“Subsidence is when land sinks relative to sea level, usually owing to extraction of subsurface water, rock or other resources.” It’s happening both inland and in coastal areas, exacerbating sea level rise.
Also, parts of the world, like the US East Coast, are sinking due to “glacial isostatic rebound”, see below.
Nature:
One in ten residents of China’s coastal cities could be living below sea level within a century, as a result of land subsidence and climate change, according to a paper published in Science today1.
Some 16% of the mapped area of China’s major cities is sinking “rapidly” — faster than 10 millimetres every year. An even greater area, roughly 45%, is sinking at a “moderate” rate, the paper says, meaning a downward trajectory of greater than 3 mm annually. Affected cities include the capital Beijing, as well as regional capitals, including Fuzhou, Hefei and Xi’an.
The situation could see one-quarter of China’s coastal lands slip below sea level within a few decades, posing “serious threats” to the hundreds of millions of people who live on the coast, the paper notes.
“Subsidence is certainly not only a problem in China. Many other parts of the world share the same problem,” says Ding Xiaoli, a geodesist at the Hong Kong Polytechnic University.
Subsidence is when land sinks relative to sea level, usually owing to extraction of subsurface water, rock or other resources.
In the famously low-lying Netherlands, roughly one-quarter of the land has subsided to below sea level. And by 2040, almost one-fifth of the world’s population is projected to be living on sinking land.
Jakarta has become the most rapidly subsiding capital in the world, prompting Indonesia to propose a new capital city.
In the United States, more than 44,000 square kilometres of land across 45 states has been directly affected by subsidence, with more than 80% of the cases relating to groundwater extraction, often for agricultural purposes.
Continue reading “Got That Sinking Feeling? You’re Not Alone. Subsidence a Global Problem”