Volcanic eruptions are classified by their violence and the viscosity of their magma. Hawaiian eruptions are the least intense, producing fluid basaltic lava flows. Strombolian eruptions follow, involving moderate bursts of glowing cinders. Vulcanian eruptions are significantly more powerful, launching dark, ash-laden clouds and solid rock fragments. At the peak of intensity is the Pelean type, named after Mount Pelée. These are characterized by extremely thick magma that traps gases until they explode, generating nuées ardentes or pyroclastic flows. This scale helps seismologists categorize the danger levels associated with different volcanic structures and their specific tectonic settings.