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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
2562_2025-03-20_08:39:05_24.0_mi_S_of_La_Quinta_3.9.pdf
March 20, 2025 269.05 KB
2561_2025-03-19_03:56:45_50.9_mi_W_of_Fortuna_3.6.pdf
March 19, 2025 164.23 KB
2560_2025-03-18_02:46:33_2.9_mi_W_of_Dublin_4.0.pdf
March 18, 2025 353.00 KB
2559_2025-03-17_03:17:21_6.5_mi_NW_of_Malibu_3.9.pdf
March 17, 2025 270.49 KB
2558_2025-03-17_02:13:45_22.6_mi_E_of_Willits_4.0.pdf
March 17, 2025 287.76 KB
2557_2025-03-16_02:42:13_14.7_mi_E_of_Gonzales_3.3.pdf
March 16, 2025 256.99 KB
2556_2025-03-16_02:06:17_15.0_mi_E_of_Gonzales_2.8.pdf
March 16, 2025 276.18 KB
2555_2025-03-09_20:03:20_6.9_mi_SW_of_Westlake_Village_4.2.pdf
March 09, 2025 275.45 KB
2554_2025-03-06_00:18:24_10.8_mi_S_of_Sequim_4.0.pdf
March 06, 2025 288.59 KB
2553_2025-03-03_16:33:39_51.4_mi_W_of_Fortuna_3.3.pdf
March 03, 2025 170.95 KB
2552_2025-03-03_13:02:36_9.7_mi_NW_of_Anacortes_4.6.pdf
March 03, 2025 344.23 KB
2551_2025-03-03_06:13:45_3.0_mi_SW_of_Burbank_3.9.pdf
March 03, 2025 374.89 KB
2550_2025-03-01_22:45:15_43.3_mi_SW_of_Fortuna_3.1.pdf
March 01, 2025 177.11 KB
2550_post_event_summary.pdf
March 01, 2025 142.30 KB
2549_2025-02-27_10:44:42_45.8_mi_W_of_Fortuna_2.9.pdf
February 27, 2025 175.88 KB
2548_2025-02-26_23:31:23_45.8_mi_W_of_Fortuna_3.8.pdf
February 26, 2025 172.62 KB
2547_2025-02-26_05:46:24_13.1_mi_NE_of_Gonzales_3.6.pdf
February 26, 2025 273.88 KB
2546_2025-02-22_10:31:25_12.5_mi_S_of_Hollister_4.0.pdf
February 22, 2025 302.71 KB
2545_2025-02-22_09:25:27_12.3_mi_S_of_Hollister_3.2.pdf
February 22, 2025 260.23 KB
2544_2025-02-22_06:40:11_12.1_mi_S_of_Hollister_3.3.pdf
February 22, 2025 276.49 KB
2543_2025-02-22_05:21:37_12.1_mi_S_of_Hollister_3.3.pdf
February 22, 2025 261.51 KB
2542_2025-02-21_21:26:33_27.7_mi_N_of_Sechelt_5.1.pdf
February 21, 2025 320.25 KB
2541_2025-02-15_14:30:12_6.8_mi_NW_of_Malibu_3.5.pdf
February 15, 2025 297.37 KB
2540_2025-02-15_07:44:05_6.8_mi_NW_of_Malibu_3.8.pdf
February 15, 2025 276.50 KB
2539_2025-02-14_00:17:04_6.2_mi_NW_of_Avenal_4.4.pdf
February 14, 2025 314.62 KB
2538_2025-02-13_21:59:16_2.0_mi_SE_of_Hayward_3.7.pdf
February 13, 2025 381.79 KB
2537_2025-02-13_19:52:13_2.0_mi_SE_of_Hayward_3.4.pdf
February 13, 2025 361.61 KB
2536_2025-02-13_07:06:36_24.7_mi_SW_of_Rio_Dell_3.6.pdf
February 13, 2025 165.80 KB
2535_2025-02-12_04:32:39_50.0_mi_W_of_Fortuna_4.3.pdf
February 12, 2025 174.40 KB
2534_2025-02-11_08:13:16_26.2_mi_SW_of_Rio_Dell_4.0.pdf
February 11, 2025 189.28 KB
2533_2025-02-10_22:23:04_28.3_mi_N_of_Ridgecrest_3.2.pdf
February 10, 2025 259.66 KB
2532_2025-02-10_17:44:55_4.1_mi_NW_of_Highland_3.5.pdf
February 10, 2025 324.85 KB
2531_2025-02-09_10:31:52_42.6_mi_W_of_Fortuna_3.5.pdf
February 09, 2025 176.81 KB
2530_2025-02-07_11:03:12_50.0_mi_W_of_Fortuna_3.6.pdf
February 07, 2025 162.13 KB
2529_2025-02-04_00:55:02_41.9_mi_W_of_Fortuna_3.7.pdf
February 04, 2025 177.05 KB
2528_2025-02-01_21:33:08_23.9_mi_SW_of_Rio_Dell_2.5.pdf
February 01, 2025 184.55 KB
2527_2025-01-26_14:03:01_42.5_mi_SW_of_Fortuna_4.0.pdf
January 26, 2025 179.37 KB
2526_2025-01-26_10:21:54_34.3_mi_W_of_Rio_Dell_3.2.pdf
January 26, 2025 176.12 KB
2525_2025-01-23_18:08:47_22.6_mi_S_of_Mexicali_B.C._4.2.pdf
January 23, 2025 263.08 KB
2517_2025-01-07_18:00:02_82.8_mi_W_of_Fortuna_2.4.pdf
January 22, 2025 158.73 KB
2524_2025-01-21_11:29:29_48.9_mi_W_of_Fortuna_3.0.pdf
January 21, 2025 162.87 KB
2523_2025-01-20_20:29:39_50.5_mi_W_of_Fortuna_3.5.pdf
January 20, 2025 172.06 KB
2522_2025-01-19_12:36:54_25.3_mi_SW_of_Rio_Dell_3.6.pdf
January 19, 2025 184.62 KB
2521_2025-01-12_16:49:21_0.7_mi_E_of_Corcoran_3.9.pdf
January 12, 2025 368.72 KB
2520_2025-01-11_12:12:40_40.6_mi_SW_of_Fortuna_3.4.pdf
January 11, 2025 177.19 KB
2519_2025-01-10_15:02:03_6.6_mi_NW_of_Daly_City_3.7.pdf
January 10, 2025 247.75 KB
2518_2025-01-08_08:20:18_29.8_mi_SW_of_Susanville_3.2.pdf
January 08, 2025 272.77 KB
2517_post_event_summary.pdf
January 07, 2025 135.54 KB