1 00:00:00,602 --> 00:00:14,363 This series presents information based in part on theory and conjecture. 2 00:00:14,363 --> 00:00:21,403 The producer's purpose is to suggest some possible explanations but not necessarily 3 00:00:21,403 --> 00:00:24,883 the only ones to the mysteries we will examine. 4 00:00:25,683 --> 00:00:30,883 In the Earth's crust slashes across 700 miles of California. 5 00:00:30,883 --> 00:00:32,883 The San Andreas Fault. 6 00:00:32,883 --> 00:00:40,884 It borders both San Francisco and Los Angeles and creates one of the world's most dangerous earthquake zones. 7 00:00:40,884 --> 00:00:48,884 Scientists are racing to find ways of predicting the next disastrous movement of the fault. 8 00:00:48,884 --> 00:00:52,884 When will the great earthquake strike California? 9 00:00:59,884 --> 00:01:03,885 California is famous for its warm and sunny climate. 10 00:01:03,885 --> 00:01:09,885 Its diverse lifestyles and spectacular vistas are as varied as any other land on Earth. 11 00:01:19,885 --> 00:01:24,885 Much of California's rugged beauty derives from violent Earth upheavals. 12 00:01:26,885 --> 00:01:30,886 The product of a phenomenon called folding. 13 00:01:30,886 --> 00:01:36,886 Deep cracks or faults in the Earth's crust scar the state from one end to the other. 14 00:01:36,886 --> 00:01:42,886 A vise, the San Andreas Fault is the longest and most dangerous. 15 00:01:43,886 --> 00:01:55,887 At 6 a.m. on February 9, 1971, Californians were jolted into awareness of the powerful forces that molded their state. 16 00:02:00,887 --> 00:02:06,887 A sudden earthquake just north of Los Angeles caused massive devastation. 17 00:02:06,887 --> 00:02:10,887 50 people were killed in the collapse of two hospitals. 18 00:02:11,887 --> 00:02:21,888 Since the quake was of only moderate size, engineers were shocked by the heavy damage to supposedly earthquake resistant buildings and freeways. 19 00:02:24,888 --> 00:02:33,888 The Richter magnitude was 6.6, releasing several hundred times less energy than the San Francisco earthquake of 1906. 20 00:02:34,888 --> 00:02:40,888 Had the shaking continued for another few seconds, the San Fernando disaster would have been far worse. 21 00:02:40,888 --> 00:02:46,889 Two dams holding 7 billion gallons of water threatened 80,000 sleeping people. 22 00:02:47,889 --> 00:02:53,889 When the dams began to collapse, only the abnormally low water level prevented catastrophe. 23 00:02:57,889 --> 00:03:02,889 Geologists soon pinpointed the quake on a minor branch of the San Andreas Fault. 24 00:03:04,889 --> 00:03:08,889 The main spine of the fault hadn't even moved. 25 00:03:09,890 --> 00:03:16,890 The San Andreas Fault system is part of a grid of faults, mountain chains and trenches in the ocean floor. 26 00:03:16,890 --> 00:03:22,890 These features mark the boundaries between huge moving slabs of the Earth's crust called plates. 27 00:03:22,890 --> 00:03:29,890 Carrying continents and oceans with them, the plates float on a hot liquid layer of the planet. 28 00:03:30,890 --> 00:03:38,891 Along the fault in California, two plates slip and grind against each other due to movement deep within the Earth. 29 00:03:39,891 --> 00:03:44,891 Dr. Tim Hall has studied the San Andreas Fault for 15 years. 30 00:03:44,891 --> 00:03:55,891 I visualize the San Andreas Fault as a 700-mile-long vertical curtain of clay that runs the length of California down to a depth of about 10 miles. 31 00:03:56,891 --> 00:04:01,892 It separates two moving plates from each other, the American plate and the Pacific plate. 32 00:04:01,892 --> 00:04:07,892 In places along that clay boundary, the fault can move along year by year. 33 00:04:07,892 --> 00:04:13,892 We call that creep. In other places along the fault, the rocks are stuck together, locked. 34 00:04:13,892 --> 00:04:21,892 A large amount of energy gets stored in the surface rocks, which is released periodically by sudden large earthquakes. 35 00:04:22,892 --> 00:04:31,893 With its many branches, the San Andreas cuts a broad swath through California from San Francisco, Oakland, San Jose to Los Angeles. 36 00:04:31,893 --> 00:04:36,893 All are in fault zones. 15 million people are vulnerable. 