Shocking NASA Finds: Why Some Cities Are Sinking Faster Than Ocean Levels Are Rising

A recent study led by NASA has revealed a hidden danger worsening sea level rise along coastlines worldwide. While we often think of melting glaciers and climate change as the main culprits, the ground itself is also sinking in some areas—this can happen even faster than the oceans are rising. Using data from satellites, researchers found locations where the land is dropping at alarming rates, increasing the risk of flooding for coastal cities sooner than we thought.

This study shows just how much we need to rethink sea level rise predictions. In certain areas, the actual rise could be double the previously expected levels by 2050. Let’s break down what this means.

Published on January 29, 2025, in Science Advances, the study focused on how land movement affects local sea levels. The team, led by Marin Govorcin from NASA’s Jet Propulsion Laboratory, used high-tech radar from ESA’s Sentinel-1 satellites to track how land elevation changed along California’s coast from 2015 to 2023.

The results were concerning: many regions are sinking by more than 0.4 inches (10 mm) per year. For example, in San Francisco Bay, where the ground is compacting, local sea levels could rise over 17 inches (45 cm) by 2050. That’s much more than previous estimates based only on ocean levels. This means we need to consider ground movement in our calculations when assessing future flooding risks.

Interestingly, land sinking isn’t just a natural occurrence. Human activities, such as groundwater extraction, oil drilling, and rapid urban development, are speeding up the sinking process. “In areas like San Francisco, the ground is sinking faster than the sea is rising,” Govorcin points out. This makes it clear that the coastal defenses we’ve built may not be enough for the challenges we face.

The study also found areas experiencing ground uplift, such as Santa Barbara and Long Beach, where the land is rising due to factors like groundwater replenishment. However, these uplift zones are localized and unpredictable, which complicates our larger climate models.

California’s coastline serves as a vital case study for understanding this risk. By mapping land movement along over 1,000 miles of coastline, researchers identified high-risk areas where land sinking is worsening sea level rise. The San Francisco Bay Area is particularly vulnerable, especially in low-lying spots like San Rafael and Corte Madera, where land is sinking significantly. Flooding that we thought would happen in decades may arrive within the next 25 years in these areas. Cities like Los Angeles and San Diego also face challenges due to unpredictable human activities.

Beyond the cities, California’s Central Valley is sinking rapidly, with some areas dropping by as much as 8 inches (20 cm) per year due to over-extraction of groundwater. As underground water levels decrease, the land above compresses and sinks, creating long-lasting effects on sea level rise.

Moreover, scientists noticed slow-moving landslides along California’s rugged coastline, particularly in areas like Big Sur. This land movement can create localized sinking hotspots, destabilizing coastal communities. Additionally, erosion is posing a threat to precious ecosystems, such as marshlands and lagoons around San Francisco and Monterey Bays, which serve as natural flood barriers.

Monitoring land movement is more important than ever. NASA’s OPERA project uses satellite data to track changes in land elevation across North America. This information aids governments and city planners in preparing for rising sea levels and potential flooding. Moreover, the upcoming NASA-ISRO Synthetic Aperture Radar (NISAR) mission promises to enhance global monitoring capabilities, providing near real-time data on land motion. This information could prove vital in predicting when and where significant sinking events may occur, potentially saving lives and costly repairs.