Dozens of coastal skyscrapers in Miami are sinking

On the barrier islands of Miami, a troubling phenomenon is unfolding. Since 2016, construction has contributed to subsidence, causing 35 high-rise buildings, including Trump Tower III, to sink as much as eight centimeters into the ground.

Researchers at the University of Houston have played a central role in identifying the cause: urban development is exerting immense pressure on the fragile land beneath these structures.

A recent study published in the journal Earth and Space Science has documented alarming rates of land subsidence between 2016 and 2023. The research highlights that Miami’s coastal skyscrapers, particularly newer constructions, are at significant risk of ground instability.

“About half of the subsiding structures are younger than 2014, and at the majority of them, subsidence decays with time. This correlation suggests that the subsidence is related to construction activities,” the report stated.

The findings suggest that the weight and vibrations from large-scale developments are pressing into the porous and sandy geology of the region, leading to gradual sinking.

Miami skyscrapers on sinking land

Subsidence refers to the gradual sinking of land due to natural or human-induced factors.

In coastal cities like Miami, this issue is particularly concerning because the underlying ground is often composed of loose sediments, limestone, and sand. These materials can compact under the weight of heavy buildings, leading to ground-level changes over time.

The process is not uniform across all structures. In some cases, the subsidence begins immediately after construction but slows as the ground settles.

In others, the sinking continues at a steady rate, raising concerns about long-term stability. The research suggests that once the land is compressed beyond a certain threshold, reversing the process becomes nearly impossible.

This slow-moving yet persistent issue raises serious concerns about Miami’s ability to maintain safe infrastructure in the face of both subsidence and rising sea levels.

The research team at the University of Houston sought to validate these findings using cutting-edge technology capable of detecting minute changes in the Earth’s surface.

Construction-induced subsidence

The research was conducted by a team from the University of Houston’s Department of Civil and Environmental Engineering, led by Professor Pietro Milillo.

The team utilized InSAR, or Interferometric Synthetic Aperture Radar, a satellite-based remote sensing method capable of detecting surface changes as small as the thickness of a credit card.

InSAR works by comparing radar signals from two images of the same area taken at different times. Even the most minor deformations of the Earth’s surface become visible using this technique, making it an invaluable tool for monitoring land stability.

Impact of heavy construction

“We attribute the sinking ground primarily to the weight and vibrations from high-rise construction,” said Milillo.

“The phenomenon, described as creep deformation, occurs when sandy layers interbedded within Miami’s porous limestone geology compress under pressure, potentially compromising structural stability.”

“Our work confirmed the spatial and temporal patterns of subsidence in the study. We demonstrated how construction-induced stresses extend well beyond building footprints, revealing risks to surrounding areas up to 320 meters away.”

The study was a collaborative effort involving several leading institutions, including the University of Houston, the University of Miami, the German Aerospace Center, NASA’s Jet Propulsion Laboratory, and the University of Hannover.

A key contributor to the study was Amin Tavakkoliestahbanati, a graduate student working under Milillo’s guidance.

Dozens of buildings sinking in Miami

The study focused on buildings located in some of Miami’s most densely developed coastal areas, including Sunny Isles Beach, Bal Harbour, and Surfside.

The researchers found that 35 buildings in these locations showed measurable subsidence, with many newer structures being the most affected.

In many cases, subsidence began immediately after construction and gradually slowed. However, in some instances, the sinking continued at a constant rate, which could indicate an ongoing risk to structural integrity.

The data also revealed that the impact of subsidence was not limited to individual buildings. Instead, the stress from these structures was transferring to the surrounding land, affecting areas far beyond the original construction sites.

Sunny Isles Beach exhibited some of the most concerning patterns. Up to 70% of newly built high-rises in this part of Miami showed measurable ground sinking. The region’s sandy subsurface geology appears to play a significant role in this phenomenon, as loose sand is more susceptible to compression under heavy loads.

“Our role as a validation partner highlights the importance of geospatial technology in urban risk assessments,” said Milillo. “By confirming these patterns, we’re helping to develop tools for safer urban planning, particularly in geologically sensitive coastal zones.”

What this means for coastal development

Miami’s barrier islands are already vulnerable to sea-level rise, coastal erosion, and extreme weather. The discovery that urban development is contributing to land subsidence adds another layer of complexity to the challenges faced by city planners, engineers, and policymakers.

As the city continues to grow, it becomes increasingly important to incorporate geological data and remote sensing tools like InSAR into urban planning. These technologies can help identify areas at risk before construction even begins, potentially preventing future structural failures.

Consequences of ground sinking in Miami

Ignoring the risks associated with subsidence could lead to severe consequences. In some cases, prolonged ground sinking can create cracks in building foundations, weaken support structures, and even lead to partial collapses. For a city like Miami, where the demand for high-rise living remains strong, addressing this issue should be a priority.

The research demonstrates the value of scientific collaboration in addressing real-world challenges, particularly in understanding construction-related subsidence.

By combining satellite-based monitoring with on-the-ground engineering expertise, researchers can provide valuable insights that help protect communities and infrastructure in vulnerable coastal regions.

Safer construction practices

The study has sparked renewed discussions about how to build safely in coastal areas prone to subsidence. Engineers, city planners, and policymakers must work together to develop strategies that mitigate the risks associated with ground sinking in Miami and beyond.

One potential approach is to implement stricter building codes that require developers to conduct detailed geotechnical assessments before construction begins.

Another possibility is to integrate long-term monitoring programs that track subsidence patterns over time, allowing authorities to intervene before structural issues become critical.

“This work showcases the transformative power of geospatial science to uncover hidden risks beneath the surface,” Milillo said. “It’s a call to action for engineers, planners, and policymakers to work together in creating resilient cities.”

By leveraging scientific advancements and promoting responsible construction practices, cities like Miami can continue to grow while ensuring the safety and stability of their urban landscapes.

The findings of this study serve as a critical reminder that what happens beneath the surface can have profound implications for the future of coastal development.

The study is published in the journal Earth and Space Science.

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