37 00:04:36,893 --> 00:04:44,893 We shall travel along the fault, seeing places where the danger is great and observing sites where crucial research is underway. 38 00:04:45,893 --> 00:04:51,894 The trip begins at Southern California's Salton Sea. 39 00:04:51,894 --> 00:04:57,894 Repeated fault movement has lifted and exposed the reddish band of rock. 40 00:04:57,894 --> 00:05:02,894 The twisted cliffs were gouged by the fault's immense power. 41 00:05:02,894 --> 00:05:08,894 Nearby, the San Andreas has made pockets of groundwater. 42 00:05:08,894 --> 00:05:14,894 Lines of palm trees and brush mark the fault's passage beneath the bleak sands. 43 00:05:19,895 --> 00:05:25,895 Outside Palm Springs, two-mile-high mountains were thrust up by millions of years of fault movement. 44 00:05:28,895 --> 00:05:31,895 The fault skirts the Los Angeles Basin. 45 00:05:32,895 --> 00:05:38,895 Its numerous sub-branches, including the one which shook San Fernando, threaten more than 10 million people. 46 00:05:41,896 --> 00:05:45,896 North of Los Angeles County, the fault carves a broad valley. 47 00:05:47,896 --> 00:05:55,896 Near Palmdale, Dr. Kerry Seed dug into the San Andreas and found a treasure trove of prehistoric earthquakes. 48 00:05:56,896 --> 00:06:02,896 Using carbon dating, each event is identified. 49 00:06:02,896 --> 00:06:09,897 The fault goes down through many distorted layers, which mark earthquakes going back to the time of Christ. 50 00:06:09,897 --> 00:06:16,897 The intervals between major quakes range from a maximum of 300 years to only half a century. 51 00:06:17,897 --> 00:06:24,897 The earthquake of 1857, largest ever recorded in Southern California, shows up as a sandblow, 52 00:06:24,897 --> 00:06:29,897 where sand and water spouted from the earth in an eerie fountain. 53 00:06:33,898 --> 00:06:41,898 Trees along the fault had their roots sheared during the quake, causing growth to slow abruptly at the 1857 ring. 54 00:06:42,898 --> 00:06:51,898 In 1975, researchers found that a broad area of desert along the fault had risen about one foot during the last 15 years. 55 00:06:54,898 --> 00:06:59,899 They began a massive survey program to monitor this Palmdale bulge. 56 00:07:01,899 --> 00:07:06,899 Survey teams worked their way tediously up from Los Angeles, measuring the land level. 57 00:07:11,899 --> 00:07:15,899 Ammonously, part of the bulge recently subsided. 58 00:07:17,899 --> 00:07:24,900 This pattern of uplift and collapse also happened before the devastating Alaskan and Chilean earthquakes. 59 00:07:27,900 --> 00:07:32,900 In Southern California, the pattern occurred once before without an earthquake. 60 00:07:33,900 --> 00:07:41,900 Does the Palmdale bulge reflect the harmless cycle or worn of a major jolt on the San Andreas Fault? 61 00:07:50,901 --> 00:07:57,901 North of Palmdale, geologists drilled deep into the fault zone to measure the stress on underground rock. 62 00:08:02,901 --> 00:08:09,901 In hope of finding a new way to forecast earthquakes, the researchers pumped water into the drill hole. 63 00:08:14,902 --> 00:08:17,902 They increased the pressure until the rock breaks. 64 00:08:20,902 --> 00:08:27,902 Knowing the natural strength of rock, they measure what added stress it is under from the earthquake fault. 65 00:08:28,902 --> 00:08:35,902 They have found that rock in the fault zone is cracked, water saturated, and close to the breaking point. 66 00:08:39,903 --> 00:08:43,903 Further north, the San Andreas cuts through hilly desert country. 67 00:08:47,903 --> 00:08:53,903 In the stark and desolate Carrizo Plain, fault features are clearer than anywhere else. 68 00:08:57,903 --> 00:09:03,904 Most ground movement here occurs during large earthquakes in jumps of several yards parallel to the fault. 69 00:09:04,904 --> 00:09:07,904 The last of these took place in 1857. 70 00:09:10,904 --> 00:09:15,904 The quakes also cause the ground to move vertically, forming ridges along the fault. 71 00:09:18,904 --> 00:09:22,904 Repeated slippage has diverted streams along the fault. 72 00:09:23,904 --> 00:09:30,905 According to carbon dating, this streambed moved 125 meters in the last 3400 years. 73 00:09:33,905 --> 00:09:36,905 The Pacific Plate slides northwest averaging 2 inches a year. 74 00:09:37,905 --> 00:09:45,905 At this rate, in 5 million years, it will carry Los Angeles past the Carrizo Plain on its way to San Francisco. 