 --> 00:02:55,871 could stop this boiling cloud 66 00:02:55,972 --> 00:02:58,974 of ash and rock. 67 00:02:59,042 --> 00:03:00,142 >> You might think that the 68 00:03:00,243 --> 00:03:01,310 people living across the water 69 00:03:01,411 --> 00:03:02,511 there in Naples would be safe 70 00:03:02,579 --> 00:03:03,679 from the volcano. But we know 71 00:03:03,780 --> 00:03:06,148 that that wouldn't be the case. 72 00:03:06,216 --> 00:03:07,683 It moves across the sea, picking 73 00:03:07,751 --> 00:03:09,151 op speed as it goes. Not 74 00:03:09,219 --> 00:03:10,586 walking, but literally running 75 00:03:10,687 --> 00:03:13,922 towards Naples. Imagine the 76 00:03:13,957 --> 00:03:16,025 panic in downtown Naples as this 77 00:03:16,059 --> 00:03:18,227 hot, dark cloud of volcanic ash 78 00:03:18,295 --> 00:03:22,097 and dust descends on the city. 79 00:03:24,834 --> 00:03:27,936 >> There's nowhere to hide. 80 00:03:27,971 --> 00:03:30,372 Men, women, and children are 81 00:03:30,407 --> 00:03:32,875 incinerated. 82 00:03:32,942 --> 00:03:34,143 >> And the temperature's 600, 83 00:03:34,210 --> 00:03:35,411 700, 800 degrees fahrenheit. 84 00:03:35,512 --> 00:03:36,679 I mean, that's enough literally 85 00:03:36,780 --> 00:03:38,580 to boil the blood in your body. 86 00:03:38,648 --> 00:03:42,318 >> Other victims suffocate. 87 00:03:42,385 --> 00:03:44,119 Anyone trapped between downtown 88 00:03:44,187 --> 00:03:47,923 Naples and the volcano is dead. 89 00:03:56,966 --> 00:03:58,300 Volcanologists had always 90 00:03:58,401 --> 00:03:59,935 believed that the city of Naples 91 00:04:00,003 --> 00:04:04,673 itself was safe from Vesuvius. 92 00:04:04,741 --> 00:04:05,941 They thought that even the 93 00:04:06,042 --> 00:04:07,409 volcano's biggest eruptions 94 00:04:07,477 --> 00:04:08,644 couldn't reach further than the 95 00:04:08,678 --> 00:04:12,281 city limits. A belief that was 96 00:04:12,315 --> 00:04:13,949 shattered by new research deep 97 00:04:14,050 --> 00:04:16,118 beneath Angevin Castle in the 98 00:04:16,219 --> 00:04:19,221 heart of Naples. 99 00:04:23,593 --> 00:04:26,929 >> Wow. This is an extraordinary 100 00:04:26,963 --> 00:04:30,666 deposit. 101 00:04:30,667 --> 00:04:32,935 Extending from this level all 102 00:04:33,036 --> 00:04:36,038 the way up to this point, 103 00:04:36,039 --> 00:04:37,573 which makes it about 4 feet 104 00:04:37,640 --> 00:04:40,943 thick. 105 00:04:41,010 --> 00:04:42,745 >> The layer Sheridan has found 106 00:04:42,812 --> 00:04:44,213 is an accumulation of ash that 107 00:04:44,314 --> 00:04:45,681 rained down on the center of 108 00:04:45,749 --> 00:04:47,683 Naples from a massive eruption 109 00:04:47,751 --> 00:04:49,385 in the bronze age, around 110 00:04:49,486 --> 00:04:52,020 1780 B.C. 111 00:04:52,122 --> 00:04:54,223 >> It traveled 10 miles from 112 00:04:54,290 --> 00:04:56,759 the volcano, across the Bay of 113 00:04:56,826 --> 00:04:58,927 Naples to this point. 114 00:04:59,028 --> 00:05:00,829 >> Miles further than any other 115 00:05:00,864 --> 00:05:02,564 previously known eruption of 116 00:05:02,665 --> 00:05:05,734 Vesuvius. Astonished scientists 117 00:05:05,769 --> 00:05:07,569 could not ignore such convincing 118 00:05:07,670 --> 00:05:09,204 evidence. 119 00:05:09,305 --> 00:05:10,639 >> Finding a deposit right in 120 00:05:10,673 --> 00:05:12,040 the center of Naples has changed 121 00:05:12,108 --> 00:05:13,475 the way people think about their 122 00:05:13,576 --> 00:05:15,177 safety from eruptions at 123 00:05:15,211 --> 00:05:17,846 Vesuvius. And people are now 124 00:05:17,914 --> 00:05:19,381 considering that Vesuvius may 125 00:05:19,449 --> 00:05:22,017 truly represent a risk to their 126 00:05:22,118 --> 00:05:24,753 safety. 127 00:05:27,824 --> 00:05:29,291 >> If Vesuvius produced such a 128 00:05:29,359 --> 00:05:31,560 massive eruption once, it can 129 00:05:31,661 --> 00:05:35,030 again. There's a further 130 00:05:35,131 --> 00:05:36,632 monumental-sized piece of 131 00:05:36,666 --> 00:05:38,033 evidence that reveals the 132 00:05:38,101 --> 00:05:39,835 awesome scale of the blast 133 00:05:39,936 --> 00:05:42,638 in 1780 B.C. These are the 134 00:05:42,672 --> 00:05:45,941 3,700-foot-high cliffs named 135 00:05:46,009 --> 00:05:50,179 Somma. It's 4,000 years ago 136 00:05:50,213 --> 00:05:53,015 on Mount vesuvius. 137 00:05:55,285 --> 00:05:56,985 A colossal eruption rips the 138 00:05:57,020 --> 00:06:00,122 volcano open. 139 00:06:03,560 --> 00:06:05,327 Molten rock blasts out of the 140 00:06:05,361 --> 00:06:06,995 cone, emptying out the 141 00:06:07,063 --> 00:06:08,497 underground reservoir that 142 00:06:08,531 --> 00:06:10,165 geologists call the magma 143 00:06:10,266 --> 00:06:12,968 chamber. This continues for 144 00:06:13,069 --> 00:06:15,437 hours until something literally 145 00:06:15,505 --> 00:06:18,073 earth-shattering happens. When 146 00:06:18,174 --> 00:06:19,908 the magma chamber empties past 147 00:06:19,976 --> 00:06:21,877 a critical point, the entire 148 00:06:21,978 --> 00:06:23,879 mountain collapses in on itself 149 00:06:23,947 --> 00:06:27,416 to fill the void below. 150 00:06:32,889 --> 00:06:35,057 The 1780 B.C. eruption was so 151 00:06:35,158 --> 00:06:37,125 massive that it brought down a 152 00:06:37,160 --> 00:06:39,995 mountain and emptied 63 billion 153 00:06:40,063 --> 00:06:41,997 cubic feet of pulverized rock 154 00:06:42,065 --> 00:06:43,265 onto the surrounding 155 00:06:43,333 --> 00:06:44,900 countryside. That's enough to 156 00:06:44,968 --> 00:06:46,335 cover the whole of Manhattan 157 00:06:46,402 --> 00:06:48,971 Island to a depth of 100 feet, 158 00:06:49,038 --> 00:06:50,606 or bury the State of Florida in 159 00:06:50,707 --> 00:06:54,977 almost half an inch of ash. 160 00:06:55,078 --> 00:06:56,612 This mega eruption is now the 161 00:06:56,713 --> 00:06:58,514 blueprint for Naples' worst-case 162 00:06:58,615 --> 00:07:02,050 scenario. It's one of the 163 00:07:02,151 --> 00:07:04,253 factors making Vesuvius the most 164 00:07:04,320 --> 00:07:07,322 dangerous volcano in the world. 165 00:07:07,357 --> 00:07:09,124 And it's why scientists are 166 00:07:09,158 --> 00:07:11,059 racing to prepare for the next 167 00:07:11,160 --> 00:07:14,062 disaster. To investigate what 168 00:07:14,163 --> 00:07:16,031 deadly forces could be unleashed 169 00:07:16,065 --> 00:07:17,699 on the city of Naples, 170 00:07:17,800 --> 00:07:19,501 scientists must understand the 171 00:07:19,602 --> 00:07:22,437 eruptions of its past. And no 172 00:07:22,505 --> 00:07:24,573 explosion is better studied than 173 00:07:24,607 --> 00:07:27,142 the one that destroyed Pompeii, 174 00:07:27,243 --> 00:07:29,344 the Roman city that lay 7 miles 175 00:07:29,412 --> 00:07:34,149 southeast of Vesuvius. In the 176 00:07:34,250 --> 00:07:37,386 year 79 A.D., an eruption killed 177 00:07:37,420 --> 00:07:40,255 25,000 people, one quarter of 178 00:07:40,323 --> 00:07:42,257 the population, and left the 179 00:07:42,325 --> 00:07:44,026 area uninhabitable for 180 00:07:44,060 --> 00:07:48,931 300 years. 181 00:07:48,932 --> 00:07:50,299 >> Behind me here is the very 182 00:07:50,333 --> 00:07:53,502 material which buried Pompeii. 183 00:07:53,503 --> 00:07:55,037 >> The volcanic debris is made 184 00:07:55,071 --> 00:07:57,139 up of ash and an unusual white 185 00:07:57,206 --> 00:07:58,774 rock. 186 00:07:58,875 --> 00:08:00,409 >> Really, first impressions are 187 00:08:00,510 --> 00:08:03,979 that it's really rather light. 188 00:08:04,047 --> 00:08:06,415 And if I get in a nice close 189 00:08:06,516 --> 00:08:08,417 look there, the rock itself is 190 00:08:08,518 --> 00:08:12,154 absolutely riddled with holes. 191 00:08:12,221 --> 00:08:13,589 >> The holes were bubbles of 192 00:08:13,690 --> 00:08:16,959 trapped volcanic gas. 193 00:08:17,060 --> 00:08:18,694 >> This light white rock is 194 00:08:18,761 --> 00:08:21,229 called pumice. Now, pumice is 195 00:08:21,297 --> 00:08:22,598 magma that's filled with 196 00:08:22,699 --> 00:08:24,232 bubbles--filled with bubbles so 197 00:08:24,334 --> 00:08:26,068 much that it'll actually be able 198 00:08:26,135 --> 00:08:27,603 to float, and pumice is the only 199 00:08:27,670 --> 00:08:28,870 rock in the world that can 200 00:08:28,972 --> 00:08:30,606 float. 