RAPID: Collaborative Research: Response to the 2016 M5.8 Pawnee Earthquake: Using MT to map Fluids in Faults

GSTDTAP

项目编号	1664579
	RAPID: Collaborative Research: Response to the 2016 M5.8 Pawnee Earthquake: Using MT to map Fluids in Faults
	Kerry Key
主持机构	University of California-San Diego Scripps Inst of Oceanography
项目开始年	2016
	2016-11-01
项目结束日期	2017-10-31
资助机构	US-NSF
项目类别	Standard Grant
项目经费	14192(USD)
国家	美国
语种	英语
英文摘要	Since 2008, there has been a dramatic increase in earthquake activity in the central United States in association with major oil and gas operations. Oklahoma is now considered one of the most seismically active states. Some of the earthquakes are occurring near populated cities and also in areas of high national security such as Cushing, Oklahoma, a major hub of the U.S. oil and gas pipeline transportation system. Unlike earthquakes in California and Alaska that can be clearly linked to deformation along plate boundaries, the cause of the earthquakes in Oklahoma remains a very contentious and highly debated topic. However, there is an increasing body of scientific evidence to suggest that the increased level of seismicity is linked to the injection of saline production wastewaters from drilling activity related to petroleum exploitation. Although seismic networks are able to detect activity and map its hypocenter, they are unable to image the distribution of fluids in the fault responsible for triggering seismicity. The magnetotelluric (MT) technique, uses naturally occurring electric and magnetic fields measured at Earth?s surface to measure conductivity structure. The 2016 M5.8 Pawnee, Oklahoma earthquake provides an unprecedented opportunity for scientists to provide a link between seismicity and imaging of fluids on or around faults. Thus we will carry out a series of two-dimensional (2D) profiles located through areas where the fault recently ruptured and seismic activity is concentrated and also across the faults in the vicinity that did not rupture. The integration of our results and ongoing seismic studies will lead to a better understanding of the links between fluid injection and seismicity. Results of this study can inform decisions by policy-makers. Electrical geophysical methods are ideally suited to image fluid bearing faults since the produced waters are highly saline and hence have a high electrical conductivity. To date, no study has imaged the fluids in the faults in Oklahoma and made a direct link to the seismicity. Several injection wells are located within a 20 km radius of the epicenter; and studies have suggested that injection of fluids in high-volume wells can trigger earthquakes as far away as 30 km. This proposal will collect MT geophysical data that will constrain the distribution of fluids in the fault zone that ruptured during the 2016 M5.8 Pawnee earthquake. Because most injection activities have been temporarily suspended following the September 3, 2016 earthquake, we have the unique opportunity to capture the state of the fluid induced seismicity process before the system is altered by additional wastewater injection. Given that seismicity in in Oklahoma has been met with public outcry, with demands for action by legislators. However, any decision by stakeholders and policy makers must be guided by sound science and unbiased data. Geologically informed approaches to characterizing induced seismicity for inclusion in seismic hazard evaluations is critical for evaluation of sensitive facilities. As a result, our proposed MT survey has multi-faceted broader impacts: (1) It will produce data-constrained results that will lead to a better understanding of migration of wastewater ? fault interactions. (2) We will produce relevant data that can be used to inform the decisions of policy-makers and stakeholders when assessing seismic hazards related to wastewater injection. (3) Our project will engage several students. Students will assist with the data acquisition and will gain hands-on experience from MT experts in how to deploy MT instrumentation. At least two of the students will come from under-represented groups, thereby building a diverse workforce in science and engineering
来源学科分类	Geosciences - Earth Sciences
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/70544
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Kerry Key.RAPID: Collaborative Research: Response to the 2016 M5.8 Pawnee Earthquake: Using MT to map Fluids in Faults.2016.