Earthquake catalog and seismicity cross sections for "Earthquake catalog for the Fairbanks region of central Alaska, 2014–2024, based on waveform cross-correlation"

Earthquake catalog and seismicity cross sections for “Earthquake catalog for the Fairbanks region of central Alaska, 2014–2024, based on waveform cross-correlation” Nealey E. Sims, Carl Tape, Natalia A. Ruppert, Michael E. West September 29, 2025 (Version 1) December 15, 2025 (Version 2) Attribution: If you use these digital files, please cite Sims et al. (2026a). Overview This collection of files (Sims et al., 2025a) is a supplement to the submitted manuscript of Sims et al. (2026a). The collection contains a text file of the seismicity catalog, as well as vertical cross sections. This collection complements a study of seismicity in Minto Flats (Sims et al., 2026b, 2025b). Description of files •Sims2025_fairbanks_zenodo.pdf (this file) A locator map for the cross sections is shown in Figure C1. •Sims2025_fairbanks_catalog.csv Enhanced and relocated seismicity catalog of 41,589 events. Columns are: yyyy-dd-mm HH:MM:SS latitude longitude depth magnitude •Sims2025_fairbanks_NS_crosssections.pdf A set of 22 SW-to-NE cross sections of the seismicity catalog. An example is displayed in Figure C2. •Sims2025_fairbanks_EW_crosssections.pdf A set of 16 NW-to-SE cross sections of the seismicity catalog. An example is displayed in Figure C3. •Interior_Alaska_segments.zip Zipped file of GIS shapefiles for the combined studies of the Minto Flats (Sims et al., 2026b) and Fairbanks (Sims et al., 2026a). •Interior_Alaska_segments.txt Text file of fault segments for the combined studies of the Minto Flats (Sims et al., 2026b) and Fairbanks (Sims et al., 2026a). Figure C4 is a temporal perspective of the catalog. Figure C5 displays location uncertainties from the Alaska Earthquake Center for the template events, prior to relocation. Figure C6 displays location uncertainties from GrowClust for the relocated catalog. 1 References Sims, N., C. Tape, N. Ruppert, and M. West, Earthquake catalog and seismicity cross sections for “Earthquake catalog for the Fairbanks region of central Alaska, based on waveform crosscorrelation for events 2014–2024”, [Data set]. Zenodo https://doi.org/10.5281/zenodo. 17229905, 2025a. Sims, N., C. Tape, N. Ruppert, and M. West, Earthquake catalog and seismicity cross sections for “High precision earthquake catalog for Minto Flats fault zone, central Alaska, reveals complex and conjugate faulting”, [Data set]. Zenodo https://doi.org/10.5281/zenodo.16278806, 2025b. Sims, N. E., C. Tape, N. A. Ruppert, and M. E. West, Earthquake catalog for the Fairbanks region of central Alaska, 2014–2024, based on waveform cross-correlation for events, Seismol. Res. Lett. (in review), 2026a. Sims, N. E., C. Tape, N. A. Ruppert, and M. E. West, High-precision earthquake catalog for Minto Flats fault zone, central Alaska, reveals complex and conjugate faulting, Bull. Seismol. Soc. Am., doi:10.1785/0120250177, 2026b. Trugman, D. T., and P. M. Shearer, GrowClust: A hierarchical clustering algorithm for relative earthquake relocation, with application to the Spanish Springs and Sheldon, Nevada, earthquake sequences, Seismol. Res. Lett.,88, 379–391, doi:10.1785/0220160188, 2017. 2 Figure C1: Transects for cross sections of the relocated seismicity catalog. SW-to-NE oriented transects are spaced 6 km and NW-to-SE transects are spaced 8 km. Data is plotted in UTM Zone 6N, WGS84 datum. 3 0 20 40 60 80 100 120 140 Distance from SW (km) 30 20 10 0 Depth (km) Map view 25 km Figure C2: Vertical cross section of seismicity parallel to the Goldstream, Fairbanks, and Salcha faults. Each cross section contains all events within 3 km of a vertical plane depicted by the red solid line in the map view at right. Reference events within 4 km of the fault plane are plotted with lower-hemisphere projection in map view (right) and back-hemisphere projection in the vertical cross section (left). Fault segments intersecting each cross section are labeled by their letters at the top. The dashed blue line depicts the Moho. 0 20 40 60 80 100 120 Distance from NW (km) 30 20 10 0 Depth (km) Map view 25 km Figure C3: Vertical cross section of seismicity perpendicular to the Goldstream (Go), Fairbanks (Fa), and Salcha (Sa) faults. Each cross section contains all events within 4 km of a vertical plane depicted by the red solid line in the map view at right. Reference events within 4 km of the fault plane are plotted with lower-hemisphere projection in map view (right) and back-hemisphere projection in the vertical cross section (left). Fault segments intersecting each cross section are labeled by their letters at the top. The dashed blue line depicts the Moho. 4 2014 2016 2018 2020 2022 2024 Year 0 25 50 75 100 125 150 175 200 Number of events per week 0 1 2 3 4 5 6 Magnitude Figure C4: Number of events within the target region, plotted in 1-week bins for the Alaska Earthquake Center catalog (cyan: 11,039) and the updated catalog of newly detected events presented in this study (black: 41,589). Events with magnitude ML≥3.5 are plotted as red stars with magnitude axis on the right. Spikes at associated with events on 2021-11-05 Mw4.1 and 2024-01-19 Mw5.2 exceed the plotting scale of 200 events/week. 5 Figure C5: Spatial distribution of hypocentral location uncertainties for template events from the Alaska Earthquake Center. Left: Vertical (depth) uncertainty for each event with color scale capped at 3km to emphasize variability in well-constrained depths. Right: Mean horizontal location uncertainty, computed as the average of the minimum and maximum horizontal uncertainties for each event. Figure C6: Estimated vertical and horizontal uncertainties of the hypocenters in the relocated catalog presented in Sims et al. (2026a). Error values at each grid node represent the mean uncertainty of events within 0.05◦of the node, computed only where at least 30 events contribute to the estimate. Gray cells indicate areas with insufficient event density to estimate a mean error. Units in km. These values are provided from GrowClust (Trugman and Shearer, 2017) and reflect relative uncertainties. 6