Groundwater characterization in arid regions using seismic and gravity attributes: Al Jaww Plain, UAE

Abstract

This paper discusses a multivariate approach aimed at geophysical characterization of subsurface rocks for groundwater exploration in arid environments. We integrate several findings obtained from a single-source, single-sensor seismic profile with gravity data to detail the tectonic settings and characterize the subsurface, water-bearing formations of the Al Jaww Plain, one of the most important groundwater reserves of the United Arab Emirates. The seismic data have been acquired in the framework of the first EAGE Middle-East Bootcamp. Edge-detection techniques applied to the Bouguer anomaly map of the Al Jaww Plain allowed us to infer the presence of unreported ENE trending tectonic lineaments. The prestack depth migrated seismic image shows a clear and previously unreported east-verging thrust affecting seismic wave propagation and consistent with gravity data which was interpreted as an evidence of a detachment fold and thrust above the bottom of Fiqa Formation. Using the first-arrival picking from the common shot gathers, we tested a coupled tomographic inversion of P-wave velocity and Q factor which was aimed at achieving a qualitative characterization of rock petrophysical properties. K-means clustering was used to classify and map subsurface areas characterized by similar observations of P- and Q-wave velocity and therefore to outline shallow zones (<600 m) that are consistent with geophysical properties which are typical for water accumulations and within the reach of water groundwater exploration.

Audio‐Magnetotelluric Survey for Groundwater Investigation in the Al‐Jaww Plain in Eastern Abu Dhabi, Al‐Ain, United Arab Emirates

“…The Quaternary and Pliocene units in this zone represent various depositional environments, including alluvial, desert plain, sabkha, and aeolian sand deposits, as depicted in Figure 6. Notably, the Quaternary deposits within the Al-Jaww Plain hold the largest reserves of fresh to slightly saline groundwater in the eastern Abu Dhabi Emirate, with TDS values ranging from 500 to 6,000 mg/L (Bruno & Vesnaver, 2021). These aquifers are crucial for water resources in the region (Bruno & Vesnaver, 2021).…”

“…This thrust is also observed in the seismic profile (Figure 7) and is consistent with findings from gravity data analysis (Abdelmaksoud et al., 2023; Ali et al., 2008). In addition, Bruno and Vesnaver (2021) interpreted the subsurface structure beneath the shallow Quaternary deposits (Zone A) of Al‐Jaww Plain as a detachment fold and thrust situated above the Fiqa Formation.…”

“…(2008), Ali and Watts (2009), Cooper et al. (2014), and Bruno and Vesnaver (2021) used seismic geophysical techniques to investigate the geological structures and stratigraphy beneath the Al‐Jaww Plain. Ali et al.…”

“…However, relatively few geophysical studies have been previously conducted on the Al-Jaww plain subsurface. Woodward (1994), Ali et al (2008), Ali and Watts (2009), Cooper et al (2014), and Bruno and Vesnaver (2021) used seismic geophysical techniques to investigate the geological structures and stratigraphy beneath the Al-Jaww Plain. Ali et al (2008) interpreted seismic horizons in this area and classified them into four different bedrock units: (deepest) Mesozoic shelf carbonates and allochthonous marine sequences, unconformably overlain by a clastic and carbonate foreland basin sequence, followed upwards by a Tertiary dominantly carbonate sequence.…”

Broadband Q-Factor Imaging for Geofluid Detection in the Gulf of Trieste (Northern Adriatic Sea)

“…where f is the frequency and A(f) is the amplitude spectrum of the waveform surrounding the extremum point t e . This property may be used directly for the Q-factor tomography, as presented by Vesnaver et al (2020), Bruno and Vesnaver (2020). In our paper, however, we exploit it to compute the high-frequency component of the anelastic absorption, to complement the low frequency part provided by reflection tomography.…”