201 00:08:30,673 --> 00:08:31,940 >> The trapped bubbles show 202 00:08:31,975 --> 00:08:33,342 exactly how the pumice was 203 00:08:33,409 --> 00:08:35,143 formed. 204 00:08:35,211 --> 00:08:36,878 >> The magma beneath the volcano 205 00:08:36,946 --> 00:08:38,513 is a bit like the cola in a 206 00:08:38,581 --> 00:08:40,782 sealed bottle like I have here. 207 00:08:40,850 --> 00:08:42,384 We have liquid and dissolved 208 00:08:42,418 --> 00:08:43,852 gas. 209 00:08:43,886 --> 00:08:45,420 >> If the pressure is released 210 00:08:45,488 --> 00:08:46,955 suddenly, the dissolved gas 211 00:08:47,023 --> 00:08:48,557 explodes out in the form of 212 00:08:48,591 --> 00:08:51,760 bubbles. 213 00:08:51,861 --> 00:08:53,695 >> The bubbles in the cola have 214 00:08:53,763 --> 00:08:55,330 turned it into a froth, and this 215 00:08:55,398 --> 00:08:57,065 frothy mass that's coming out of 216 00:08:57,133 --> 00:08:59,101 the cola is just like in a magma 217 00:08:59,135 --> 00:09:00,969 chamber. When the gas escapes 218 00:09:01,037 --> 00:09:02,771 from the magma, it forms a magma 219 00:09:02,839 --> 00:09:04,506 froth, which violently comes out 220 00:09:04,607 --> 00:09:06,241 the volcanic vent. 221 00:09:06,309 --> 00:09:07,609 >> So the discovery of pumice 222 00:09:07,677 --> 00:09:09,378 proves that the volcano created 223 00:09:09,412 --> 00:09:11,647 magma foam, and that can only 224 00:09:11,681 --> 00:09:14,149 mean one thing: The eruption 225 00:09:14,217 --> 00:09:16,051 must've involved a major 226 00:09:16,119 --> 00:09:19,221 explosion. 227 00:09:28,131 --> 00:09:30,198 >> The explosion sent the 228 00:09:30,266 --> 00:09:32,934 magmatic foam and ash over 229 00:09:33,002 --> 00:09:34,836 17 miles into the atmosphere. 230 00:09:34,904 --> 00:09:36,538 This is twice the height of your 231 00:09:36,572 --> 00:09:39,641 average cruising aircraft. 232 00:09:39,709 --> 00:09:41,009 >> Amazingly, there is a 233 00:09:41,110 --> 00:09:42,611 surviving eyewitness account of 234 00:09:42,645 --> 00:09:44,446 the disaster written 2,000 years 235 00:09:44,480 --> 00:09:47,716 ago. Every detail of the 236 00:09:47,750 --> 00:09:49,084 eruption was noted by the 237 00:09:49,152 --> 00:09:52,187 17-year-old Pliny the Younger 238 00:09:52,288 --> 00:09:53,922 who was, in effect, one of the 239 00:09:53,990 --> 00:09:57,192 world's first volcanologists. 240 00:09:57,293 --> 00:09:59,261 >> Pliny, a naturalist, produced 241 00:09:59,362 --> 00:10:01,430 the first scientific recording 242 00:10:01,531 --> 00:10:04,266 of a complete volcanic sequence. 243 00:10:04,367 --> 00:10:07,436 He writes, "a cloud was forming. 244 00:10:07,470 --> 00:10:09,071 its appearance and shape would 245 00:10:09,105 --> 00:10:10,906 best be expressed as being that 246 00:10:10,973 --> 00:10:13,008 of an umbrella pine," similar to 247 00:10:13,109 --> 00:10:14,710 this large tree I have behind 248 00:10:14,744 --> 00:10:17,546 me. "cinched, stretched upward 249 00:10:17,647 --> 00:10:20,248 like an extremely tall trunk, it 250 00:10:20,283 --> 00:10:22,884 then spread out like branches." 251 00:10:22,919 --> 00:10:24,419 >> So the cloud spread out at 252 00:10:24,454 --> 00:10:25,921 the top, forming a mushroom 253 00:10:25,988 --> 00:10:28,190 shape which is still known as 254 00:10:28,257 --> 00:10:33,895 a Plinian Column. For Pompeii, 255 00:10:33,963 --> 00:10:36,098 this cloud was lethal. The 256 00:10:36,165 --> 00:10:37,799 pumice and ash was carried by 257 00:10:37,900 --> 00:10:39,701 the prevailing wind to fall like 258 00:10:39,736 --> 00:10:41,436 a deadly gray snow on the 259 00:10:41,537 --> 00:10:44,005 ancient city. 260 00:10:44,040 --> 00:10:45,373 >> And it was this volcanic 261 00:10:45,441 --> 00:10:46,975 fallout that started to thicken 262 00:10:47,009 --> 00:10:48,610 the air. The people who were 263 00:10:48,644 --> 00:10:50,278 initially amazed by the volcanic 264 00:10:50,346 --> 00:10:51,980 eruption now started to find it 265 00:10:52,081 --> 00:10:56,918 difficult to breathe. 266 00:10:56,986 --> 00:10:58,186 >> Many of the victims of 267 00:10:58,254 --> 00:10:59,554 Pompeii suffocated on the 268 00:10:59,622 --> 00:11:02,791 fine ash. 269 00:11:02,825 --> 00:11:04,326 >> We see a picture of people 270 00:11:04,427 --> 00:11:06,161 struggling to breathe. Like this 271 00:11:06,229 --> 00:11:07,596 body here, which is curled up 272 00:11:07,630 --> 00:11:09,531 with their hands close to their 273 00:11:09,599 --> 00:11:11,900 face, essentially recording the 274 00:11:12,001 --> 00:11:13,969 last final breaths of the people 275 00:11:14,003 --> 00:11:17,506 as they filled up with ash and 276 00:11:17,540 --> 00:11:19,141 hot, fiery dust from the 277 00:11:19,175 --> 00:11:20,642 volcano. 278 00:11:20,710 --> 00:11:21,910 >> Such a rain of ash falling 279 00:11:21,978 --> 00:11:23,278 onto the crowded streets of 280 00:11:23,346 --> 00:11:25,046 Naples today would cause 281 00:11:25,081 --> 00:11:29,084 millions of casualties. In 282 00:11:29,185 --> 00:11:30,719 trying to solve the mystery of 283 00:11:30,820 --> 00:11:32,154 what makes Vesuvius the most 284 00:11:32,188 --> 00:11:34,456 dangerous volcano in the world, 285 00:11:34,524 --> 00:11:35,991 scientists have uncovered 286 00:11:36,058 --> 00:11:40,629 2 crucial pieces of evidence. 287 00:11:40,730 --> 00:11:42,497 The pumice from Pompeii proves 288 00:11:42,532 --> 00:11:44,065 that Vesuvius can produce 289 00:11:44,133 --> 00:11:45,901 explosive eruptions, the most 290 00:11:45,968 --> 00:11:47,702 devastating type of volcanic 291 00:11:47,804 --> 00:11:51,339 blast. A thick layer of volcanic 292 00:11:51,440 --> 00:11:53,341 ash found underneath Naples 293 00:11:53,442 --> 00:11:54,810 shows that Vesuvius has the 294 00:11:54,911 --> 00:11:56,812 power to stretch out and destroy 295 00:11:56,879 --> 00:12:01,616 the city. A similar-sized blast 296 00:12:01,684 --> 00:12:03,351 today could kill 3 million 297 00:12:03,452 --> 00:12:04,786 people, which would be the 298 00:12:04,821 --> 00:12:06,621 world's highest volcanic death 299 00:12:06,722 --> 00:12:09,724 toll. Geologists know that some 300 00:12:09,792 --> 00:12:11,226 victims would die of 301 00:12:11,294 --> 00:12:13,361 suffocation. But the discovery 302 00:12:13,429 --> 00:12:15,630 of charred human bones are clues 303 00:12:15,698 --> 00:12:17,966 to another, more terrifying 304 00:12:18,067 --> 00:12:20,635 death wrought by Vesuvius. 305 00:12:29,536 --> 00:12:31,070 >> Geologists are investigating 306 00:12:31,138 --> 00:12:32,572 the deadly threat of Mount 307 00:12:32,606 --> 00:12:36,976 Vesuvius. Remains at the Roman 308 00:12:37,011 --> 00:12:38,811 settlement of Pompeii show how 309 00:12:38,846 --> 00:12:42,382 thousands died: Buried by a 310 00:12:42,483 --> 00:12:46,552 choking rain of ash and rock. 311 00:12:52,293 --> 00:12:55,228 But in 1981, excavations 4 miles 312 00:12:55,296 --> 00:12:57,397 to the west of Vesuvius show 313 00:12:57,498 --> 00:12:59,198 that an even more horrific fate 314 00:12:59,300 --> 00:13:00,933 awaited the people of this Roman 315 00:13:01,035 --> 00:13:05,305 Town: Herculaneum. When the 316 00:13:05,406 --> 00:13:06,939 volcano erupted in the year 317 00:13:07,007 --> 00:13:09,842 79 A.D., Herculaneum was a busy 318 00:13:09,943 --> 00:13:13,313 resort town of 10,000 people. 319 00:13:13,380 --> 00:13:15,315 But surprisingly when the ruins 320 00:13:15,382 --> 00:13:17,216 were first excavated, a mere 321 00:13:17,284 --> 00:13:21,487 15 bodies were found. 322 00:13:21,488 --> 00:13:23,022 >> Many people thought that was 323 00:13:23,090 --> 00:13:24,357 because they could see the 324 00:13:24,391 --> 00:13:25,658 eruption early on and were able 325 00:13:25,759 --> 00:13:27,760 to escape. But when they dug 326 00:13:27,761 --> 00:13:29,562 down further, here to the 327 00:13:29,663 --> 00:13:31,197 shoreline and to these 328 00:13:31,298 --> 00:13:32,832 boathouses, this is where they 329 00:13:32,933 --> 00:13:35,468 found the truth. 