متن انگلیسی در مورد آتشفشان / فان پاتوق

- Volcanic Hazards The section below describes different types of volcanic hazards. It is taken from a USGS brochure and gives you some idea of the terminology used and associated properties. The information is for reference only.
**Eruption Columns An explosive eruption blasts molten and solid rock fragments (tephra) into the air with tremendous force. The largest fragments (bombs) fall back to the ground near the vent, usually within 3 km. The smallest rock fragments (ash) continue rising into the air, forming a huge, billowing eruption column. Volcanic ash is composed of fragments of