Corcoran, a farm town in California’s San Joaquin Valley, began going underground. From the outside the changes are not very visible, but they can be well tracked by NASA satellite images, reported May 25 edition of The New York Times.
Over the past 14 years the city has sunk 11.5 feet (about 3.5 meters) in some places. According to experts, the cause is blowing out of the ground, which occurs when a large amount of water escapes from the underground soil, causing the underlying sediment to settle.
Each year, all 7.47 square miles (about 800 hectares) of Corcoran, with its 21,960 inhabitants, settle very little as the soil sinks from a few cm to almost 0.6 m. No houses, buildings or roads are collapsing. The subsidence is not as dramatic, but its effect on the city’s topography is significant, experts say.
The Water Resources Management Agency believes that the city will sink another 1.8-3.4 meters in the next 19 years. Currently, the shells of the drinking water wells are destroyed, and the city dam had to be rebuilt at a cost of $10 million.
According to the U.S. Geological Survey, land in Corcoran and other parts of the San Joaquin Valley has been gradually but steadily shrinking, largely because agricultural companies have been pumping groundwater to irrigate their crops for decades.
On May 19, it was reported that a huge iceberg had broken away from Antarctica. The size of the glacier exceeded the area of the Spanish island of Mallorca.