Why Large Cracks Are Appearing Across Arizona’s Desert — And What Scientists Say Is Driving the Change
Arizona is widely known for its expansive deserts, dramatic canyon landscapes, and rapid population growth. From agriculture and mining to technology and renewable energy, the state has become a major economic and cultural center in the American Southwest.
Yet beneath this visible success, a quieter transformation has been unfolding—one that is increasingly shaping Arizona’s physical landscape.
Across multiple regions of the state, long fractures are opening in the ground, cutting through desert terrain, farmland, roads, and, in some cases, areas near residential development. These features, known as earth fissures, have emerged as one of Arizona’s most persistent geological challenges.
What Are Earth Fissures?
Earth fissures are deep, elongated cracks that form when the ground surface breaks apart due to movement below. Unlike earthquakes, they do not occur suddenly with shaking or noise. Instead, they often develop silently and appear with little warning.
Some fissures are narrow at the surface but extend many feet downward. Others widen over time, becoming visible scars across the desert floor. In Arizona, certain fissures stretch for miles, making them among the longest documented in the United States.
While similar features exist in other arid regions, Arizona has experienced them at an unusually large scale and frequency.
A Statewide Issue, Not an Isolated One
Arizona spans more than 113,000 square miles and is home to over seven million people. Major urban centers such as Phoenix and Tucson continue to expand, while rural areas support agriculture, mining, and energy production.
The state also contains globally recognized landmarks like the Grand Canyon, reinforcing its image as a place of natural stability and permanence.
Earth fissures challenge that perception.
The first officially documented fissure in Arizona was recorded in Cochise County in 1976. At the time, it was viewed as a rare geological anomaly. Over the decades that followed, however, similar cracks appeared in other parts of the state.
Today, the Arizona Geological Survey has identified more than 270 earth fissures statewide, with new ones continuing to emerge.
Why Arizona Is Especially Vulnerable
Unlike earthquakes or volcanic activity, Arizona’s fissures are not caused by tectonic forces. Instead, scientists point to a human-driven process: groundwater depletion.
Much of Arizona relies on underground aquifers—natural reservoirs of water stored in layers of sediment and rock. These aquifers have supported agriculture and urban growth for decades, particularly in regions where surface water is limited.
As groundwater is pumped out faster than it can be naturally replenished, the underground layers begin to compact. This process, known as land subsidence, causes the ground surface to sink gradually.
Where subsurface stresses concentrate, the land fractures, forming fissures that extend upward to the surface.
The Hidden Nature of the Risk
One of the most challenging aspects of earth fissures is their unpredictability. They do not always form directly above the areas where groundwater is being extracted. Instead, stresses can travel laterally through sediment layers, causing fissures to appear far from pumping sites.
This makes forecasting their exact locations extremely difficult.
From a distance, a fissure may resemble a shallow erosion channel or dry wash. Up close, however, its true scale becomes apparent. Some fissures are more than fifteen feet deep and wide enough to damage roads, irrigation systems, and other infrastructure.
Impacts on Communities and Infrastructure
While many fissures occur in sparsely populated desert areas, others lie uncomfortably close to human development.
In agricultural regions, fissures have damaged fields, irrigation canals, and farm equipment. In developing suburbs, they have caused cracked foundations, uneven roads, and compromised utility lines.
In some cases, homeowners first notice subtle signs: a driveway that begins to split, doors that no longer align, or walls that develop unexplained cracks.
Repairing this type of damage can be costly, and insurance coverage is often limited. Because fissures originate deep underground, surface repairs address symptoms rather than causes.
Counties Most Affected
Earth fissures are most concentrated in south-central Arizona, particularly in Pinal, Maricopa, and Pima counties.
Pinal County, located between Phoenix and Tucson, has a long history of groundwater use for agriculture. Decades of pumping have lowered aquifer levels significantly, increasing the likelihood of subsidence and fissure formation.
Maricopa County, home to Phoenix and its rapidly expanding suburbs, faces similar challenges as development pushes into previously undeveloped desert areas.
Pima County, which includes Tucson, has also documented fissures in rural zones surrounding the city.
How the Problem Developed Over Time
The fissure issue did not emerge overnight. During the population boom of the 1970s and 1980s, groundwater extraction intensified to support farming and urban growth. Early fissures were often overlooked or misidentified as erosion features.
By the 1990s and early 2000s, development accelerated, sometimes without comprehensive geological assessments. Homes and infrastructure were built on land later found to be vulnerable to subsidence.
Advances in satellite imagery, aerial surveys, and ground-based sensors eventually revealed the full extent of the issue. Scientists observed long, linear features appearing repeatedly in the same regions, indicating ongoing movement.
Monitoring and Mapping Efforts
Mapping has become one of the most effective tools for managing fissure risk. The Arizona Geological Survey uses satellite data, GPS measurements, drone imagery, and laser-based surveys to detect ground movement and identify fissures.
These maps help planners and developers avoid high-risk areas and guide infrastructure design. However, coverage remains incomplete, especially in remote or rapidly developing regions.
Even in mapped areas, new fissures can still form as conditions change.
Climate and Population Pressures
Arizona’s challenges are compounded by climate conditions. Prolonged droughts reduce natural recharge of aquifers, while rising temperatures increase water demand.
Heavy seasonal rains, particularly during monsoon periods, can destabilize already weakened soils, causing fissures to expand or reappear.
At the same time, continued population growth increases water consumption and places additional structural load on the land through construction.
Can Fissures Be Fixed?
Once a fissure forms, there is no practical way to reverse it. Filling cracks with soil or concrete can stabilize specific locations—such as beneath roads or pipelines—but does not eliminate the underlying instability.
Engineers focus instead on risk management: monitoring activity, reinforcing critical infrastructure, and restricting development in high-risk zones.
Long-term prevention depends largely on groundwater management. Reducing overuse, promoting water recycling, and balancing extraction with recharge are central to limiting future subsidence.
Policy and Planning Responses
Some Arizona counties now require developers to consult fissure maps before construction. Others have introduced stricter groundwater regulations or designated certain areas as unsuitable for development.
These measures represent a shift toward proactive planning, though implementation varies across regions.
Looking Ahead
Earth fissures may not affect every part of Arizona, but they reflect a deeper issue: the strain placed on a fragile environment by long-term resource use.
The cracks spreading across the desert are not sudden disasters. They are gradual signals of imbalance between human activity and natural systems.
Whether Arizona can balance growth, water use, and land stability will shape the state’s future.
For scientists, planners, and residents alike, the message is clear: what lies beneath the surface matters just as much as what is built above it.
