U.S. DEPARTMENT OF THE INTERIOR NO. 12-12-EXP GEOLOGICAL SURVEY FEB 22, 2013 ROUTINE MINING SEISMICITY IN THE UNITED STATES DECEMBER 2012 ORIGIN TIME GEOGRAPHIC DEPTH MAGNITUDE Q SD GAP NO. F-E REGION, CONTRIBUTED MAGNITUDES AND COMMENTS UTC COORDINATES GS STA DAY HR MN SEC LAT LONG mb MS USED 08 21 00 13.1* 44.107 N 105.479 W 0 G B 0.7 199 9 WYOMING. ML 3.1 (GS). 21 km (13 miles) S of Gillette. 12 19 05 35.2 43.829 N 105.163 W 0 G A 1.0 27 68 WYOMING. mbLg 2.9 (GS). ML 3.5 (GS). 57 km (36 miles) SSE of Gillette. 13 20 54 37.5 45.217 N 106.685 W 0 G A 1.7 77 28 EASTERN MONTANA. mbLg 2.4 (GS). ML 3.1 (GS). 51 km (32 miles) NNE of Sheridan. 13 21 03 53.0* 43.850 N 105.149 W 0 G B 0.9 105 8 WYOMING. ML 3.3 (GS). 57 km (35 miles) SSE of Gillette. 15 20 11 17.3 43.640 N 105.099 W 0 G A 1.3 53 88 WYOMING. ML 3.5 (GS). 76 km (47 miles) WSW of Newcastle. 15 20 21 07.4 43.525 N 105.296 W 0 G A 1.5 65 15 WYOMING. ML 3.2 (GS). 81 km (50 miles) E of Midwest. 15 22 31 12.3* 43.744 N 105.294 W 0 G B 0.6 79 6 WYOMING. ML 2.5 (GS). 63 km (39 miles) SSE of Gillette. 15 23 49 51.8* 48.380 N 115.975 W 0 G B 1.7 161 6 WESTERN MONTANA. ML 3.3 (GS). 31 km (19 miles) W of Libby. 16 19 57 50.8 43.875 N 105.411 W 0 G A 1.4 56 11 WYOMING. ML 3.1 (GS). 47 km (29 miles) SSE of Gillette. 16 23 00 33.8 43.638 N 105.174 W 0 G A 1.2 78 18 WYOMING. ML 3.4 (GS). 77 km (48 miles) SSE of Gillette. 17 19 16 58.9* 45.248 N 106.911 W 0 G B 0.9 100 8 EASTERN MONTANA. ML 2.5 (GS). 50 km (31 miles) N of Sheridan. 19 19 06 06.8 43.676 N 105.293 W 0 G A 1.8 50 58 WYOMING. ML 3.5 (GS). 70 km (44 miles) SSE of Gillette. 21 19 11 21.4 43.739 N 105.132 W 0 G A 1.6 52 16 WYOMING. ML 3.4 (GS). 68 km (42 miles) SSE of Gillette. 21 21 05 52.2* 45.154 N 106.946 W 0 G B 0.5 103 8 EASTERN MONTANA. mbLg 3.0 (GS). 37 km (23 miles) N of Sheridan. 22 20 10 25.4 43.563 N 105.185 W 0 G A 1.8 81 12 WYOMING. ML 3.1 (GS). 85 km (53 miles) SSE of Gillette. 23 20 05 44.0 43.708 N 105.225 W 0 G A 1.0 74 12 WYOMING. ML 3.1 (GS). 69 km (43 miles) SSE of Gillette. 23 20 26 30.6* 43.511 N 105.266 W 0 G B 0.2 122 6 WYOMING. ML 3.1 (GS). 83 km (51 miles) E of Midwest. 24 20 00 43.8 43.711 N 105.298 W 0 A 0.9 42 61 WYOMING. ML 3.5 (GS). 67 km (41 miles) SSE of Gillette. 24 20 45 02.8 45.786 N 106.867 W 0 G A 1.2 99 25 EASTERN MONTANA. ML 3.1 (GS). 22 km (14 miles) WSW of Colstrip. 26 20 03 42.3 43.791 N 105.255 W 0 G A 1.4 26 70 WYOMING. mbLg 2.9 (GS). ML 3.2 (GS). 59 km (37 miles) SSE of Gillette. 26 21 38 14.7* 45.156 N 106.925 W 0 G B 0.6 103 7 EASTERN MONTANA. mbLg 2.5 (GS). 40 km (25 miles) N of Sheridan. 26 22 04 37.3* 43.514 N 105.162 W 0 G B 0.8 83 9 WYOMING. mbLg 2.6 (GS). 86 km (53 miles) NNE of Douglas. 30 20 01 05.1 43.804 N 105.300 W 0 G A 0.8 68 15 WYOMING. ML 3.3 (GS). 56 km (35 miles) SSE of Gillette. 31 19 01 03.3 43.525 N 105.451 W 0 G A 1.4 186 43 WYOMING. ML 3.2 (GS). 68 km (42 miles) E of Midwest. For origin times after September 30, 2002, USGS computations of hypocenters and magnitudes for routine mining events are listed in this publication only for exceptionally large events and for events that are also listed in the Reviewed Event Event Bulletins (REB) of the International Data Center of the United Nations' Comprehensive Nuclear-Test-Ban Treaty Organization.