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 chimney which transfers molten rock known as magma from depth to the Earth's surface.Magma erupting from a volcano is called lava and is the material which builds up the cone surrounding the vent. A volcano is active if it is erupting lava, releasing gas or generates seismic activity. volcano is a vent or chimney which transfers molten rock known as magma from depth to the Earth's surface.