California is facing significant changes in the elevation of its territory, and a new analysis by NASA revealed which areas are losing height the fastest. The study, based on satellite measurements from 2015 to 2023, identified both accelerated subsidence and areas that, on the contrary, show slight uplift of the land. According to NASA, these vertical movements, combined with rising sea levels, could increase the risk of flooding and directly affect coastal and inland communities in the state in the coming decades. Areas of California with the greatest subsidence, according to NASA. The study, led by NASA's Jet Propulsion Laboratory (JPL), indicated that several areas of the San Francisco Bay Area are among the most affected. Localities like San Rafael, Corte Madera, Foster City, and Bay Farm Island are sinking more than 10 millimeters per year (approximately 0.4 inches annually), a figure considered worrisome for densely populated regions. According to NASA, this type of subsidence causes the relative sea level to rise even faster, which could translate to up to an additional 45 centimeters by 2050, especially in low-lying areas of the bay. In addition to the coastal area, the report also highlighted subsidence in the Central Valley, attributed primarily to intensive groundwater pumping. This phenomenon not only reduces the elevation of the land, but can also damage agricultural infrastructure, roads, and hydraulic systems.

Other areas exhibit subsidence linked to erosion, compacted urban fill, and natural geological movements. According to the analysis, mountainous and coastal regions in the southern part of the state also show differentiated subsidence, although of lesser intensity.

Why is California sinking?

According to JPL specialists, several factors explain these movements:

NASA emphasizes that land subsidence cannot be analyzed in isolation: when added to the global rise in sea level,The threat to coastal communities is multiplying. According to JPL, areas of the San Francisco Bay Area could face more frequent flooding during periods of heavy rain or high tides.

A map that helps anticipate risks

The study is part of the work prior to the launch of NISAR, the joint NASA-ISRO satellite that will monitor millimeter-scale changes in the Earth's surface. The agency notes that this type of map will allow state and local authorities to implement adaptation measures such as:

According to NASA, this data also makes it possible to differentiate which areas are subsiding naturally and which are affected by human activity, key information for long-term planning.