Nearly 6,000 skyscrapers soar into the sky in New York, adding to the charm of one of the world’s most admired cities. But the weight of the gigantic buildings exerts a considerable strain and causes the US city to sink by 1-2 millimeters. A very small measure yes, but in the long run the deformation of the soil could increase the risk of flooding and was mapped by comparison Satellite data with models of subsurface geology. The study was published in the journal Earth’s Future by a team of experts from the University of Rhode Island led by the geologist Tom Parsons who in the past has already devoted his studies to the “weight” of cities on the ground.
The researchers calculated the cumulative mass of more than a million buildings in New York City, which turns out to be approximate 764 million tons. They then divided the city into a square grid 100 meters on each side and converted the mass of the buildings into downward pressure, taking gravity into account. However, the weight of roads, sidewalks, bridges and railways was not taken into account. This data has been fed into models that depict the complex geology of the subsurface, which consists largely of Sand, silt, clayey sediments and rock outcrops. The experts were able to determine that the Big Apple on a srather colorful underground, which reacts differently to the weight of buildings.
The soils, richer in clayey sediments and artificial infill, are more prone to the phenomenon of subsidence (i.e. subsidence), with an average value of 294 millimeters measured in lower Manhattan; More resilient soils are allowed to recover after the buildings are constructed, while the rockier subsoil upon which many skyscrapers are anchored barely moves.
By comparing this data to satellite ground level measurements, the researchers have developed a new and more detailed map of subsidence in New York. The purpose of the study, according to the researchers, is “to raise awareness that every new skyscraper will be built in zones.” Coastal, river or lake shore areas could contribute to future flood risk“.
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