Final answer:
Volcanic gases can accumulate near volcanoes forming dangerous air pockets, as explained by the 1986 Lake Nyos disaster where supersaturated carbon dioxide gas was released and killed over 1700 people.
Step-by-step explanation:
True, volcanic gases can indeed accumulate in hollows near volcanoes, creating dangerous pockets of air. When a volcanic eruption releases gases into the atmosphere, most of these gases are water vapor, but they also include greenhouse gases such as carbon dioxide and acidic pollutants like sulfur dioxide. Over time, gases like carbon dioxide can become supersaturated in lakes formed in volcanic craters, as was the case with Lake Nyos in Cameroon. If the pressure decreases or the temperature increases, the gases may be released in a violent outburst, flowing down into nearby hollows and valleys, forming deadly pockets of air denser than the surrounding atmosphere. This can lead to asphyxiation of humans and animals in those areas, as unfortunately happened in the 1986 Lake Nyos disaster. Therefore, the presence of such gas accumulations is a considerable hazard in volcanic regions.