330 00:13:39,173 --> 00:13:40,807 >> The boathouses hid a grisly 331 00:13:40,841 --> 00:13:44,377 secret. These are the remains of 332 00:13:44,478 --> 00:13:46,379 the romans caught trying to flee 333 00:13:46,447 --> 00:13:48,815 the volcano. The skeletons still 334 00:13:48,849 --> 00:13:50,550 lie exactly where they fell 335 00:13:50,584 --> 00:13:55,288 2,000 years ago. 336 00:13:55,356 --> 00:13:56,656 >> It's hard to imagine what it 337 00:13:56,757 --> 00:13:58,291 must've been like: Over 300 men, 338 00:13:58,392 --> 00:13:59,559 women, and children here at the 339 00:13:59,660 --> 00:14:01,461 water's edge in Herculaneum. 340 00:14:01,528 --> 00:14:02,929 Here the boathouses providing 341 00:14:03,030 --> 00:14:04,297 shelter from the falling 342 00:14:04,365 --> 00:14:05,798 volcanic debris. And it was 343 00:14:05,833 --> 00:14:06,899 these boathouses that were gonna 344 00:14:06,934 --> 00:14:08,735 become the final resting place 345 00:14:08,836 --> 00:14:13,740 of their tomb in Herculaneum. 346 00:14:13,841 --> 00:14:15,742 >> For geologist Dr. Jerram, 347 00:14:15,843 --> 00:14:17,110 these remains hold the primary 348 00:14:17,211 --> 00:14:19,212 clue to exactly what happened 349 00:14:19,279 --> 00:14:21,114 during the eruption 2,000 years 350 00:14:21,181 --> 00:14:25,017 ago. The mass grave is treated 351 00:14:25,085 --> 00:14:28,755 like a crime scene. Photographic 352 00:14:28,822 --> 00:14:30,390 evidence is taken back to the 353 00:14:30,457 --> 00:14:31,657 laboratory for further 354 00:14:31,725 --> 00:14:36,729 investigation. The positions of 355 00:14:36,764 --> 00:14:38,398 the bodies themselves are the 356 00:14:38,432 --> 00:14:40,333 first clue to how quickly a 357 00:14:40,401 --> 00:14:42,769 volcano can kill. 358 00:14:42,803 --> 00:14:45,171 >> Here we have a body that sat 359 00:14:45,239 --> 00:14:47,607 up against the boathouse wall in 360 00:14:47,674 --> 00:14:50,143 Herculaneum, and in the arms of 361 00:14:50,177 --> 00:14:53,613 this adult is a child. And they 362 00:14:53,680 --> 00:14:55,148 sat there almost as though they 363 00:14:55,215 --> 00:14:56,783 were relaxing or resting against 364 00:14:56,850 --> 00:14:58,251 the wall. It's almost as though 365 00:14:58,318 --> 00:14:59,419 you could be sat there chatting 366 00:14:59,486 --> 00:15:01,154 with this person, and then 367 00:15:01,221 --> 00:15:03,890 they've been killed. 368 00:15:03,957 --> 00:15:05,391 >> There are further clues to be 369 00:15:05,426 --> 00:15:07,059 found in the fine detail of the 370 00:15:07,161 --> 00:15:09,896 victims' bones. 371 00:15:09,963 --> 00:15:11,431 >> At the end of many of the 372 00:15:11,498 --> 00:15:14,700 bones you see this blackened 373 00:15:14,768 --> 00:15:16,936 coloration, and this can be seen 374 00:15:16,970 --> 00:15:18,871 on many of the examples in 375 00:15:18,972 --> 00:15:20,706 Herculaneum. And it really seems 376 00:15:20,774 --> 00:15:22,875 to occur at the points--like 377 00:15:22,976 --> 00:15:25,211 here at a sort of elbow joint: 378 00:15:25,245 --> 00:15:26,712 The points on the body where 379 00:15:26,780 --> 00:15:28,347 there's very little flesh and 380 00:15:28,415 --> 00:15:29,682 the bone is very, very close to 381 00:15:29,783 --> 00:15:31,317 the surface. 382 00:15:31,418 --> 00:15:32,952 >> For years scientists debated 383 00:15:33,053 --> 00:15:34,487 what the discoloration could 384 00:15:34,521 --> 00:15:38,424 mean. Until in 1991, researchers 385 00:15:38,492 --> 00:15:40,059 from the University of Naples 386 00:15:40,160 --> 00:15:43,129 came up with a simple solution. 387 00:15:43,163 --> 00:15:44,664 >> I'm gonna re-create the one 388 00:15:44,698 --> 00:15:46,232 experiment that unlocked what 389 00:15:46,333 --> 00:15:48,868 happened at Herculaneum. 390 00:15:48,936 --> 00:15:50,336 >> Dr. Jerram is burning several 391 00:15:50,404 --> 00:15:52,038 pig bones at increasingly 392 00:15:52,072 --> 00:15:54,507 superheated temperatures. 393 00:15:54,575 --> 00:15:55,408 >> I'm going to rack up the 394 00:15:55,476 --> 00:15:57,243 temperatures, start to try and 395 00:15:57,311 --> 00:15:59,512 burn the flesh on the bones, and 396 00:15:59,613 --> 00:16:00,980 then hopefully get to the point 397 00:16:01,048 --> 00:16:02,381 where I can start to produce 398 00:16:02,416 --> 00:16:03,683 blackening of the bones and 399 00:16:03,784 --> 00:16:05,318 reproduce the colors that we see 400 00:16:05,385 --> 00:16:06,953 in the Herculaneum bone 401 00:16:07,020 --> 00:16:09,055 deposits. 402 00:16:09,122 --> 00:16:10,523 >> dr. Jerram burns one bone 403 00:16:10,591 --> 00:16:12,792 At 500 degrees and another at 404 00:16:12,860 --> 00:16:19,131 700 degrees fahrenheit. 405 00:16:19,233 --> 00:16:20,566 >> The flesh is all starting to 406 00:16:20,601 --> 00:16:22,969 burn now, but clearly we're not 407 00:16:23,036 --> 00:16:25,037 really burning the bone yet. 408 00:16:25,105 --> 00:16:26,606 >> It is not until Dr. Jerram 409 00:16:26,673 --> 00:16:27,874 raises the temperature to 410 00:16:27,975 --> 00:16:30,409 900 degrees that the bone itself 411 00:16:30,511 --> 00:16:32,512 is burned. 412 00:16:32,579 --> 00:16:34,213 >> Well, it finally looks like 413 00:16:34,248 --> 00:16:35,481 we've got somewhere where we're 414 00:16:35,516 --> 00:16:38,184 starting to burn the bone. 415 00:16:38,252 --> 00:16:39,585 >> Scraping away the charred 416 00:16:39,620 --> 00:16:41,254 meat and skin reveals the bone 417 00:16:41,321 --> 00:16:46,325 underneath. 418 00:16:46,360 --> 00:16:47,760 >> Here on this picture from 419 00:16:47,794 --> 00:16:49,262 Herculaneum, you can see on the 420 00:16:49,329 --> 00:16:50,696 end of this bone these brown 421 00:16:50,797 --> 00:16:52,164 into black transitions with some 422 00:16:52,266 --> 00:16:54,066 nice white bone behind. You 423 00:16:54,167 --> 00:16:55,801 know, this is exactly what we're 424 00:16:55,903 --> 00:16:57,436 seeing in the 900-degree 425 00:16:57,538 --> 00:17:00,339 experiment. So we can produce 426 00:17:00,440 --> 00:17:01,774 the blackened bone features that 427 00:17:01,808 --> 00:17:03,743 we see at Herculaneum with high 428 00:17:03,810 --> 00:17:05,778 temperatures burning the bone 429 00:17:05,812 --> 00:17:07,580 that's exposed. But the bone 430 00:17:07,614 --> 00:17:08,981 that's covered by a bit of flesh 431 00:17:09,082 --> 00:17:11,150 gets protected and stays white. 432 00:17:11,251 --> 00:17:12,852 And this could be the only way 433 00:17:12,920 --> 00:17:14,387 in which we get these blackened 434 00:17:14,454 --> 00:17:17,089 none features at Herculaneum. 435 00:17:19,893 --> 00:17:21,260 >> The blackened bones show that 436 00:17:21,361 --> 00:17:22,795 on the day of the eruption, the 437 00:17:22,829 --> 00:17:24,530 air temperature 4 miles from the 438 00:17:24,598 --> 00:17:28,200 volcano reached 900 degrees 439 00:17:28,235 --> 00:17:30,503 Fahrenheit. That's hotter than 440 00:17:30,571 --> 00:17:32,204 the blast from an aircraft's 441 00:17:32,239 --> 00:17:38,945 jet engine. For years scientists 442 00:17:39,046 --> 00:17:40,780 puzzled over how Vesuvius 443 00:17:40,847 --> 00:17:42,315 could've raised temperatures so 444 00:17:42,382 --> 00:17:45,785 high miles from the volcano. But 445 00:17:45,852 --> 00:17:47,587 then a totally different type of 446 00:17:47,654 --> 00:17:50,022 clue suggested the answer at the 447 00:17:50,057 --> 00:17:52,291 small town of Boscoreale, just 448 00:17:52,326 --> 00:17:56,829 one mile southeast of Vesuvius. 449 00:18:00,634 --> 00:18:02,001 >> This strange pillar-like 450 00:18:02,102 --> 00:18:03,436 structure--I mean, at first 451 00:18:03,470 --> 00:18:04,470 impression it looks like some 452 00:18:04,538 --> 00:18:06,072 very strange, weird concrete 453 00:18:06,106 --> 00:18:07,907 post. But it's far more 454 00:18:08,008 --> 00:18:09,542 fascinating than that, and the 455 00:18:09,610 --> 00:18:11,510 clues are really in the base. 456 00:18:11,545 --> 00:18:14,013 We see a number of smaller 457 00:18:14,081 --> 00:18:15,615 structures radiating from the 458 00:18:15,649 --> 00:18:17,383 base. These are actually roots. 