Which progression results when differential wave erosion undermines a stack?

💡 Explanation

Arch formation precedes collapse because wave action erodes less resistant material at the stack's base via hydraulic action, creating an arch. Therefore, an arch forms until the roof collapses under gravity, rather than protective caprock or lagoon growth.

• Which mechanism primarily controls sediment sorting within an alluvial fan environment during flood events?
• Which risk increases for unguided rockets launched near the subtropical jet stream?
• Which outcome results from hydraulic action eroding stacks?
• Which outcome occurs more slowly as agricultural topsoil undergoes drastic reduction in arthropod populations?
• Which outcome occurs when excessive sediment accumulates behind a coastal barrier due to substantial longshore drift?
• Which outcome occurs when groundwater weakens a fault?