Which outcome occurs when lahars block valley passages?

💡 Explanation

A lahar is volcanic debris flow; blocking river channels causes impoundment. This forms a lahar-dammed lake because the blockage redirects flow accumulating material; therefore, a lake forms, rather than an increase in volcanic intensity.

• Which mechanism explains stream channel pattern changes when base level significantly drops due to rapid tectonic uplift?
• Which process causes terraced landscapes within an alluvial river valley environment?
• Which mechanism influences stream course alignment in areas bisected by a transform fault?
• Which mechanism most directly enhances stream downcutting into bedrock in humid temperate climates?
• Which outcome results when coastal upwelling weakens unexpectedly along the western coastline of South America?
• Which atmospheric motion results because the Coriolis effect deflects air masses moving poleward in Hadley cells?