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Post ShakeAlert Message Summaries


Post ShakeAlert Message Summaries provide information about earthquakes detected by the USGS component of ShakeAlert Earthquake Early Warning System (see graphic below). They summarize how accurately the ShakeAlert system estimated an earthquake’s location, magnitude, shaking intensities, how much warning time for selected nearby cities, and how many seismic stations contributed data to these estimates. Estimated warning times on the summaries does not include the additional time it takes for ShakeAlert Licensed Operators to deliver alerts to end-users (e.g. alert delivery to cell phones). Summaries are automatically generated for earthquakes with an estimated peak magnitude (M) of 3.5 or larger. For earthquakes estimated at M4.0 or larger, ShakeAlert Messages are human-reviewed and forwarded to the USGS Earthquake Hazards Program to be posted at www.earthquake.usgs.gov.  ShakeAlert produces summaries for earthquakes less than M4.0 to test software readiness, but the results are generally not reviewed for quality or accuracy. 

Roles of the USGS and Technical Partners in the ShakeAlert System. This graphic is available in the ShakeAlert Messaging Toolkit.

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
2104_2023-01-01_05:18:17_6.7_mi_N_of_Fortuna_2.9.pdf
January 01, 2023 247.30 KB
2103_2022-12-31_12:12:26_17.8_mi_S_of_La_Quinta_4.2.pdf
December 31, 2022 349.85 KB
2102_2022-12-31_11:41:09_7.8_mi_N_of_Big_Bear_Lake_3.5.pdf
December 31, 2022 326.55 KB
2101_2022-12-24_19:33:44_6.5_mi_NE_of_Rio_Dell_4.2.pdf
December 24, 2022 289.83 KB
2089_2022-12-20_10:34:25_13.4_mi_SW_of_Fortuna_6.1.pdf
December 24, 2022 245.48 KB
2100_2022-12-24_05:13:07_21.2_mi_SW_of_Rio_Dell_3.1.pdf
December 24, 2022 203.06 KB
2099_2022-12-22_08:47:13_13.8_mi_W_of_Fortuna_3.7.pdf
December 22, 2022 221.94 KB
2098_2022-12-22_02:22:50_2.0_mi_NE_of_Union_City_3.3.pdf
December 22, 2022 410.22 KB
2097_2022-12-21_16:28:16_4.6_mi_E_of_Fortuna_3.7.pdf
December 21, 2022 275.31 KB
2096_2022-12-21_01:07:33_19.2_mi_W_of_Fortuna_3.4.pdf
December 21, 2022 203.25 KB
2095_2022-12-20_22:06:34_7.5_mi_SW_of_Fortuna_4.3.pdf
December 20, 2022 241.93 KB
2094_2022-12-20_15:09:05_4.8_mi_E_of_Fortuna_4.0.pdf
December 20, 2022 277.87 KB
2093_2022-12-20_13:53:19_12.6_mi_SW_of_Fortuna_3.5.pdf
December 20, 2022 222.72 KB
2092_2022-12-20_13:35:06_9.4_mi_SW_of_Fortuna_3.8.pdf
December 20, 2022 235.69 KB
2091_2022-12-20_10:52:39_7.5_mi_W_of_Fortuna_3.4.pdf
December 20, 2022 239.56 KB
2090_2022-12-20_10:39:02_3.7_mi_W_of_Rio_Dell_4.6.pdf
December 20, 2022 264.27 KB
2088_2022-12-17_11:39:42_0.7_mi_NE_of_El_Cerrito_3.9.pdf
December 17, 2022 382.60 KB
