Polly Spring@polly_spring

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New York City sinking under buildings

New York City is gradually sinking under its own mass. With more than a million buildings spread across its five boroughs, it is considered one of the heaviest urban environments on the planet. The combined weight of these structures is estimated at around 1.68 trillion pounds or 762 billion kilograms, which is roughly comparable to about 1.9 million fully loaded Boeing 747 aircraft. Research suggests that this immense load is contributing to a process called subsidence, where land slowly settles or sinks over time. On average, parts of New York City are lowering by about 1 to 2 millimetres each year, with some locations experiencing rates closer to 4.5 millimetres annually. However, the buildings are only part of the explanation. Certain areas sit on softer sediments or reclaimed land that compress more easily under pressure. In addition, groundwater changes and long term geological recovery from the last Ice Age are also influencing gradual ground movement. While these shifts are extremely small on a yearly basis, they become more meaningful over long periods. At the same time, sea levels around New York are rising faster than the global average. The combination of rising oceans and slowly sinking land increases the risk of flooding, particularly in low lying neighbourhoods, transport systems, and coastal infrastructure. Scientists note that this is not unique to New York. Other major cities such as Jakarta, Shanghai, Mexico City, and parts of Tokyo are also experiencing land subsidence, often due to a mix of natural and human influenced factors. Although this process is far too slow to notice day to day, its effects accumulate over decades. There is no indication that the city’s buildings are at risk of sudden failure or collapse. New York will continue to stand, but the ground beneath it is slowly shifting downward, shaped by both geological forces and the scale of human development. Source: "The Weight of New York City: Possible Contributions to Subsidence From Anthropogenic Sources." Earth's Future

3mo

Polly Spring@polly_spring

关注

New York City sinking under buildings

New York City is gradually sinking under its own mass. With more than a million buildings spread across its five boroughs, it is considered one of the heaviest urban environments on the planet. The combined weight of these structures is estimated at around 1.68 trillion pounds or 762 billion kilograms, which is roughly comparable to about 1.9 million fully loaded Boeing 747 aircraft. Research suggests that this immense load is contributing to a process called subsidence, where land slowly settles or sinks over time. On average, parts of New York City are lowering by about 1 to 2 millimetres each year, with some locations experiencing rates closer to 4.5 millimetres annually. However, the buildings are only part of the explanation. Certain areas sit on softer sediments or reclaimed land that compress more easily under pressure. In addition, groundwater changes and long term geological recovery from the last Ice Age are also influencing gradual ground movement. While these shifts are extremely small on a yearly basis, they become more meaningful over long periods. At the same time, sea levels around New York are rising faster than the global average. The combination of rising oceans and slowly sinking land increases the risk of flooding, particularly in low lying neighbourhoods, transport systems, and coastal infrastructure. Scientists note that this is not unique to New York. Other major cities such as Jakarta, Shanghai, Mexico City, and parts of Tokyo are also experiencing land subsidence, often due to a mix of natural and human influenced factors. Although this process is far too slow to notice day to day, its effects accumulate over decades. There is no indication that the city’s buildings are at risk of sudden failure or collapse. New York will continue to stand, but the ground beneath it is slowly shifting downward, shaped by both geological forces and the scale of human development. Source: "The Weight of New York City: Possible Contributions to Subsidence From Anthropogenic Sources." Earth's Future

3mo