"A little over a decade ago, the southern midcontinent, USA, began experiencing more earthquakes and attention focused on how disposal of large volumes of brine from oil production could trigger earthquakes. This volume examines that phenomenon in Arkansas, Oklahoma, Texas, Kansas, Colorado, and New Mexico, and details the regulatory response to it"--
Positive magnetic, gravity, and thermal anomalies in the Charleston and New Madrid areas may Tertiary midcrustal plutons; regional compressive stress concentrated around the plutons may release as earthquakes.
Subsurface injection of wastewater co-produced alongside oil and gas (O&G) has been linked to an increasing number of earthquake events throughout the southern mid-continent of the United States. In Texas, the average count of seismic events per year have risen over the past decade. This study aims to compare injection of produced water into the subsurface and increased number of earthquakes in the Panhandle Region of Texas. For this study, saltwater disposal and enhanced oil recovery through underground injection control (UIC) wells in the Texas Panhandle were analyzed from 1983-2018. During this same period, a total of 64 earthquakes of M ≥ 2.5 were recorded. The average earthquake rates increased from 1.21 events per year (1983-2007) to 3.50 events per year (2008-2018). A total of 1,926 active UIC wells in the Texas Panhandle were identified from the Railroad Commission of Texas database during the study period. This research identified 54 geologic stratigraphic formations present in the region and focused on the 34 target formations into which wastewater was injected. Cumulative UIC volumes were found to be localized by geographic regions and geologic formations, where a total of 2.26 billion barrels (Bbbls, where 1 barrel = 159 liters) of wastewater were injected. Approximately 87% of the total disposal volume (1.96 Bbbls) was injected into seven geologic formations, including the igneous Precambrian basement; another 27 formations received less than 100 million barrels (MMbbls) each. Monthly UIC rates in the Panhandle fluctuated in time, similar to overall O&G industry activity. From this analysis, 61% of earthquake events are considered to be possibly or probably induced by a combination of UIC and O&G practices. Additionally, this research identified regions at risk of potentially hosting future earthquakes induced by current UIC and O&G operations. Understanding how and where UIC practices and O&G operations are affecting seismicity rates in the State of Texas can allow researchers and regulators propose strategies to reduce or mitigate negative externalities such as induced seismicity
This volume addresses recent developments in the principal seismically active regions of the United States: the Pacific Coast; the western mountain area; the New Madrid area; New England; and the southeastern United States, including Charleston, South Carolina.
A review and evaluation of our knowledge of the structure of the crust and upper mantle of the continental United States, exclusive of Alaska, as determined from geophysical observations. Covers geophysical methods of studying the crust and upper mantle; a region-by-region review of crustal and upper-mantle structure; continental overviews based on the different geophysical methods; and geologic and petrologic syntheses based largely on the geophysical results.
The 'sedimentary cover' refers to the stratified rocks of youngest Proterozoic and Phanerozoic age that rest upon the largely crystalline basement rocks of the continental interior. This volume presents data and interpretations of the geophysics of the craton and summarizes the craton's tectonic evolution. It also presents the stratigraphy, structural history, and economic geology of specific sedimentary basins (e.g. Appalachian basin) and regions (e.g. Rocky Mountains). It concludes with a discussion of the currently popular theories of cratonal tectonics, & unresolved questions are identified.