San Francisco earthquake of 1906

The San Francisco earthquake of 1906 happened in and near San Francisco, California, United States, North America, in the year 1906. It began at 5:12 A.M. on April 18, 1906 and lasted 151 seconds. The most severe shaking of the ground occurred during the first 60 seconds. The shaking decreased in strength during the next 30 seconds until it stopped. One second later, the shaking began again, lasting another 60 seconds with less strength than that of the preceding 90 seconds of shaking. There were at least two aftershocks. The center of the quake was in the Pacific Ocean. Before the quake reached the city, a swimmer at the beginning of dawn observed the serf to be coming cross-wise rather than parallel to the beach. In the water, he was struck by a small tidal wave, nearly drowned and was then so shaken by the water that the beach appeared to be phosphorescent. The people in San Francisco had already heard of earthquakes, such as the one in Alaska in 1899, the one in Charleston in 1886 and so forth. The New Geology of the Space Age explains earthquakes using the theory of plate tectonics in which separate regions of the Earth’s crust are moving on lava currents beneath, the heat caused by nuclear activity.

Worst quakes of 20th Century

1906 was the most seismically dangerous year of the twentieth century because that year, around the world, several large cities were destroyed. On January 31, there was an earthquake in the Pacific Ocean which shook Ecuador and Colombia, sending large tidal waves as far as Hawaii. Starting on February 16, St. Lucia Island in the Caribbean had several earthquakes over a period of three weeks. The city of Shemakha in the Caucasus Mountains on the west coast of the Caspian Sea had an earthquake on February 21. On March 17, the town of Formosa, Taiwan near China was shaken. Mt. Vesuvius in Naples, Italy erupted for ten days, beginning on April 6, and after the San Francisco quake, the port city of Valparaiso in Chile was destroyed in mid August. Chinese astrologers had predicted 1906 would be a “year of the Fire Horse.”.

Location

The city of San Francisco, named after St. Francis of Assisi, is located on a peninsula between the Pacific Ocean and San Francisco bay in central California, U.S.A. To the east of the city, on the other side of the bay, is Oakland and Mt. Diablo, thirty miles away, from which summit the entire fragile-looking city of San Francisco can be viewed. Although the two-peaked mountain, from which old maps were drawn, abruptly rises from flatland, it is not a volcano. It was formed by the same forces that caused the San Andreas Fault, an earthquake-prone area between San Francisco and San Diego on the western coast of the United States: over many, many millions of years, so the thinking goes, the floor of the Pacific Ocean moved east, bumped into North America and then began moving North West.

The times

In 1906, recent scientific and technological advancements included the equation E=mc^2, which described such things as a candle getting smaller as it burned. There were about 100,000 automobiles in the United States, i.e. there were still a lot of horses and bicycles on the roads. The Wright brothers had recently invented the airplane. New York City was building its first two sky scrapers. Teddy Roosevelt was President and had begun the Panama Canal, and people had heard of Sigmund Freud’s book, The Interpretation of Dreams. Radio and movies were very new. The San Francisco earthquake of 1906 was the first earthquake ever filmed. Unlike the Lisbon earthquake of 1755, no sinners were hung by priests for causing the earthquake. Instead, scientists became more interested in the natural phenomena of the earth and in predicting and dealing with earthquakes.

Plate tectonic theory

According to the tectonic plate theory, the surface of the earth, its crust, is cracked into several large regions called plates. These plates are moved up and down and sideways by currents and bubbles in the layer of lava many miles thick beneath, called the earth’s mantle. Below the mantle is the earth’s molten metal core, spinning at a different speed than the surface. It is very hot because of friction, gravity, chemical reactions, radioactive decay and stored radiant energy from the sun’s rays hitting the surface. Where the tectonic plates move away from each other, volcanic islands form. When they crash into each other, mountains form. Earthquakes happen where the tectonic plates of the Earth’s crust slide alongside each other, such as the Pacific plate and the North American plate. The North American plate and the European are pulling apart in Iceland one-tenth of an inch each year. Such measurements are because of the continental drift theory of the shape of South America in relation to that of Africa. The theory is that the continents have been moving apart for 300 million years and were all once one larger continent called Pangaea which was formed by older continents coming together, and so forth, with the earth being over 4.5 billion years old. Yet tectonic plate theory doesn’t at first seem to account for the 1886 earthquakes in Charleston, South Carolina, in which the ground moved up and down as well as from side to side, since the state is nowhere near the edge of the North American plate. Another example is the earthquake centered in the town of New Madrid Missouri, at the end of 1811. This quake was felt as far away as Montreal, Canada in the year a large comet was in the sky. At New Madrid, the epicenter of the quake, the ground moved only about twelve inches to and fro with a loud roaring noise but also moved up and down causing horses to loose their footing and fall down. Crevasses in the ground opened with a hissing sound, and the Mississippi River flowed backwards for a few minutes. The answer usually given to these exceptions is that the North American Plate is a group of smaller intra-plates, although some consider the New Madrid earthquake evidence of the North American Plate beginning to split in half, in which case volcanoes could form in Missouri.

