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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
2219_2023-08-20_21:41:01_4.1_mi_SE_of_Ojai_5.0.pdf
August 20, 2023 321.65 KB
2218_2023-08-20_06:24:26_33.2_mi_SE_of_Mexicali_B.C._3.1.pdf
August 20, 2023 229.60 KB
2217_2023-08-18_10:46:10_27.1_mi_SE_of_Mexicali_B.C._3.5.pdf
August 18, 2023 233.67 KB
2216_2023-08-17_21:08:00_13.5_mi_SW_of_Rio_Dell_4.0.pdf
August 17, 2023 226.82 KB
2214_2023-08-10_19:17:18_3.7_mi_NW_of_Parkfield_4.5.pdf
August 10, 2023 295.64 KB
2213_2023-08-08_15:58:35_27.2_mi_SE_of_Mexicali_B.C._3.5.pdf
August 08, 2023 238.73 KB
2212_2023-08-08_10:17:23_5.0_mi_N_of_Snoqualmie_4.0.pdf
August 08, 2023 349.59 KB
2211_2023-08-08_08:47:38_28.6_mi_SE_of_Mexicali_B.C._3.4.pdf
August 08, 2023 227.97 KB
2210_2023-08-06_18:57:01_36.3_mi_N_of_Ridgecrest_2.7.pdf
August 06, 2023 246.33 KB
2209_2023-08-02_05:38:08_5.4_mi_NW_of_Calipatria_3.6.pdf
August 02, 2023 278.61 KB
2208_2023-07-30_13:49:04_8.6_mi_N_of_Morgan_Hill_3.6.pdf
July 30, 2023 305.88 KB
2207_2023-07-17_03:46:31_78.1_mi_S_of_Mexicali_B.C._3.9.pdf
July 17, 2023 191.03 KB
2206_2023-07-17_01:56:21_24.3_mi_SW_of_Rio_Dell_2.3.pdf
July 17, 2023 187.95 KB
2205_2023-07-16_19:37:19_99.0_mi_SE_of_Mexicali_B.C._4.3.pdf
July 16, 2023 197.45 KB
2204_2023-07-16_19:16:03_96.6_mi_SE_of_Mexicali_B.C._4.5.pdf
July 16, 2023 192.48 KB
2203_2023-07-16_10:37:12_77.6_mi_S_of_Mexicali_B.C._4.0.pdf
July 16, 2023 193.53 KB
2202_2023-07-14_02:45:58_13.6_mi_NE_of_Healdsburg_3.4.pdf
July 14, 2023 290.23 KB
2201_2023-07-13_01:42:53_67.2_mi_SW_of_Mexicali_B.C._4.1.pdf
July 13, 2023 210.18 KB
2200_2023-07-09_05:30:39_12.1_mi_NE_of_Healdsburg_3.5.pdf
July 09, 2023 272.22 KB
2199_2023-07-09_04:57:31_11.9_mi_NE_of_Healdsburg_3.1.pdf
July 09, 2023 252.01 KB
2198_2023-07-04_14:58:49_15.9_mi_SW_of_Rio_Dell_3.9.pdf
July 04, 2023 213.59 KB
2197_2023-07-03_17:57:01_61.8_mi_W_of_Fortuna_3.9.pdf
July 03, 2023 158.53 KB
2196_2023-07-02_09:29:49_11.6_mi_S_of_Malibu_4.1.pdf
July 02, 2023 246.93 KB
2195_2023-06-28_23:26:43_7.2_mi_NW_of_Calipatria_2.3.pdf
June 28, 2023 252.97 KB
2194_2023-06-24_10:10:33_17.3_mi_E_of_Barstow_3.4.pdf
June 24, 2023 251.18 KB
2193_2023-06-19_06:49:11_27.3_mi_N_of_California_City_3.5.pdf
June 19, 2023 247.01 KB
2192_2023-06-18_03:44:59_7.6_mi_SE_of_Ukiah_4.2.pdf
June 18, 2023 295.30 KB
2191_2023-06-16_23:19:57_3.4_mi_W_of_Malibu_2.6.pdf
June 16, 2023 220.27 KB
2190_2023-06-15_18:03:48_23.6_mi_SW_of_Rio_Dell_3.4.pdf
June 15, 2023 187.48 KB
2189_2023-06-13_22:45:43_15.0_mi_N_of_Greenfield_3.5.pdf
June 13, 2023 269.56 KB
2188_2023-06-03_12:01:18_12.9_mi_E_of_Cloverdale_4.3.pdf
June 03, 2023 292.40 KB
2187_2023-06-02_00:23:04_10.1_mi_NW_of_Reno_3.9.pdf
June 02, 2023 303.19 KB
2186_2023-05-30_20:24:52_11.5_mi_SE_of_Port_Hueneme_3.2.pdf
May 30, 2023 229.72 KB
2185_post_event_summary.pdf
May 27, 2023 132.99 KB
2184_2023-05-26_11:26:24_28.4_mi_SW_of_Susanville_4.1.pdf
May 26, 2023 295.83 KB
2182_2023-05-21_03:26:29_44.7_mi_E_of_Bishop_4.1.pdf
May 23, 2023 244.30 KB
2183_2023-05-21_18:44:01_71.1_mi_W_of_Fortuna_5.5.pdf
May 21, 2023 179.66 KB
2156_2023-04-12_06:30:34_13.1_mi_E_of_Cloverdale_3.1.pdf
May 19, 2023 277.79 KB
2163_2023-04-20_03:35:47_5.5_mi_E_of_Clayton_3.7.pdf
May 19, 2023 355.28 KB
2176_2023-05-12_02:54:45_27.9_mi_SW_of_Susanville_3.9.pdf
May 19, 2023 274.19 KB
2177_2023-05-12_10:18:41_27.3_mi_SW_of_Susanville_5.3.pdf
May 12, 2023 338.14 KB
2175_2023-05-11_23:19:41_27.7_mi_SW_of_Susanville_5.7.pdf
May 11, 2023 323.67 KB
2174_2023-05-06_14:16:02_3.7_mi_NW_of_Calexico_3.5.pdf
May 06, 2023 280.79 KB
2173_2023-05-03_01:40:24_17.5_mi_N_of_Ridgecrest_3.5.pdf
May 03, 2023 295.42 KB
2172_2023-05-01_23:13:47_2.5_mi_SE_of_Point_Arena_3.7.pdf
May 01, 2023 243.75 KB
2171_2023-04-30_11:44:03_6.9_mi_NW_of_Calipatria_3.0.pdf
April 30, 2023 261.72 KB
2170_2023-04-30_07:58:19_6.9_mi_NW_of_Calipatria_3.6.pdf
April 30, 2023 321.71 KB
2169_2023-04-30_07:32:12_7.3_mi_NW_of_Calipatria_2.9.pdf
April 30, 2023 283.91 KB
2168_2023-04-30_07:19:17_7.9_mi_NW_of_Calipatria_2.8.pdf
April 30, 2023 262.80 KB
2167_2023-04-30_07:09:34_6.4_mi_NW_of_Calipatria_3.7.pdf
April 30, 2023 276.31 KB