By analysing the fingerprints of ash layers found within a peat core, and matching those back to the eruption, we can determine the age of that peat section.
O dda-dansoddi olion bysedd yr haenau lludw sydd i’w canfod mewn craidd mawn, a pharu’r rheiny gyda’r ffrwydrad, gallwn bennu oedran y rhan honno o’r mawn.