The Norris Uplift Anomaly (NUA) has resurfaced, showcasing the dynamic geology of Yellowstone National Park. This phenomenon, attributed to surface movement in the region, has been closely monitored by scientists from the Yellowstone Volcano Observatory. Recent GPS data indicates noteworthy uplift in the area south of Norris Geyser Basin.
Norris Uplift Anomaly Overview
The NUA was first identified between 1996 and 2004, when the ground in this area moved upward by approximately 12 centimeters (nearly 5 inches). This uplift was linked to magma accumulation located about 14 kilometers (almost 9 miles) beneath the surface. Following this period, the area experienced subsidence of around 7 centimeters (about 3 inches) until the changes stabilized for about a decade.
Recent Developments
From 2013 to 2020, ground movement shifted sporadically between uplift and subsidence, likely due to the presence of shallow water influenced by magma activity. Notably, the NUA resumed uplift in July 2025, with continuous GPS stations indicating a displacement of about 1.5 centimeters (0.6 inches) by the year’s end.
- Initial Uplift (1996-2004): 12 centimeters (5 inches)
- Subsequent Subsidence (2004-2013): 7 centimeters (3 inches)
- Recent Uplift (July-December 2025): 1.5 centimeters (0.6 inches)
Monitoring Techniques
The recent uplift was confirmed through various monitoring techniques, including horizontal velocity measurements and interferometric synthetic aperture radar (InSAR). This method utilizes satellite radar images to detect even minor ground shape changes. Data spanning October 2024 to October 2025 showed approximately 2 centimeters (0.8 inches) of uplift along the north rim of the caldera.
Earthquake Activity
During this uplift period, there was a minor increase in seismicity. In total, 1,113 earthquakes were recorded in 2025, which is lower than the typical annual range of 1,500 to 2,500. A notable increase in earthquake events occurred from September to December 2025, particularly near the NUA, suggesting that disturbances may be linked to changes in subsurface stress.
Conclusion
While the resurgence of the Norris Uplift Anomaly raises questions about volcanic hazards, scientists assert it is merely a representation of Yellowstone’s ongoing geological dynamics. Current deformation levels are minor compared to other caldera systems. The Yellowstone Volcano Observatory will continue to monitor these developments, providing updates and insights on the region’s geological behavior.
For more information about the Norris Uplift Anomaly and continuous updates, visit El-Balad.