459 00:18:17,451 --> 00:18:18,818 You see them feeding back into 460 00:18:18,885 --> 00:18:20,653 this big stump-like feature. 461 00:18:20,721 --> 00:18:23,889 This is a fossilized tree. 462 00:18:23,924 --> 00:18:25,358 >> The tree was buried in 463 00:18:25,425 --> 00:18:27,193 volcanic material. As the 464 00:18:27,260 --> 00:18:28,995 original wood rotted away, it 465 00:18:29,096 --> 00:18:31,263 was replaced by rock and ash, 466 00:18:31,365 --> 00:18:32,832 which mixed with water and set 467 00:18:32,899 --> 00:18:35,201 like concrete. 468 00:18:35,268 --> 00:18:36,836 >> Almost like a jell-o mold 469 00:18:36,903 --> 00:18:38,471 of a tree upstanding. It was 470 00:18:38,538 --> 00:18:41,540 upstanding over 2,000 years ago. 471 00:18:41,642 --> 00:18:43,075 >> The shape of the tree is 472 00:18:43,143 --> 00:18:45,778 deeply significant. 473 00:18:45,879 --> 00:18:46,779 >> And as we work up this 474 00:18:46,880 --> 00:18:49,515 fossilized tree, it suddenly 475 00:18:49,583 --> 00:18:50,983 veers and bends at this point 476 00:18:51,051 --> 00:18:52,785 here. Now, if we can imagine 477 00:18:52,853 --> 00:18:54,587 about 2,000 years ago, this tree 478 00:18:54,688 --> 00:18:56,589 was alive. And suddenly it's 479 00:18:56,657 --> 00:18:59,659 been wrenched over and bent 480 00:18:59,693 --> 00:19:01,227 towards that way, and it's also 481 00:19:01,328 --> 00:19:02,695 been fossilized in that 482 00:19:02,796 --> 00:19:04,563 position. Now, when we look at 483 00:19:04,598 --> 00:19:05,765 the local geography, we know 484 00:19:05,799 --> 00:19:07,500 that Vesuvius is over that way. 485 00:19:07,567 --> 00:19:09,235 So some force which is bending 486 00:19:09,302 --> 00:19:11,871 this tree and fossilizing it 487 00:19:11,972 --> 00:19:13,339 must've been coming from that 488 00:19:13,407 --> 00:19:15,474 region. 489 00:19:15,509 --> 00:19:16,976 >> The clues of superheated 490 00:19:17,044 --> 00:19:18,377 temperatures miles from the 491 00:19:18,478 --> 00:19:20,579 volcano and a force that bent 492 00:19:20,614 --> 00:19:22,748 a tree almost double suggest 493 00:19:22,783 --> 00:19:27,887 only one thing. They're evidence 494 00:19:27,954 --> 00:19:29,689 that Vesuvius produced another 495 00:19:29,756 --> 00:19:35,695 deadly weapon: 496 00:19:35,762 --> 00:19:41,133 A pyroclastic flow. 497 00:19:41,201 --> 00:19:42,768 >> Pyroclastic flows are a 498 00:19:42,836 --> 00:19:44,770 dynamic mixture of hot rock, 499 00:19:44,871 --> 00:19:47,106 ash, and gases that move fast 500 00:19:47,140 --> 00:19:48,874 and violently down the side of 501 00:19:48,942 --> 00:19:51,677 a volcanic Mountain. 502 00:19:51,778 --> 00:19:53,512 >> These deadly boiling clouds 503 00:19:53,580 --> 00:19:55,948 reach speeds of up to 450 miles 504 00:19:56,016 --> 00:19:58,050 per hour, faster than a bullet 505 00:19:58,151 --> 00:20:00,453 train, and temperatures of up to 506 00:20:00,487 --> 00:20:03,089 2,000 degrees fahrenheit, hot 507 00:20:03,123 --> 00:20:07,359 enough to melt gold. 508 00:20:07,394 --> 00:20:08,828 >> At the early stages of the 509 00:20:08,929 --> 00:20:10,529 eruption here at Herculaneum, 510 00:20:10,564 --> 00:20:11,664 you'd have seen a big, erupted 511 00:20:11,732 --> 00:20:13,432 cloud coming out of Vesuvius 512 00:20:13,467 --> 00:20:14,433 and heading off up into the 513 00:20:14,468 --> 00:20:17,369 atmosphere. But just imagine 514 00:20:17,471 --> 00:20:19,071 how scared you would've been 515 00:20:19,106 --> 00:20:20,206 watching this cloud suddenly 516 00:20:20,273 --> 00:20:21,907 turn around, and the black cloud 517 00:20:21,975 --> 00:20:23,476 starts heading towards 518 00:20:23,543 --> 00:20:24,910 Herculaneum. This cloud of hot 519 00:20:24,978 --> 00:20:26,912 material--hot, boiling, bubbling 520 00:20:26,980 --> 00:20:28,714 pyroclastic material--starts to 521 00:20:28,749 --> 00:20:30,449 enter the city streets, starts 522 00:20:30,517 --> 00:20:32,184 enveloping you and heading off 523 00:20:32,285 --> 00:20:33,886 down towards the port. And that 524 00:20:33,920 --> 00:20:35,554 was it: The pyroclastic flows 525 00:20:35,622 --> 00:20:38,724 that hit Herculaneum. 526 00:20:48,101 --> 00:20:49,802 >> Just hours later, the town 527 00:20:49,836 --> 00:20:53,005 was buried completely. 528 00:20:56,610 --> 00:20:58,077 Striving to understand how 529 00:20:58,111 --> 00:21:00,012 deadly Vesuvius can be, 530 00:21:00,080 --> 00:21:01,647 investigators have found vital 531 00:21:01,715 --> 00:21:03,549 clues to the devastation from 532 00:21:03,650 --> 00:21:05,651 the searing heat of pyroclastic 533 00:21:05,719 --> 00:21:09,088 flows of the past. Horrific 534 00:21:09,156 --> 00:21:11,190 burns on human bones prove 535 00:21:11,258 --> 00:21:13,058 temperatures got to a blazing 536 00:21:13,093 --> 00:21:16,462 900 degrees Fahrenheit 4 miles 537 00:21:16,563 --> 00:21:20,900 from the volcano. And a 538 00:21:20,967 --> 00:21:23,636 2,000-year-old fossilized tree 539 00:21:23,703 --> 00:21:25,171 reveals the power of the 540 00:21:25,238 --> 00:21:27,273 speeding flow of hot rock, gas, 541 00:21:27,340 --> 00:21:32,912 and ash down the Mountainside. 542 00:21:33,013 --> 00:21:34,713 But pyroclastic flows are not 543 00:21:34,781 --> 00:21:36,081 the only deadly force in 544 00:21:36,149 --> 00:21:39,785 Vesuvius' arsenal. It has an 545 00:21:39,820 --> 00:21:43,189 ultimate weapon: Rivers of 546 00:21:43,256 --> 00:21:45,191 molten rock that pour down the 547 00:21:45,258 --> 00:21:47,193 mountainside to burn and bury 548 00:21:47,260 --> 00:21:50,729 all in its path. 549 00:21:54,751 --> 00:21:56,118 >> Vesuvius has yet another 550 00:21:56,220 --> 00:21:58,688 deadly weapon in its arsenal. 551 00:21:58,755 --> 00:22:00,556 One that was captured on film 552 00:22:00,591 --> 00:22:02,592 during its most recent eruption 553 00:22:02,659 --> 00:22:07,697 on March 18, 1944. 554 00:22:07,764 --> 00:22:09,131 >> Cameras record the spectacle 555 00:22:09,199 --> 00:22:11,300 of Mount Vesuvius. 556 00:22:11,401 --> 00:22:13,736 >> A 5-mile-high cloud of ash 557 00:22:13,770 --> 00:22:15,304 climbed into the sky over 558 00:22:15,405 --> 00:22:21,410 Vesuvius. Pyroclastic flows 559 00:22:21,478 --> 00:22:24,914 rushed down its slopes. 560 00:22:28,752 --> 00:22:31,587 But worse was to come. Floods of 561 00:22:31,655 --> 00:22:33,389 molten rock overflowed from the 562 00:22:33,490 --> 00:22:34,957 lip of the crater to swallow up 563 00:22:35,025 --> 00:22:41,030 entire Italian villages. 564 00:22:41,098 --> 00:22:43,466 34 died, and thousands were 565 00:22:43,500 --> 00:22:46,569 left homeless. 566 00:22:50,173 --> 00:22:51,674 These rivers of magma on the 567 00:22:51,742 --> 00:22:53,543 surface of the Earth are called 568 00:22:53,577 --> 00:22:56,579 lava flows. 569 00:22:56,580 --> 00:22:57,847 >> One of the most prominent 570 00:22:57,948 --> 00:22:59,215 features in Vesuvius' landscape 571 00:22:59,283 --> 00:23:01,384 today is this river of molten 572 00:23:01,451 --> 00:23:04,120 lava, solidified lava, on the 573 00:23:04,187 --> 00:23:07,223 sides of Vesuvius. 574 00:23:07,224 --> 00:23:08,457 >> There are significant 575 00:23:08,492 --> 00:23:10,826 deposits of the 1944 lava flow 576 00:23:10,928 --> 00:23:13,095 extending 12 miles down the 577 00:23:13,130 --> 00:23:16,465 side of the cone. 578 00:23:21,572 --> 00:23:24,941 >> And looking at it closely, 579 00:23:25,008 --> 00:23:26,909 I can see that there are no 580 00:23:26,944 --> 00:23:28,444 bubbles. 581 00:23:28,478 --> 00:23:29,812 >> Unlike the lightweight pumice 582 00:23:29,846 --> 00:23:31,347 that rained on Pompeii, this 583 00:23:31,381 --> 00:23:33,649 solidified lava is dense and 584 00:23:33,750 --> 00:23:36,652 hard. 585 00:23:36,753 --> 00:23:37,920 >> And actually, that is the 586 00:23:38,021 --> 00:23:39,088 clue that is telling me that 587 00:23:39,122 --> 00:23:40,656 this was not an explosive 588 00:23:40,724 --> 00:23:42,258 eruption. This wasn't hurled 589 00:23:42,292 --> 00:23:44,560 into the air. Instead, the gases 590 00:23:44,661 --> 00:23:46,529 seeped through the lava before 591 00:23:46,563 --> 00:23:50,399 they came to the surface. 