Connecting with Holt's Textbooks People, Places, and Change
World Geography Today
American Civics:
Chapter 15 Citizenship in the Community
Holt Science & Technology, © 2005, Earth Science
This shows an aerial view of Sumatra, Indonesia, one of the regions devastated by the tsunami. This photo was taken on January 1, 2005. (U.S. Navy photo by Photographer’s Mate Airman Patrick M. Bonafede)(Click on photo for larger view)
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Holt Glossary
tsunamis (sooh-NAH-mees) Huge waves created by undersea tectonic activity, such as earthquakes |
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Holt Atlas
India
Indian Ocean
Indonesia
Sri Lanka
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Could it happen in the United States?
Research Links
Air Force Airman First Class Sara McClaskey, of the 733rd Air Mobility Squadron, readies a cargo net on an aircraft pallet bound to Southeast Asia as part of disaster relief following the a 9.0 magnitude earthquake that struck the coast of Indonesia causing tsunami waves that have affected 12 countries. The 18th Wing is providing relief supplies and personnel to help with the humanitarian effort. (U.S. Air Force photo by Tech. Sgt. Richard Freeland)
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Tsunami ! Indonesian Earthquake Causes Tsunami
The strongest earthquake in 40 years struck off of the coast of the Indonesian island of Sumatra. The tremor measured 9.0 on the Richter scale—a force about 2 million times that of the atomic bombs that leveled Hiroshima, Japan, in World War II. This quake sent tsunami (sooh-NAH-mee) waves up to 50 feet (15 meters) tall all the way to the shores of eastern Africa, 3,000 miles (5,000 kilometers) away. The waves traveled up to 500 miles per hour (800 kilometers per hour) and struck 11 nations, resulting in the second-highest death toll ever from a seismic event.
The quake was the result of tectonic plate collision. According to the theory of plate tectonics, Earth’s crust is divided into slow-moving plates. The December 26 quake happened when the India plate slid below the Burma plate about 6 miles (10 km) beneath the ocean floor. This rapid movement forced the ocean floor and water upward. The energy was then transmitted across the ocean, causing huge tsunami waves.
Identifying Cause and Effect
Explain the cause-and-effect relationship between tectonic plate movement and tsunami waves.
Historical Understanding
Tsunami is a Japanese word meaning "harbor wave." Tsunamis have struck Japan throughout its history. These enormous waves are caused by earthquakes, volcanoes, or landslides. The Pacific Ocean has had its fair share of these monster waves due to the activity of the region’s tectonic plates. In 1960 the largest quake of the twentieth century struck off the South American coast, sending out enormous tsunamis that were still lethal when they hit Japan. Japan was hit again in 1963 and 1983. Many Japanese coastal communities have built sea walls to help hold back the water. They have also designed buildings so that they can better withstand a tsunami, but perhaps the best protection is an early warning system.
The Pacific Ocean now has such an early-warning system, which consists of devices placed three miles deep in the ocean. The devices are capable of measuring a tsunami only a millimeter in height. The measurements are transmitted to a buoy floating on the water’s surface, which then sends information to a satellite. Computers use the data to detect the unique pattern of a tsunami. This system can warn potential impact sites of impending danger so that people can be evacuated in time to save lives. Early warning systems are planned for the Indian Ocean as well as for the Atlantic, the Caribbean, and the Gulf of Mexico.
Summarizing
What are the Japanese doing to protect themselves from tsunami waves? Why?
Geographical Understanding
A tsunami has the characteristics of any other ocean wave. It does not transport water, as it seems to. Rather, it is energy moving through water, forcing the water to move up and down as the energy passes through. Tsunamis consist of a series of crests (high points) and troughs (low points). Normal ocean waves are created by wind, which transfers some of its energy to the water, but tsunamis are caused by any one of three high-energy events. A common cause is earthquakes, which violently move the sea floor as well as the water above the point of the quake. Underwater landslides also quickly move land and water and can create a tsunami, although these tsunamis do not travel as far as others do. Lastly, underwater or coastal volcanic eruptions can quickly displace volumes of water, creating tsunami waves.
In the open ocean, tsunamis can travel at speeds up to 720 kilometers an hour, but they may be only a meter high. A sailor on a ship far from land might not notice a tsunami as it passes under the ship. As tsunamis approach the shore, however, the rising sea floor forces the waves to rear up and crash onto land. As each wave rises, it pulls the water from the shoreline to add to its volume, briefly exposing vast stretches of ocean floor and expanding beach areas.
Finding the Main Idea
What is the main idea in the first paragraph under Geographical Understanding?
Why Study Geography?
Tilly Smith, a ten-year-old British girl, saved over a hundred lives using what she had learned about tsunamis in her geography class. Tilly was on vacation in Thailand and was enjoying the local beach when she noticed that the ocean waters were quickly disappearing, exposing more and more of the sandy beach. She knew this was the sign of a coming tsunami and was able to convince hotel workers to evacuate the beach before the tsunami arrived. None of the adults on the beach seemed to have recognized the danger that Tilly did, and this points out the importance of understanding geographic concepts.
What You Can Do
Click here for a list of organizations aiding the tsunami victims.
Civics Understanding
The tsunami waves had devastating effects, not only in the loss of life, but in the loss of land that was sucked out to sea and in the destruction of houses and businesses. Much of the land reshaped by the waves will, over time, return to its pre-tsunami state, but a group of Indian islands called the Andaman and Nicobar islands may have been forever changed. An aerial survey of the islands shows that one has been divided into two islands and another has become three separate islands since the disaster.
The destruction of resort areas, such as in Phuket and Khao Lak in Thailand, is having an economic impact on countries who rely on tourist dollars. Tourism accounts for 6 percent of Thailand’s gross domestic product. Travel agencies worldwide are trying to convince vacationers to return quickly to Southeast Asia to help revive the region.
Problem Solving
How might tour operators convince people to vacation in areas that are rebuilding after the tsunami? |