Which statement concerning SIGMET advisories is correct?

SIGMETs, or Significant Meteorological Information advisories, are critical alerts issued by meteorological authorities to inform pilots of hazardous weather conditions that could impact flight safety. One primary purpose of SIGMETs is to communicate information regarding significant meteorological phenomena, including volcanic eruptions.

Volcanic eruptions can cause significant hazards to aviation, such as ash clouds that can damage aircraft engines, disrupt aerodynamics, and reduce visibility. Therefore, when a volcanic eruption occurs, it merits a SIGMET so that all pilots in the vicinity are made aware and can take appropriate safety measures. This specificity is essential for maintaining safe flying conditions and preventing potentially catastrophic encounters with ash clouds.

In contrast, other options refer to less severe weather phenomena or weather conditions that do not qualify for a SIGMET. For example, light icing and light turbulence would generally be covered by other advisories rather than requiring a SIGMET. Widespread areas of dense fog do not typically generate SIGMETs either, as they impact visibility but do not pose the same level of aviation hazard as volcanic activity. Thus, the issuance of SIGMETs for volcanic eruptions is a clear example of the advisory's purpose in addressing significant aviation hazards.