592 00:23:50,467 --> 00:23:52,001 >> Only a very free-flowing and 593 00:23:52,102 --> 00:23:53,669 liquid lava could've let the 594 00:23:53,737 --> 00:23:55,638 gases escape underground in 595 00:23:55,672 --> 00:23:58,207 this way. And with very little 596 00:23:58,275 --> 00:24:00,209 explosive gas left inside the 597 00:24:00,277 --> 00:24:02,578 lava, it flowed out rather than 598 00:24:02,646 --> 00:24:05,815 burst out of the volcano. 599 00:24:05,849 --> 00:24:07,717 >> Lavas will flow down the 600 00:24:07,751 --> 00:24:09,819 slope using the easiest way, and 601 00:24:09,886 --> 00:24:11,253 this is going to be very much 602 00:24:11,288 --> 00:24:12,722 the same path as water will 603 00:24:12,756 --> 00:24:13,923 take. 604 00:24:14,024 --> 00:24:15,257 >> Floods of lava at more than 605 00:24:15,292 --> 00:24:17,360 2,000 degrees fahrenheit poured 606 00:24:17,394 --> 00:24:20,563 down the slopes. Lava flows are 607 00:24:20,664 --> 00:24:22,298 the hottest natural material on 608 00:24:22,366 --> 00:24:24,467 the face of the Earth: Vesuvius's 609 00:24:24,568 --> 00:24:27,103 ultimate weapon, an unstoppable 610 00:24:27,204 --> 00:24:29,472 force destroying all in their 611 00:24:29,573 --> 00:24:33,342 path. 612 00:24:33,377 --> 00:24:34,710 >> And the word "lava"--it 613 00:24:34,745 --> 00:24:36,545 actually comes from the Italian, 614 00:24:36,647 --> 00:24:38,614 and it was coined in here. It 615 00:24:38,649 --> 00:24:39,915 comes from lavare, which is 616 00:24:39,983 --> 00:24:42,518 "to wash." and it is basically 617 00:24:42,552 --> 00:24:44,286 explaining how lava flows: Once 618 00:24:44,388 --> 00:24:45,721 they move over a city, they wash 619 00:24:45,756 --> 00:24:49,992 out everything. Nothing is left. 620 00:24:55,098 --> 00:24:57,166 >> Since 1944, Vesuvius has been 621 00:24:57,200 --> 00:25:00,569 quiet. A calm has settled on the 622 00:25:00,637 --> 00:25:02,705 people living in its shadow, and 623 00:25:02,739 --> 00:25:05,007 today Vesuvius is even a popular 624 00:25:05,075 --> 00:25:09,378 tourist attraction. But teams of 625 00:25:09,446 --> 00:25:11,180 scientists still go into the 626 00:25:11,248 --> 00:25:13,382 crater searching for any signs 627 00:25:13,450 --> 00:25:15,017 that the volcano may be 628 00:25:15,085 --> 00:25:16,552 awakening. 629 00:25:16,653 --> 00:25:20,790 >> Ok. Let's go. 630 00:25:20,824 --> 00:25:22,525 >> It's a 1,000-foot drop to 631 00:25:22,559 --> 00:25:24,927 the crater floor. 632 00:25:24,995 --> 00:25:28,464 >> Let's go down slowly. 633 00:25:28,532 --> 00:25:31,534 Got a lot of rock falling today. 634 00:25:31,635 --> 00:25:33,235 >> The volcano is crumbling in 635 00:25:33,270 --> 00:25:35,805 on itself. The walls made up of 636 00:25:35,906 --> 00:25:37,540 loose rock thrown out in the 637 00:25:37,607 --> 00:25:39,909 1944 eruption are slowly 638 00:25:39,976 --> 00:25:43,913 collapsing back into the crater. 639 00:25:48,552 --> 00:25:49,985 Even before he reaches the 640 00:25:50,087 --> 00:25:52,521 bottom, Orsi can see and smell 641 00:25:52,556 --> 00:25:55,191 gas and feel the heat of 642 00:25:55,258 --> 00:25:59,462 volcanic activity. 643 00:25:59,463 --> 00:26:01,063 >> Yeah, the smoke you see 644 00:26:01,098 --> 00:26:03,799 around here--it's gas coming 645 00:26:03,900 --> 00:26:06,001 through fumaroles. 646 00:26:06,002 --> 00:26:07,369 >> A fumarole is a crack in the 647 00:26:07,437 --> 00:26:08,904 Earth's crust which emits steam 648 00:26:08,972 --> 00:26:12,341 and gas from deep underground. 649 00:26:12,375 --> 00:26:14,009 >> And it's an indication, one 650 00:26:14,077 --> 00:26:15,177 of the indication, that the 651 00:26:15,212 --> 00:26:17,546 volcano's still active. 652 00:26:17,614 --> 00:26:19,348 >> A live volcano positioned 653 00:26:19,416 --> 00:26:21,350 next to a city of 3 million 654 00:26:21,451 --> 00:26:23,085 needs to be under constant 655 00:26:23,153 --> 00:26:25,521 surveillance, so much so that 656 00:26:25,555 --> 00:26:27,356 it is now the most closely 657 00:26:27,390 --> 00:26:32,094 monitored volcano on Earth. 658 00:26:32,162 --> 00:26:33,729 >> Composition of the gas and 659 00:26:33,797 --> 00:26:35,798 temperature--it's related to 660 00:26:35,866 --> 00:26:38,334 the state of the volcano. 661 00:26:38,368 --> 00:26:40,069 >> These gases are the volcano's 662 00:26:40,137 --> 00:26:42,338 early warning system. Any 663 00:26:42,439 --> 00:26:43,906 significant change in their 664 00:26:43,974 --> 00:26:45,641 temperature or composition would 665 00:26:45,709 --> 00:26:47,409 set the scientists' alarm bells 666 00:26:47,444 --> 00:26:52,782 ringing. Today's examination 667 00:26:52,816 --> 00:26:55,351 shows no change. So for the 668 00:26:55,418 --> 00:26:58,587 moment, Naples is safe. But 669 00:26:58,622 --> 00:27:00,456 this lack of activity is not 670 00:27:00,524 --> 00:27:06,896 necessarily a reassuring sign. 671 00:27:06,963 --> 00:27:08,063 >> Because I think there is a 672 00:27:08,165 --> 00:27:10,499 pattern on how Vesuvius behaves 673 00:27:10,534 --> 00:27:12,134 in terms of you seem to have a 674 00:27:12,169 --> 00:27:15,037 period of quietness, and then 675 00:27:15,071 --> 00:27:17,273 you have a very large eruption. 676 00:27:17,340 --> 00:27:18,707 And then you tend to have a 677 00:27:18,809 --> 00:27:20,342 period of quietness, and then 678 00:27:20,443 --> 00:27:25,447 another large eruption. 679 00:27:25,515 --> 00:27:27,316 >> So the danger is the longer 680 00:27:27,350 --> 00:27:29,718 the volcano stays quiet, the 681 00:27:29,786 --> 00:27:31,153 more magma is allowed to 682 00:27:31,221 --> 00:27:33,155 accumulate, so when it does 683 00:27:33,223 --> 00:27:35,057 finally erupt, the bigger the 684 00:27:35,091 --> 00:27:39,328 blast will be. New clues at 685 00:27:39,362 --> 00:27:40,896 Vesuvius have concerned the 686 00:27:40,997 --> 00:27:41,997 volcanologists who are 687 00:27:42,065 --> 00:27:46,869 investigating its deadly power. 688 00:27:46,903 --> 00:27:48,604 Dense, solidified rock is 689 00:27:48,672 --> 00:27:50,673 evidence that Vesuvius possesses 690 00:27:50,707 --> 00:27:52,441 the ultimate weapon: 691 00:27:52,509 --> 00:27:54,143 High-temperature lava flows 692 00:27:54,177 --> 00:27:55,778 capable of destroying all in 693 00:27:55,812 --> 00:27:59,248 their path. Hot fumaroles in 694 00:27:59,316 --> 00:28:00,983 the crater prove the volcano 695 00:28:01,084 --> 00:28:04,320 is still active. 696 00:28:07,624 --> 00:28:09,325 But new scientific techniques 697 00:28:09,392 --> 00:28:11,594 reveal a vast magma bomb hidden 698 00:28:11,628 --> 00:28:14,396 miles underneath the volcano. 699 00:28:14,431 --> 00:28:17,166 A bomb that is primed and could 700 00:28:17,234 --> 00:28:21,237 blow at any time. 701 00:28:26,949 --> 00:28:28,216 >> Scientists have uncovered 702 00:28:28,283 --> 00:28:29,584 clues suggesting that the 703 00:28:29,651 --> 00:28:31,819 awesome power of Mount Vesuvius 704 00:28:31,887 --> 00:28:33,621 could soon be unleashed in a 705 00:28:33,722 --> 00:28:35,456 massive and devastating 706 00:28:35,524 --> 00:28:38,593 explosion. 707 00:28:46,268 --> 00:28:47,635 >> For an eruption to happen, 708 00:28:47,703 --> 00:28:49,137 volcanoes need 2 things. They 709 00:28:49,171 --> 00:28:50,671 need a source of magma, which is 710 00:28:50,772 --> 00:28:52,039 a magma chamber close to the 711 00:28:52,074 --> 00:28:53,608 surface, and they also need a 712 00:28:53,609 --> 00:28:55,176 trigger. It's a bit like a bomb 713 00:28:55,244 --> 00:28:58,146 and a fuse. So once you have 714 00:28:58,180 --> 00:28:59,547 these 2 things in place, it 715 00:28:59,615 --> 00:29:03,084 could blow at any time. 716 00:29:03,152 --> 00:29:04,619 >> The key evidence is bubbling 717 00:29:04,720 --> 00:29:06,087 up through the ground just 718 00:29:06,155 --> 00:29:11,058 10 miles west of the volcano. 