The Old Faithful Geyser in Calistoga, Califomia, puts on an exciting show for tourists. Each time it erupts, steam and hot water shoot over 60 feet into the air. The water comes from an underground river. When water from this river flows over hot magma, the water becomes boiling
hot. Forced through cracks in the earth's rocky crust, water and steam surge out of the ground.
Old Faithful in California is one of the world's three "old faithful" geysers, which erupt at regular intervals. Its Intervals are typically
30 minutes apart. Some researchers believe that changes in this pattern can signal earthquakes. Before several major quakes, there were unusual
delays in Old Faithful's eruptions. For example, on the day before a major quake in 1975, the interval lengthened to 120 minutes. The geyser later
resumed its usual pattern
magma melted rock
Which statement identifies two main ideas of the passage?
1. The Old Faithful Geyser is located in California above an underground river. A change in the Old Faithful Geyser's regular pattern
signaled an earthquake In 1975,
02. The eruptions of the Old Faithful Geyser create dramatic displays that attract many tourists. Researchers study the Old Faithful
Geyser to learn why it erupts every 30 minutes,
3. The eruptions of the Old Faithful Geyser shoot steam and hot water hundreds of feet into the air. Old Faithful is famous because it
erupts more frequently than other geysers,
04. The Old Faithful Geyser erupts when heated underground water rises through cracks in the earth's crust. Changes in Old Faithful's
pattern of eruptions have been associated with earthquakes.