75 00:09:46,905 --> 00:09:54,906 Midway between Los Angeles and San Francisco on the Pacific Coast is the Diablo Canyon Nuclear Plant. 76 00:09:55,906 --> 00:10:03,906 The facility was originally designed to withstand an earthquake on the San Andreas Fault of Richter Magnitude 8.5. 77 00:10:04,906 --> 00:10:11,906 During construction, however, geologists discovered a nearby fault offshore, the Haasgrie Fault. 78 00:10:12,906 --> 00:10:16,906 Ralph Rana is a county environmental worker who lives near the site. 79 00:10:17,907 --> 00:10:25,907 I'm opposed to the nuclear power plant at the Diablo Canyon because there's an earthquake fault running 2.5 miles from the plant itself. 80 00:10:26,907 --> 00:10:31,907 And that fault happens to be 250 miles long and it's a major earthquake fault in California. 81 00:10:32,907 --> 00:10:38,907 A very large earthquake in 1927. Magnitude 7.5 occurred on that fault. 82 00:10:38,907 --> 00:10:43,908 A magnitude 8 earthquake is also possible on the Haasgrie Fault. 83 00:10:44,908 --> 00:10:48,908 Richard Davin represents the plant's owner, Pacific Gas and Electric. 84 00:10:49,908 --> 00:10:55,908 There are earthquake faults around the Ablo Canyon, of course. There's a San Andreas Fault 48 miles away, but there's a Haasgrie Fault which is closer. 85 00:10:56,908 --> 00:10:58,908 And that's the one that has been of the major concern in the last several years. 86 00:10:59,908 --> 00:11:04,908 And as a result, it's been the most thoroughly investigated fault probably in California outside of the San Andreas. 87 00:11:04,908 --> 00:11:09,909 And we have designed that plant to withstand the maximum earthquake that could ever be expected to occur on that fault. 88 00:11:10,909 --> 00:11:18,909 Those of us who live close to the plant or 7 miles away myself are wondering whether we are up to be guinea pigs in this experiment or not. 89 00:11:19,909 --> 00:11:24,909 People talk about earthquakes even bigger and bigger and bigger to kind of earthquake that would split this containment structure in half. 90 00:11:25,909 --> 00:11:31,909 I think when we got that kind of an earthquake, we've reached the end of the world because before that would happen, California would be in the ocean. 91 00:11:31,909 --> 00:11:41,910 After the Haasgrie Fault was found, PG&E strengthened the plant. The adequacy of their precautions is controversial. 92 00:11:42,910 --> 00:11:45,910 We're only beginning to understand the dynamics of earthquakes. 93 00:11:46,910 --> 00:11:53,910 Whether any possible ground shock could cause hazardous release of nuclear radiation remains unknown. 94 00:11:53,910 --> 00:12:00,911 Further north, the fault continues to pass through major population centers. 95 00:12:01,911 --> 00:12:07,911 A great earthquake would cause incalculable disaster. Is there a way to predict it? 96 00:12:08,911 --> 00:12:16,911 The little town of Hollister lies 80 miles south of San Francisco on the San Andreas Fault's Calaveras branch. 97 00:12:16,911 --> 00:12:24,912 August 6th, 1979. The strongest earthquake since 1911. 98 00:12:25,912 --> 00:12:30,912 San Pintello was outside landscaping when it struck. 99 00:12:31,912 --> 00:12:36,912 I stood here and you could look out over the hills. You could see the hills rolling into each other. 100 00:12:37,912 --> 00:12:43,912 They're just sort of bending. The ground was moving, the house was moving. 101 00:12:43,912 --> 00:12:48,912 Everything seems to be tilting, especially the hills tilting toward each other. 102 00:12:49,913 --> 00:12:53,913 And of course I could see the trees shimmering over here. I didn't know it was just eerie. 103 00:12:55,913 --> 00:13:01,913 The fault at Hollister isn't blocked. Slow creep and small shakes tear the land beneath the center of town. 104 00:13:02,913 --> 00:13:07,913 Houses are twisted out of shape. 105 00:13:07,913 --> 00:13:13,913 Streets and curbs are cracked and broken. 106 00:13:14,914 --> 00:13:21,914 In this region of unusual activity, instruments monitor fault movement. 107 00:13:22,914 --> 00:13:27,914 Hill sides are dotted with reflectors for laser beams. 