What is tephra?

Tephra refers specifically to the volcanic material that is ejected during an eruption. This includes a variety of particles such as ash, pumice, and volcanic rock fragments that are expelled from a volcano and can be distributed over large distances by wind and pyroclastic flows. This material can vary in size and composition, and it is categorized based on particle size, with terms like volcanic ash (very fine material) and lapilli (larger fragments) included in the classification. Understanding tephra is crucial in volcanology and for assessing volcanic hazards, as it can affect air quality, agriculture, and infrastructure in nearby regions.