What is indicated if the altimeter setting is low?

When the altimeter setting is low, it means that the pressure at which the altimeter is calibrated to read correctly is lower than the standard atmospheric pressure at sea level. This situation leads to a miscalibration of the altimeter. Specifically, if the altimeter setting is lower than the actual pressure, the altimeter will indicate a higher altitude than the aircraft's true altitude.

As the altimeter relies on the ambient pressure to compute altitude, a low setting results in the altimeter reading more altitude than is actually present, because it interprets the surrounding atmospheric pressure as being higher than it truly is. Therefore, the indicated altitude appears higher than the actual altitude over the ground, which can lead to potential safety hazards, particularly during landing and takeoff, where precise altitude awareness is crucial.

The other options don't accurately capture the implications of a low altimeter setting. The correct answer highlights the understanding of altimeter function and atmospheric pressure relationship necessary for safe flight operations.