Recent surveys have found increasing erosion along the eastern bank of the Mississippi River near Memphis, Tennessee, prompting speculation that the iconic Pyramid, once the tallest building in Memphis, is sinking. Incredibly, the three-decade-old structure was already sinking when it opened and has continued to sink at a rate of several inches per year ever since.
The Pyramid originally functioned as both a sports and entertainment venue, hosting basketball games and concerts. Despite the distinctive pyramid-like shape of its design, the structure had a conventional broad and shallow foundation which, despite the best efforts of civil engineering, has continued to sink.
Geologists attribute the Pyramid’s sinking to a combination of factors, including the weight of the metal superstructure, made from two-foot-thick plates of metal, and the presence of a pod of solid soil beneath its foundation caused by an earthquake in 1811. This pod of soil, determined to be 5 to 10 feet thick, expanded and filled up the new building’s foundation when construction began in 1991.
Today, Memphis is on track to become the second fastest-sinking city in the United States. In the Pyramid’s 30 years of existence, it has sunk 4 feet into the earth, with the Eastern side sinking at a faster rate than the Western side. The phenomenon known as Persistent Sinking Syndrome (PSS) has also been found in other parts of the world such as Mexico City, Rome, and Beijing. Unfortunately, it’s unclear if the Pyramid will continue to sink or if its pace of sinking will accelerate.
Experts agree the structure must be monitored on a regular basis to observe any changes in its sink rate. Historically, the rate of sinking has been slow and consistent, so it’s unlikely the Pyramid will suddenly disappear into the Mississippi anytime soon. But even a small amount of sinking can be devastating.
In the meantime, several proposals have been suggested as potential solutions. One proposal involves using a foundation-stabilizing grout to inject a solid base beneath the Pyramid’s foundation. The grout would create a cushion-like feel and help to reduce the rate of sinking. Additionally, there has been talk of relocating the Pyramid to higher ground. However, with the cost of the project estimated at nearly $300 million, it’s unlikely this proposal will gain traction.
Environmental Effects
The environmental impacts of the Pyramid’s sinking have been largely overlooked. As the structure sinks into the earth, it has created a void that has been filled with sediment and aquatic life sustainably, making the area around the Pyramid’s foundation a rich natural habitat. Additionally, the Pyramid’s foundation has acted as a stabilizing force in the wave action of the Mississippi River, reducing shoreline erosion and reducing the risk of flooding.
But the Mississippi River is notoriously fickle and the Pyramid has been through its own share of turbulent weather. Most recently, a 2017 storm caused significant structural damage to the Pyramid. At the time, Memphis Mayor Jim Strickland said, “It’s a testament to how powerful the river can be. In all my years I’ve never seen an effect quite like this on the Mississippi.”
The Pyramid’s sinking has also exposed the foundation to potential staining from the river’s sediment and debris. As the Pyramid’s foundation sinks further, there is an increased risk of water damage which could further degrade the structure and alter its appearance.
For now, the Pyramid remains standing tall, at least for the time being. But until the occurrence of the Pyramid’s sinking is studied more closely, experts will be unable to accurately determine exactly how and when the structure may sink further.
Economic Impacts
The economic impacts of the Pyramid’s sinking have been largely dismissed because it remains a popular entertainment destination. Despite its sinking, the Pyramid still draws thousands of visitors each year, and its size and iconic architecture make it an attractive destination for tourists.
The Pyramid serves as a major cultural and economic hub for the Memphis area, particularly for the nearby Pyramid mall, which draws millions of visitors to the area each year. As the Pyramid continues to sink, the mall could suffer as shaking, noise, and vibrations could occur due to other aspects of construction or sinking. The mall, like other businesses and homes along the Mississippi River, could also be damaged or ruined if the Pyramid is submerged.
As the Pyramid continues to sink, it is likely to have an adverse effect on the local economy, as the area has become heavily dependent on the Pyramid for both tourism and economic activity.
Researchers at the University of Memphis’s Center for Applied Earth Science and Engineering Research are conducting studies to better understand the effects of the Pyramid’s sinking, focusing primarily on the economic impact of the structure’s continued sinking. The researchers predict that if the Pyramid is allowed to sink, it could potentially lead to job losses, reduced tax revenue, and even the eventual abandonment of the area surrounding the Pyramid.
Public Perception
The Pyramid has been part of the Memphis landscape for nearly 30 years and locals have a strong emotional connection with the iconic structure. Its distinctive shape has become a symbol of the city, and many consider it to be one of the most important structures in Memphis history. For those reasons, many are concerned about the possibility of the Pyramid becoming submerged in the rapidly eroding Mississippi River.
The public debate surrounding the Pyramid’s sinking has generated a lot of discussion. There are those who argue the structure should be preserved, even if it means spending hundreds of millions of dollars to do so. Others, however, argue the Pyramid should be allowed to sink and the area should be allowed to become a natural habitat. Still, others believe the Pyramid should be moved to higher ground.
Regardless of how the Pyramid’s fate is ultimately decided, it is clear that the structure will always be an important part of the Memphis landscape. The public will likely keep a close eye on the Pyramid’s continuing sinking and take no chances with the iconic structure.
Policy Strategies
As the Pyramid continues to sink, city leaders and experts are trying to come up with policy strategies that could help mitigate the impacts of its sinking. One proposal involves the use of soil-stabilizing grouts that could be used to strengthen the Pyramid’s foundation and reduce the rate of sinking. Additionally, there are proposals to build a seawall around the structure to protect it from flooding and erosion.
The City of Memphis is also exploring a number of different strategies for preserving the Pyramid, such as the option of relocating the Pyramid to higher ground. This option would likely be costly, but it could be a viable solution.
Although the sinking of the Pyramid is an emotional issue for many in the Memphis area, city and state leaders seem to be taking a pragmatic approach to the situation. With experts studying the situation and policy proposals on the table, they are attempting to find a solution that makes sense both economically and environmentally.
Impact of Rising Waters
Climate change has been a major factor in the Pyramid’s sinking. The Mississippi River is the longest river in the United States and its waters have been steadily rising for decades. In addition, the area around the Pyramid has seen more than six inches of rain on average since the structure was built, adding to the amount of water that has contributed to the Pyramid’s sinking.
Scientists predict that the area around the Pyramid could see up to three feet of sea level rise by 2050, which could further worsen the situation. If the Pyramid continues to sink, it is possible the entire structure could become submerged in the rising water.
Fortunately, the Pyramid has a number of built-in protections that make it less vulnerable to the effects of rising waters. These protections include a steel base that is designed to maintain its shape as the ground beneath it erodes, as well as a series of steel-reinforced braces that extend along the perimeter of the foundation.
The Pyramid has withstood the test of time, but the effects of rising waters on the structure are still uncertain. The experts agree that further study is needed to understand the full impact of rising waters on the Pyramid and to determine the best ways to protect it.
Conclusion
As climate change accelerates, the Mississippi River and its surroundings are likely to face greater challenges in the coming years. Whether the iconic Pyramid is able to withstand the test of time, or is eventually submerged in the waters of the Mississippi, remains to be seen.
Though the Pyramid’s fate is still uncertain, the city of Memphis and the experts are doing their best to protect this historic structure and the area around it. Until a permanent solution is found, the Pyramid will continue to serve as a monument of strength, endurance, and resilience.
