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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
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
2055_post_event_summary.pdf
September 22, 2022 296.00 KB
2053_2022-09-20_23:49:57_7.3_mi_NW_of_Calipatria_1.8.pdf
September 21, 2022 295.66 KB
2054_2022-09-21_02:43:10_22.6_mi_SW_of_Rio_Dell_3.8.pdf
September 21, 2022 228.69 KB
2052_2022-09-20_22:41:41_7.2_mi_NW_of_Calipatria_2.3.pdf
September 20, 2022 296.67 KB
2051_2022-09-20_14:03:08_28.3_mi_N_of_Willits_3.9.pdf
September 20, 2022 298.03 KB
2050_2022-09-18_06:55:48_14.8_mi_E_of_Coachella_3.5.pdf
September 18, 2022 291.30 KB
2049_2022-09-16_16:12:42_38.8_mi_SE_of_South_Lake_Tahoe_3.9.pdf
September 16, 2022 334.42 KB
2048_2022-09-15_20:07:05_12.7_mi_SW_of_Los_Banos_3.3.pdf
September 15, 2022 312.66 KB
2047_2022-09-14_01:39:39_4.0_mi_NE_of_Santa_Rosa_4.4.pdf
September 14, 2022 340.26 KB
2046_2022-09-09_12:56:14_13.7_mi_NE_of_Healdsburg_3.0.pdf
September 09, 2022 314.15 KB
2045_2022-09-08_08:08:25_7.5_mi_N_of_Bangor_Trident_Base_3.8.pdf
September 08, 2022 342.88 KB
2043_2022-09-03_17:04:55_4.0_mi_N_of_Eastvale_3.6.pdf
September 06, 2022 403.84 KB
2042_2022-09-01_13:36:22_17.4_mi_NE_of_Greenfield_4.0.pdf
September 02, 2022 314.90 KB
2041_2022-08-30_08:44:40_21.8_mi_SE_of_Mexicali_B.C._3.9.pdf
August 30, 2022 280.63 KB
2040_2022-08-13_12:33:35_9.7_mi_S_of_Blue_Lake_3.7.pdf
August 13, 2022 291.08 KB
2039_2022-08-08_20:44:14_37.5_mi_SE_of_South_Lake_Tahoe_4.7.pdf
August 08, 2022 327.60 KB
2038_2022-08-02_21:44:06_28.0_mi_SW_of_Rio_Dell_3.9.pdf
August 02, 2022 188.09 KB
2037_post_event_summary.pdf
August 01, 2022 106.18 KB
2036_2022-07-28_20:49:30_44.6_mi_W_of_Fortuna_2.5.pdf
July 30, 2022 120.69 KB
2035_post_event_summary.pdf
July 28, 2022 209.92 KB
2034_2022-07-25_11:21:07_44.9_mi_S_of_Tijuana_B.C._4.5.pdf
July 25, 2022 235.95 KB
2033_2022-07-23_01:41:04_7.4_mi_SE_of_Oroville_4.2.pdf
July 23, 2022 314.07 KB
2032_2022-07-18_17:07:58_26.6_mi_N_of_Tehachapi_3.4.pdf
July 18, 2022 274.99 KB
2031_2022-07-17_18:18:39_26.3_mi_NW_of_Westmorland_3.4.pdf
July 17, 2022 303.36 KB
2030_2022-07-17_15:44:26_26.7_mi_N_of_Tehachapi_3.7.pdf
July 17, 2022 280.84 KB
2029_2022-07-17_11:34:47_26.3_mi_N_of_Tehachapi_3.4.pdf
July 17, 2022 274.74 KB
2028_2022-07-17_08:19:59_10.6_mi_E_of_Cloverdale_3.5.pdf
July 17, 2022 311.83 KB
2027_2022-07-15_01:19:06_7.8_mi_NE_of_Ridgecrest_4.3.pdf
July 15, 2022 290.19 KB
2026_2022-07-06_06:15:46_29.4_mi_N_of_Tehachapi_3.5.pdf
July 06, 2022 280.04 KB
2025_2022-07-02_15:57:24_36.0_mi_SW_of_Rio_Dell_2.7.pdf
July 02, 2022 159.76 KB
2024_2022-06-29_04:19:36_6.4_mi_NW_of_Calipatria_3.0.pdf
June 29, 2022 293.16 KB
2023_2022-06-28_11:57:40_11.0_mi_SW_of_Clearlake_3.8.pdf
June 28, 2022 311.87 KB
2022_2022-06-24_09:05:12_7.2_mi_NW_of_Parkfield_3.5.pdf
June 24, 2022 287.03 KB
2021_2022-06-20_03:40:29_20.6_mi_SE_of_Mexicali_B.C._3.7.pdf
June 20, 2022 266.62 KB
2020_2022-06-13_09:40:43_8.3_mi_SW_of_Lakeport_3.3.pdf
June 13, 2022 296.71 KB
2019_2022-06-12_22:44:40_24.0_mi_SE_of_Mexicali_B.C._3.1.pdf
June 12, 2022 273.56 KB
2018_2022-06-09_22:26:59_25.9_mi_SW_of_Rio_Dell_3.8.pdf
June 09, 2022 201.32 KB