Scientists say the Pacific plate is moving toward the northwest, while the North American plate is moving toward the southeast. These two huge plates come together at what is called a fault line.
This line between the plates in California is called the San Andreas Fault. It is along or near this fault line that most of California’s earthquakes take place, as the two tectonic plates move in different directions.
The city of Los Angeles is about fifty kilometers from the San Andreas Fault. Many smaller fault lines can be found throughout the area around Los Angeles. A major earthquake in nineteen ninety-four happened along one of these smaller fault lines.
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STEVE EMBER: The story of plate tectonics begins with the German scientist Alfred Wegener in the early part of the twentieth century. He proposed that the continents had moved and were still moving.
Wegener said the idea came to him when he saw that the coasts of South America and Africa could fit together like two pieces of a puzzle. He suspected that the two continents might have been one, then split apart.
Wegener said the continents had once been part of a huge area of land he called Pangaea. He said the huge continent had split more than two hundred million years ago. And, he said the pieces were still floating apart.
FAITH LAPIDUS: Alfred Wegener investigated the idea that continents move. He pointed out a line of mountains that appears from east to west in South Africa. Then he noted another line of mountains that looks almost exactly the same in Argentina, on the other side of the Atlantic Ocean. He found fossil remains of the same kind of an early plant in areas of Africa, South America, India, Australia and even Antarctica.
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2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25