2087_2022-12-09_05:33:33_12.4_mi_E_of_Cloverdale_2.8.pdf
December 09, 2022 316.16 KB
2086_2022-12-07_14:13:22_26.3_mi_N_of_Tehachapi_3.5.pdf
December 07, 2022 291.17 KB
2085_2022-12-06_00:10:37_8.2_mi_SE_of_Avenal_4.2.pdf
December 06, 2022 295.74 KB
2084_2022-12-05_23:13:16_11.4_mi_E_of_San_Jose_3.7.pdf
December 05, 2022 384.20 KB
2083_2022-12-02_12:21:48_14.4_mi_S_of_Bishop_4.0.pdf
December 02, 2022 327.22 KB
2082_2022-12-01_15:28:29_26.8_mi_W_of_Imperial_4.0.pdf
December 01, 2022 301.46 KB
2081_2022-11-26_03:50:17_68.5_mi_W_of_Port_Alberni_4.8.pdf
November 26, 2022 263.36 KB
2080_2022-11-14_20:27:18_12.4_mi_E_of_Cloverdale_3.1.pdf
November 14, 2022 314.20 KB
2079_2022-11-08_17:35:07_21.1_mi_SW_of_Rio_Dell_2.6.pdf
November 08, 2022 216.15 KB
2078_2022-11-07_05:10:26_77.0_mi_S_of_Mexicali_B.C._3.7.pdf
November 07, 2022 160.85 KB
2077_2022-11-07_04:59:02_77.8_mi_S_of_Mexicali_B.C._4.3.pdf
November 07, 2022 175.47 KB
2076_2022-11-07_02:01:27_13.7_mi_E_of_Willits_3.8.pdf
November 07, 2022 306.61 KB
2075_2022-11-04_20:27:36_12.1_mi_E_of_Cloverdale_2.9.pdf
November 04, 2022 312.40 KB
2074_2022-11-04_20:26:32_12.1_mi_E_of_Cloverdale_3.4.pdf
November 04, 2022 310.81 KB
2073_2022-10-25_22:08:37_12.1_mi_E_of_San_Jose_3.6.pdf
October 25, 2022 369.63 KB
2072_2022-10-25_18:42:02_12.1_mi_E_of_San_Jose_5.0.pdf
October 25, 2022 374.01 KB
2071_2022-10-23_18:16:22_2.2_mi_E_of_Fortuna_4.3.pdf
October 23, 2022 267.05 KB
2070_2022-10-21_18:50:26_11.0_mi_E_of_Cloverdale_2.9.pdf
October 21, 2022 308.13 KB
2069_2022-10-20_07:55:16_32.6_mi_E_of_Rio_Dell_4.1.pdf
October 20, 2022 298.78 KB
2068_2022-10-20_00:02:34_11.2_mi_E_of_Cloverdale_3.4.pdf
October 20, 2022 312.48 KB
2067_2022-10-19_23:59:49_12.2_mi_SW_of_Clearlake_3.4.pdf
October 20, 2022 313.00 KB
2066_2022-10-19_23:59:04_10.9_mi_E_of_Cloverdale_3.5.pdf
October 20, 2022 312.05 KB
2065_2022-10-15_17:30:41_13.5_mi_NE_of_Healdsburg_3.2.pdf
October 15, 2022 319.95 KB
2064_2022-10-11_06:19:06_103.1_mi_SE_of_Mexicali_B.C._3.8.pdf
October 12, 2022 154.00 KB
2063_2022-10-07_22:45:05_38.3_mi_E_of_Santee_3.5.pdf
October 07, 2022 341.02 KB
2062_2022-10-07_12:52:35_17.4_mi_E_of_Lebanon_4.4.pdf
October 07, 2022 325.21 KB
2061_2022-10-04_16:38:34_22.3_mi_SE_of_Mexicali_B.C._3.5.pdf
October 04, 2022 263.83 KB
2060_2022-10-01_02:02:32_48.6_mi_SW_of_Sooke_2.8.pdf
October 01, 2022 228.65 KB
2059_2022-09-27_08:03:39_26.3_mi_N_of_Tehachapi_3.7.pdf
September 27, 2022 276.07 KB
2058_2022-09-26_05:18:31_12.2_mi_SW_of_Clearlake_2.7.pdf
September 26, 2022 317.76 KB
2057_2022-09-24_19:27:37_38.9_mi_W_of_Rio_Dell_4.6.pdf
September 24, 2022 158.95 KB
2044_2022-09-04_18:57:55_17.2_mi_E_of_Gonzales_3.5.pdf
September 23, 2022 316.00 KB
2056_2022-09-23_06:58:34_13.8_mi_S_of_Clearlake_3.3.pdf
September 23, 2022 323.12 KB