Christian Poppeliers, associate professor of physics, has been awarded a research grant from the National Science Foundation that will fund an experiment in seismic data collection and analysis. Also, this grant will provide opportunities for undergraduate students to conduct research with the physicist.
The grant, titled Deployment of a simultaneous broadband gradiometers to quantify the effects of aperture and near-surface geology on gradient-derived wavefied attributes, will allow Poppeliers and his team of student researchers to deploy several seismometers simultaneously, (termed a ‘seismic array’) to study how various array designs impact the accuracy and uncertainty of the measurement of seismic waves. It also will allow them to analyze the impact that local geology has on parameters that are estimated from the data collected with seismic arrays. The instruments deployed will record local, regional, and global earthquakes for approximately 24 months, after which the data collected will be examined.
“No one in my field has quantified how good these type of seismic array measurements are,” Poppeliers said. “The more I read in my field, the more I thought we need to take a step back and examine how much we could trust this type of data,” he said.
The uncertainties, or errors, in the actual data can have a huge impact on the accuracy of the parameters that are calculated from the seismic waves, and thus effect the interpretation of the results, he added.
“In addition, the concept of how the geology directly beneath the instrument impacts how seismic P waves are partitioned into S waves has never been developed–many researches have mentioned in passing that it might have an impact, but we hope to provide a definitive answer.”
Poppeliers explained that this has a direct impact on our knowledge of how seismic wave energy propagates through the earth and has applications in underground nuclear explosion detection, engineering earthquake resistant buildings, and basic Earth structure.
His team, which will include two to four undergraduate students, will deploy 14 seismometers at the Savannah River Site in the summer of 2013. The instruments will record global earthquakes for approximately one year. In Summer 2014, they will re-deploy seven of the instruments to a site in Edgefield county. The two sets of instruments will then be allowed to collect data for another year.