GEOLOGY

Detailed explanation-1: -If a magma has low viscosity (it is runny), gas can escape easily, so when the magma erupts at the surface it forms lava flows. These eruptions are (relatively!) gentle, effusive eruptions.

Detailed explanation-2: -Shield volcanoes, those with broad, gentle slopes, produce the quietest eruptions. The Hawaiian Islands are not only home to active shield volcanoes, but the chain is actually built entirely by them. The two most common types of volcanoes known for producing explosive eruptions are cinder cones and stratovolcanoes.

Detailed explanation-3: -Effusive eruptions involve the outpouring of basaltic magma that is relatively low in viscosity and in gas content. Explosive eruptions generally involve magma that is more viscous and has a higher gas content. Such magma is often shattered into pyroclastic fragments by explosive gas expansion during an eruption.

Detailed explanation-4: -Shield Volcanoes Because mafic lava is low viscosity, when it erupts from a volcano it flows downslope away from the vent, gradually cooling and crystallizing. Because of the relative ease of flow, basaltic volcanoes are broad, with gentle slopes.