Electronic Supplement to
The 2015 Mw 6.4 Pishan Earthquake: Seismic Hazards of an Active Blind Wedge Thrust System at the Western Kunlun Range Front, Northwest Tibetan Plateau

by Tao Li, Jie Chen, Lihua Fang, Zhuxin Chen, Jessica A. Thompson, and Chengzao Jia

This electronic supplement contains tables of the relocated Pishan seismicity and fault area with moment magnitudes, a map, and figures of seismic reflection profiles.

Seismic Reflection Profiles and Interpretations

This study uses three 2D high-resolution seismic reflection profiles to determine subsurface geometry of the Hetian fold belt. The profile location and the uninterpreted and interpreted seismic reflection data are given in Figures S1–S4 and in Figure 3 of the main article.

Catalog of the Pishan Mainshock and Aftershocks

The double-difference method (Waldhauser and Ellsworth, 2000; Fang et al., 2015) is applied to relocate the mainshock and 487 aftershocks of the 2015 Pishan event (Table S1). The time interval is 3–7 July 2015.

Moment Magnitude Calculations

This study uses the empirical relation provided by Wells and Coppersmith (1994) to estimate potential moment magnitude of each segment of the Hetian fold belt (Table S2). The moment magnitude (Mw) and rupture area (RA, in square kilometers) have the relation Mw = 4.07 + 1.02log(RA).

Figures

Figure S1. Satellite image and structures of the Hetian fold belt and the location of seismic reflection profiles (black lines) used in this study. All seismic reflection profiles are migrated and depth converted, assuming a uniform velocity of ~3000 m/s.

Figure S2. (a) Uninterpreted and (b) interpreted seismic reflection profile C–C′ across the Yaheshtagh and East Slik anticlines (pre-GS, pregrowth strata). See Figure S1 for the location.

Figure S3. (a) Uninterpreted and (b) interpreted seismic reflection profile D–D′ across the Guman and Slik anticlines (pre-GS, pregrowth strata). See Figure S1 for the location.

Figure S4. (a) Uninterpreted and (b) interpreted seismic reflection profile E–E′ across the Guman anticline (pre-GS, pregrowth strata). See Figure S1 for the location.

Tables

Table S1. Catalog of relocated Pishan seismicity during the period 3–7 July 2015. Event parameters: date and time (YYYY, MM, DD, HH, MM, SS.SS); LON, longitude (°); LAT, latitude (°); DEP, depth below the land surface (km); EX, EY, and EZ are the average location error of the hypocenters (km) in the directions of longitude, latitude, and depth, respectively; MAG, magnitude.

Table S2. Fault area and corresponding moment magnitude for each segment of the Hetian fold belt, assuming that the base of seismicity is localized along the lower detachment surface. See Figures S2–S4 for the fold and fault names.

References

Fang, L. H., J. Wu, W. Wang, W. Du, J. Su, C. Wang, T. Yang, and Y. Cai (2015). Aftershocks observation and analysis of the 2013 Ms 7.0 Lushan earthquakes, Seismol. Res. Lett. 86, no. 4, 1135–1142, doi: 10.1785/0220140186.

Waldhauser, F., and W. Ellsworth (2000). A double-difference earthquake location algorithm: Method and application to the Northern Hayward fault, California, Bull. Seismol. Soc. Am. 90, 1353–1368.

Wells, D., and K. Coppersmith (1994). New empirical relationships among magnitude, rupture length, rupture width, rupture area, and surface displacement, Bull. Seismol. Soc. Am. 84, 974–1002.

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