Which risk increases when magma viscosity rises in stratovolcanoes?

💡 Explanation

Elevated magma viscosity increases the risk of pyroclastic flow, because increased silica content creates resistance to flow, causing explosive eruptions via pressure build-up. Therefore pyroclastic flows intensify, rather than expanding lava flow, due to lower flow mobility being the trigger.

• Which outcome occurs when freeze-thaw cycles induce solifluction on steep Arctic slopes?
• Which outcome increases when soil parent material weathers in poorly-drained areas?
• In arid climates, which consequence results when deflation exposes caliche layers?
• Which effect occurs due to overriding plate deformation?
• Which phenomenon significantly reduces a river's sediment-carrying capacity when it enters a lake or ocean?
• Which risk increases when a building constructed on permafrost causes thawing of ground ice at the foundation?