The Spanish name

Spain began taking control of California, on the west coast of southern North America, in 1769 and established the San Francisco Mission in 1776. Spain’s territory in North America became independent from Spain and called Mexico by 1831. The United States wanted the west coast of the continent, so in 1841 a lot of U.S. farmers and businessmen began moving to California by ship and horse-drawn wagon. In 1846, the U.S. settlers in California rebelled against Mexico, which surrendered California to the U.S. in 1848 nine days after U.S. newspapers reported easy-to-find gold in California, which became a U.S. state in 1850. Many white people looking for gold moved to San Francisco, which kept its Spanish name although the city was controlled by people who spoke English as their first language. People born during the “gold rush” were in their fifties in 1906. Before the earthquake, Governor Pardee considered California’s economy to be in blessed condition.

Climate of surprise

In the United States, the formal west is west of Amarillo, Texas, and like elsewhere on planet Earth at that longitude, it is mostly desert. Near Winslow, Arizona, there is a meteor crater 4,000 feet wide and 600 feet deep. Discovered in the 1870s, people wondered if it was caused by water, dryness, wind, lava, ancient miners or meteor impact. Geologists found the crater was 50,000 years old. It was discovered because after the “gold rush,” the U.S. government had mappings and searches for metal for industry done of the country’s western territories. A famous government-funded surveyor, who loved American Indians, discovered a mining broker’s advertisements to be a fraud, resulting in speculators losing hundreds of millions of dollars. One surveyor, a young Army officer, is said to have wanted the continent’s dark natives to be exterminated. Another was a geology professor and one-armed civil-war veteran who liked American Indians and who was famous for canoeing in the Grand Canyon. He opposed trying to exploit the dry west or changing its unique desert ecosystems. Because of the harsh climate publicized by the surveys, U.S. geologists wondered why the territory first conquered by Spain was so dry rather than why the east near the Gulf of Mexico was not. New Geology’s answer since 1969 has been plate tectonics: the west of the United States is imagined to have bulged up out of the Pacific Ocean, causing the Rocky Mountains to reduce rainstorms heading inland.

San Andreas

Parkfield, California by the San Andreas Fault is halfway between San Francisco and Los Angeles and has mild earthquakes several times a year and larger ones every few decades. As a result, it has many earthquake-detection devices in boxes, and there was once an expensive project in that town involving drilling a deep well for scientific instruments. Its Cholame Creek Bridge is famous. Built in 1936, it crosses the San Andreas Fault. It’s west abutment has moved five feet north since it was built. The San Andreas Fault is a crack separating the Pacific tectonic plate from the North American tectonic plate. Parkfield and San Francisco are right next to the fault. San Francisco experienced earthquakes before the big one of 1906. The epicenter of an earthquake is estimated by the time observed by witnesses or by comparing seismograph reports from different locations, using the speed of sound in rock in calculations. The quake’s epicenter may have been as close as a mile from San Francisco or as far as forty miles to the north. There, someone noticed afterward that a farmer’s fence stopped and then restarted twenty feet to the right. The 750 mile long San Andreas Fault is just to the west of San Francisco. Further south, it is a little east of Palm Springs and it ends a little north east of San Diego, with hot springs and steam. In northern California, the Pacific Plate is rubbing against the North American plate while in southern California, it is pulling away. Other big earthquakes have occurred in California. On July 28, 1769, Spanish explorers traveling north from San Diego experienced a quake which had aftershocks for a week. On July 9, 1857, Los Angeles had one. Reports included huge wavelike shaking which lasted up to three minutes. A nearby river flowed backwards. Fish were thrown out of a lake. Ridges five feet high and fifteen feet across rose and fell in succession in some fields, and the Los Angeles River temporarily changed course.

A major port

The San Andreas Fault is a long, thin valley in the Coast Mountain Range, which looks from above like a long snap in the Earth’s surface, basically from Palm Springs to San Francisco. In 1776, Spain built and occupied Fort San Francisco and Mission San Francisco and established the Town of Yerba Buena, the lots of which remained unsold until 1835 after Mexico had left Spain. In 1847, the island had a population of 200 people and was conquered by the U.S. during a war with Mexico. Six months later, the town had become a city of over 450 people. Its name was changed to San Francisco because that is what the U.S. sailors had thought it was called. After gold was discovered in the biggest mountains of California, in 1848, the population of the town at first went down because people left to look for gold. Then, in 1849, thousands of gold hunters arrived in hundreds of ships, which their crews abandoned. The ships came from all over the world. There were high prices and fights, poor sanitation, cholera outbreaks, and the dead were left on the beach for the tide to take away. After the three-year Gold Rush, San Francisco’s docks began to be called the Barbary Coast, because many young men were forced to become merchant sailors to pay off their bar tabs. By 1863, the population of San Francisco, including its China Town, was over 100,000 people. Photographs show a city looking as if it had been there a long time. In 1873, the city began to have cable cars pull groups of people up hills too steep for horses to pull them. By 1906, San Francisco was a smoggy factory town with a sixteen-story building, a polluted bay, lowering pressure in its fire hydrants and 400,000 people, including neighborhoods of hobo shacks. The $10,000 raised in southern California for Italy to help the victims of a volcano went to San Francisco instead.

