Hazard Implications of the 2016 Mw 5.0 Cushing, OK Earthquake from a Joint Analysis of Damage and InSAR Data

The Cushing Hub in Oklahoma, one of the largest oil storage facilities in the world, is federally designated as critical national infrastructure. In 2014, the formerly aseismic city of Cushing experienced a Mw 4.0 and 4.3 induced earthquake sequence due to wastewater injection. Since then, an M4+ earthquake sequence has occurred annually (October 2014, September 2015, November 2016). Thus far, damage to critical infrastructure has been minimal; however, a larger earthquake could pose significant risk to the Cushing Hub. In addition to inducing earthquakes, wastewater injection also threatens the Cushing Hub through gradual surface uplift. To characterize the impact of wastewater injection on critical infrastructure, we use Differential Interferometric Synthetic Aperture Radar (DInSAR), a satellite radar technique, to observe ground surface displacement in Cushing before and during the induced Mw 5.0 event. Here, we process interferograms of Single Look Complex (SLC) radar data from the European Space Agency (ESA) Sentinel-1A satellite. The preearthquake interferograms are used to create a time series of cumulative surface displacement, while the coseismic interferograms are used to invert for earthquake source characteristics. The time series of surface displacement reveals 4⁻5.5 cm of uplift across Cushing over 17 months. The coseismic interferogram inversion suggests that the 2016 Mw 5.0 earthquake is shallower than estimated from seismic inversions alone. This shallower source depth should be taken into account in future hazard assessments for regional infrastructure. In addition, monitoring of surface deformation near wastewater injection wells can be used to characterize the subsurface dynamics and implement measures to mitigate damage to critical installations

Predictive geohazard mapping using LiDAR and satellite imagery in Missouri and Oklahoma, USA

”Light Detection and Ranging (LiDAR) and satellite imagery have become the most utilized remote sensing technologies for compiling inventories of surficial geologic conditions. Point cloud data obtained from multi-spectral remote sensing methods provide a detailed characterization of the surface features, in particular, the detailed surface manifestations of underlying geologic structures. When combined, point clouds eliminate bias from visual inconsistencies and/or statistical values. This research explores the competence of point clouds derived from LiDAR and Unmanned Aerial Systems (UAS) as a predictive tool in evaluating various geohazards. It combines these data sets with other remote sensing techniques to evaluate the sensitivity of the respective datasets to temporal changes in the earth’s surface (potentially detectable at a centimeter-scale). A two-phase research approach was employed to test several hazard mapping scenarios in three geographic areas in the U.S. Midcontinent as follows: 1) UAS-derived surficial deformations near the epicenter of the 2016 Mw 5.8 Pawnee, Oklahoma earthquake (Paper I); 2) UAS mapping of recent earthquake epicenters in Noble Payne and Pawnee counties of Oklahoma State (Paper II); and, 3) Evaluation of geohazards in Greater Cape Girardeau Southeast Missouri (Paper III). These analyses detected geomorphic changes in the study locations, such as ground subsidence, soil heave and expansion, liquefaction-induced structures, dynamically-induced consolidation, and surface fault rupture. The studies underscore the importance of early hazard identification and providing information to relevant data users to make informed decisions”--Abstract, page iv

Lessons for Remote Post-earthquake Reconnaissance from the 14 August 2021 Haiti Earthquake

