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Post ShakeAlert Message Summaries


Post ShakeAlert Message Summaries provide information about earthquakes detected by the ShakeAlert Earthquake Early Warning System and ShakeAlert’s performance during these events. They summarize how accurately the ShakeAlert System estimated the earthquake’s location and magnitude, how many seismic stations contributed data to these estimates, and how much warning time nearby cities may have received. These summaries are automatically generated for all USGS-issued ShakeAlert Messages with an estimated peak magnitude (M) of 3.5 or larger. Only at M 4.0 or larger are ShakeAlert Messages human-reviewed and forwarded to the National Earthquake Information Center to be posted at www.earthquake.usgs.gov. Summaries for earthquakes less than M 4.0 provide our scientists with more frequent tests of software readiness, but their results are generally not reviewed for quality or accuracy.

Please Note: USGS does not warrant that this information resource will be available without interruption, be error-free, or that any errors must be corrected. Post ShakeAlert Message Summaries are provided “AS IS” and without any warranty, express, implied, or otherwise, regarding its accuracy or performance. Any reliance upon this resource is at the express and sole risk of the user, including its employees, assigns, and insurers.

FileDate PostedSize
2266_2023-12-07_06:16:51_16.0_mi_SW_of_Los_Banos_3.8.pdf
December 07, 2023 282.43 KB
2265_2023-12-06_04:30:22_18.8_mi_W_of_El_Centro_3.7.pdf
December 06, 2023 240.16 KB
2264_2023-12-01_07:43:27_18.0_mi_W_of_El_Centro_4.5.pdf
December 01, 2023 291.14 KB
2263_2023-11-28_07:59:39_6.2_mi_NE_of_Big_Bear_Lake_3.5.pdf
November 28, 2023 284.40 KB
2262_2023-11-27_10:37:40_27.3_mi_N_of_Tehachapi_3.5.pdf
November 27, 2023 263.58 KB
2261_2023-11-22_15:49:00_6.7_mi_W_of_Fortuna_3.3.pdf
November 22, 2023 192.38 KB
2260_2023-11-11_03:58:12_45.8_mi_W_of_Fortuna_2.7.pdf
November 11, 2023 175.23 KB
2259_2023-11-11_03:43:42_38.4_mi_W_of_Fortuna_3.0.pdf
November 11, 2023 173.96 KB
2258_2023-11-11_03:15:25_36.0_mi_W_of_Fortuna_4.2.pdf
November 11, 2023 179.99 KB
2257_2023-11-05_05:12:57_10.0_mi_W_of_Imperial_3.5.pdf
November 05, 2023 241.93 KB
2256_2023-11-03_20:12:18_4.9_mi_SE_of_Ojai_4.0.pdf
November 03, 2023 297.22 KB
2255_2023-10-28_05:40:18_36.1_mi_SE_of_South_Lake_Tahoe_4.2.pdf
October 28, 2023 310.65 KB
2254_2023-10-28_01:38:31_1.3_mi_N_of_Millbrae_4.1.pdf
October 28, 2023 339.78 KB
2253_2023-10-27_20:33:36_10.3_mi_E_of_Cloverdale_3.0.pdf
October 27, 2023 250.31 KB
2252_2023-10-26_16:37:43_57.1_mi_NE_of_Alturas_3.8.pdf
October 26, 2023 204.27 KB
2251_2023-10-23_14:42:15_3.5_mi_SW_of_Isleton_2.9.pdf
