Final answer:
Lava flows from quiet eruptions are characterized by low-viscosity lava that leads to gentle, effusive eruptions, whereas explosive eruptions are caused by high-viscosity magma trapping gases, resulting in violent, dangerous eruptions.
Step-by-step explanation:
The difference in lava flows from quiet and explosive eruptions is primarily due to the viscosity and gas content of the magma. Quiet eruptions tend to have low-viscosity lava, which flows easily and results in gentle effusive eruptions. This effusive activity is exemplified by the volcanoes in Hawaii, where lava runs down the flanks of volcanoes, forming broad, gently sloping shield volcanoes. In contrast, explosive eruptions occur when high-viscosity magma traps gases, building up pressure until it is released violently. This type of eruption can produce pyroclastic flows, ash plumes, and significant alterations to the landscape, such as the pyroclastic flows from Mount Vesuvius that devastated Pompeii.