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Post ShakeAlert Message Summaries


Post ShakeAlert Message Summaries provide information about earthquakes detected by the ShakeAlert Earthquake Early Warning System and ShakeAlert’s performance during these events. They summarize how accurately the ShakeAlert System estimated the earthquake’s location and magnitude, how many seismic stations contributed data to these estimates, and how much warning time nearby cities may have received. These summaries are automatically generated for all USGS-issued ShakeAlert Messages with an estimated peak magnitude (M) of 3.5 or larger. Only at M 4.0 or larger are ShakeAlert Messages human-reviewed and forwarded to the National Earthquake Information Center to be posted at www.earthquake.usgs.gov. Summaries for earthquakes less than M 4.0 provide our scientists with more frequent tests of software readiness, but their 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.

FileDate PostedSize
1919_2021-10-24_140102_1_9_mi_N_of_Maywood_3_9.pdf
October 24, 2021 379.57 KB
1918_2021-10-24_111051_11_5_mi_E_of_Cloverdale_2_6.pdf
October 24, 2021 303.21 KB
1917_2021-10-24_064912_15_4_mi_W_of_Westmorland_3_5.pdf
October 24, 2021 304.18 KB
1916_2021-10-24_040922_8_9_mi_E_of_Cloverdale_2_6.pdf
October 24, 2021 298.91 KB
1915_2021-10-23_042800_11_8_mi_E_of_Cloverdale_2_7.pdf
October 23, 2021 303.91 KB
1914_2021-10-23_025632_67_1_mi_SW_of_Imperial_Beach_3_5.pdf
October 23, 2021 114.83 KB
1913_2021-10-22_023017_13_8_mi_E_of_Mammoth_Lakes_3_4.pdf
October 22, 2021 308.40 KB
1912_2021-10-20_085715_12_9_mi_S_of_Hollister_4_0.pdf
October 20, 2021 334.78 KB
1911_2021-10-20_052051_10_9_mi_E_of_Cloverdale_2_7.pdf
October 20, 2021 304.21 KB
1910_2021-10-20_040504_13_6_mi_NE_of_Healdsburg_3_4.pdf
October 20, 2021 308.91 KB
1899_2021-10-06_142527_26_0_mi_S_of_Bishop_3_5.pdf
October 06, 2021 296.57 KB
1898_2021-10-04_230748_10_6_mi_NE_of_Gonzales_3_8.pdf
October 04, 2021 329.10 KB
1897_2021-10-03_120200_7_3_mi_N_of_Morgan_Hill_3_4.pdf
October 03, 2021 367.13 KB
1896_2021-10-02_192226_1_9_mi_N_of_San_Leandro_3_5.pdf
October 02, 2021 391.66 KB
1895_2021-10-02_021514_1_9_mi_N_of_San_Leandro_3_2.pdf
October 02, 2021 390.67 KB
1894_2021-10-02_014220_8_4_mi_SE_of_Tehachapi_3_6.pdf
October 02, 2021 279.34 KB
1893_2021-10-01_051219_13_5_mi_NE_of_Healdsburg_2_8.pdf
October 01, 2021 305.84 KB
1892_2021-09-30_124503_2_3_mi_E_of_Santa_Rosa_3_4.pdf
September 30, 2021 323.17 KB
1891_2021-09-30_063742_18_2_mi_SW_of_Rio_Dell_3_3.pdf
September 30, 2021 223.59 KB
1890_2021-09-29_123315_36_4_mi_SE_of_South_Lake_Tahoe_3_3.pdf
