111-4 Monitoring Subsidence at an Operational Deep Geological Repository Using InSAR in the Delaware Basin, New Mexico

Session: Using Near Surface Geophysics to Investigate Geological Problems (Posters)

Poster Booth No.: 227

Presenting Author:

Noha Ismail Medhat

Authors:

Ismail Medhat, Noha¹, Holt, Robert², Yarbrough, Lance³, Oommen, Thomas⁴, Ward, Anderson⁵, Lepchitz, Zach⁶, Salness, Richard⁷

Abstract:

The Delaware Basin near Carlsbad, New Mexico, is a geologically intricate region beneath an arid surface, containing abundant evaporite minerals such as halite, anhydrite, sylvite, and potassium salts. This area has a long-standing history of mineral extraction, especially potash mining. It is also the site of the Waste Isolation Pilot Plant (WIPP), a critical Deep Geological Repository (DGR) for transuranic radioactive waste. As a result, a detailed understanding of subsurface hydraulic conditions is essential for both sustainable resource extraction and environmental stewardship.

In this study, Interferometric Synthetic Aperture Radar (InSAR) data were analyzed to detect and interpret patterns of land subsidence. A Differential InSAR (DInSAR) approach, utilizing the Small Baseline Subset (SBAS) method, enabled precise mapping of slow vertical ground movements. These deformation signals were then compared with known human activities in the region. Preliminary analysis indicates mean subsidence rates of -60 mm/year, with maximum localized displacement exceeding -500 mm from 2016 to 2025. The spatial and temporal patterns of deformation suggest multiple contributing sources, most prominently historic and ongoing potash extraction.

These results represent the first use of InSAR to monitor ground movement at an operational DGR. This remote sensing approach provides a valuable, non-invasive means of characterizing geomechanical behavior in an area where traditional monitoring may be limited. Potential applications include long-term risk assessment, post-closure surveillance, and identifying zones for further hydraulic investigation. This work underscores the utility of InSAR-derived ground deformation data in guiding subsurface investigations in geologically and operationally complex regions.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

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