For anyone who lives in California, earthquakes are a common occurrence. Southern California itself has over a thousand earthquakes each year, although most of them are too minor to be felt. The reason behind such high incidence of earthquakes in California is because the state lies in the San Andreas fault zone. It is a major fault zone that forms the tectonic boundary between the Pacific and the North American tectonic plates.
Cause of Earthquakes in California
The Earth's crust is made up of a number of plates that are constantly on the move. Stretching or compression in the plates causes fractures along the Earth's surface. These fractures are known as faults. When the plates rub or slide past each other they form a transform boundary. The San Andreas fault is the most famous transform boundary that stretches over 1000 miles. It has the Pacific Plate to its west and the North American Plate to its east. Scientific studies have shown that the Pacific Plate is moving in the northwest direction as related to the North American Plate. The tension that is created due to constant rubbing of the two plates is the major reason of earthquakes in California.
Major Earthquakes in California
Though few records are available, the first major earthquake for California is believed to have occurred in 1769, probably near the San Andreas fault. It occurred in the Los Angeles area of California in which four violent shocks were felt. Some of the major earthquakes that occurred in California in the 20th century are:
By Debopriya Bose
Make Your Own Preparedness Kit
Cause of Earthquakes in California
The Earth's crust is made up of a number of plates that are constantly on the move. Stretching or compression in the plates causes fractures along the Earth's surface. These fractures are known as faults. When the plates rub or slide past each other they form a transform boundary. The San Andreas fault is the most famous transform boundary that stretches over 1000 miles. It has the Pacific Plate to its west and the North American Plate to its east. Scientific studies have shown that the Pacific Plate is moving in the northwest direction as related to the North American Plate. The tension that is created due to constant rubbing of the two plates is the major reason of earthquakes in California.
Major Earthquakes in California
Though few records are available, the first major earthquake for California is believed to have occurred in 1769, probably near the San Andreas fault. It occurred in the Los Angeles area of California in which four violent shocks were felt. Some of the major earthquakes that occurred in California in the 20th century are:
- The 1906 San Francisco Earthquake
On the morning of April 18, 1906, San Fransisco and the northern coast of California were shaken by a severe earthquake of a moment magnitude of 7.8. Dubbed as one of the worst natural disasters of its times, the 1906 San Francisco earthquake ruptured the San Andreas fault for over 296 miles. The epicenter is believed to have been somewhere close to Mussel Rock on the coast of Daly City. The earthquake caused around 3000 deaths and left 225,000 to 3000,000 people homeless. The earthquake and the ensuing fire destroyed over 80% of the city. By the 1900s San Francisco had developed as the financial and cultural center of the west. Although the city recovered quickly from the destruction, the earthquake diverted trade and population towards Los Angeles. - The 1952 Kern County Earthquake
The Kern County Earthquake of 1952 occurred on the White Wolf fault that lies to the north of where the San Andreas and the Garlock faults intersect. It measured 7.5 on the moment magnitude scale and was the second strongest earthquake of the century after the 1906 San Fransisco earthquake. It killed 12 people and caused damage to property worth over $50 million. - The 1971 San Fernando Earthquake
Also known as the Sylmar earthquake, this earthquake hit the San Fernando Valley near Sylmar in the early morning of February 9, 1971. The earthquake with a moment magnitude of 6.6, caused 65 deaths and damage to property worth over $500 million. Most of the deaths were caused due to the collapse of Veteran's Administration Hospital at San Fernando and the Olive View Community Hospital in Sylmar. The earthquake caused a total surface rupture of 19 kilometers and a dip of up to 2 meters. - The 1989 Loma Prieta Earthquake
The Loma Prieta earthquake was a destructive earthquake that struck the San Francisco Bay Area of California on October 17, 1989. It measured 6.9 on the moment magnitude scale and destroyed property worth $6 billion. It killed over 3000 people and rendered 8,000 to 12,000 people homeless. - The 1994 Northridge Earthquake
On the morning of January 17, 1994, a strong earthquake measuring 6.7 on the moment magnitude scale hit Los Angeles. The earthquake that lasted for 20 seconds produced the strongest ground motions ever felt in urban America. Major freeways and office buildings collapsed. The earthquake injured as many as 8700 people and caused loss of $25 billion to property. Although the epicenter of the earthquake was in Resada, it is referred to as the Northridge Earthquake due to the large scale destruction it caused in that area.
By Debopriya Bose
Make Your Own Preparedness Kit
