Shield Volcanoes: These are formed when non-explosive activity leads to the slow accumulation of hot, runny basaltic lava. The lava can flow great distances, leading to volcanoes with gentle slopes and a large circumference. For instance, Mauna Loa in Hawaii, with its shallow crater and 6° slope, is a classic example. Fun fact: Mauna Loa's height from its base on the sea floor is a whopping 9,750 m!

Composite (or Strato) Volcanoes: These volcanoes are created by alternating eruptions of fragmental material and lava outflows. They are marked by slopes of 3° near the summit and 5° near the base. Famous examples include Mount Etna and Vesuvius in Italy, Chimborazo and Popacatepetl in Mexico. Ever seen an eruption that blows the top off a volcano and forms a secondary cone within? That's a feature of composite volcanoes!

Cinder Volcanoes: Cinder volcanoes form around the vent as solid material accumulates into a steep conical hill, creating a cone. Their steepness can be between 30°–40°, based on the material's size. Volcano Du Fuego in Guatemala, which stands at 3,350 m, is a cool example of this type. In the U.S, places like Big Cinder Butte and Inferno Cone are also cinder volcanoes.

Lava Eruptions: The amount of silica in the lava defines the nature of the eruption. The lava at meeting points of oceans and continents absorbs silica-rich sediments, causing the lava to become more viscous. This can cause violent eruptions, like in Japan and the Philippines. Iceland and Hawaii, however, have continuous eruptions due to less viscous lava.

Pyroclastic Eruptions: These are explosive eruptions resulting in pyroclastic rock (hardened lava fragments). They are classified into Strombolian, Vulcanian, Vesuvian, Plinian, and Pelean eruptions based on their magnitude and the nature of the ejected material. The famous 79 AD eruption of Vesuvius was a Vesuvian eruption, and the one that occurred in Mount Pelee in 1902 was a Pelean eruption.