The correct option is (c) 2 and 3 only.
Explanation
The Richter scale is a standard scale used to compare earthquakes. It describes the magnitude of an earthquake by measuring the seismic waves that cause the earth to shake. It is based on a mathematical logarithmic formula.
Statement-wise Analysis:
- Statement 1 is Incorrect: The Richter scale is not a linear scale; it is a logarithmic scale (base 10). On a linear scale, steps are equal (e.g., 1, 2, 3), but on a logarithmic scale, each step represents a multiplication by a specific factor rather than simple addition.
- Statement 2 is Correct: Because the scale is logarithmic, small increases in magnitude correspond to huge increases in released energy. An earthquake of magnitude 6 releases significantly more energy than one of magnitude 4, leading to much greater destructive potential.
- Statement 3 is Correct: The relationship between magnitude and energy is such that for every increase of 1 in magnitude, the energy released increases by a factor of approximately 31.6 (often approximated as 32). Therefore, an increase of 2 in magnitude corresponds to an energy increase of approximately $31.6 \times 31.6$, which equals roughly 1000 times more destructive energy.
Key Takeaway:
On the Richter scale, an increase of 1 unit in magnitude implies a 10-fold increase in wave amplitude and approximately a 32-fold increase in energy. An increase of 2 units implies a 1000-fold increase in energy.