On 14th August 2021, a magnitude 7.2 earthquake struck the Tiburon Peninsula in the Caribbean nation of Haiti, approximately 150 km west of the capital Port-au-Prince. Aftershocks up to moment magnitude 5.7 followed and over 1,000 landslides were triggered. These events led to over 2,000 fatalities, 15,000 injuries and more than 137,000 structural failures. The economic impact is of the order of US$1.6 billion. The on-going Covid pandemic and a complex political and security situation in Haiti meant that deploying earthquake engineers from the UK to assess structural damage and identify lessons for future building construction was impractical. Instead, the Earthquake Engineering Field Investigation Team (EEFIT) carried out a hybrid mission, modelled on the previous EEFIT Aegean Mission of 2020. The objectives were: to use open-source information, particularly remote sensing data such as InSAR and Optical/Multispectral imagery, to characterise the earthquake and associated hazards; to understand the observed strong ground motions and compare these to existing seismic codes; to undertake remote structural damage assessments, and to evaluate the applicability of the techniques used for future post-disaster assessments. Remote structural damage assessments were conducted in collaboration with the Structural Extreme Events Reconnaissance (StEER) team, who mobilised a group of local non-experts to rapidly record building damage. The EEFIT team undertook damage assessment for over 2,000 buildings comprising schools, hospitals, churches and housing to investigate the impact of the earthquake on building typologies in Haiti. This paper summarises the mission setup and findings, and discusses the benefits, and difficulties, encountered during this hybrid reconnaissance mission

Preliminary Magnitude and Distance Damage Thresholds for Light-Frame Wood Buildings in Induced Earthquakes

Since 2009, the frequency of (moment) magnitude (Mw) 3.0 earthquakes and larger in the Central United States, and especially Oklahoma (OK), has risen from an average of 2 per year, to 200-700 per year. This increase in seismicity is a result of injection of large quantities of wastewater generated from oil and gas activities deep underground. In this study, damage to built infrastructure from induced earthquakes is investigated through nonlinear dynamic analysis and probabilistic damage assessment for a light-frame wood structure. Specifically, we focus here on investigating the smallest Mw injectioninduced earthquake that may cause damage to the building of interest at various distances from the hypocenter (R). The simulations are based on a two-story multifamily dwelling, which is designed with lateral strength and detailing consistent with modern code requirements in Pawnee, OK. For a Mw 4.5 earthquake, damage is observed at R = 15 km or closer. While for an earthquake R = 3 km from the site, damage is observed 56% of the time at Mw 4.5 and occurs 100% of the time when Mw 5.5 and above.This research was supported by the National Science Foundation under award number 1520846 and by the Civil, Architectural, and Environmental Engineering at the University of Colorado, Boulder

Lessons for Remote Post-earthquake Reconnaissance from the 14 August 2021 Haiti Earthquake

On 14th August 2021, a magnitude 7.2 earthquake struck the Tiburon Peninsula in the Caribbean nation of Haiti, approximately 150 km west of the capital Port-au-Prince. Aftershocks up to moment magnitude 5.7 followed and over 1,000 landslides were triggered. These events led to over 2,000 fatalities, 15,000 injuries and more than 137,000 structural failures. The economic impact is of the order of US$1.6 billion. The on-going Covid pandemic and a complex political and security situation in Haiti meant that deploying earthquake engineers from the UK to assess structural damage and identify lessons for future building construction was impractical. Instead, the Earthquake Engineering Field Investigation Team (EEFIT) carried out a hybrid mission, modelled on the previous EEFIT Aegean Mission of 2020. The objectives were: to use open-source information, particularly remote sensing data such as InSAR and Optical/Multispectral imagery, to characterise the earthquake and associated hazards; to understand the observed strong ground motions and compare these to existing seismic codes; to undertake remote structural damage assessments, and to evaluate the applicability of the techniques used for future post-disaster assessments. Remote structural damage assessments were conducted in collaboration with the Structural Extreme Events Reconnaissance (StEER) team, who mobilised a group of local non-experts to rapidly record building damage. The EEFIT team undertook damage assessment for over 2,000 buildings comprising schools, hospitals, churches and housing to investigate the impact of the earthquake on building typologies in Haiti. This paper summarises the mission setup and findings, and discusses the benefits, and difficulties, encountered during this hybrid reconnaissance mission.</jats:p

Lessons for Remote Post-earthquake Reconnaissance from the 14 August 2021 Haiti Earthquake