719 00:29:11,160 --> 00:29:12,693 >> Some overriding sense that 720 00:29:12,728 --> 00:29:14,162 this area is one of intense 721 00:29:14,263 --> 00:29:15,429 heat, when all around me it's 722 00:29:15,497 --> 00:29:16,898 not just the sun that's hot and 723 00:29:16,965 --> 00:29:18,533 baking down. When there's 724 00:29:18,600 --> 00:29:20,334 steaming gas coming out of the 725 00:29:20,402 --> 00:29:23,037 ground in cracks and fissures, 726 00:29:23,071 --> 00:29:24,338 it's that the whole ground is 727 00:29:24,439 --> 00:29:25,606 kind of alive with thermal 728 00:29:25,707 --> 00:29:27,141 activity. And it just tells me, 729 00:29:27,176 --> 00:29:28,676 screaming out loud, that there's 730 00:29:28,710 --> 00:29:30,311 heat just percolating up from 731 00:29:30,345 --> 00:29:34,081 the ground towards me. 732 00:29:34,149 --> 00:29:35,383 >> The steam gets to 733 00:29:35,450 --> 00:29:36,651 temperatures as high as 734 00:29:36,718 --> 00:29:42,290 300 degrees fahrenheit. 735 00:29:42,391 --> 00:29:43,624 >> And the steam is also coming 736 00:29:43,659 --> 00:29:45,293 up with a gas called sulfur 737 00:29:45,360 --> 00:29:47,261 dioxide, and I can smell it 738 00:29:47,296 --> 00:29:48,629 really strong. In fact, it's 739 00:29:48,664 --> 00:29:50,097 almost choking when you get the 740 00:29:50,199 --> 00:29:53,568 wind blowing it into your face. 741 00:29:53,635 --> 00:29:55,102 So the telltale sign of this 742 00:29:55,170 --> 00:29:57,471 activity, the sulfur dioxide 743 00:29:57,539 --> 00:29:59,106 activity, is the coating of 744 00:29:59,174 --> 00:30:00,841 yellow material, yellow sulfur 745 00:30:00,909 --> 00:30:02,109 crystals, on all the rocks 746 00:30:02,177 --> 00:30:04,111 around me. There's only one 747 00:30:04,179 --> 00:30:05,546 thing on Earth that can drive 748 00:30:05,647 --> 00:30:07,381 this kind of activity--the 749 00:30:07,449 --> 00:30:09,083 sulfur, the hot geothermal 750 00:30:09,184 --> 00:30:11,419 springs, and the hot gas--and 751 00:30:11,453 --> 00:30:13,454 that's magma at quite shallow 752 00:30:13,522 --> 00:30:15,790 levels. 753 00:30:15,824 --> 00:30:17,191 >> For years scientists have 754 00:30:17,292 --> 00:30:18,993 known that a chamber of molten 755 00:30:19,094 --> 00:30:21,696 rock lies under Vesuvius, but 756 00:30:21,730 --> 00:30:25,066 nobody could see it. Then in 757 00:30:25,100 --> 00:30:27,468 2001, geologists used a 758 00:30:27,536 --> 00:30:29,370 pioneering new technology to 759 00:30:29,438 --> 00:30:31,172 investigate the ground under 760 00:30:31,240 --> 00:30:34,008 and around the Mountain. It's 761 00:30:34,109 --> 00:30:35,643 similar to the way a doctor uses 762 00:30:35,744 --> 00:30:37,345 ultrasound equipment to reveal 763 00:30:37,379 --> 00:30:39,080 the shape and size of a human 764 00:30:39,147 --> 00:30:44,252 baby in the womb. At Vesuvius, 765 00:30:44,286 --> 00:30:46,354 volcanologists used sound waves 766 00:30:46,455 --> 00:30:49,056 billions of times more powerful 767 00:30:49,091 --> 00:30:50,524 to take a picture under the 768 00:30:50,559 --> 00:30:54,829 Earth. They detonated small 769 00:30:54,896 --> 00:30:56,264 explosions at different 770 00:30:56,365 --> 00:31:00,001 locations around the volcano, 771 00:31:00,068 --> 00:31:01,736 radiating waves out under the 772 00:31:01,803 --> 00:31:05,373 ground. Measuring the speed of 773 00:31:05,440 --> 00:31:07,074 the waves reveals whether the 774 00:31:07,142 --> 00:31:08,276 rock through which they're 775 00:31:08,377 --> 00:31:10,278 traveling is solid or more 776 00:31:10,345 --> 00:31:12,546 liquid, hotter or colder than 777 00:31:12,648 --> 00:31:17,785 the surrounding ground. 778 00:31:17,819 --> 00:31:19,353 Computers mapping the wave 779 00:31:19,454 --> 00:31:20,988 movements from the surface print 780 00:31:21,089 --> 00:31:23,457 out a ghostly but terrifying 781 00:31:23,525 --> 00:31:26,527 shape. 782 00:31:29,898 --> 00:31:31,232 >> For the first time seeing 783 00:31:31,266 --> 00:31:32,800 that sort of information is very 784 00:31:32,901 --> 00:31:35,803 exciting for geologists. 785 00:31:35,904 --> 00:31:37,805 >> The magma chamber is so wide, 786 00:31:37,873 --> 00:31:39,440 it stretches well beyond the 787 00:31:39,508 --> 00:31:41,075 one-mile base of the cone 788 00:31:41,143 --> 00:31:46,247 itself. 789 00:31:46,348 --> 00:31:49,250 >> It's 250 square miles, or 790 00:31:49,351 --> 00:31:50,685 about half the size of New York 791 00:31:50,719 --> 00:31:52,053 City. So that's quite an 792 00:31:52,087 --> 00:31:56,090 impressive feature. 793 00:31:56,158 --> 00:31:57,725 >> It's not only impressive. 794 00:31:57,793 --> 00:32:00,528 It's also potentially deadly. 795 00:32:00,629 --> 00:32:02,263 The vast reservoir of molten 796 00:32:02,331 --> 00:32:04,065 magma could fuel Vesuvius' 797 00:32:04,166 --> 00:32:08,235 greatest eruption. But still 798 00:32:08,270 --> 00:32:10,604 no one knows for sure what might 799 00:32:10,639 --> 00:32:12,907 set off this seemingly inactive 800 00:32:12,974 --> 00:32:14,608 magma. 801 00:32:14,676 --> 00:32:15,876 >> There's some really exciting 802 00:32:15,911 --> 00:32:17,078 wvidence that's been found that 803 00:32:17,145 --> 00:32:18,312 suggests that Vesuvius might 804 00:32:18,347 --> 00:32:19,613 have a bit of an unusual 805 00:32:19,681 --> 00:32:21,048 trigger. 806 00:32:21,083 --> 00:32:22,350 >> In searching for the secret 807 00:32:22,417 --> 00:32:24,085 trigger mechanism of Vesuvius, 808 00:32:24,152 --> 00:32:25,886 Dr. Petford examines the pattern 809 00:32:25,954 --> 00:32:27,788 of when past eruptions have 810 00:32:27,823 --> 00:32:30,991 occurred. 811 00:32:31,059 --> 00:32:32,259 >> What this line here 812 00:32:32,327 --> 00:32:33,361 represents is a timeline from 813 00:32:33,428 --> 00:32:36,597 1600, where I'm stood, up to 814 00:32:36,631 --> 00:32:38,065 pretty much now. 815 00:32:38,133 --> 00:32:39,633 >> Each stick represents an 816 00:32:39,701 --> 00:32:41,135 eruption of Vesuvius during 817 00:32:41,169 --> 00:32:44,038 the last 400 years. 818 00:32:44,072 --> 00:32:46,073 >> The first one is here at 819 00:32:46,174 --> 00:32:50,244 about 1631. Then there have been 820 00:32:50,312 --> 00:32:52,246 3 more significant volcanic 821 00:32:52,347 --> 00:32:53,948 eruptions. 822 00:32:53,982 --> 00:32:55,783 >> As the timeline takes shape, 823 00:32:55,851 --> 00:32:58,052 Dr. Petford inputs more data. 824 00:32:58,153 --> 00:32:59,620 This time the dates of another 825 00:32:59,721 --> 00:33:01,255 seemingly unrelated set of 826 00:33:01,356 --> 00:33:04,492 natural disasters. 827 00:33:04,526 --> 00:33:05,726 >> We've got records of 828 00:33:05,761 --> 00:33:07,361 earthquake activity, as well. 829 00:33:07,396 --> 00:33:08,763 So I'm gonna use these stones 830 00:33:08,830 --> 00:33:11,565 here to represent Earthquakes, 831 00:33:11,633 --> 00:33:12,566 and these would be Earthquakes 832 00:33:12,634 --> 00:33:14,168 that took place within about 833 00:33:14,269 --> 00:33:16,871 100 miles of the volcano. 834 00:33:16,905 --> 00:33:18,372 >> Ss Dr. Petford positions the 835 00:33:18,473 --> 00:33:19,907 major Earthquakes of the last 836 00:33:20,008 --> 00:33:22,443 400 years, a pattern emerges 837 00:33:22,544 --> 00:33:24,879 between the tremors and activity 838 00:33:24,913 --> 00:33:28,015 at Vesuvius. It has been 839 00:33:28,083 --> 00:33:29,717 possible to investigate this 840 00:33:29,818 --> 00:33:31,552 supposed link only because there 841 00:33:31,620 --> 00:33:33,187 are such uniquely detailed 842 00:33:33,255 --> 00:33:37,158 records about the volcano. 843 00:33:40,262 --> 00:33:41,896 Vesuvius has been inhabited for 844 00:33:41,963 --> 00:33:43,964 so long that every one of its 845 00:33:43,999 --> 00:33:45,699 eruptions of the past 1,000 846 00:33:45,734 --> 00:33:47,635 years has been meticulously 847 00:33:47,702 --> 00:33:50,538 documented. Also, the volcano 848 00:33:50,605 --> 00:33:53,507 sits in an Earthquake hot spot. 849 00:33:53,542 --> 00:33:55,242 This region experiences more 850 00:33:55,277 --> 00:33:57,011 tremors than anywhere else in 851 00:33:57,078 --> 00:33:59,046 Europe: Activity that has 852 00:33:59,080 --> 00:34:00,781 generated further detailed 853 00:34:00,816 --> 00:34:05,619 records for geologists to study. 