Sorry for the late update, I've gotten a bit caught up in the end of this project and the aftermath. After Gary returned from his trip, I ended up doing another week-and-a-half of cross-correlation, but once I got that data, we were able to run it through another one of Gary's programs called "Progressive Multiple Event Location", or PMEL. This program basically reduces the effects of any errors from the given seismic velocity model and from random scatter. We placed certain combinations of constraints on the data, including spacial restrictions and velocity model parameters. Gary sent the results to his brother to be put on that iView3D program I mention some number of posts ago, and we found something interesting. Below are two pictures depicting the space underneath Bering Glacier, both of them facing west. The four different data sets all use the same seismic velocity model, but with different spacial constraints:

See the trend among them? The dipping trend, that is. Each of the data sets suggests that the seismicity in Alaska's Yakatat block, where Bering Glaicer and the nearby Bagley Icefield are located, dips to the north, but at the same time, the clouds of data are noticeably diffuse.

After organizing the results, I gave a brief talk on the project to some local faculty and grad students. It was my first science talk of any kind, and the faculty say I did all right for my first time, even though I knew even as I gave the talk that I could have done some parts better. They offered constructive criticism too, which I closely payed attention to considering my limited experience in this kind of environment.

I ran into some living arrangement conflicts shortly before the end of my project, since I had to move out of my dorm room at IU Bloomington a week before heading back to Minnesota for the new school year. Fortunately, Gary was kind enough to let me stay at his house during that time, and I thank him greatly for that. During this time, we also created an abstract for the project, which will be submitted to the AGU and which goes as follows:

Title: Seismicity of the Bering Glacier Region:  Inferences Relocations using data from STEEP

Authors:  Panessa, A., G. L. Pavlis, R. Hansen, N. Ruppert

We relocated earthquakes recorded from 1990 to 2007 in the area of the Bering Glacier in southeastern Alaska to test a hypothesis that faults in this area are linked to glaciers.  We used waveform correlation to improve arrival time measurements for data from all broadband channels including all the data from the STEEP experiment.  We used a novel form of correlation based on interactive array processing of common receiver gathers linked to a three-dimensional grid of control points.  This procedure produced 8556 gathers that we processed interactively to produce improved arrival time estimates.  The interactive procedure allowed us to select which events in each gather were sufficiently similar to warrant correlation.  Redundancy in the result was resolved in a secondary correlation that aligned event stacks of the same station-event pair associated with multiple control points.  This procedure yielded only 2240 waveforms that correlated and modified only a total of 524 arrivals in a total database of 12263 arrivals.  The correlation procedure changed arrival times on 145 of 509 events in this database.  Events with arrivals constrained by correlation were not clustered but were randomly distributed throughout the study area.  We used a version of the Progressive Multiple Event Location (PMEL) that analyzed data at each control point to invert for relative locations and a set of path anomalies for each control point.  We applied the PMEL procedure with different velocity models and constraints and compared the results to a HypoDD solution produced from the original arrival time data.  The relocations are all significant improvements from the standard single-event, catalog locations. The relocations suggest the seismicity in this region is mostly linked to fold and thrust deformation in the Yakatat block.  There is a suggestion of a north-dipping trend to much of the seismicity, but the dominant trend is a fairly diffuse cloud of events largely confined to the Yakatat block south of the Bagley Icefield. 

(To avoid any confusion, the following is not part of the abstract)

I'm looking forward to attending the AGU meeting in San Francisco for multiple reasons: 1) This will be my first real, exciting step into the general geological society; 2) This will be my first trip to California, a place I knew I would be visiting at some point, and a place I know I will see more of the future; 3) One of my professors for this semester, the only real seismologist at the University of Minnesota, will also be attending the AGU meeting, and I will be looking forward to seeing him there.

I'm getting very excited about this event, and it's only early September! Before I know it, my poster will be printed, I'll be finishing up any final exams that fall before AGU (two of them conflict and will have to be made up), and I'll be setting a new record for the most "western" trip I will have taken in the USA (and I thought Montana was far). Until next time, see you later.