The Richter scale is a numerical logarithmic scale developed and introduced by American seismologist Charles R. Richter in 1935. The purpose of the scale is to measure the amplitude of the largest trace recorded by a standard seismograph one hundred kilometers from the epicenter of an earthquake. Tables have been formulated to demonstrate the magnitude of any earthquake from any seismograph. For example, for a one-unit increase in magnitude, there is an increase of times thirty in released energy. To put that another way, each number on the Richter scale represents an earthquake ten times as strong as one of the next lower magnitude. Specifically, an earthquake of magnitude 6 is ten times as strong as an earthquake of magnitude 5. The Richter scale considers earthquakes of 6.75 as great and 7.0 to 7.75 as major. An earthquake that reads 4 to 5.5 would be expected to cause localized damage, and those of magnitude 2 may be felt. It is estimated that almost one million earthquakes occur each year, but most of them are so minor that they pass undetected. In fact, more than one thousand earthquakes of a magnitude of 2 or less occur every day. 1. 1. What does this passage mainly discuss?
(A) Earthquakes
(B) The Richter Scale
(C) Charles F. Richter
(D) Seismography
2. 2 . In what kind of textbook would this passage most likely be found?
(A) History
(B) Biography
(C) Geology
(D) Mathematics
3. 3. According to information in the passage, what does the Richter scale record?
(A) The distance from the epicenter
(B) The amplitude of the largest trace
(C) The degree of damage
(D) The location of the epicenter
4. 4. The word “standard” in line 3 could be replaced by ...
(A) reliable
(B) complex
(C) conventional
(D) abandoned 5. What is the value of the tables?