Wednesday, March 20, 2013

SAGEEP

Just now I'm sitting in the Denver airport after attending the SAGEEP meeting run by EEGS (environmental and engineering geophysical society). This is a annual meeting of scientists working on shallow geophysical problems. It is a small group, maybe hundred 100 people at this meeting. The entire membership somewhere between 400 and 600. They are struggling with the opportunity for a potential merger with the SEG organization. This group has been active on its own for nearly 30 years and you can imagine the concerns of becoming part of a much larger organization.

But I did not come here for politics. My interest was in seeing some small vendors in the exhibition hall who either would not be found at the annual SEG meeting or be lost in the shuffle at such a large affair. In this I was successful.

I had a chance to sit down and have some beers with people from Sensors and Software, a company from whom I had just purchased a GPR system. The issue was how to survey quickly across good terrain like that we might find in a rock quarry. Turns out they have a small wheeled vehicle beautifully suited to the purpose, including a distance activated trigger on the wheel. The deal was made.

Another need we had at University of Arkansas is software to build a near surface model from the kind of seismic dated generated by a 48 channel system and hammer source. In the high production world of commercial 3-D seismic data, this job falls to tomography software which is largely automatic. The tomography tends to generate smooth near surface models devoid of hard contacts and layers. This is fine as an effective medium solution to do statics for deeper reflection seismic data. But my work on the outcrop and in the shallow subsurface recognizes there are discrete layers and refractors we want to map as accurately as possible. This harkens back to the early days seismology when people did serious refraction interpretation, a skill largely lost in production 3-D seismic shops these days.

The most rigorous form of these refraction analysis solutions is the Generalized Reciprocal Method (GRM) of Derrick Palmer published in the 1980s. It is brilliant, but difficult to understand and implement. Thankfully Charlie Stoyer (ex-CSM professor) has done this laborious job for us. I sat down with Charlie for 30 minutes, we talked through the software (including an example), and came up with a nice, realistic near surface model. The workflow is involved and requires significant human input for data quality judgment and parameters. Exactly the sort of thing I want my students to understand. The interface is clean and tight, and allows quick QA/QC from shot records to to final model. I noticed some small tick marks on the final model and asked Charlie about them. He said "Oh, those are uncertainty bars. I can remove them." I said "Don't you dare, I want my students to see them." The deal was made; another sale.

Finally, I talked to a company which makes a trailer mounted thumper seismic source. This is a necessary addition to our arsenal of hammer source and Vibroseis unit available through the UArk civil engineering department. But I was late for a lunch meeting with Mike Sullivan of FairfieldNodal, a meeting later with John Stockwell of CSM, and dinner that evening with my daughter Sam in Boulder. The thumper company will send me a quote so we can communicate and figure out a way to close this deal too.

Other societies such as a APG and SPE hold regional meetings throughout the US and the world (my fledgling research group has submitted seven abstracts to the midcontinent AAPG meeting in Wichita this fall). Regional meetings don't replace national meetings, they compliment them, allowing workers dealing with regional problems to meet on a smaller scale, a more intimate scale, and vendors to deal with that group specifically.

SEG may want to reconsider the regional meeting model, or lose that market to others who do.

John Stockwell in his domain (below)

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