Current Activity of the Long Point Fault in Houston, Texas Constrained by Continuous GPS Measurements (2013–2018)

Abstract

The Long Point Fault is one of the most active urban faults in Houston, Texas, which belong to a complex system of normal growth faults along the Texas Gulf Coast. To assess the activity of the Long Point Fault, a GPS array with 12 permanent stations was installed along the two sides of the 16-km-long fault scarp in 2013. GPS datasets were processed with the Precise Point Positioning (PPP) and Double-Difference (DD) methods. The daily PPP solutions with respect to the International Global Navigation Satellite System (GNSS) Reference Frame 2014 (IGS14) were converted to the Stable Houston Reference Frame (Houston16). The six-year continuous GPS observations indicate that the Long Point Fault is currently inactive, with the rates of down-dip-slip and along-strike-slip being below 1 mm/year. The Long Point Fault area is experiencing moderate subsidence varying from 5 to 11 mm/year and a coherent horizontal movement towards the northwest at a rate of approximately 2 to 4 mm/year. The horizontal movement is induced by the subsidence bowl that has been developing since the 1980s in the Jersey Village area. Current surficial damages in the Long Point Fault area are more likely caused by ongoing uneven subsidence and its induced horizontal strains, as well as the significant seasonal ground deformation, rather than deep-seated or tectonic-controlled fault movements. The results from this study suggest a cause-and-effect relationship between groundwater withdrawals and local faulting, which is pertinent to plans for future urban development, use of groundwater resources, and minimization of urban geological hazards.

Detection and Monitoring of Tunneling-Induced Riverbed Deformation Using GPS and BeiDou: A Case Study

“…Owing to the fact that this project is the first shield driven tunnel beneath the Hutuo River in Shijiazhuang, a significant concern regarding the riverbed deformation and tunneling safety occurred during the excavations. Based on our experiences from previous GPS monitoring projects [21][22][23][24][25], we established a GPS monitoring network with one base station (BASE) and six rover stations named GPS1, GPS2, GPS3, GPS4, GPS5, and GPS6 ( Figure 1b). The base station was installed at the headquarters of the project, about two kilometers away from the river (Figure 1a).…”

Rapid Land Subsidence in Tianjin, China Derived from Continuous GPS Observations (2010–2019)

“…GPS positions are initially defined as a set of coordinates with respect to a global reference frame. In general, a global geodetic reference frame is a no-net-rotation (NNR) reference frame, which is realized with an approach of minimiz- ing the overall horizontal movements of a large number of selected reference stations distributed worldwide (Rebischung et al, 2016). As a consequence, GPS-derived site velocities with respect to a global reference frame are often dominated by long-term drift and rotations of the tectonic plate on which the site is located, glacial isostatic adjustment, and other secular motions (Yu and Wang, 2017).…”

“…PPP daily solutions could achieve 2-4 mm horizontal accuracy (root mean square of residuals) and 5-8 mm vertical accuracy in north China (Bao et al, 2017;Guo et al, 2019). The PPP solutions are defined in an Earth-Centered-Earth-Fixed (ECEF) Cartesian coordinate system that defines a position as a pair of x, y, and z coordinates with respect to the International GNSS Service (IGS) reference frame 2014 (IGS14) (Rebischung et al, 2016). IGS14 is the latest in a series of GNSS reference frames (e.g., IGS00, IGS05, IGS08) adopted by IGS.…”

“…NChina16 provides the 7parameters for transforming ECEF-XYZ coordinates from IGS08 to the regional reference frame. Since NChina16 is aligned to IGS08, the IGS14 coordinates are firstly transformed to IGS08 according to the parameters provided by IGS (Rebischung et al, 2016). NChina16 will be updated and aligned to IGS14 in 2020.…”

GPS geodetic infrastructure for subsidence and fault monitoring in Houston, Texas, USA

“…The Chicot, Evangeline, and Jasper aquifers are the major aquifers underlying the Greater Houston region. Land subsidence in this region is primarily caused by the compaction of clay lenses in the Chicot and Evangeline aquifers throughout the region and the Jasper aquifer in the northern part of the region due to groundwater withdrawal (e.g., Kearns et al, 2015;Turco et al, 2015;Kasmarek and Ramage, 2017;Qu et al, 2019). Ground deformation associated with subsidence and faulting has caused widespread damage to residential, commercial, industrial buildings, and public infrastructure since the 1950s.…”