stratovolkanok

Stratovolkanok, commonly referred to as stratovolcanoes or composite volcanoes, are a type of volcano characterized by steep, conical profiles built from alternating layers of hardened lava, tephra, pumice, and volcanic ash. They typically erupt viscous magmas—andesitic to rhyolitic—that trap gases until pressure builds, often producing explosive eruptions.

Most stratovolcanoes form at convergent plate boundaries where subduction drives melting of mantle rocks. The alternating layers result from periodic eruptions that lay down ash and pumice between lava flows. Their steep slopes arise from the viscous magma, which tends to pile up near the vent rather than flow far.

Activity can vary from effusive lava flows to powerful explosive events (Plinian to Vulcanian), generating pyroclastic flows, ash clouds, and volcanic surges. Hazards include ash fall, pyroclastic flows, lava domes, lahars, and sector collapse. Monitoring uses seismicity, gas measurements, ground deformation, and remote sensing to forecast eruptions and mitigate risks.

Notable examples include Mount Fuji (Japan), Mount Vesuvius (Italy), Mount St. Helens (USA), Mount Etna (Italy), Merapi (Indonesia), and Sakurajima (Japan). Stratovolcanoes are common around the Pacific Ring of Fire and other subduction zones, with eruption histories ranging from long quiescent periods to sudden, catastrophic events.