Collapse sinkhole

Definition

A collapse sinkhole is a depression or hole in the ground caused by the sudden collapse of surface material into an underground cavity, often resulting from the erosion of soluble bedrock such as limestone. These features are part of karst topography, where groundwater plays a crucial role in dissolving minerals and creating underground voids. When these voids become unstable, it can lead to dramatic surface collapses that can be hazardous to people and infrastructure.

5 Must Know Facts For Your Next Test

1. Collapse sinkholes can occur suddenly and can vary in size from small depressions to large craters capable of swallowing buildings or roads.
2. These sinkholes are most common in regions with limestone bedrock, where acidic groundwater erodes the rock over time, creating cavities.
3. The risk of collapse sinkholes increases during heavy rainfall when water saturates the ground, adding weight and potentially destabilizing the surface.
4. Collapse sinkholes can be distinguished from other types of sinkholes, such as solution sinkholes, which form more gradually as surface materials dissolve.
5. In some cases, human activities like drilling, mining, or excessive groundwater withdrawal can trigger the collapse of sinkholes.

Review Questions

• How do collapse sinkholes differ from solution sinkholes in terms of formation and appearance?
  • Collapse sinkholes form suddenly when surface materials give way due to the destabilization of an underground cavity, resulting in an immediate depression. In contrast, solution sinkholes develop more gradually as water dissolves the soluble bedrock over time, leading to a slow subsidence of the surface. While both types are associated with karst landscapes, collapse sinkholes often present more dramatic and hazardous changes to the landscape.
• What role does groundwater play in the formation of collapse sinkholes, and how can heavy rainfall affect this process?
  • Groundwater is critical in forming collapse sinkholes as it erodes soluble bedrock like limestone through a process known as dissolution. This erosion creates underground voids that can eventually lead to collapses. Heavy rainfall can exacerbate this process by saturating the ground and increasing pressure on these cavities. When too much weight is added or if water destabilizes the surrounding soil, it heightens the risk for sudden collapses.
• Evaluate the potential hazards associated with collapse sinkholes and their impact on human activities and infrastructure.
  • Collapse sinkholes pose significant hazards due to their sudden nature and potential for large-scale ground failure. They can damage roads, buildings, and utilities, leading to costly repairs and potential injuries or loss of life. In urban areas, where land use is dense, a collapse can disrupt services and require emergency response efforts. Understanding the conditions that lead to these formations is essential for effective land-use planning and risk management to minimize impacts on communities.

Related terms

Karst topography: A landscape formed from the dissolution of soluble rocks, characterized by features such as sinkholes, caves, and underground rivers.

Groundwater: Water that resides beneath the Earth's surface in soil pore spaces and fractures of rock formations, which contributes to the erosion of bedrock and the formation of sinkholes.

Dissolution: The process by which minerals are dissolved by water, playing a critical role in the development of karst features and cavities.