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.

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.
File | Date Posted | Size | |
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2317_2024-04-05_01:34:24_35.0_mi_NE_of_Chico_4.9.pdf
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April 05, 2024 | 297.73 KB | |
2316_2024-04-04_06:50:49_10.6_mi_E_of_Cloverdale_3.0.pdf
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April 04, 2024 | 266.11 KB | |
2314_2024-03-20_15:09:49_36.2_mi_N_of_Tehachapi_3.4.pdf
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March 20, 2024 | 264.03 KB | |
2313_2024-03-18_23:57:26_13.7_mi_NE_of_Gonzales_3.4.pdf
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March 19, 2024 | 255.48 KB | |
2311_2024-03-16_11:19:58_23.8_mi_SW_of_Rio_Dell_2.7.pdf
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March 17, 2024 | 175.96 KB | |
2310_2024-02-29_02:21:45_8.8_mi_SE_of_Oakley_3.8.pdf
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February 29, 2024 | 325.18 KB | |
2309_2024-02-26_17:25:43_40.7_mi_NE_of_Emmett_4.9.pdf
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February 26, 2024 | 266.05 KB | |
2308_2024-02-26_12:44:31_34.2_mi_W_of_Rio_Dell_2.7.pdf
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February 26, 2024 | 177.75 KB | |
2307_2024-02-21_14:01:32_2.5_mi_S_of_Parkfield_3.7.pdf
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February 21, 2024 | 253.65 KB | |
2306_2024-02-16_07:38:40_4.3_mi_S_of_Rancho_Cucamonga_3.8.pdf
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February 16, 2024 | 330.60 KB | |
2305_2024-02-14_07:53:13_6.1_mi_N_of_Westmorland_3.9.pdf
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February 14, 2024 | 292.34 KB | |
2304_2024-02-12_23:54:43_9.0_mi_W_of_Bishop_3.9.pdf
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February 13, 2024 | 251.92 KB | |
2303_2024-02-12_10:18:36_0.6_mi_SE_of_El_Centro_3.6.pdf
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February 12, 2024 | 260.79 KB | |
2302_2024-02-12_08:59:51_0.6_mi_W_of_El_Centro_4.0.pdf
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February 12, 2024 | 265.27 KB | |
2301_2024-02-12_08:42:43_1.6_mi_S_of_Imperial_2.4.pdf
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February 12, 2024 | 283.17 KB | |
2300_2024-02-12_08:38:26_2.0_mi_NW_of_El_Centro_3.7.pdf
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February 12, 2024 | 279.38 KB | |
2299_2024-02-12_08:36:25_1.7_mi_NW_of_El_Centro_4.8.pdf
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February 12, 2024 | 302.41 KB | |
2298_2024-02-10_09:49:44_41.1_mi_SE_of_Mexicali_B.C._3.2.pdf
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February 10, 2024 | 220.41 KB | |
2297_2024-02-10_07:20:19_24.3_mi_SW_of_Rio_Dell_4.0.pdf
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February 10, 2024 | 197.38 KB | |
2296_2024-02-09_21:47:27_7.2_mi_NW_of_Malibu_4.5.pdf
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February 09, 2024 | 291.87 KB | |
2295_2024-02-09_09:54:34_40.6_mi_SW_of_Fortuna_2.9.pdf
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February 09, 2024 | 176.04 KB | |
2294_post_event_summary.pdf
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February 09, 2024 | 180.53 KB | |
2293_2024-02-07_09:36:37_26.1_mi_SW_of_Susanville_3.6.pdf
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February 07, 2024 | 265.55 KB | |
2292_2024-02-05_08:56:19_18.6_mi_S_of_Mexicali_B.C._3.7.pdf
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February 05, 2024 | 216.42 KB | |
2290_2024-02-05_00:45:37_10.0_mi_SW_of_Ukiah_3.2.pdf
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February 05, 2024 | 250.53 KB | |
2291_2024-02-05_01:06:53_22.1_mi_NE_of_Tehachapi_3.8.pdf
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February 05, 2024 | 271.60 KB | |
2290_post_event_summary.pdf
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February 05, 2024 | 254.99 KB | |
2289_post_event_summary.pdf
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February 03, 2024 | 142.57 KB | |
2288_2024-02-02_15:08:59_65.8_mi_W_of_Fortuna_5.0.pdf
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February 02, 2024 | 172.35 KB | |
2287_2024-02-01_17:32:54_12.7_mi_S_of_Hollister_3.4.pdf
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February 01, 2024 | 260.99 KB | |
2286_2024-01-28_12:07:40_6.5_mi_N_of_Westmorland_2.9.pdf
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January 28, 2024 | 233.43 KB | |
2285_2024-01-28_06:30:14_57.0_mi_W_of_Fortuna_3.3.pdf
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January 28, 2024 | 160.16 KB | |
2284_2024-01-26_21:28:13_13.6_mi_SW_of_Clearlake_4.0.pdf
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January 26, 2024 | 316.82 KB | |
2283_2024-01-26_16:42:04_11.9_mi_E_of_Cloverdale_3.1.pdf
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January 26, 2024 | 275.00 KB | |
2282_2024-01-25_03:43:19_1.2_mi_W_of_San_Bernardino_4.4.pdf
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January 25, 2024 | 332.59 KB | |
2281_2024-01-23_05:26:10_11.9_mi_S_of_Fort_Jones_4.1.pdf
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January 23, 2024 | 220.49 KB | |
2280_2024-01-15_10:44:10_61.6_mi_S_of_Avalon_4.5.pdf
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January 15, 2024 | 202.87 KB | |
2279_2024-01-12_16:24:46_12.5_mi_S_of_Hollister_3.1.pdf
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January 12, 2024 | 265.89 KB | |
2278_2024-01-06_18:32:47_13.4_mi_N_of_Ukiah_3.5.pdf
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January 06, 2024 | 261.62 KB | |
2277_2024-01-05_18:55:54_11.9_mi_NE_of_Rancho_Cucamonga_4.4.pdf
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January 05, 2024 | 339.98 KB | |
2276_2024-01-01_16:27:32_11.6_mi_S_of_Rancho_Palos_Verdes_3.9.pdf
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January 01, 2024 | 280.64 KB | |
2275_2023-12-30_08:29:10_10.4_mi_NE_of_Ridgecrest_3.3.pdf
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December 30, 2023 | 255.63 KB | |
2274_2023-12-30_02:26:27_17.4_mi_NE_of_Arvin_3.5.pdf
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December 30, 2023 | 271.88 KB | |
2273_2023-12-29_07:10:11_11.8_mi_E_of_Cloverdale_3.5.pdf
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December 29, 2023 | 268.68 KB | |
2272_2023-12-28_12:03:26_45.5_mi_W_of_Fortuna_3.5.pdf
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December 28, 2023 | 166.57 KB | |
2271_2023-12-28_07:00:43_46.5_mi_W_of_Fortuna_3.8.pdf
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December 28, 2023 | 164.93 KB | |
2270_2023-12-24_15:14:04_13.1_mi_NW_of_Bangor_Trident_Base_4.1.pdf
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December 24, 2023 | 314.71 KB | |
2269_2023-12-09_21:46:04_8.1_mi_NW_of_Calipatria_3.2.pdf
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December 09, 2023 | 248.27 KB | |
2268_2023-12-09_21:44:53_8.1_mi_W_of_Calipatria_3.2.pdf
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December 09, 2023 | 270.67 KB | |
2267_2023-12-09_20:04:46_8.4_mi_W_of_Calipatria_3.2.pdf
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December 09, 2023 | 242.43 KB |