Waves of dry land

On October 21, 1868, San Francisco with its miles of brick buildings experienced a rather large earthquake. It lasted 60 seconds. Streets rose and fell. The ground shook. Horses panicked. People rushed into the streets. Buildings were damaged. The spire of a synagogue fell on the pharmacy next door, the building in which Scientific American Magazine had offices collapsed. The front of City Hall was in ruins. After the earthquake, Grand Opera House and the 800-room Palace Hotel were built. 38 years later, during the 1906 quake, the Italian tenor, Enrico Caruso, was staying at the Palace Hotel to sing at the Grand Opera House. Rich people who attended the opera had small cars, some of which were electric. At the time, the city had eighty fire stations with horse-drawn wagons and had thirty-eight steam powered fire engines. Early in the morning, the cablecar engine buildings started pulling the low cables which were like those of a roller coaster on a larger scale. On Wednesday, April 18, 1906, the steamship National City, 87 miles north of San Francisco and 29 miles offshore, felt a sudden upward motion, then a trembling and a forward jolt at 5:03 in the morning. Seven minutes later, in San Francisco, the ground thundered. Eyewitnesses saw huge waves in the ground. A police officer reported a rotary motion which caused part of a building near him to fall. A mile west of him, at City Hall, the shaking of the ground began at 5:10 in the morning. To the east, on the other side of the bay, it began at 5:12 in the morning. At the Palace Hotel, the famous opera singer woke thinking at first he was on a ship at sea. After the hotel was evacuated, it burned to the ground. The thundering in the ground traveled southeastward getting weaker. It was centered along the San Andreas fault and reached Palm Springs. The earthquake was more severe north of San Francisco than south of the city. To the north, most of Santa Rosa’s brick buildings collapsed, its wooden buildings slid off their foundations, and then grape arbors in the countryside were seen rising and falling on waves of earth. By 5:12 A.M., the official time of San Francisco’s experience, the epicenter was at a point on the San Andreas fault about two miles south of the city, at Mussel Rock which became a tourist attraction in a park.

Measuring the quake’s strength

An earthquake size detector, based on the idea of a pen hanging from a string against paper, was used by Catholic missionaries in China in the 1750s. Then, in 1854, such devices were named seismographs, seismos meaning earthquake in Greek. In 1906, there were 96 seismographs in the world. Suggestive of plate tectonics, a seismograph in far away China detected the 1906 earthquake in San Francisco. This was not believed by some people and was considered impressive by others about the strength of the quake. Scientists also interested in such issues as “does a train or the land around it move,” began investigating where the epicenter of the quake was and at what second the shock began. The California State Earthquake Commission determined the epicenter to be north of San Francisco near the village of Olema. Years later, using data from the China seismograph and elsewhere around the world, the epicenter was found to be south of San Francisco, in Mussel Rock Park. Someone wrote a paper saying that witnesses, such as himself, who found the earthquake exciting, and took smiling photos of it, were feeling this way to cope. The earthquake in San Francisco in 1906 sparked a few fires in the northeast of the city, which was near the ships. The shaking of the ground caused underground water pipes to break, as one man found out when he tried to take a bath. The telephones stopped working. Electricity wires fell. Gas pipes broke. The shaking caused some of the buildings to collapse, or parts of them. A soldier ordered sleepy actor John Barrymore to help pick up bricks out of the street. Some of the buildings were dynamited to help make the firebreaks, for by midday there was a wall of flame a mile and a half long moving northeastward and then westward in the city. The fire was contained in the northeast of the city and burned until it ran out of flammable material three days later, when it rained. A huge number of people, 500, had died and 225,000 had become homeless.

