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