Land sinking, water encroaching

A recent article in The Boston Globe Land around the US is sinking detailed the "hot spots" of sinking land in the United States. Some of the sinking is due to long-term tectonic activity, some to human extraction from the earth (oil, gas, and coal, water for drinking, and minerals used in LED batteries), causing voids down below that the surface sinks to meet. A small part is due to the accumulated mass of large buildings.Many of the fastest sinking places are in Southeast Asia and are due most to the extraction of clean groundwater for people to drink.The biggest sinkers in the US are along the Gulf and East coasts:

  • Houston is sinking at about 17 millimeters per year and some areas have lost 3 meters of elevation since 1917.

  • New Orleans & Tampa Bay are sinking at about 6 millimeters per year, but some areas in these cities are sinking at 508 millimeters per year.

  • New York is sinking at about 1-2 millimeters per year.

  • Norfolk, VA is sinking at 3.5 millimeters per year.

Groundwater extraction is the biggest culprit in these US cities and some places are taking steps to reduce its extraction. 

Read More