854 00:34:05,720 --> 00:34:07,188 When all this information was 855 00:34:07,255 --> 00:34:08,789 analyzed together, a 856 00:34:08,824 --> 00:34:10,624 statistically proven link was 857 00:34:10,725 --> 00:34:13,894 found. The evidence for this 858 00:34:13,962 --> 00:34:15,863 relationship is convincing at 859 00:34:15,897 --> 00:34:20,334 Vesuvius. But the idea that 860 00:34:20,368 --> 00:34:22,269 earthquakes can cause eruptions 861 00:34:22,337 --> 00:34:23,904 is still hotly debated 862 00:34:23,972 --> 00:34:25,639 worldwide. 863 00:34:25,707 --> 00:34:27,541 >> The idea that Earthquakes and 864 00:34:27,609 --> 00:34:29,176 volcanoes are related is not a 865 00:34:29,244 --> 00:34:30,544 new idea. In fact, it was 866 00:34:30,612 --> 00:34:32,246 Charles Darwin on his journeys 867 00:34:32,314 --> 00:34:33,814 to South America in the 1800s 868 00:34:33,882 --> 00:34:35,182 who first proposed that there 869 00:34:35,250 --> 00:34:36,517 could be a link between an 870 00:34:36,618 --> 00:34:37,885 Earthquake and a volcano he saw 871 00:34:37,953 --> 00:34:39,720 erupt a few days afterwards. 872 00:34:39,788 --> 00:34:42,089 >> Darwin was in Chile in 1835 873 00:34:42,157 --> 00:34:44,425 when an Earthquake struck. Days 874 00:34:44,526 --> 00:34:46,494 later, he witnessed the eruption 875 00:34:46,528 --> 00:34:49,997 of a chain of volcanoes. To him, 876 00:34:50,065 --> 00:34:51,999 a relationship was clear that 877 00:34:52,067 --> 00:34:54,768 one was the cause of the other. 878 00:34:54,803 --> 00:34:56,070 >> And really since then, over 879 00:34:56,137 --> 00:34:57,338 the last couple of hundred years 880 00:34:57,405 --> 00:34:58,606 geologists have debated back and 881 00:34:58,673 --> 00:35:00,341 forth how real, if you like, 882 00:35:00,408 --> 00:35:01,609 this cause-and-effect 883 00:35:01,676 --> 00:35:02,977 relationship is between 884 00:35:03,078 --> 00:35:04,812 Earthquakes and volcanoes. 885 00:35:04,880 --> 00:35:06,080 >> Despite continuing 886 00:35:06,147 --> 00:35:07,781 controversy, many scientists do 887 00:35:07,816 --> 00:35:09,517 believe that the next huge 888 00:35:09,584 --> 00:35:11,252 eruption from Vesuvius may be 889 00:35:11,353 --> 00:35:15,222 triggered by an Earthquake. The 890 00:35:15,257 --> 00:35:16,891 theory suggests that pressure 891 00:35:16,958 --> 00:35:18,359 waves rippling through the 892 00:35:18,426 --> 00:35:19,894 Earth's crust can squeeze the 893 00:35:19,961 --> 00:35:23,163 magma chamber. 894 00:35:23,265 --> 00:35:24,532 >> If you imagine that this 895 00:35:24,599 --> 00:35:25,799 bottle represents a magma 896 00:35:25,901 --> 00:35:27,668 chamber down beneath a volcano 897 00:35:27,702 --> 00:35:29,169 and that the water inside the 898 00:35:29,237 --> 00:35:31,705 bottle here is lava or magma, 899 00:35:31,806 --> 00:35:33,440 then as the Earthquake pressure 900 00:35:33,508 --> 00:35:35,242 wave moves towards the magma 901 00:35:35,343 --> 00:35:37,244 chamber, it interacts with the 902 00:35:37,312 --> 00:35:39,313 walls and starts to squash the 903 00:35:39,347 --> 00:35:41,348 chamber. The chamber walls sort 904 00:35:41,416 --> 00:35:43,117 of pinch together like this, and 905 00:35:43,184 --> 00:35:44,852 it drives the magma up to the 906 00:35:44,920 --> 00:35:47,655 surface. 907 00:35:50,926 --> 00:35:52,393 >> But even then, the eruption 908 00:35:52,494 --> 00:35:54,762 may be delayed. Historical 909 00:35:54,829 --> 00:35:56,564 records suggest the volcano may 910 00:35:56,631 --> 00:35:58,666 not stir for months or even 911 00:35:58,767 --> 00:36:00,568 years after an Earthquake has 912 00:36:00,635 --> 00:36:02,570 passed. 913 00:36:02,637 --> 00:36:03,938 >> And there could be some good 914 00:36:04,039 --> 00:36:05,205 reasons for that. One might be 915 00:36:05,307 --> 00:36:07,308 that the Earthquake builds up 916 00:36:07,375 --> 00:36:08,576 pressure slowly inside the 917 00:36:08,643 --> 00:36:09,910 volcano. 918 00:36:09,945 --> 00:36:11,111 >> So the effect of the pressure 919 00:36:11,212 --> 00:36:13,380 waves are not immediate. 920 00:36:13,481 --> 00:36:14,648 >> Or that you need more than 921 00:36:14,683 --> 00:36:15,749 one Earthquake. You might need 922 00:36:15,817 --> 00:36:16,917 multiple Earthquakes that 923 00:36:16,952 --> 00:36:18,118 progressively increase the 924 00:36:18,219 --> 00:36:19,453 pressure inside the volcano. 925 00:36:19,487 --> 00:36:20,854 >> Each wave squashing the 926 00:36:20,922 --> 00:36:23,624 chamber a little more each time. 927 00:36:23,725 --> 00:36:24,992 >> Until the last Earthquake 928 00:36:25,060 --> 00:36:26,226 that comes along is effectually 929 00:36:26,261 --> 00:36:27,528 the straw that breaks the 930 00:36:27,629 --> 00:36:28,696 camel's back. And it's that 931 00:36:28,730 --> 00:36:29,997 Earthquake that pushes the 932 00:36:30,065 --> 00:36:31,432 system into critical instability 933 00:36:31,499 --> 00:36:33,601 and makes an eruption. 934 00:36:33,635 --> 00:36:34,969 >> After thousands of years of 935 00:36:35,003 --> 00:36:37,004 study, scientists still do not 936 00:36:37,072 --> 00:36:39,173 fully understand what causes an 937 00:36:39,207 --> 00:36:41,709 eruption. 938 00:36:41,810 --> 00:36:43,043 >> So an important thing about 939 00:36:43,078 --> 00:36:44,778 Vesuvius is that if we can make 940 00:36:44,813 --> 00:36:46,246 sense of this data set that 941 00:36:46,348 --> 00:36:47,815 we've got for this volcano, we 942 00:36:47,882 --> 00:36:49,416 can come up with a new model for 943 00:36:49,451 --> 00:36:50,818 Earthquake-related volcanic 944 00:36:50,885 --> 00:36:53,587 eruptions. Vesuvius could be the 945 00:36:53,622 --> 00:36:55,623 world leader in helping us to 946 00:36:55,724 --> 00:36:57,091 understand how other volcanoes 947 00:36:57,158 --> 00:36:58,359 on the planet might work in a 948 00:36:58,426 --> 00:37:01,095 similar way. 949 00:37:04,699 --> 00:37:05,899 >> If Earthquakes are the 950 00:37:05,967 --> 00:37:07,635 trigger for Vesuvius, then it is 951 00:37:07,702 --> 00:37:09,436 possible that the next eruption 952 00:37:09,504 --> 00:37:14,675 may already have started. 953 00:37:14,709 --> 00:37:16,677 2 massive Earthquakes recently 954 00:37:16,711 --> 00:37:18,612 sent shock waves racing through 955 00:37:18,680 --> 00:37:21,315 the ground near the volcano. 956 00:37:21,349 --> 00:37:23,417 In 2002, the first quake struck 957 00:37:23,451 --> 00:37:25,252 just 40 miles northeast of 958 00:37:25,353 --> 00:37:27,421 Vesuvius. This was a 959 00:37:27,455 --> 00:37:31,058 magnitude 5.4 tremor. 30 people 960 00:37:31,159 --> 00:37:32,860 died, and thousands were 961 00:37:32,894 --> 00:37:36,163 evacuated from their homes. 962 00:37:36,264 --> 00:37:39,166 Even more recently, in 2009 a 963 00:37:39,267 --> 00:37:41,802 magnitude 6.3 Earthquake killed 964 00:37:41,870 --> 00:37:43,704 more than 300 people in the town 965 00:37:43,805 --> 00:37:46,507 of l'aquilla 60 miles north of 966 00:37:46,541 --> 00:37:49,043 the volcano. This was the worst 967 00:37:49,077 --> 00:37:50,711 such disaster in Italy for 968 00:37:50,779 --> 00:37:53,981 30 years. The concern is that 969 00:37:54,049 --> 00:37:55,349 the shock waves from these 970 00:37:55,417 --> 00:37:56,950 quakes may already have shaken 971 00:37:56,985 --> 00:37:58,686 Vesuvius' monstrous magma 972 00:37:58,720 --> 00:38:00,354 chamber and triggered the start 973 00:38:00,422 --> 00:38:03,524 of a new eruption. The clues are 974 00:38:03,591 --> 00:38:05,392 adding up in the race to predict 975 00:38:05,427 --> 00:38:07,795 when Vesuvius will erupt. 976 00:38:07,896 --> 00:38:09,163 Scientists have gathered 977 00:38:09,230 --> 00:38:12,599 2 startling pieces of evidence. 