On 14th August 2021, a magnitude 7.2 earthquake struck the Tiburon Peninsula in the Caribbean nation of Haiti, approximately 150 km west of the capital Port-au-Prince. Aftershocks up to moment magnitude 5.7 followed and over 1,000 landslides were triggered. These events led to over 2,000 fatalities, 15,000 injuries and more than 137,000 structural failures. The economic impact is of the order of US$1.6 billion. The on-going Covid pandemic and a complex political and security situation in Haiti meant that deploying earthquake engineers from the UK to assess structural damage and identify lessons for future building construction was impractical. Instead, the Earthquake Engineering Field Investigation Team (EEFIT) carried out a hybrid mission, modelled on the previous EEFIT Aegean Mission of 2020. The objectives were: to use open-source information, particularly remote sensing data such as InSAR and Optical/Multispectral imagery, to characterise the earthquake and associated hazards; to understand the observed strong ground motions and compare these to existing seismic codes; to undertake remote structural damage assessments, and to evaluate the applicability of the techniques used for future post-disaster assessments. Remote structural damage assessments were conducted in collaboration with the Structural Extreme Events Reconnaissance (StEER) team, who mobilised a group of local non-experts to rapidly record building damage. The EEFIT team undertook damage assessment for over 2,000 buildings comprising schools, hospitals, churches and housing to investigate the impact of the earthquake on building typologies in Haiti. This paper summarises the mission setup and findings, and discusses the benefits, and difficulties, encountered during this hybrid reconnaissance mission.</jats:p

Geo-engineered induced seismicity and the effects on federal infrastructure

“The study of human-induced seismicity and the effects on civil engineering systems are not completely understood or often studied. Moreover, existing studies are focused on the cause of the seismicity and not on the potential damage to infrastructure from these seismic events. There are recent studies that are beginning to focus on shallow induced seismic activity and the effects on infrastructure by establishing innovative ways to quantify that damage. These studies that focus on the potential damage neglect to included considerations for small magnitude cluster events. As geo-induced seismic events increase, soil fatigue becomes of greater concern to structures within the seismic zone. Short duration impulse loads affect foundations and structures to the point of potential failure. Although these events can be almost unnoticeable at first, over time have the capability to become a larger issue that has the potential to fail. There is a need for quantitative data to identify potential risk to structures from induced seismic events as well as a need to reassess and potentially modify existing risk assessment evaluations of infrastructure, most importantly critical infrastructure. The U.S. Army Corps of Engineers (USACE) is responsible for hydroelectric power, flood protection, recreational areas, navigational channels and water supply along the waterways that were either constructed prior to seismic design requirements or designed to a lower seismic level than current seismic activity. The potential damage from human-induced seismic activity is becoming more urgent as the increase in seismic events occur”--Abstract, page iv

Quantifying the Onset of Damage for Light Frame Wood Buildings in Induced Earthquakes

Since 2009, the frequency of (moment) magnitude (M) 3.0 earthquakes and larger in the Central United States, and especially Oklahoma, has risen from an average of 2 per year, to 200-700 per year. This increase in seismicity is a result of the deep injection of large quantities of wastewater from oil and gas activities underground. In this study, damage to built infrastructure from induced earthquakes is investigated through nonlinear dynamic analysis and probabilistic damage assessment for light-frame wood structures common in Oklahoma. Specifically, we focus here on investigating the smallest magnitude of injection-induced earthquake that may cause damage to the buildings of interest at various distances from the hypocenter (R). The simulations are based on two-story commercial, multifamily, and single-family buildings, which are designed with lateral strength and detailing consistent with modern code requirements in Pawnee, OK, and modeled nonlinearly in the Timber3D software simulations of the buildings. Ground shaking is defined by target spectra from the Novakovich et al. (2018) ground motion prediction equation (GMPE) based on the M and R of each earthquake scenario of interest. For each scenario, 25 records are selected to match the median and expected variance in the target spectra, providing the excitation for the nonlinear simulation models. Damage is identified as occurring if story drifts exceed a level associated with screws or nails popping out, minor cracking of wallboard, and warping or cracking of wallpaper in light-frame wood shear walls. This damage is minor, but is damage that many homeowners would choose to repair. The results show that larger magnitude events result in higher damage probabilities and have the potential to impact the structures at further distances. For example, a M 3 event, is unlikely to damage the structures of interest, whereas a M 5.5 is likely (i.e., 50% probability) to cause damage up to 20 km away from the earthquakes source. The minimum magnitude that is associated with any damage to the structures is a M 4 with R < 7.5 km, but the probability of damage is 10% or lower. The minimum magnitude that has a damage probability of 50% is a M 5 event with R < 12 km. Magnitude and distance thresholds are used by government and regulatory agencies to define appropriate action thresholds, where injection volumes are reduced or stopped, for injection well operators. The goal of these thresholds is to mitigate the risk from induced seismicity

