You may already know that oceans are rising due to factors such as melting glaciers and thermal water expansion. But other factors contribute to coastal flooding; in the case of New York City, the land is sinking.
NASA researchers have been studying why the land under New York City is sinking, and they recently published their findings in a new report. Unfortunately, the results indicate a concerning outlook for the city. In some areas, such as Brooklyn, Queens, and Staten Island, the rate of sinking is a staggering 1.2 inches per decade.
These changes impact everyone, not just those living in high-risk zones. Even visitors to New York will experience the financial implications and potential intermittent construction delays. For example, La Guardia Airport recently underwent an $8 billion renovation to counteract just part of the problem, partly funded by airport fees charged to travelers. La Guardia remains at a high risk of flooding, which means additional expenses to alleviate those problems.
The rate at which the ground is sinking relative to rising sea levels is influenced by several factors, including natural and human activities. Experts say densification and the construction of NYC’s massive sky-scrapers play a key role in sinking ground, adding that every new structure built at a coastal location has the potential to contribute to future flood risks.
The scientists who study changes in the Earth’s shape, called geodesists, have traditionally based their work on ground-based tools. However, satellite-based (GPS) navigation means that rising and falling ground levels can be studied far more accurately than ever before. New tools are allowing scientists to study ground levels with improved accuracy. Powerful computer systems and satellite monitoring now allow geodesists to better evaluate the rate at which the ground is sinking in areas like New York.
When it comes to the Big Apple, the risk of flooding is no minor issue. In the last 100 years, sea levels around New York City have risen by one foot – a rate of around 1.2 inches per decade. While this increase might seem manageable, the speed at which the oceans are rising, in contrast to the land sinking, is accelerating. Models created by an independent body of scientists place this increase at between 8 and 30 inches of ocean rise by 2050. These forecasts increase apprehension about sinking land and the resulting implications.
While rising oceans or sinking may seem like minor changes, there are already significant consequences. For example, research indicates that the escalation of ocean water levels likely facilitated Hurricane Sandy’s flooding area to increase by 25 square miles inland – impacting over 80,000 more people in New York and New Jersey alone.
While it doesn’t tell a tale of imminent catastrophe, the NASA report points to some serious global concerns. A study done by the University of Rhode Island on 99 coastal cities showed that, in many cases, urban areas are sinking even faster than oceans are rising. Satellite imaging data projects that rising oceans will challenge coastal cities much sooner than anticipated.
Given the rapid pace at which cities are being affected by rising sea levels, experts are already forecasting that some urban regions face heightened risks. While it may still be a while off, the accelerated sinking of land and the sheer mass of New York’s sky-scrapers means the ‘Big Apple’ will eventually join that group.