List two primary and two secondary impacts of volcanic activity giving detail of each

Primary impacts are those that affect the area in close proximity to the volcano immediately after a volcanic event. A first impact is that of the release of tephra which is solid material that can range in size which are ejected into the atmosphere. Examples of tephra material include volcanic bombs and ash particles. A second primary impact is the release of volcanic gases into the atmosphere. These gasses can include carbon dioxide, carbon monoxide, hydrogen sulphide and sulphur dioxide. Immediate threats from such releases can include suffocation from carbon monoxide due to this gas being heavier than air. Secondary impacts are those that occur days to years after the initial event and may be more diffuse in impact, operating on a local and global scale. For example, a secondary impact that may occur a year after volcanic activity are meltwater flooding events. Where volcanic activity occurs under glaciers and ice caps, the heat generated from volcanic activity can melt ice and lead to large releases of water to lowland regions. A secondary impact that may occur months to years after a volcanic event includes climate change. Releases of volcanic debris into the atmosphere can reduce solar radiation to the surface of the earth, thus altering the global radiation budget and leading to a cooling of the global climate.