Economic shocks

Mayor Schmitz ordered army troops to kill looters. He telegraphed the mayor of Oakland for help and then the governor of California. General Funston sent cables to the War Department in Washington. After the fire was out, the homeless were put in tents sent by the army. These towns had the word camp in their names. A few moths later, the tents were replaced by small green cottages which were inhabited for several years. People continued their habit of going to work. Yet, five months later, most of the debris remained where it had fallen. People spent less, saving their money. Insurance companies couldn’t pay in full. The city told insurance companies and other investors that lack of planning had caused “the fire” and that the city had learned its lesson. The stock market went down as insurance companies tried to pay. Twelve insurance companies went out of business, their stockholders having lost their wealth. One insurance company reopened, giving its policyholders shares of stock instead of money. A group non-Chinese tried to move the China Town in San Francisco to a location southeast of the city, but the retired queen of China refused to sell China’s property on Stockton Street. The business of making movies grew in Los Angeles rather than San Francisco, possibly because of the earthquake.

Cultural effects

Because the 1906 San Francisco earthquake immediately followed the 1906 volcano in Italy, the Pentecostals, or Negro Methodists, used “preventing the wrath of God” as a good reason for more people to go to prayer meetings. Politicians used the loss of documents in the fire as a reason to worry about illegal immigration. Most of San Francisco’s Caucasian poets, writers, composers and other artists who founded its Bohemian Club left the city. The city council’s plan to bulldoze through neighborhoods and businesses to make wide boulevards radiating from city hall, large houses, parks with fountains, and a marble subway was forgotten. The science of architecture learned from what happened, improving fire protection systems and the strength and flexibility of buildings. Scientists became more interested in studying earthquakes and learned the Pacific Plate was pushing the North American Plate and then suddenly moved 21 feet North of San Francisco. The City of San Francisco planned how to respond to future earthquakes, and scientists began looking at possible early-warning signs such as increases in micro-earthquakes.

Keeping record of earthquakes

File:Seismogram of San Francisco earthquake of 1906.JPG

The two biggest earthquakes in the Americas occurred in Chile in 1960 and in Alaska in 1964. Their magnitudes were 9.3 and 9.5 respectively. Most earthquakes are much weaker and are more frequent than destructive earthquakes. In 1857, Mallet measured earthquake intensity by comparing the damage and change in one place with another. In the 1880s, de Rossi and Forel made an intensity scale from one to ten. One meant a slight, harmless quake felt by people and Ten meant a large, disastrous quake. In 1902, Sieberg published a twelve-step scale. In 1990, an international meeting of scientists came up with another twelve-level scale, the EMS. Level One is so slight it can’t be felt. Level Twelve is completely devastating. The levels are based on possible observations of the shock waves, land change and building wreckage. Scales based on human observation are considered to measure intensity. Those based on measurement by devices of ground motion are considered to measure magnitude. The one that sounds like it describes earthquakes is named after its inventor, Charles Richter. The Richter scale is logarithmic: six on the scale means much more than twice three, and so forth. The data is collected by seismic sensors. For example, sensors in California transmit data to telegraph-like drawing devices thousands of miles away. On the wide, slow-moving paper, the tall, vertical scale is in millimeters and the flat, horizontal scale is in minutes. If a tall line appears on the seismogram, its height tells an earthquake’s magnitude. The epicenter can be found if there are sensors sending data from three different locations. Government employees, college professors, architects an others study earthquakes to understand them and to find ways to improve safety. One scientist’s peaceful theory of earthquakes is a form of pantheism. The theory considers the Earth with its lava currents, electric charges, chemical reactions, and glacially slow selective decisions to be, in its totality, alive and involuntarily twitching. Another “no fault” theory has large regions of the Earth’s surface separated by cracks and bumping into each other. A related theory contends large meteors caused earthquakes and huge tidal waves 65 million years ago, ending the Cretaceous Period. Currents in the lava on which the surface of the Earth is said to float is another theory. Evidence for this was found in 2002. There was a 7.9 earthquake in Alaska, and about that time some of the geysers in Yellowstone Park in Wyoming steamed more frequently. The geysers are considered to be the result of an old volcano. The bottom of Yellowstone Lake was found to be rising and falling during the year and lava was discovered a few thousand feet under the lake. Studying earthquakes has made preventative measures possible. For example, it was discovered that Alaska’s oil pipeline which carries large amounts of the mysterious fuel long distances would cross an earthquake zone. As the huge pipe crosses the earthquake zone it rests above ground on wheels and shock absorbers. Another example of useful results from the study of earthquakes is the State of California’s map of earthquake zones, which allows more appropriate architectural planning. 1906 government reports on the San Francisco earthquake have proven to be more reliable than at least one of the disaster books that were thrown together that year.

See also

• Earthquake

References

→Article forked from Wikinfo, April 5, 2011.

• Phillips, R. S., editor. MCMLXXI. San Francisco, city. Funk & Wagnalls New Encyclopedia. USA: Rand McNally Co. ISBN-0-8343-0051-6
• Winchester, Simon. (2005). A Crack in the Edge of the World: America and the Great California Earthquake of 1906, New York, NY: Harper-Collins. ISBN-13: 978-0-06-057199-3

External links

• The Virtual Museum of the City of San Francisco
• The Bancroft Library