108 00:13:28,914 --> 00:13:34,914 A unique two-color system tracks deep earth movement across the fault. 109 00:13:34,914 --> 00:13:39,915 Four months before the August quake, the ground began to creep. 110 00:13:40,915 --> 00:13:45,915 Movement lasted for ten weeks, followed by a period of quiet. 111 00:13:46,915 --> 00:13:51,915 Then the earthquake struck. 112 00:13:52,915 --> 00:13:58,915 It is hoped the laser will eventually provide a reliable way to forecast earthquakes. 113 00:13:59,915 --> 00:14:05,916 West of Hollister, the San Andreas Fault gouges a narrow valley. 114 00:14:14,916 --> 00:14:18,916 Geologist Tim Hall supervises excavation into the fault. 115 00:14:19,916 --> 00:14:24,916 We're looking for a record of earthquakes in California before recorded history. 116 00:14:24,916 --> 00:14:30,917 And the way that we do that is look for layers that have been displaced by the San Andreas and attempt to date them. 117 00:14:31,917 --> 00:14:36,917 The goal of our study is to predict how often the San Andreas will move in the future. 118 00:14:39,917 --> 00:14:44,917 On the northern San Andreas, the earliest known great earthquake occurred in 1838. 119 00:14:45,917 --> 00:14:49,917 Only 68 years before the 1906 disaster. 120 00:14:49,917 --> 00:14:56,918 If such a small interval is typical, the next major shake may be overdue in the Bay Area. 121 00:15:01,918 --> 00:15:08,918 Slashing north along a chain of valleys and long narrow lakes, the San Andreas Fault cuts the San Francisco Peninsula in two. 122 00:15:10,918 --> 00:15:17,918 On the shore of San Francisco Bay is Marine World, where studies of the San Francisco Bay are carried out. 123 00:15:17,918 --> 00:15:22,919 This is Marine World, where studies of animal behavior may give warning of earthquakes to come. 124 00:15:25,919 --> 00:15:28,919 Peter Gross is director of Land Animals. 125 00:15:29,919 --> 00:15:38,919 What we have here at Marine World is the entire collection of both land and sea animals being viewed on a daily basis by all the keepers and the trainers and the handlers. 126 00:15:39,919 --> 00:15:49,920 And what they're looking for is any kind of an unusual sustained behavior that might show flight or fear, which we can then document as happening just before an earthquake. 127 00:15:50,920 --> 00:15:59,920 About a half hour before the big earthquake, these animals, which ordinarily mixed together and peacefully coexist amongst themselves, all separated and went into their own species. 128 00:16:00,920 --> 00:16:08,920 The zebras all stayed together, the antelope all went to one area. They just didn't want to mix with each other during this period of unrest and fear. 129 00:16:09,920 --> 00:16:15,921 I think that the animals are a lot more in tune to nature's sounds than people are. 130 00:16:17,921 --> 00:16:21,921 Trainer Paul Barkman recalls the morning before another earthquake. 131 00:16:22,921 --> 00:16:29,921 When we finally did get them out of the barn, we watered them down. They all refused to drink and they refused to eat all day long. 132 00:16:30,921 --> 00:16:36,922 We have one lead elephant, Jenny. She's the oldest. And she was thumping the whole day long and she was trumpeting what she very seldom does. 133 00:16:37,922 --> 00:16:47,922 And the other elephants were answering her back and they were just really hard to control the whole day until after 4 o'clock when the quake hit, then they were fine. 134 00:16:48,922 --> 00:16:53,922 Reports of strange animal behavior before earthquakes go back thousands of years. 135 00:16:54,922 --> 00:17:04,923 So far, however, it has proven difficult to use such information for reliable prediction. There is still no sure way to warn of an earthquake. 136 00:17:07,923 --> 00:17:12,923 On the western edge of San Francisco Bay, homes are often built on compacted landfield. 137 00:17:13,923 --> 00:17:22,923 This kind of land can amplify ground shaking up to 10 times and turn wet, sandy soil nearly to quicksand. 138 00:17:24,923 --> 00:17:31,924 Bracks up to 3 feet wide could split foundations and bring thousands of houses crashing down on their owners. 139 00:17:34,924 --> 00:17:40,924 On the east side of San Francisco Bay, the Hayward Branch of the Fault cuts through city after city. 140 00:17:41,924 --> 00:17:49,924 In 1836 and again in 1868, huge earthquakes here caused little damage because the area was barely inhabited. 