SCIENTISTS RECOGNIZE THE THREAT

I had been working on earthquake hazards for seven years when I moved from Ohio to western Oregon in 1977. There was a sense of relief that I could study earthquakes while living in Ohio or Oregon and yet not worry about being in the path of an earthquake myself. Certainly, I knew that Oregon, as part of the northwestern United States, is close to the Cascadia subduction zone, the boundary where the oceanic Juan de Fuca tectonic plate is driving eastward beneath North America. However, in 1977 the subduction zone appeared to be unique in the Pacific Ring of Fire in that seismographs are recording essentially no earthquakes on it at all (see Figure 1.3). In addition, there have been no giant earthquakes on the subduction zone in recorded history, meaning since before the days of the Lewis and Clark expedition in 1804–1806. Some scientists believed that subduction was taking place without building up strain to be relieved by an earthquake. So I could work on your earthquake problem without worrying that it might be my problem as well.

However, my scientific colleagues weren't so sure. The USGS had convened a workshop that I attended in Olympia, the Washington State capital, on a possible earthquake hazard to the Pacific Northwest. Scientists at Caltech, including Tom Heaton, discussed in the preceding chapter, were pointing out that, despite the lack of earthquakes, Cascadia is similar to other subduction zones that have had massive earthquakes, including the Chile subduction zone off southern South America that in 1960 had experienced an earthquake of magnitude 9.5, the largest earthquake ever recorded. That earthquake spawned a deadly tsunami that caused damage and loss of life as far away as Japan (see Figure 8.3). Then, in May 1980, Mt. St. Helens volcano blew off its top, spewing pyroclastic flows and ash, and taking 57 lives. Because of the general view that active volcanoes are an indication of active subduction, the Cascade volcanoes suddenly stopped being simply scenic wonders, and the subduction zone suddenly stopped being a scientific curiosity and became a worry to people living nearby, including local scientists.

After the 1906 earthquake, the scene shifted to the Los Angeles metropolitan area. Unlike San Francisco, Los Angeles was considered by the general public as relatively free from earthquakes, although earthquakes were felt in the desert east of Los Angeles. Earthquakes had taken place in Los Angeles as early as 1769 during the Portolá exploratory expedition and again in 1800 and 1812, when earthquakes severely damaged the San Juan Capistrano mission south of Los Angeles. However, these earthquakes took place when California was still Alta California, a territory ruled by Spain. These events took place too long ago to be part of any conversation about earthquake hazards, although an earthquake in 1920 damaged the Inglewood district near the soon-to-be-discovered Newport–Inglewood fault. After that earthquake, despite the efforts of John C. Branner of Stanford, the propaganda machine of Los Angeles developers swung into action to reassure investors that Los Angeles had nothing to fear from San Francisco-type earthquakes! But then, an earthquake of magnitude 6.4 hammered the small resort city of Santa Barbara in 1925, taking 12 lives, but again the business interests minimized awareness of the damage and danger. People living in Santa Barbara did not appreciate their losses being downplayed in this way, even by their own Congressional representative.

However, there was now a research institution in southern California interested in earthquakes: the California Institute of Technology (Caltech), including engineers, seismologists, and geologists. Its president, Robert Millikan, a future Nobel Prize-winning physicist, was a major influence on a recently graduated physicist-turned-seismologist named Charles Richter.

On March 10, 1933, the Long Beach earthquake of magnitude 6.4 struck the Newport–Inglewood fault, taking 120 lives and inflicting damage of more than $400 million in today's dollars. The propaganda machine, led by the Los Angeles Chamber of Commerce, dutifully rolled out its usual soothing remarks, but it was now the middle of the Great Depression, and resistance was weak because of the collapse of the real-estate market. In addition, the earthquake severely damaged schools in the region, and outraged parents went directly to Sacramento, the state capital, to demand action. The result was the Field Act and Riley Act, with the Field Act the more important since it was enforced at the state level.

THE NAHRIN EARTHQUAKE

We headed north from Kabul on a warm day in July 2002, on our way to Baghlan Province and the town of Nahrin, which had been devastated by a moderate-magnitude earthquake four months earlier. In the SUV belonging to Shelter for Life International were Chris Madden and I from Earth Consultants International and Harry van Burik and Lee Molini from Shelter for Life. We were there to investigate the earthquake, working with Shelter for Life, an NGO (non-governmental organization) that had been funded by the US Agency for International Development (USAID) to help Nahrin rebuild.

At first, the countryside looked very much like Pakistan, where I had been working on earthquake projects for nearly 25 years. But there was a difference. We passed the hulks of burnt-out tanks, and our driver pointed to little painted stones along the side of the road, marking the location of land mines. Don't go there.

The previous October, nine months earlier, Afghanistan had been attacked by its most recent invader, the United States, operating as part of NATO. In September 1996, five and a half years before, Taliban insurgents had captured Kabul and installed a rigid form of Islam, closing girls’ schools, holding public executions in the stadium, and hanging the previous pro-Communist leader, President Najibullah. The Taliban had provided a base for Osama bin Laden to plan the al-Qaida attacks of September 11, 2001, against the United States. The Taliban refused to turn over bin Laden and other al-Qaida operatives to the United States, and a month later the Americans launched their offensive.

