Sinkholes have been causing havoc recently - but what exactly are they?

There have been many stories about sinkholes opening up recently in the UK and elsewhere, swallowing cars and creating scenes worthy of a sci-fi blockbuster. However, geographers know that these features can be formed through natural processes (such as those occurring in karst landscapes) but their dramatic appearance can also be triggered by human activity. The photograph below is from 2010 and shows a 200ft sink hole that appeared in Guatemala City, killing at least one man when it caused a three-storey building to collapse. Thankfully, those that have appeared in recent months closer to home have not resulted in any deaths but these eerie features have been appearing more frequently of late. The reasons behind this are concerned with both human and physical Geography.The video below shows footage from both the UK and around the world and gives an overview of the causes of ground collapse.http://youtu.be/qZpzKuuP9PQ

This article from The Independent is excellent. It breaks the content down into the following headings:

1. What is a sinkhole?

2. What are the different types?

3. What causes them?

4. Why are there so many now?

5. How bad have we got it?

6. What about the rest of the world?

For anyone studying Rocks, Resources and Scenery (or a similar topic) at GCSE this would be an interesting read. It also highlights links between physical geography topics (meteorology, geology, weathering for example) and human topics (climate change and urbanisation) as well as cross-curricular links with chemistry.

A BBC Horizon Documentary Swallowed by a Sinkhole is available on iPlayer until 3rd March.