September 29, 2021 310.07 KB
1889_2021-09-29_061634_9_7_mi_NW_of_Marina_2_8.pdf
September 29, 2021 326.86 KB
1888_2021-09-29_055359_2_8_mi_NE_of_Westmorland_3_0.pdf
September 29, 2021 287.25 KB
1887_2021-09-28_194118_11_8_mi_SE_of_Parkfield_3_3.pdf
September 28, 2021 285.49 KB
1886_2021-09-28_151212_36_3_mi_SE_of_South_Lake_Tahoe_4_0.pdf
September 28, 2021 313.56 KB
1885_2021-09-27_222755_16_8_mi_S_of_Rio_Dell_2_8.pdf
September 27, 2021 248.58 KB
1884_2021-09-26_085130_16_9_mi_S_of_Rio_Dell_3_6.pdf
September 26, 2021 247.44 KB
1883_2021-09-25_121208_38_6_mi_SE_of_South_Lake_Tahoe_2_9.pdf
September 25, 2021 310.33 KB
1882_2021-09-24_192815_11_5_mi_E_of_Ridgecrest_3_3.pdf
September 24, 2021 236.44 KB
1881_2021-09-23_015341_37_6_mi_SE_of_South_Lake_Tahoe_3_6.pdf
September 23, 2021 305.26 KB
1880_2021-09-22_175937_58_8_mi_SE_of_Tijuana_B_C__3_2.pdf
September 22, 2021 210.12 KB
1879_2021-09-22_095745_9_8_mi_NW_of_Marina_3_4.pdf
September 22, 2021 330.11 KB
1878_2021-09-21_225732_16_5_mi_SW_of_Palm_Springs_3_5.pdf
September 21, 2021 353.66 KB
1877_2021-09-21_224130_16_7_mi_SW_of_Palm_Springs_3_7.pdf
September 21, 2021 360.35 KB
1876_2021-09-21_111556_17_5_mi_NE_of_Indio_3_3.pdf
September 21, 2021 282.73 KB
1875_2021-09-19_000914_3_4_mi_S_of_San_Ramon_3_2.pdf
September 19, 2021 410.97 KB
1874_2021-09-18_192031_37_7_mi_SE_of_South_Lake_Tahoe_4_2.pdf
September 18, 2021 309.63 KB
1873_2021-09-18_025834_0_8_mi_SE_of_Carson_4_4.pdf
September 18, 2021 341.20 KB
1872_2021-09-17_125158_21_8_mi_SE_of_Mexicali_B_C__3_7.pdf
September 17, 2021 268.48 KB
1871_2021-09-15_122944_42_4_mi_SE_of_South_Lake_Tahoe_3_5.pdf
September 15, 2021 316.37 KB
1870_2021-09-14_184527_6_6_mi_NE_of_Milpitas_2_9.pdf
September 14, 2021 401.77 KB
1869_2021-09-14_073851_16_5_mi_NW_of_Coalinga_4_0.pdf
September 14, 2021 294.40 KB
1868_2021-09-13_145935_7_6_mi_W_of_Simi_Valley_3_6.pdf
September 13, 2021 311.62 KB
1866_2021-09-09_033838_37_1_mi_SE_of_South_Lake_Tahoe_2_8.pdf
September 09, 2021 309.31 KB
1865_2021-09-08_211752_22_0_mi_SE_of_Mexicali_B_C__3_2.pdf
September 08, 2021 264.31 KB
1864_2021-09-06_223424_10_9_mi_E_of_Cloverdale_3_3.pdf
September 06, 2021 300.58 KB
1863_2021-09-05_233922_42_4_mi_NW_of_Ridgecrest_3_3.pdf
September 05, 2021 295.71 KB
1862_2021-09-05_052745_4_9_mi_E_of_Ukiah_3_5.pdf
September 05, 2021 284.12 KB
1861_2021-09-03_054420_4_8_mi_E_of_Ukiah_3_6.pdf
September 03, 2021 285.90 KB
1860_2021-08-31_160956_15_5_mi_E_of_Gonzales_4_4.pdf
August 31, 2021 320.36 KB
1859_2021-08-30_231143_3_9_mi_SW_of_Mexicali_B_C__2_7.pdf
August 30, 2021 264.74 KB