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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
2410_2024-10-09_09:44:47_12.4_mi_SE_of_Mexicali_B.C._3.0.pdf
October 09, 2024 269.32 KB
2410_2024-10-09_09:44:47_12.0_mi_SE_of_Mexicali_B.C._3.2.pdf
October 09, 2024 270.72 KB
2409_2024-10-09_06:05:43_13.0_mi_SE_of_Mexicali_B.C._3.2.pdf
October 09, 2024 254.79 KB
2408_2024-10-08_16:27:34_116.7_mi_W_of_Fortuna_4.3.pdf
October 08, 2024 154.64 KB
2408_post_event_summary.pdf
October 08, 2024 135.83 KB
2407_2024-10-06_10:51:08_4.5_mi_N_of_Eastvale_4.0.pdf
October 06, 2024 347.91 KB
2407_2024-10-06_10:51:08_4.6_mi_N_of_Eastvale_4.1.pdf
October 06, 2024 349.02 KB
2406_2024-10-06_08:07:44_11.5_mi_E_of_Cloverdale_2.7.pdf
October 06, 2024 261.24 KB
2406_2024-10-06_08:07:44_11.1_mi_E_of_Cloverdale_3.0.pdf
October 06, 2024 260.60 KB
2405_post_event_summary.pdf
October 05, 2024 137.73 KB
2404_2024-10-02_00:45:18_6.6_mi_NW_of_Avenal_4.0.pdf
October 02, 2024 290.51 KB
2403_2024-10-01_19:56:21_4.6_mi_SE_of_Upland_3.5.pdf
October 01, 2024 356.52 KB
2403_2024-10-01_19:56:21_4.7_mi_SE_of_Upland_3.1.pdf
October 01, 2024 356.54 KB
2402_2024-09-29_09:47:33_5.5_mi_E_of_Watsonville_4.2.pdf
September 29, 2024 313.25 KB
2402_2024-09-29_09:47:33_5.5_mi_E_of_Watsonville_4.4.pdf
September 29, 2024 313.25 KB
2401_2024-09-28_15:32:04_37.7_mi_SE_of_South_Lake_Tahoe_3.6.pdf
September 28, 2024 288.14 KB
2400_2024-09-26_18:24:28_44.4_mi_NW_of_Ridgecrest_3.7.pdf
September 26, 2024 265.01 KB
2399_2024-09-26_11:05:20_8.9_mi_N_of_Oak_Bay_4.0.pdf
September 26, 2024 292.43 KB
2398_2024-09-16_11:22:08_3.8_mi_N_of_Malibu_3.7.pdf
September 16, 2024 293.94 KB
2398_2024-09-16_11:22:08_4.3_mi_N_of_Malibu_3.6.pdf
September 16, 2024 293.89 KB
2397_2024-09-12_16:37:28_7.4_mi_SW_of_Malibu_3.2.pdf
September 12, 2024 286.88 KB
2396_2024-09-12_14:28:19_4.8_mi_S_of_Malibu_4.7.pdf
September 12, 2024 292.89 KB
2395_2024-09-10_07:01:03_13.2_mi_NE_of_Calistoga_2.9.pdf
September 11, 2024 301.55 KB
2395_2024-09-10_07:01:04_8.7_mi_NE_of_Calistoga_3.4.pdf
September 10, 2024 299.82 KB
2394_2024-09-07_17:34:20_4.9_mi_SE_of_Rancho_Cucamonga_3.9.pdf
September 07, 2024 356.43 KB
2393_2024-09-07_17:05:45_4.4_mi_N_of_Eastvale_3.5.pdf
September 07, 2024 350.04 KB
2392_2024-09-07_14:30:36_13.3_mi_NE_of_Healdsburg_4.3.pdf
September 07, 2024 315.06 KB
2391_2024-09-06_12:07:06_26.4_mi_SE_of_South_Lake_Tahoe_3.7.pdf
September 06, 2024 286.97 KB
2390_2024-08-15_16:39:31_3.7_mi_NW_of_Lake_Elsinore_3.5.pdf
August 15, 2024 331.54 KB
2390_2024-08-15_16:39:31_3.7_mi_W_of_Lake_Elsinore_3.9.pdf
August 15, 2024 331.46 KB
2389_2024-08-12_19:20:23_0.8_mi_SE_of_San_Marino_4.6.pdf
August 12, 2024 337.75 KB
2388_2024-08-11_09:45:12_22.3_mi_N_of_Ridgecrest_3.8.pdf
August 11, 2024 284.37 KB
2388_2024-08-11_09:45:13_22.6_mi_N_of_Ridgecrest_3.8.pdf
August 11, 2024 268.84 KB
2387_2024-08-08_02:09:14_14.7_mi_SW_of_Arvin_4.6.pdf
August 08, 2024 344.37 KB
2386_2024-08-07_23:43:32_16.3_mi_E_of_Maricopa_3.8.pdf
August 08, 2024 329.40 KB
2386_2024-08-07_23:43:32_16.5_mi_E_of_Maricopa_3.9.pdf
August 07, 2024 329.80 KB
2385_2024-08-07_10:39:19_16.2_mi_E_of_Maricopa_3.6.pdf
August 07, 2024 286.10 KB
2385_2024-08-07_10:39:19_16.3_mi_E_of_Maricopa_3.5.pdf
August 07, 2024 285.79 KB
2382_2024-08-07_06:52:28_16.9_mi_SW_of_Arvin_3.5.pdf
August 07, 2024 276.71 KB
2383_post_event_summary.pdf
August 07, 2024 294.17 KB
2384_post_event_summary.pdf
August 07, 2024 294.17 KB
2382_2024-08-07_06:52:28_16.6_mi_SW_of_Arvin_3.5.pdf
August 07, 2024 277.03 KB
2380_2024-08-07_04:09:55_14.1_mi_SW_of_Arvin_5.4.pdf
August 07, 2024 358.34 KB
2381_2024-08-07_04:17:09_15.3_mi_SW_of_Arvin_4.2.pdf
August 07, 2024 281.04 KB
2379_2024-07-29_20:00:51_15.5_mi_E_of_Barstow_4.8.pdf
July 29, 2024 292.39 KB
2378_2024-07-21_22:09:51_10.6_mi_W_of_Rancho_Palos_Verdes_3.5.pdf
July 21, 2024 228.01 KB
2377_2024-07-17_21:59:27_31.5_mi_S_of_La_Quinta_3.5.pdf
July 17, 2024 281.24 KB
2376_2024-07-11_16:55:39_12.4_mi_SW_of_Coronado_2.8.pdf
July 11, 2024 206.37 KB