Reading Comprehension 9 : The Old Faithful in Yellowstone Park

  A geyser is the result of underground water under the combined conditions of high temperatures and increased pressure beneath the surface of the Earth. Since temperature rises about 1F for every sixty feet under the Earth surface, and pressure increases with depth, water that seeps down in cracks and fissures until it reaches very hot rocks in the Earth’s interior becomes heated to a temperature of approximately 290°F.

         Water under pressure can remain liquid at temperatures above its normal boiling point, but in a geyser, the weight of the water nearer the surface exerts so much pressure on the deeper water that the water at the bottom of the geyser reaches much higher temperatures than does the water at the top of the geyser. As the deep water becomes hotter, and consequently lighter, it suddenly rises to the surface and shoots out of the surface in the form of steam and hot water. In turn, the explosion agitates all the water in the geyser reservoir, creating further explosions. Immediately afterward, the water again flows into the underground reservoir, heating begins, and the process repeats itself.

         In order to function, then, a geyser must have a source of heat, a reservoir where water can be stored until the temperature rises to an unstable point, an opening through which the hot water and steam can escape, and underground channels for resupplying water after an eruption.

         Favorable conditions for geyser exist in regions of geologically recent volcanic activity, especially in areas of more than average precipitation. For the most part, geysers are located in three regions of the world: New Zealand, Iceland, and the Yellowstone National Park area of the United States. The most famous geyser in the world is Old Faithful in Yellowstone Park. Old Faithful erupts every hour, rising to a height of 125 to 170 feet and expelling more than ten thousand gallons during each eruption. Old Faithful earned its name because, unlike most geysers, it has never failed to erupt on schedule even once in eighty years of observation.

 Vocabulary
geyser: Air mancur panas
Beneath: Di bawah
surface : Permukaan
Since : sejak
rise : Naik
pressure : tekanan
crack : retakan
Fissures: celah-celah
Liquid: Cairan
Boiling: Mendidih
exerts : Menggunakan
Reservior : waduk
furher : Lebih lanjut
Afterward ; setelah itu
Favorable: baik
Regions : Wilayah-wilayah
famous: Terkenal

Main Idea
1.The beginning process of geyser creation
2.The Futher process of geyser creation
3. Geyser resupplying water after an eruption.
4. Old Faithful in Yellowstone Park is the most famous geyser in the world

Summary
A geyser is a result of underground water under the combined conditions of high temperature and increased pressure beneath the earth’s surface.
A Geyser eruption occur the weight of the water nearer the surface exerts so much pressure on the deeper water that the water at the bottom of the geyser reaches much higher temperatures than does the water at the top of the geyser. it suddenly rises to the surface and shoots out of the surface in the form of steam and hot water.
A geyser must have a source of heat, a reservoir where water can be stored until the temperature rises to an unstable point.
The most famous geyser in the world is Old Faithful in Yellowstone Park. Old Faithful erupts every hour unlike most geysers, it has never failed to erupt on schedule.

Questions:

  1. What is the main topic of the passage?
  2. What is an important factor for a geyser to erupt?
  3. What does the word it in paragraph 1 refer to?
  4. What is happened as depth increases?
  5. For what reason does the author mention New Zealand and Iceland in paragraph 4?
  6. How many times does Old Faithful erupt?
  7. What does the word expelling in paragraph 4 mean?
  8. What does the author intent by the statement : Old Faithful earned its name because, unlike most geysers, it has never failed to erupt on schedule even once in eighty years of observation?
  9. According to the passage, mention some requirements for a geyser to function!