
Introduction The luxurious beachfront high-rises of Miami’s barrier islands are facing an alarming problem: they are sinking. This phenomenon, known as subsidence, poses a severe threat not only to Miami but to coastal cities worldwide. With rising sea levels compounding the issue, it’s time to take action.
What the Study Reveals A recent study published in the journal Earth and Space Science highlights the gravity of the situation:
Researchers found that 35 buildings on Miami’s barrier islands sank by 2 to 8 centimetres between 2016 and 2023.
The sinking, or subsidence, is happening “almost everywhere,” according to Manoochehr Shirzaei, a geophysicist at Virginia Tech.
Subsidence and sea-level rise together pose a massive flood risk, with an estimated $109 billion of US coastal property at risk by 2050.
Why Coastal Cities Are Sinking
Subsidence is not unique to Miami. Coastal cities around the globe are sinking due to their massive weight and groundwater extraction. This issue is exacerbated by rising sea levels, doubling the risk of flooding.
Key insights:
“One centimetre of sea-level rise and one centimetre of subsidence have the same effects on flooding hazards,” explained Farzaneh Aziz Zanjani and Falk Amelung, authors of the study.
Major affected regions include:
Eastern and southern Asia
Europe
Africa
Australia
The US East Coast, including cities like New York and Baltimore
The Cost of Inaction The consequences of subsidence are far-reaching and expensive:
Increased Flood Risks: Combining subsidence with sea-level-rise projections, researchers estimate that by 2050:
518,000 more Americans could face high-tide flooding.
288,000 additional properties, valued at $109 billion, could be at risk.
Structural Damage: Subsidence can compromise a building’s safety by causing uneven sinking, leading to cracks or distortions.
The Role of Satellites in Early Detection Satellites offer a promising solution for identifying and addressing the problem before it becomes catastrophic:
Miami’s researchers used satellite data to assess the subsidence of buildings.
Following the 2021 collapse of Champlain Towers South in Surfside, Florida, they found no evidence of subsidence at the site but observed sinking in other areas associated with nearby construction.
Vibrations from construction may cause sandy layers in the limestone foundation to shift, leading to subsidence.
Solutions and Future Steps Early detection and intervention are key to mitigating the risks:
Monitoring Hotspots: Satellite remote sensing can identify areas at risk of uneven subsidence.
Structural Reinforcements: Targeting at-risk buildings can help prevent damage.
Further Research: Miami researchers aim to secure funding to study the city’s sediments and investigate uneven subsidence patterns.
Conclusion The sinking of Miami’s high-rises is a stark reminder of the challenges coastal cities face. By leveraging satellite technology and investing in preventive measures, we can safeguard these vulnerable areas. As the study’s authors caution, “There are no indications that subsidence will come to a stop.” It’s time to act before it’s too late.
References
Zanjani, F. A., & Amelung, F. (2023). Study published in Earth and Space Science.
Business Insider interview with researchers.
Data from Virginia Tech geophysicist Manoochehr Shirzaei.