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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
1848_post_event_summary.pdf
July 21, 2021 107.01 KB
1847_2021-07-21_100531_17_1_mi_SW_of_Rio_Dell_4_3.pdf
July 21, 2021 229.72 KB
1846_2021-07-18_132410_44_8_mi_SE_of_South_Lake_Tahoe_3_9.pdf
July 18, 2021 332.16 KB
1845_2021-07-18_064612_24_8_mi_SW_of_Rio_Dell_5_1.pdf
July 18, 2021 207.11 KB
1844_2021-07-17_004454_39_5_mi_SE_of_South_Lake_Tahoe_3_5.pdf
July 17, 2021 320.58 KB
1843_2021-07-17_003254_40_4_mi_SE_of_South_Lake_Tahoe_3_0.pdf
July 17, 2021 327.24 KB
1842_2021-07-15_141828_39_5_mi_SE_of_South_Lake_Tahoe_4_0.pdf
July 15, 2021 324.56 KB
1841_2021-07-14_034613_38_7_mi_SE_of_South_Lake_Tahoe_4_1.pdf
July 14, 2021 319.83 KB
1840_2021-07-12_034333_47_8_mi_W_of_Fortuna_3_8.pdf
July 12, 2021 142.15 KB
1839_2021-07-09_051035_37_3_mi_SE_of_South_Lake_Tahoe_4_7.pdf
July 09, 2021 322.55 KB
1838_2021-07-09_050418_38_1_mi_SE_of_South_Lake_Tahoe_4_3.pdf
July 09, 2021 322.46 KB
1837_2021-07-09_014600_38_2_mi_SE_of_South_Lake_Tahoe_4_9.pdf
July 09, 2021 318.12 KB
1836_2021-07-09_002748_39_1_mi_SE_of_South_Lake_Tahoe_4_4.pdf
July 09, 2021 340.51 KB
1835_2021-07-09_000521_43_2_mi_SE_of_South_Lake_Tahoe_4_0.pdf
July 09, 2021 317.03 KB
1834_2021-07-08_235853_37_4_mi_SE_of_South_Lake_Tahoe_4_5.pdf
July 09, 2021 327.26 KB
1833_2021-07-08_234743_36_7_mi_SE_of_South_Lake_Tahoe_3_7.pdf
July 08, 2021 319.24 KB
1832_2021-07-08_234441_36_2_mi_SE_of_South_Lake_Tahoe_3_5.pdf
July 08, 2021 326.04 KB
1831_2021-07-08_233341_39_2_mi_SE_of_South_Lake_Tahoe_4_9.pdf
July 08, 2021 362.09 KB
1830_2021-07-08_231103_39_8_mi_SE_of_South_Lake_Tahoe_3_6.pdf
July 08, 2021 327.31 KB
1829_post_event_summary.pdf
July 08, 2021 386.39 KB
1827_2021-07-08_224948_38_7_mi_SE_of_South_Lake_Tahoe_5_9.pdf
July 08, 2021 352.24 KB
1828_post_event_summary.pdf
July 08, 2021 331.23 KB
1827_2021-07-08_224948_38_7_mi_SE_of_South_Lake_Tahoe_6_2.pdf
July 08, 2021 349.28 KB
1826_2021-07-06_023801_8_8_mi_NE_of_Ridgecrest_3_6.pdf
July 06, 2021 269.44 KB
1825_2021-07-03_232351_2_2_mi_W_of_Los_Banos_3_8.pdf
July 03, 2021 340.89 KB
1824_2021-07-03_082225_3_9_mi_NW_of_Fontana_3_5.pdf
July 03, 2021 356.71 KB
1823_2021-06-29_012948_2_2_mi_SE_of_San_Leandro_4_1.pdf
June 29, 2021 379.42 KB
1822_2021-06-23_082537_23_3_mi_SW_of_Loyalton_3_6.pdf
June 23, 2021 353.32 KB
1821_2021-06-18_082225_16_1_mi_W_of_El_Centro_3_5.pdf
June 18, 2021 293.51 KB
1819_2021-06-12_043946_9_5_mi_NW_of_Calipatria_4_3.pdf
June 14, 2021 328.43 KB
1817_2021-06-12_043028_9_5_mi_NW_of_Calipatria_3_9.pdf
June 14, 2021 313.16 KB
1816_2021-06-14_031624_10_2_mi_E_of_Cloverdale_3_5.pdf
June 14, 2021 319.42 KB
1815_2021-06-13_174313_7_0_mi_N_of_Westmorland_3_1.pdf
June 13, 2021 306.09 KB
1814_2021-06-13_065447_10_1_mi_E_of_Cloverdale_3_5.pdf
June 13, 2021 320.72 KB
1813_2021-06-12_141639_8_7_mi_NW_of_Calipatria_2_8.pdf
June 12, 2021 307.95 KB
1812_2021-06-12_111229_8_7_mi_NW_of_Shelton_3_6.pdf
June 12, 2021 332.54 KB
1811_2021-06-12_055520_10_0_mi_NW_of_Calipatria_3_6.pdf
June 12, 2021 307.50 KB
1810_2021-06-12_042734_9_5_mi_NW_of_Calipatria_3_4.pdf
June 12, 2021 310.79 KB
1809_2021-06-11_104553_5_3_mi_E_of_Watsonville_3_5.pdf
June 11, 2021 339.07 KB
1808_post_event_summary.pdf
June 07, 2021 172.87 KB
1806_2021-06-07_211911_7_6_mi_W_of_Calipatria_3_4.pdf
June 07, 2021 310.14 KB
1807_2021-06-07_214643_7_9_mi_NW_of_Calipatria_2_7.pdf
June 07, 2021 306.34 KB
1805_2021-06-07_210828_7_7_mi_NW_of_Calipatria_4_3.pdf
June 07, 2021 322.66 KB
1804_2021-06-07_155803_6_2_mi_NW_of_Calipatria_2_5.pdf
June 07, 2021 303.89 KB
1803_2021-06-07_054435_6_5_mi_W_of_Calipatria_3_4.pdf
June 07, 2021 306.54 KB
1802_2021-06-06_035137_26_8_mi_S_of_Hood_River_4_0.pdf
June 06, 2021 327.23 KB
1801_2021-06-06_030823_6_6_mi_W_of_Calipatria_3_5.pdf
June 06, 2021 306.59 KB
1800_2021-06-05_190707_5_7_mi_W_of_Calipatria_2_8.pdf
June 05, 2021 298.68 KB
1799_2021-06-05_190531_6_5_mi_W_of_Calipatria_3_4.pdf
June 05, 2021 302.26 KB
1798_2021-06-05_175558_6_9_mi_W_of_Calipatria_5_3.pdf
June 05, 2021 285.68 KB