Here is the homework~~~

 

I saw the Guatemala Sinkhole after you said. It was so terrible, but really amazing situation.

 

A sinkhole, also known as a sink, shake hole, swallow hole, swallet, doline or cenote, is a natural depression or hole in the earth's surface caused by karst process - the chemical dissolution of carbonate rocks.

 

The sinkholes are common where the rock below the land surface is limestone, carbonate rock, salt beds, or rocks that can naturally be dissolved by circulating ground water. As the rock dissolves, spaces and caverns develop underground. These sinkholes can be dramatic because the surface land usually stays intact until there is not enough support. Then, a sudden collapse of the land surface can occur.

 

Sinkholes may vary in size from less than 1 to 300 meters both in diameter and depth. The sinkhole made at Guatemala on june 1 was 30 meter diameter and 60 meter depth.

 

Simillarly, bluehole is made on sea.

 

See you tomorrow. Thank you.