VOA慢速英语2009年-SCIENCE IN THE NEWS - Could Typhoons Help(在线收听) |
VOICE ONE: This is SCIENCE IN THE NEWS in VOA Special English. I'm Bob Doughty. VOICE TWO: And I'm Faith Lapidus. This week, we will tell how some storms might help to prevent large earthquakes. We will tell about the winner of the two thousand nine World Food Prize. We will also tell about a study of one of the world's most unusual-looking animals. (MUSIC) VOICE ONE: New research suggests that ocean storms could be helping to prevent powerful earthquakes -- at least on the island of Taiwan. Typhoons often strike the island during the second half of the year. Typhoon is the name used for major storms in the western Pacific Ocean. Scientists call them cyclones when they develop over the Indian Ocean. Recently, scientists reported that typhoons striking Taiwan can cause slow earthquakes. Slow earthquakes are different from violent earthquakes, which happen suddenly and can be extremely destructive. Instead, slow earthquakes release their energy over a period of hours or even days. People cannot feel slow earthquakes on the ground, and instruments like seismometers cannot measure them. However, scientists say a slow earthquake could be helping to release pressure, and possibly preventing more powerful quakes. VOICE TWO: In the study, scientists placed highly sensitive measuring equipment two hundred to two hundred seventy meters under the ocean's surface. These devices were placed in holes near eastern Taiwan. This same area is also where two major tectonic plates meet. As many as twenty tectonic plates cover the Earth's surface. The plates can cause earthquakes as they move. The scientists collected measurements from two thousand two until two thousand seven. The information they gathered suggests typhoons and slow earthquakes near Taiwan are linked. The equipment measured twenty slow earthquakes during the five-year observation period. Of those twenty, eleven took place at the same time as typhoons. VOICE ONE: Typhoons cause atmospheric pressure to drop. The scientists suggest that this causes a reduction in pressure on the land where the plates meet. As a result, one side of the fault area lifts, causing the pressure that has been building up inside to be released. This could explain why Taiwan has a large number of small earthquakes, but rarely a major one. The findings were published last month in the British journal Nature. The lead researcher was Chiching Liu of the Institute for Earth Sciences at Academia Sinica in Taipei. The findings help to show how and why different kinds of earthquakes take place. This, scientists believe, could lead to better earthquake predictions. (MUSIC) VOICE TWO: You are listening to the VOA Special English program SCIENCE IN THE NEWS. With Bob Doughty, I'm Faith Lapidus in Washington. (MUSIC) Sorghum is an important grain for Africa. Millions of Africans have more to eat because of Gebisa Ejeta. The Ethiopian scientist developed sorghum seeds that can resist long dry periods. The seeds can also resist the Striga weed, a big cause of crop failures in Africa. Now his work has earned him the World Food Prize from the World Food Prize Foundation in Des Moines, Iowa. Secretary of State Hillary Clinton made the announcement last month in Washington, D.C. She said Professor Ejeta did not just develop the seeds. He also worked to get them to farmers. He will receive the two hundred fifty thousand dollar award at a ceremony in October. He is only the second African to win the prize since it was established in nineteen eighty-six. Monty Jones, a rice expert from Sierra Leone, was the winner in two thousand four. VOICE ONE: Gebisa Ejeta is a professor at Purdue University in Indiana. Over the years, he has worked with farmers and seed companies and developed more than eighty seed types for Africa. In the early nineteen eighties, Professor Ejeta developed the first sorghum hybrid seeds. These resisted drought and led to a major increase in production. Drought is not the only enemy. Striga is a parasitic plant that Africans commonly call witchweed. The weed attacks sorghum and other crops and steals water and nutrients from the roots. In the nineteen nineties, Gebisa Ejeta and another Purdue researcher identified the complex relationships between Striga and sorghum plants. That finding led to the development of seeds resistant to both Striga and drought. VOICE TWO: Gebisa Ejeta was raised in a one-room hut in a rural village in west-central Ethiopia. His mother wanted him to get an education. He walked twenty kilometers to school in a neighboring town. He left home on Sunday nights and returned on Fridays. For secondary school, he attended an agricultural and technical school. It was established by Oklahoma State University under an American government program. From there he received an invitation to study at Purdue, where he continued his education. But Professor Ejeta has never forgotten his African roots. Today he urges other scientists to turn their attention to Africa's needs. (MUSIC) VOICE ONE: The long-beaked echidna is one of the oldest and rarest mammals on Earth. It is also one of the most unusual-looking animals. About the size of a small dog, echidnas look like a mixture of a porcupine, an anteater, a pig and a mole. Echidnas are part of a group of egg-laying mammals called monotremes. The only other kind of monotreme alive today is the platypus. There are four kinds of echidnas: three species are long-nosed, while another has a short nose. Echidnas are like birds and reptiles because they lay eggs. And, like birds they have a single opening with which they produce eggs, have sex and expel waste. But echidnas are mammals, so they feed their young, called puggles, with milk. VOICE TWO: The long-beaked echidna is an endangered animal that only lives north of Australia, on New Guinea and nearby islands. Until recently, almost nothing had been written about echidnas living in the wild. This is partly because they are very private, live in areas without human beings, and only come out to feed at night. It takes great patience to study this secretive creature. Biologist Muse Opiang became interested in the echidna while working as a researcher in the rain forests of New Guinea. The Journal of Mammology recently published his report about the echidna. It was one of the first reports published on the biology of the animal. Mister Opiang spent years searching for echidnas. Over twenty months, he spent almost six thousand hours searching in a protected area in the Simbu Province of Papua New Guinea. His research was carried out between two thousand and two thousand three. During this period, he only found twelve echidnas, five of which he captured twice. In total, he found twenty-two echidnas over five years. VOICE ONE: Muse Opiang studied how echidnas eat, by digging in the earth with their long noses to find worms. And, he captured them temporarily to record their mass, length and estimated age. He studied more than two hundred echidna shelters to understand where they like to hide and how often they change homes. Mister Opiang also placed a computer chip into the skin of the animals for identification purposes. Some echidnas received a radio transmitter so he could follow their movement. These devices were not always helpful since they easily became disconnected. VOICE TWO: Mister Opiang's study gives new information about the echidna and its behavior. And, it provides examples of how to search for and study this animal. But many questions remain. For example, experts are still not sure what kind of animals hunt echidnas. Other researchers praised Muse Opiang's report. They say it will help scientists better understand how to protect long-beaked echidnas and the areas where they live. (MUSIC) VOICE ONE: This SCIENCE IN THE NEWS program was written by Dana Demange, Jerilyn Watson and Brianna Blake. Mario Ritter was our producer. I'm Bob Doughty. VOICE TWO: And I'm Faith Lapidus. We would like to hear from you. Write to us at Special English, Voice of America, Washington, D-C, two-zero-two-three-seven, U-S-A. Or send your e-mails to [email protected]. Join us again next week for more news about science in Special English on the Voice of America. |
原文地址:http://www.tingroom.com/voa/2009/7/78984.html |