A new map released by NASA reveals that certain parts of California are gradually sinking, which exacerbates the risks associated with rising global sea levels. This phenomenon is particularly concerning, as it can have severe implications for the state’s coastal regions and inhabitants.
California’s Sinking Problem
According to a study led by NASA, California is losing ground at an alarming rate, with some areas sinking as much as 20 centimeters per year. The research team used satellite radar to track over 1,000 miles of uplift and subsidence along the California coast, discovering that the state’s central region, particularly the Central Valley, is experiencing significant Land subsidence. This is largely attributed to the extraction of groundwater, which is causing the land to sink at an unprecedented rate.
The study highlights the unpredictability of vertical earth movements, both in terms of scale and speed. For instance, areas like Santorini have experienced strong movements that can awaken dormant volcanoes. Similarly, California’s sinking problem is driven by a combination of natural forces, such as tectonic activity, and human influences, including groundwater pumping.
The Causes of California’s Sinking
The sinking of California is a complex issue, driven by both natural and human-induced factors. The extraction of groundwater is a significant contributor to the problem, as it causes the land to sink. Additionally, the injection of wastewater and other human activities are also playing a role in the state’s subsidence. Natural phenomena, such as tectonic activity, are also contributing to the sinking of California.
It’s estimated that by 2050, sea levels in California will rise by anywhere from 15 to 350 centimeters, compared to 2000 levels. This, combined with the sinking of the land, poses a significant threat to the state’s coastal regions, including cities, beaches, and aquifers. The phenomenon is not unique to California, as similar sinking has been observed in other parts of the world.
Identifying Critical Areas
By combining radar measurements from the European Space Agency’s Sentinel-1 satellites with data from the global satellite navigation system, the research team was able to capture detailed information about land movements in California. This allowed them to identify critical areas that will be at greater risk due to rising sea levels in the coming decades. These areas include cities, beaches, and aquifers, which will require close monitoring and planning to mitigate the impacts of sea-level rise.
The team also identified areas with high subsidence rates, particularly in the Central Valley, where groundwater levels can drop by as much as 20 centimeters per year. This is influenced by fluctuations in groundwater levels, which can have significant consequences for the state’s water supply and ecosystem.
Areas of Greatest Concern
The research team revealed that certain areas, including Los Angeles and San Diego counties, require continuous monitoring due to their high subsidence rates. In particular, the Chula Vista aquifer in San Diego County, the Santa Ana aquifer in Orange County, and the Santa Clara aquifer in the Bay Area have experienced significant declines in groundwater levels, which can have severe consequences for the state’s water supply.
However, not all areas in California are sinking. In fact, some regions, such as the Santa Barbara underground water basin, have seen a steady replacement of groundwater since 2018, resulting in areas of annual elevation. Similar trends have been observed in Long Beach, where fluid extraction and injection are carried out in association with gas and oil recovery.
The findings of this study are now being used to inform California state policymakers about sea-level changes and help develop strategies to mitigate the impacts of subsidence and sea-level rise.