A new campaign was undertaken by Justinian's nephew Germanus Justinus, but he died in 551 CE, succeeded by the general Narses. In 553 CE, Narses defeated Totila and Italy was once again Roman. Justinian's reign lasted almost 40 years, but it was not always popular.
Volcanism is the phenomenon of eruption of molten rock (magma) onto the surface of the Earth or a solid-surface planet or moon, where lava, pyroclastics and volcanic gases erupt through a break in the surface called a vent.ome of this magma may cool extremely rapidly and will form volcanic glass (rocks without crystals) such as obsidian. Magma that remains trapped below ground in thin intrusions cools slower than magma exposed to the surface and produces rocks with medium-sized crystals.
A volcano is a vent or fissure in Earth's crust through which lava, ash, rock and gases erupt. A volcano is also a mountain formed by the accumulation of these eruptive products.Let's take a look at how volcanoes form: Earth's crust is 40 to 250 miles (64 to 402 kilometers) thick. volcano is a vent or fissure in Earth's crust through which lava, ash, rock and gases erupt. A volcano is also a mountain formed by the accumulation of these eruptive products.