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 approximately 1 F for every sixty feet under the earth’s surface, and pressure increases with depth, the water that seeps down in crack and fissures until it reaches very hot rock in the earth interior becomes heated to temperature in excess of 290 F.
Because of the greater pressure, the water shoots out of the surface in the form of steam and hot water. The result is a geyser. In order to function, then a geyser must have a source of heat, 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 some regions of the world including New Zealand, Iceland, and the Yellowstone National Park area of the United States. The most famous geyser in the world is Old Faithfull in Yellow Park. Old Faithfull erupts almost every hour, rising to a height of 125 to 170 feet and expelling more than ten thousand gallons during each eruption.
1. The text is about … .
A. some reasons why a geyser forms
B. the formation process of a geyser
C. some factors that form a geyser
D. a few conditions for a geyser to form
E. what makes a geyser form
2. How does a geyser form?
A. From a huge tension of heated water coming out from the earth crack.
B. By the rise of temperature, pressure, and hot steam.
C. From the heated temperature in earth crack that absorbs water.
D. From the temperature and absorbed water that occurs on earth surface.
E. By the hot water and temperature of hot rock that occurs on earth surface.
3. Paragraph 2 mentions … conditions for a geyser to function.
4. Steam and hot water shoot out of the surface because of … .
A. hot rock and water
B. temperature and pressure
C. greater pressure
D. high temperature and increased pressure
E. underground temperature and increased pressure
5. A geyser is basically … .
A. heat and vapor
B. steam and hot water
C. opening and crack
D. a volcanic eruption
E. escaping steam
6. The word it in paragraph refers to … .
7. What does ‘an opening through which water and steam can escape’ mean?
A. a crack in the earth
B. a big hole in the earth
C. a cave on the earth’s surface
D. a door through which you enter
E. an underground cave
8. Use context clues. What does the word expelling in the last paragraph probably mean?