Identify and Monitor Growth Faulting Using InSAR over Northern Greater Houston, Texas, USA

Feifei Qu,Zhong Lu,Weiyu Zheng,Jin-Woo Kim

doi:10.3390/rs11121498

Abstract

Growth faults are widely distributed in the Greater Houston (GH) region of Texas, USA, and the existence of faulting could interrupt groundwater flow and aggravate local deformation. Faulting-induced property damages have become more pronounced over the last few years, necessitating further investigation of these faults. Interferometric synthetic aperture radar (InSAR) has been proved to be an effective way for mapping deformations along and/or across fault traces. However, extracting short-wavelength small-amplitude creep signal (about 10–20 mm/yr) from long time span interferograms is extremely difficult, especially in agricultural or vegetated areas. This study aims to position, map and monitor the rate, extent, and temporal evolution of faulting over GH at the highest spatial density using Multi-temporal InSAR (MTI) technique. The MTI method, which maximizes usable signal and correlation, has the ability to identify and monitor faulting and provide accurate and detailed depiction of active faults. Two neighboring L-band Advanced Land Observing (ALOS) tracks (2007–2011) are utilized in this research. Numerous areas of sharp phase discontinuities have been discerned from MTI-derived velocity map. InSAR measurements allow us to position both previously known faults traces as well as nucleation of new fractures not previously revealed by other ground/space techniques. Faulting damages and surface scarps were evident at most InSAR-mapped fault locations through our site investigations. The newly discovered fault activation appears to be related to excessive groundwater exploitation from the Jasper aquifer in Montgomery County. The continuous mining of groundwater from the Jasper aquifer formed new water-level decline cones over Montgomery County, corroborating the intensity of new fractures. Finally, we elaborate the localized fault activities and evaluate the characteristics of faulting (locking depth and slip rate) through modeling MTI-derived deformation maps. The SW–NE-oriented faults pertain to normal faulting with an average slip rate of 7–13 mm/yr at a shallow locking depth of less than 4 km. Identifying and characterizing active faults through MTI and deformation modeling can provide insights into faulting, its causal mechanism and potential damages to infrastructure over the GH.

Highlights

Greater Houston, Texas, USA, comprising Montgomery, Grimes, Waller, Harris, Liberty, Chambers, Austin, Fort Bend, Brazoria and Galveston Counties, located on the Gulf coastal plain, is laced by numerous growth faults [1,2,3] (Figure 1)
We processed SAR images from Advanced Land Observing (ALOS) PALSAR datasets utilizing the Multi-temporal InSAR (MTI) method described in Section 3 and generated two annual line-of-sight (LOS) deformation maps of Greater Houston (GH) area during 2007 and 2011
Three regional fault zones pass through the northern GH area: Yegua fault zone, Hitchcock fault zone, and the Wilcox Fault Zone, which runs across Montgomery County [3]

Summary

Introduction

Greater Houston, Texas, USA (hereafter GH), comprising Montgomery, Grimes, Waller, Harris, Liberty, Chambers, Austin, Fort Bend, Brazoria and Galveston Counties, located on the Gulf coastal plain, is laced by numerous growth faults [1,2,3] (Figure 1). Hundreds of paved roads and homes in the Houston area are being offset by faults and require frequent maintenance. Factories, commercial establishments, and railroads have been affected by fault movement, and it costs several million dollars to repair such structures. 2019, 22of of 23 million dollars to repair such structures a year [6]. There are more subtle or hidden effects of a year [6]. Therehave are more or hidden effects of faulting have been recognized and faulting which neversubtle been recognized and many breakswhich may not be never related to faulting because many breaks may not be related to faulting because the existence of faults is unknown [6,7]

Objectives

Results

Discussion

Conclusion