Relocated Seismicity Catalogs on the Discovery Transform Fault, 4S on the East Pacific Rise

Two relocated earthquake catalogs are provided for the Discovery Transform Fault located at 4ºS on the East Pacific Rise. There is a microseismicity catalog representing one year of activity recorded during a 2008 ocean bottom seismometer deployment, which includes 12,635 events with local magnitudes, ML, between 0 and 4.1. The second catalog includes 24 years (1 January 1990 - 1 April 2013) of earthquakes obtained from the global Centroid Moment Tensor (CMT) catalog, a total of 15 events, with seismic moment magnitudes, MW, between 5.4 and 6.0.

Microseismicity was relocated using the HypoDD relocation algorithm (Waldhauser, 2001), while the CMT events were relocated using a teleseismic surface-wave cross-correlation technique (McGuire, 2008). The 15 CMT events all relocated into one of five distinct rupture patches on the Discovery Transform Fault. In general, microseismicity was found to be reduced within these large, repeating rupture patches.

A more detailed description of the methodology used to relocate both catalogs, as well as a discussion on the correlation between seismic behavior and fault structure on the Discovery Transform Fault is provided in:

Wolfson-Schwehr, M., Boettcher, M. S., McGuire, J. J., & Collins, J. A. (2014). The relationship between seismicity and fault structure on the Discovery transform fault, East Pacific Rise. Geochemistry, Geophysics, Geosystems, 15(9), 3698–3712. https://doi.org/10.1002/2014GC005445

Seismic Catalogs:

Discovery_CMT_relocated_seismicity_1990_2013.csv

Discovery_relocated_microseismicity_2008.csv

Additional References:

1. McGuire, J. J. (2008). Seismic cycles and earthquake predictability on East Pacific Rise transform faults. Bulletin of the Seismological Society of America, 98(3), 1067-1084. https://www.whoi.edu/cms/files/McGuire_BSSA_2008_48643.pdf

2. Waldhauser, F. (2001). hypoDD--A program to compute double-difference hypocenter locations. 
    https://academiccommons.columbia.edu/doi/10.7916/D8SN072H