Which of the following statements with reference to Richter scale is/are correct ? 1. It is the intensity scale of an earthquake. 2. Richter indicates the amount of energy released during the earthquake. Select the answer using the code given below :

The Richter scale is a magnitude scale, not an intensity scale [1]. Magnitude measures the size or strength of an earthquake based on the energy released at its source, whereas intensity refers to the visible damage and effects observed on the surface [4]. The intensity of an earthquake is typically measured using the Modified Mercalli Scale, which ranges from 1 to 12 [1]. Statement 1 is therefore incorrect. Statement 2 is correct because the Richter scale specifically relates to the amount of energy released during a seismic event [1]. It is a logarithmic scale where each whole number increase represents a tenfold increase in measured wave amplitude and approximately a 32-fold increase in the actual energy released [2]. While modern seismologists often use the Moment Magnitude Scale for larger events, the Richter scale remains the foundational magnitude scale for measuring energy release [2].

Sources

1. [1] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 3: Interior of the Earth > Measuring Earthquakes > p. 21
2. [4] Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 17: Contemporary Issues > Earthquakes > p. 8
3. [2] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 14: Earthquakes > 14.5. Richter Magnitude Scale > p. 182