978 00:38:15,670 --> 00:38:17,604 A huge magma bomb beneath 979 00:38:17,706 --> 00:38:19,440 Vesuvius proves the volcano is 980 00:38:19,507 --> 00:38:21,308 primed with the fuel for a 981 00:38:21,342 --> 00:38:24,445 massive explosion. The 982 00:38:24,512 --> 00:38:25,946 historical pattern of 983 00:38:25,980 --> 00:38:27,314 Earthquakes and eruptions 984 00:38:27,348 --> 00:38:28,682 suggests the trigger may already 985 00:38:28,783 --> 00:38:33,253 have been pulled. Each new piece 986 00:38:33,321 --> 00:38:35,255 of information takes scientists 987 00:38:35,323 --> 00:38:37,424 one step forward in their quest 988 00:38:37,492 --> 00:38:39,426 to foretell when Vesuvius may 989 00:38:39,527 --> 00:38:42,963 blow. But even predicting the 990 00:38:43,064 --> 00:38:45,132 eruption may not be enough to 991 00:38:45,166 --> 00:38:47,067 save the lives of the 3 million 992 00:38:47,135 --> 00:38:50,571 citizens of Naples. 993 00:38:55,321 --> 00:38:56,521 >> Recent discoveries around 994 00:38:56,589 --> 00:38:58,156 Vesuvius reveal that if a blast 995 00:38:58,224 --> 00:39:01,226 like the one in 1780 B.C. 996 00:39:01,327 --> 00:39:02,494 occurred today, 997 00:39:02,595 --> 00:39:03,562 it would reach the heart 998 00:39:03,596 --> 00:39:05,497 of Naples, a metropolitan area 999 00:39:05,598 --> 00:39:09,468 with 3 million people. 1000 00:39:09,502 --> 00:39:10,869 >> Vesuvius is an active 1001 00:39:10,970 --> 00:39:13,672 volcano, and it's also 1002 00:39:13,673 --> 00:39:15,774 explosive. So it's quite 1003 00:39:15,875 --> 00:39:18,009 dangerous. In addition to that, 1004 00:39:18,044 --> 00:39:20,145 there is a very large population 1005 00:39:20,213 --> 00:39:22,047 living around Vesuvius. So also 1006 00:39:22,048 --> 00:39:25,117 the risk is very high. 1007 00:39:30,590 --> 00:39:31,857 >> Studies of the surrounding 1008 00:39:31,924 --> 00:39:33,191 landscape suggest that the 1009 00:39:33,226 --> 00:39:35,594 volcano's most lethal force, the 1010 00:39:35,661 --> 00:39:37,829 pyroclastic flow, would not only 1011 00:39:37,864 --> 00:39:39,664 reach Naples but would be 1012 00:39:39,765 --> 00:39:41,299 concentrated down in the 1013 00:39:41,334 --> 00:39:44,970 direction of the city. The high 1014 00:39:45,037 --> 00:39:47,005 cliffs of Somma partly surround 1015 00:39:47,039 --> 00:39:49,141 the cone of Vesuvius. If there 1016 00:39:49,208 --> 00:39:51,143 was an eruption, these walls 1017 00:39:51,210 --> 00:39:53,111 would act like a funnel 1018 00:39:53,146 --> 00:39:54,579 channeling the majority of the 1019 00:39:54,647 --> 00:39:56,481 boiling volcanic debris to the 1020 00:39:56,549 --> 00:40:02,487 west: Straight towards the city. 1021 00:40:02,555 --> 00:40:04,923 Vesuvius is like a loaded gun 1022 00:40:04,957 --> 00:40:10,829 pointed right at Naples. 1023 00:40:10,830 --> 00:40:12,197 >> The new evidence that we have 1024 00:40:12,231 --> 00:40:13,365 is really important. It points 1025 00:40:13,399 --> 00:40:15,200 to one very critical point: That 1026 00:40:15,234 --> 00:40:18,737 Naples is not safe. This area 1027 00:40:18,738 --> 00:40:20,038 could be hit. It could be 1028 00:40:20,139 --> 00:40:21,873 targeted. 1029 00:40:21,941 --> 00:40:23,008 >> This new information, in 1030 00:40:23,042 --> 00:40:24,676 addition to the discovery of 1031 00:40:24,744 --> 00:40:26,278 volcanic deposits in the heart 1032 00:40:26,312 --> 00:40:28,113 of Naples, has spurred the city 1033 00:40:28,181 --> 00:40:31,016 to review its 2001 evacuation 1034 00:40:31,050 --> 00:40:32,951 plan. 1035 00:40:33,019 --> 00:40:34,853 >> The evacuation plan currently 1036 00:40:34,921 --> 00:40:36,121 only deals with those people who 1037 00:40:36,189 --> 00:40:37,956 live on the slopes of Vesuvius 1038 00:40:38,024 --> 00:40:39,291 and the villages and towns 1039 00:40:39,392 --> 00:40:40,592 around, and that's about 600,000 1040 00:40:40,660 --> 00:40:43,094 people. The city of Naples, here 1041 00:40:43,129 --> 00:40:44,863 where I am now, isn't presently 1042 00:40:44,931 --> 00:40:47,199 included in the evacuation plan. 1043 00:40:47,233 --> 00:40:48,567 Of course, that's where the 1044 00:40:48,634 --> 00:40:50,035 majority of people live. 1045 00:40:50,136 --> 00:40:51,836 >> Geologists are key to putting 1046 00:40:51,904 --> 00:40:55,774 new evacuation plans in place. 1047 00:40:55,841 --> 00:40:58,310 But planning is the easy part. 1048 00:40:58,377 --> 00:40:59,844 Knowing when to put those plans 1049 00:40:59,912 --> 00:41:01,479 into action is the most 1050 00:41:01,581 --> 00:41:03,381 difficult call to make. 1051 00:41:03,382 --> 00:41:05,650 >> The decision of evacuating 1052 00:41:05,685 --> 00:41:07,185 or not and when to evacuate is 1053 00:41:07,220 --> 00:41:08,954 probably the $1 million 1054 00:41:09,021 --> 00:41:11,022 question. 1055 00:41:11,023 --> 00:41:12,357 >> If scientists seem to 1056 00:41:12,391 --> 00:41:13,658 exaggerate a threat and 1057 00:41:13,726 --> 00:41:15,360 recommend an evacuation, the 1058 00:41:15,394 --> 00:41:16,928 next time people might not pay 1059 00:41:16,996 --> 00:41:19,130 attention. 1060 00:41:19,198 --> 00:41:20,565 >> If they're evacuated too 1061 00:41:20,666 --> 00:41:23,201 late, the price might be 1062 00:41:23,302 --> 00:41:25,470 thousands of people dead. 1063 00:41:25,538 --> 00:41:26,738 >> It's a dilemma faced by 1064 00:41:26,839 --> 00:41:33,111 volcanologists around the world. 1065 00:41:33,179 --> 00:41:35,180 Mount Vesuvius is only one of 1066 00:41:35,214 --> 00:41:38,950 3,000 active volcanoes. 9% of 1067 00:41:39,018 --> 00:41:40,552 the world's population, some 1068 00:41:40,586 --> 00:41:43,121 450 million people, live in 1069 00:41:43,189 --> 00:41:45,023 areas threatened by a volcanic 1070 00:41:45,091 --> 00:41:47,826 blast. Mount Rrainier stands 1071 00:41:47,927 --> 00:41:50,395 54 miles from the 500,000 1072 00:41:50,463 --> 00:41:54,899 residents of Seattle. 1073 00:41:54,934 --> 00:41:56,635 Popocatepetl is located 1074 00:41:56,669 --> 00:41:58,937 44 miles from 9 million people 1075 00:41:59,005 --> 00:42:02,574 in Mexico City. 1076 00:42:02,642 --> 00:42:04,709 And Mount Fuji stands 60 miles 1077 00:42:04,744 --> 00:42:06,578 from the 12 million citizens 1078 00:42:06,646 --> 00:42:09,648 of Tokyo. 1079 00:42:16,455 --> 00:42:18,356 On average, 3 volcanoes a year 1080 00:42:18,391 --> 00:42:20,292 erupt, causing deaths and 1081 00:42:20,393 --> 00:42:23,461 injuries. 1082 00:42:28,067 --> 00:42:29,701 The hope is that lessons learned 1083 00:42:29,769 --> 00:42:31,536 from Vesuvius will one day help 1084 00:42:31,604 --> 00:42:34,906 protect people around the globe. 1085 00:42:42,715 --> 00:42:44,249 Mount Vesuvius still has many 1086 00:42:44,350 --> 00:42:46,951 secrets to tell. But so far, 1087 00:42:46,986 --> 00:42:48,586 geologists have put together a 1088 00:42:48,621 --> 00:42:50,422 disturbing portrait of what many 1089 00:42:50,489 --> 00:42:52,357 call the world's most dangerous 1090 00:42:52,425 --> 00:42:55,527 volcano. 1091 00:43:00,132 --> 00:43:01,533 Pumice from the ruins of 1092 00:43:01,600 --> 00:43:02,967 Pompeii: Evidence of the 1093 00:43:03,069 --> 00:43:06,938 explosive power of Vesuvius. 1094 00:43:06,972 --> 00:43:08,807 Charred human bones demonstrate 1095 00:43:08,874 --> 00:43:10,875 the 900-degree temperatures of 1096 00:43:10,976 --> 00:43:12,444 the Mountain's pyroclastic 1097 00:43:12,511 --> 00:43:15,880 flows. Ancient layers of ash 1098 00:43:15,948 --> 00:43:17,582 in downtown Naples prove that 1099 00:43:17,616 --> 00:43:19,884 Vesuvius has the power to engulf 1100 00:43:19,985 --> 00:43:24,322 the city. And new seismic 1101 00:43:24,423 --> 00:43:26,157 investigations reveal a 1102 00:43:26,258 --> 00:43:29,127 250-square-mile magma chamber 1103 00:43:29,161 --> 00:43:33,164 sitting under the volcano. 1104 00:43:33,232 --> 00:43:37,335 It's a ticking time bomb. 1105 00:43:37,436 --> 00:43:38,970 Geologists who study how the 1106 00:43:39,038 --> 00:43:40,872 Earth was made believe that 1107 00:43:40,940 --> 00:43:42,674 it's a geological certainty that 1108 00:43:42,708 --> 00:43:44,743 Naples will one day feel the 1109 00:43:44,844 --> 00:43:49,748 wrath of the volcano. Even now, 1110 00:43:49,815 --> 00:43:51,483 Vesuvius is armed and waiting 1111 00:43:51,484 --> 00:43:53,184 for it's next eruption 1112 00:43:53,885 --> 00:43:54,985 Dynamic proof 1113 00:43:54,986 --> 00:43:57,986 that the Earth is never at rest. 1114 00:43:57,987 --> 00:44:00,987 -- Sync, corrected by elderman -- -- for www.MY-SUBS.com --