Mechanisms and Mitigation of Injection-Induced Earthquakes

Injection-induced seismicity caused by wastewater injection is a continuing problem for the central and eastern United States. Mitigation of induced earthquakes often focuses on operational parameters like injection rate. While pore pressure increase has been the main mechanism invoked in injection-induced seismicity, other mechanisms like Coulomb static stress transfer may play a role. In this dissertation, I examine the mechanisms of injection –induced earthquakes in relation to mitigation.I investigate the role of aggregate injection rate, the combined injection rate of multiple wells, by modeling pore pressure increase caused by 22 wastewater disposal wells injecting into the same disposal zone within 30 km of seismicity in Greeley, Colorado. I find that the wells 15 – 30 km from the seismicity contribute approximately 44% of pore pressure increase at the location of the earthquakes. Therefore, aggregate injection rate and well spacing is important when planning mitigation strategies. I also derive a simple relation between pore pressure change and surface deformation that can be used to constrain hydraulic parameters of confined aquifers to a first-order. This relation can estimate expected surface deformation associated with pore pressure model results, which can then be compared to observed surface deformation using geodetic techniques. I validate this relation by constraining the storativity of an aquifer in Texas that experienced uplift associated with wastewater disposal.Finally, I investigate the role of small magnitude earthquakes in induced seismicity. I use generic models to test if small magnitude earthquakes can cumulatively transfer, through earthquake interactions, stress of a magnitude comparable to pore pressure increase from wastewater injection. I find that the stress caused by earthquake interactions (Coulomb static stress transfer) is comparable in magnitude to pore pressure increase. However, the area influenced by the increased stress is much smaller than in pore pressure diffusion. This means that earthquake interactions may induce more earthquakes though over a smaller area than pore pressure increase. If earthquake interactions induce additional events, reduction in injection rate or even shutting down a well may not mitigate seismicity. Therefore, earthquake interactions should be taken into account when planning mitigation, especially the timing of mitigation measures

Surface Deformation and Seismicity Linked to Fluid Injection in the Raton Basin

It is suggested that deep fluid injection may cause surface uplift and subsidence in oil and gas producing regions in addition to seismicity. This study uses the Raton Basin as an example to investigate the hydromechanical processes of surface uplift and subsidence following fluid injection and relate them to the region's seismic history. The Raton Basin, in southern central Colorado and northern central New Mexico, has experienced wastewater injection related to coalbed methane and gas production starting in 1994 and increased seismicity since 2001. In this study, we estimate the extent and magnitude of total vertical deformation in the Raton Basin from 1994 to 2020, and short-term deformation between the years 2017 to 2020 following a sharp decline in injection rates. Most modeled uplift between 1994 and 2020 occurred near the southern wells, where the greatest cumulative volume of wastewater was injected. However, modeled subsidence occurred around the southern and eastern wells between 2017 and 2020, after the rate of injection decreased. This shows that while the magnitude of uplift corresponds to cumulative injection volume and maximum rate in the long-term, short-term incremental deformation (uplift or subsidence) is controlled by changes in the rate of injection. The increased number of yearly earthquake events follow periods of modeled rapid uplifting throughout the basin, suggesting that surface deformation is caused by the same injection induced pore pressure perturbations that initiate seismicity.</p