141 00:17:51,925 --> 00:17:55,925 Today, however, dozens of schools and hospitals stand in the fault zone. 142 00:17:57,925 --> 00:18:05,925 In the aftermath of the San Fernando Quake, where some buildings that met all earthquake codes collapsed, standards throughout the state were toughened. 143 00:18:06,925 --> 00:18:10,925 Schools along the Hayward Fault were reinforced or replaced. 144 00:18:12,925 --> 00:18:18,926 A dam, not unlike the ones that began collapsing at San Fernando, is being rebuilt. 145 00:18:20,926 --> 00:18:25,926 In Berkeley, the Hayward Fault rims the campus of the University of California. 146 00:18:26,926 --> 00:18:30,926 It runs beneath the football stadium, which is slowly being split in half. 147 00:18:31,926 --> 00:18:35,926 Dr. Bruce Bould heads the University's seismographic station. 148 00:18:36,926 --> 00:18:53,927 According to the calculations that I have made based on the work along the San Andreas Fault recently, the chances of a great earthquake affecting either the San Francisco area or the Los Angeles area in the next 10 years are about 50-50. 149 00:18:54,927 --> 00:19:01,927 If a great earthquake of magnitude 7 or 8 occurred in the Bay Area, undoubtedly there would be considerable loss of life. 150 00:19:02,927 --> 00:19:07,928 Most Californians are not well prepared for another great earthquake like that of 1906. 151 00:19:08,928 --> 00:19:13,928 North of San Francisco, the San Andreas slices through Marin County. 152 00:19:14,928 --> 00:19:16,928 The little town of Olima straddles the fault. 153 00:19:17,928 --> 00:19:23,928 On April 18, 1906, a giant tremor broke the earth. 154 00:19:24,928 --> 00:19:27,928 It shifted roads and fences at incredible 20 feet. 155 00:19:29,928 --> 00:19:37,929 Olima was the epicenter for California's greatest earthquake disaster, known as the San Francisco earthquake. 156 00:19:47,929 --> 00:19:53,929 That earthquake claimed 700 lives. 157 00:19:58,930 --> 00:20:04,930 Today, the death toll from a major shock along the San Andreas could reach the tens of thousands. 158 00:20:06,930 --> 00:20:11,930 Only a few miles from the fault, San Francisco remains exquisitely vulnerable. 159 00:20:12,930 --> 00:20:18,930 Collapse of older buildings, showers of debris and fire would inflict a heavy toll. 160 00:20:19,930 --> 00:20:26,931 In Southern California, stress has been building up on the main fissure of the San Andreas for more than 120 years. 161 00:20:27,931 --> 00:20:35,931 If the historic pattern is followed, the stress will be relieved by a cataclysm many times larger than the San Fernando earthquake. 162 00:20:41,931 --> 00:20:45,931 It is frightening to imagine that disaster multiplied a hundredfold. 163 00:20:46,931 --> 00:20:51,932 Thousands dead, families homeless, firestorms raging out of control. 164 00:20:53,932 --> 00:20:57,932 1906 type disaster would cause unimaginable chaos. 165 00:20:58,932 --> 00:21:03,932 But earthquakes recorded in Asia and Alaska were any yet seen in California. 166 00:21:04,932 --> 00:21:09,932 Perhaps we have yet to learn the full power of the San Andreas fault. 167 00:21:12,933 --> 00:21:16,933 The San Andreas is the most closely watched earthquake fault in the world. 168 00:21:18,933 --> 00:21:21,933 Hundreds of instruments monitor its slightest tremble. 169 00:21:23,933 --> 00:21:28,933 If it is possible, reliable earthquake forecasting belongs to the future. 170 00:21:29,933 --> 00:21:31,933 Earth science is only in its infancy. 171 00:21:32,933 --> 00:21:38,934 The forces that mold our planet and cause the ground to shake beneath our feet remain mysterious. 172 00:21:42,934 --> 00:21:47,934 Coming up next in search of continues with an investigation into the Siberian Fireball. 173 00:21:48,934 --> 00:21:53,934 Then on FBI the untold stories, an agent is trapped into a dangerous meeting with drug traffickers. 174 00:21:54,934 --> 00:22:00,934 And later tonight, Fridrich Paulus loses at Stalingrad and defects to the Russians on Hitler's generals. 175 00:22:01,934 --> 00:22:04,935 At 9, here on the History Channel, where the past comes alive. 176 00:22:11,935 --> 00:22:12,935 .