Since November 5, 2013, earthquakes in the Reno-Azle area, northeast of Fort Worth, TX, have raised scientific questions about the nature of these sequences and heightened local and national concern about the impact of shale gas production on infrastructure and subsurface structures. While all North Texas events to date have been less than magnitude 4, seismologists are unable to evaluate the potential maximum magnitude for such faults and define the associated hazards. Scientists at SMU have installed and are operating a temporary seismic network in the Reno-Azle area to acquire data that may be used to locate and characterize the correlation and improve identification of swarm-like earthquakes and relative event locations. Size mechanisms and accelerations, associated with the events will allow the size, nature, and hazard of the fault to be estimated. The spatial relation of the felt earthquakes to fluid injection points related to shale gas development in Texas and other states remains a major question. Understanding if and/or how injection of fluids into the crystalline crust reactivates otherwise inactive faults has important implications for seismology, the energy industry, and society.
Week #5 has certainly had its ups and downs. On Monday and Tuesday, I spent most of the day trying to use a previously written MATLAB function, but could not figure it out. I finally was able to compile a script using the function and it did not do what I was thought it did which was obviously frustrating since I had essentially wasted two days. Fed up with searching, I just started to write my own functions and it is going pretty well so far. My advisor also helped me write a perl script to automate getting data from Antelope, but I am having trouble writing variations on my own. Instead, I have been using MATLAB to do the same thing, which is perhaps more complicated, but I actually know the syntax, so the learning curve is not quite as steep. It is a little scary that I only have one month left, but I'm hoping the end of my project will soon be in sight and I can begin writing my abstract and designing my poster.
As I near the end of week #4, I feel that I have made a lot of progress. I am becoming more proficient in MATLAB, Unix, and Antelope and learning more about my project every day. The primary challenge I have faced has been something simple: asking questions. After my first few days, I had so many questions that I didn’t even know where to start. I got off to a slow start because I tried to figure everything out myself; however, I feel that I am moving much more freely and am able to function on my own. Although I have previous MATLAB experience, I am learning a lot of new things that I’m sure will help me in the future. One thing I definitely feel that I could improve on is time-management. I spend a fair amount of time waiting for code to run and about half of the time is spent reading about upcoming NBA free agency on the Internet. This time could (and should!) be used to do other things, but I’m not entirely sure what yet. Hopefully this bad habit will be eradicated sometime next week.
Sorry I am a little late...
Week three was definitely an interesting week here at SMU. One of the biggest things I have learned about my project is that the conclusions will perhaps have a larger political and social impact than scientific. This project is getting a lot of publicity in the area because seismicity is directly affecting people and the local economy. My advisor was invited to be on a discussion panel including reporters, politicians, and an energy industry representative. The event was sponsored by NPR and StateImpact. There was an audience and the discussion was broadcasted on the radio as well. Throughout the discussion, the panelists were generally met with hostility from the crowd, which consisted of citizens of Azle, Reno, and other nearby towns being shaken by small magnitude earthquakes. People were angry that the temporal correlation between oil and gas activity in the area and unprecedented seismicity is not enough to scientifically prove that oil and gas activity caused the seismicity. Although this may seem obvious to a scientist, they are not to blame for having such strong feelings. This event was certainly eye-opening and in a strange way inspiring. It made me feel like what I am doing could really help people.
On a different note, the following day, Heather (my advisor) and I returned to Azle to help teach kids about earthquakes at a science camp and the local library. I was tasked with building an “earthquake machine” that was interactive and would help kids understand earthquakes better. Not being much of a craftsman, I was not very confident in my ability to make such a machine. Fortunately, I was able to put something together. It wasn’t too impressive, but it worked and was a hit at the science fair! I think the kids really enjoyed it.
Now, I am beginning to cross-correlate data in GISMO, a MATLAB based waveform analysis toolbox. I expect to be doing this for the next few weeks, as this is the bulk of my project. I am very glad that I have experience with MATLAB. I could not imagine how much harder my work would be if I was learning MATLAB throughout these first few weeks. I expect that week four will be a rather frustrating week, but I hope to be productive.
This summer, I will be processing passive source seismic time series data by waveform cross correlation. The instruments used to record the signals are primarily accelerometers, broadband seismometers, and short-period seismometers. Some instruments have been recording since 8 November 2013, three days after a swarm of twenty-five earthquakes between magnitude 2.0 and 3.6 were identified in Azle, TX, and continue to record today. From what I understand, this data has been seen by few eyes and is very private due to media coverage of the project. For the past week, I have been picking events and will hopefully begin processing the data in the next week or so. The tools I will be using to do my research are Matlab, Antelope, Unix, and GMT.
There are a few key things I would like to accomplish before the end of my internship. Within the first third, I would like to learn to identify earthquakes in a seismogram, become familiar with Antelope and Unix, and read as many papers about the North Texas seismic studies as possible to familiarize myself with the topic. Within the second third, I would like to be able to independently conduct myself in the lab, perform waveform cross-correlation, and begin forming ideas to write in my abstract. Within the final third, I would like to improve event locations, compare locations and rates with faults, write my results into an abstract, and create relevant figures for my poster. Overall, my desire is to stimulate progress of my project by being a productive researcher and learn about both seismology and research in general.