October 23, 2023 335.95 KB
2251_post_event_summary.pdf
October 23, 2023 341.87 KB
2250_2023-10-19_02:04:05_3.3_mi_SW_of_Isleton_2.8.pdf
October 20, 2023 315.75 KB
2250_post_event_summary.pdf
October 19, 2023 321.71 KB
2249_2023-10-18_16:29:14_2.7_mi_SW_of_Isleton_4.5.pdf
October 18, 2023 356.16 KB
2248_post_event_summary.pdf
October 16, 2023 268.32 KB
2247_2023-10-16_10:31:25_18.4_mi_W_of_Eureka_4.1.pdf
October 16, 2023 189.53 KB
2246_2023-10-16_10:20:49_12.7_mi_S_of_Rio_Dell_4.8.pdf
October 16, 2023 252.04 KB
2245_2023-10-15_19:52:15_9.9_mi_NE_of_Ojai_3.5.pdf
October 15, 2023 246.61 KB
2244_2023-10-15_19:50:16_10.3_mi_NE_of_Ojai_3.7.pdf
October 15, 2023 282.88 KB
2243_2023-10-09_02:21:08_6.6_mi_S_of_Port_Townsend_4.5.pdf
October 09, 2023 327.99 KB
2242_2023-10-08_21:30:23_11.7_mi_E_of_Cloverdale_3.7.pdf
October 08, 2023 286.76 KB
2241_2023-10-08_15:39:11_11.3_mi_E_of_Cloverdale_3.0.pdf
October 08, 2023 273.45 KB
2240_2023-10-01_19:29:36_16.9_mi_SW_of_Rio_Dell_3.7.pdf
October 01, 2023 229.53 KB
2239_2023-10-01_15:41:29_16.7_mi_SW_of_Rio_Dell_4.2.pdf
October 01, 2023 243.98 KB
2238_2023-09-30_17:16:48_14.7_mi_SW_of_Fortuna_4.2.pdf
September 30, 2023 187.55 KB
2237_2023-09-30_15:26:26_6.8_mi_SW_of_Fortuna_4.6.pdf
September 30, 2023 246.35 KB
2236_2023-09-27_20:00:21_36.2_mi_SE_of_South_Lake_Tahoe_3.6.pdf
September 27, 2023 278.32 KB
2215_2023-08-13_15:28:58_10.3_mi_SW_of_Trinidad_3.7.pdf
September 21, 2023 219.93 KB
2235_2023-09-19_04:13:10_9.0_mi_W_of_Patterson_4.6.pdf
September 19, 2023 352.13 KB
2234_2023-09-19_00:15:32_8.9_mi_W_of_Patterson_4.1.pdf
September 19, 2023 311.12 KB
2233_2023-09-18_06:20:52_12.0_mi_E_of_Cloverdale_3.5.pdf
September 18, 2023 316.97 KB
2232_2023-09-14_02:43:54_15.6_mi_E_of_Gonzales_3.4.pdf
September 14, 2023 259.21 KB
2231_2023-09-08_17:24:38_41.2_mi_SE_of_Dunsmuir_4.9.pdf
September 08, 2023 328.02 KB
2230_2023-08-29_08:05:33_33.4_mi_SE_of_Avalon_4.0.pdf
August 29, 2023 211.00 KB
2229_2023-08-24_14:57:03_4.1_mi_SE_of_Ojai_3.4.pdf
August 24, 2023 245.29 KB
2228_2023-08-22_11:39:19_5.1_mi_SE_of_Ojai_4.0.pdf
August 22, 2023 294.24 KB
2227_2023-08-21_23:50:25_3.4_mi_SE_of_Ojai_3.5.pdf
August 21, 2023 259.70 KB
2226_2023-08-21_05:41:23_3.5_mi_SE_of_Ojai_3.2.pdf
August 21, 2023 259.49 KB
2225_2023-08-21_05:25:17_4.3_mi_SE_of_Ojai_3.6.pdf
August 21, 2023 270.82 KB
2224_2023-08-20_22:55:15_4.9_mi_E_of_Ojai_3.2.pdf
August 20, 2023 273.39 KB
2223_2023-08-20_22:52:50_4.9_mi_E_of_Ojai_3.2.pdf
August 20, 2023 263.39 KB
2222_2023-08-20_22:18:16_3.9_mi_SE_of_Ojai_3.8.pdf
August 20, 2023 271.97 KB
2221_2023-08-20_21:47:29_2.6_mi_E_of_Ojai_2.1.pdf
August 20, 2023 274.29 KB
2220_2023-08-20_21:45:26_3.7_mi_E_of_Ojai_3.6.pdf
August 20, 2023 281.12 KB