If a major solar storm (solar flare) reaches the Earth, which of the following are the possible effects on the Earth?

1. GPS and navigation systems could fail.
2. Tsunamis could occur at equatorial regions.
3. Power grids could be damaged.
4. Intense auroras could occur over much of the Earth.
5. Forest fires could take place over much of the planet.
6. Orbits of the satellites could be disturbed.
7. Shortwave radio communication of the aircraft flying over polar regions could be interrupted. Select the correct answer using the code given below:

A solar flare is a sudden release of energy from the Sun, emitting intense electromagnetic radiation.

Here's an analysis of the statements:

• Statement 1 is correct: GPS and navigation systems rely on satellite signals, which can be disrupted by solar flares.
• Statement 2 is incorrect: Tsunamis are caused by undersea earthquakes or volcanic eruptions, not solar flares.
• Statement 3 is correct: Power grids are vulnerable to geomagnetic disturbances caused by solar flares, potentially leading to blackouts.
• Statement 4 is correct: Solar flares can cause intense auroras (Northern and Southern Lights) over a wider area than usual.
• Statement 5 is incorrect: There is no direct correlation between solar flares and forest fires.
• Statement 6 is correct: Satellite orbits can be affected by the increased atmospheric drag caused by the heating of the atmosphere during a solar flare.
• Statement 7 is correct: Shortwave radio communication, especially for aircraft flying over polar regions, can be interrupted due to increased ionization in the atmosphere.

Hence, the correct answer is C: 1, 3, 4, 6, and 7 only.