Ismail Fidha Farzana, Saibi Hakim
Geosciences Department, College of Science, United Arab Emirates University, P.O. Box 15551, Al-Ain, United Arab Emirates.
Sci Rep. 2025 Jul 11;15(1):25038. doi: 10.1038/s41598-025-10324-3.
This paper investigates subsurface structures within the United Arab Emirates University (UAEU) campus using microgravity survey. Gravity methods are widely used in geophysical exploration to detect density variations that may indicate subsurface anomalies. The primary objective of this research is to generate the Bouguer anomaly map of the UAEU campus to map subsurface structures and to assess potential geological hazards such as cavities. A total of 76 gravity stations were measured across the UAEU campus using the Scintrex CG-6 gravimeter. The acquired gravity data underwent standard processing to obtain the Bouguer anomaly, including tidal, instrumental drift, latitude, free air, Bouguer, and terrain corrections. The first Bouguer anomaly map of the UAEU campus was produced, revealing gravity values ranging from 112.8 to 115.1 mGal. High gravity anomalies are concentrated in the north-eastern and western regions, while lower gravity anomalies are predominantly observed in the southeastern and southwestern areas. Gravity gradient derivative techniques, such as the horizontal gradient, tilt angle, horizontal derivative of tilt angle and analytic signal were applied to the Bouguer anomaly. A 3-D gravity inversion was performed, modeling density variations from the surface down to a depth of 300 m below the sea level. The study successfully identified significant density contrasts indicative of probable cavities or low-density bodies, lithological variations and possible faults zones dominant structural trends along WNW-ESE, NW-SE, N-S, and E-W directions in the study area. Two distinct geological layers were identified: a shallow layer extending up to approximately 50 m and a comparatively deeper layer ranging from 50 to 100 m in depth. The 3-D inversion model delineated two prominent low-density anomalies at depths of 125-175 m from surface, suggesting the presence of cavities or low-density zones. This research represents the first high-resolution microgravity study of the UAEU campus, establishes a baseline microgravity dataset for the UAEU campus. The results enhance understanding of subsurface and highlight the need for further geotechnical and geophysical investigations to validate and refine cavity detection and hazard assessments.
本文利用微重力测量研究了阿联酋大学（UAEU）校园内的地下结构。重力方法在地球物理勘探中被广泛应用，以检测可能指示地下异常的密度变化。本研究的主要目的是生成阿联酋大学校园的布格异常图，以绘制地下结构并评估潜在的地质灾害，如空洞。使用Scintrex CG - 6重力仪在阿联酋大学校园内共测量了76个重力站。采集到的重力数据经过标准处理以获得布格异常，包括潮汐、仪器漂移、纬度、自由空气、布格和地形校正。制作了首张阿联酋大学校园的布格异常图，显示重力值范围为112.8至115.1毫伽。高重力异常集中在东北部和西部地区，而较低重力异常主要出现在东南部和西南部地区。将重力梯度导数技术，如水平梯度、倾斜角、倾斜角的水平导数和解析信号，应用于布格异常。进行了三维重力反演，模拟了从地表到海平面以下300米深度的密度变化。该研究成功识别出显著的密度差异，表明可能存在空洞或低密度体、岩性变化以及可能的断层带，研究区域内主要构造趋势为WNW - ESE、NW - SE、N - S和E - W方向。识别出两个不同的地质层：一个浅层延伸至约50米，一个相对较深的层深度在50至100米之间。三维反演模型在距地表125 - 175米深度处描绘出两个突出的低密度异常，表明存在空洞或低密度区。本研究是对阿联酋大学校园的首次高分辨率微重力研究，为阿联酋大学校园建立了一个基线微重力数据集。研究结果增进了对地下情况的了解，并突出了进一步进行岩土工程和地球物理调查以验证和完善空洞检测及灾害评估的必要性。