The Taliban had never completely conquered Afghanistan. The northern part of the country is dominated by minorities, principally Tajiks and Uzbeks, who speak different dialects and follow a different brand of Islam than does the Taliban, dominated by the Pashtuns. They formed the Northern Alliance, a loosely organized group of militants who kept the Taliban at bay until 2000, when a Taliban offensive captured the city of Nahrin and drove its inhabitants into the Hindu Kush Mountains to the east. The American invasion was coordinated with the Northern Alliance and made taking over the country, including the area around Nahrin, much easier than it would have been otherwise.

INTRODUCTION AND FRUSTRATION

As earthquake scientists, we study a natural phenomenon that could destroy a city and could kill tens of thousands of people. For that reason, we are frequently interviewed on television and radio to discuss earthquakes. Invariably, the first thing our interviewer wants to know is “When's the next Big One?” When our answer is “I don't know, exactly,” we frustrate our interviewer, who may start to lose interest. “You've been studying this problem for decades, and you still don't know?” But we are required to talk about identifying earthquakes in advance and say why we're not farther along in answering this question.

In our defense, it should be noted that it is difficult to predict anything. Will the stock market plunge us into a new recession like the one in 2008? Will we suffer a nuclear attack from North Korea? Will we suffer a drought next summer as bad as last summer? Each of these questions has its own army of prognosticators, so the earthquake people have lots of company.

The section on China (Chapter 12) describes the world's first successful earthquake “prediction” in Haicheng, Manchuria – an earthquake of magnitude 7.3 in February 1975. A year-and-a-half later, while the Chinese were still basking under the impression that they had figured out how to predict earthquakes, the nearby city of Tangshan was destroyed by an earthquake of magnitude 7.8, with the loss of more than 240,000 lives. The Haicheng earthquake had been preceded by foreshocks that had rattled the city and alerted its inhabitants to the danger, but the Tangshan earthquake had no foreshocks. It came as a complete surprise. Back to the drawing boards, not just the Chinese but all of us.

The US Geological Survey (USGS) thought it had a key to forecasting an earthquake on the San Andreas fault in a segment of the Coast Ranges of central California. This segment, at the tiny village of Parkfield, experienced moderate-sized earthquakes of magnitude 6 to 6.4 in 1857, 1881, 1901, 1922, 1934, and 1966, repeating every two to three decades.

INTRODUCTION

During my lifetime, the earth sciences have undergone a scientific revolution, as significant as the discovery that matter is composed of atoms containing a nucleus and electrons, or the discovery of DNA. This is the theory of plate tectonics, which completely knocks the props out from what I was taught in graduate school. This theory provides an explanation of why Earth, probably unique among the inner planets, is afflicted with earthquakes. I lived through this paradigm shift, and I now regard it as one of the most thrilling scientific adventures in my own life. Some of the major discoveries in this revolution were made by graduate students who were my own age.

THE PARADIGM SHIFT TO PLATE TECTONICS

Up until World War II, most geologists had no doubt that continents and ocean basins had always been where we now find them, although Alfred Wegener, a German meteorologist, had postulated the theory of continental drift as early as 1912 in the first edition of his book, The Origin of Continents and Oceans. Wegener had observed that you could close up the Atlantic Ocean, and the continents would come back together, like fitting together the pieces of a jigsaw puzzle. In addition, after fitting the puzzle pieces back together into a supercontinent Wegener called Pangaea, the picture on top of the jigsaw puzzle matched. Fossil plants and shallow-water animals on one side of the puzzle were found to be similar to those on the other side, even though the two sides are now separated by thousands of miles of ocean floor. Wegener argued that these plants and animals could not have made their way from one continent across the deep ocean to the other.

Wegener's idea was rejected by the scientific establishment of Europe and North America, but it was attractive to geologists in the Union of South Africa, especially Alexander du Toit. He pointed out that the geology of mountain ranges in South Africa is very similar to the geology of mountain ranges in South America after the continents had been fitted back together.

INTRODUCTION

The second part of this book describes some of the earthquake time bombs that threaten large populations around the world. Some are selected because of their cultural history, including the fourteenth- and fifteenth-century earthquakes in central China, the 1755 Lisbon, Portugal, earthquake, and earthquakes in Palestine, including some described in the Bible. Some are discussed because the cities are in the news for other reasons, such as Kabul, Tehran, and Caracas. Caracas is an example of a city in which its leaders take no interest in the earthquake threat the city faces, and, instead, appear to go out of their way to ignore the problem.

Caracas is an end-member city well known for taking no steps against earthquakes. In contrast, Istanbul is a city with a violent earthquake past, most recently the pair of earthquakes in western Turkey in 1999, but Istanbul is taking major steps to strengthen the city against the next earthquake. Those steps are a work in progress, and the corruption that has been so costly after past earthquakes may frustrate the city's efforts to upgrade its buildings and protect its citizens against earthquakes. Time will tell if Istanbul is successful.

On the other hand, the first time bombs discussed in this section are cities that have been taking steps against earthquake damage and have provided leadership elsewhere in the world. These include cities in California, the Pacific Northwest, Japan, New Zealand, and Chile. In all of these places, the paradigm shift has occurred among the scientists and engineers living there, but for various reasons, the general public is not fully engaged in the problem and its solution. This may come as a surprise to people living in each of these cities, especially in California. But in places like Los Angeles, the job is not done, and the millions of people living there are at great risk, in part because of budget cuts and loopholes in existing laws and bending the rules to accommodate the rush to urban development. In Los Angeles, the mayor has taken on this problem with technical assistance from the USGS and committees within the mayor's office and from other specialists, and if the earthquake takes its time striking southern California, the city may get lucky.