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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
1761_2021-02-28_084538_32_0_mi_SW_of_King_City_3_8.pdf
February 28, 2021 262.96 KB
1760_2021-02-25_193019_10_6_mi_E_of_Cloverdale_3_5.pdf
February 25, 2021 320.61 KB
1759_post_event_summary.pdf
February 23, 2021 211.30 KB
1758_2021-02-22_013813_5_5_mi_NE_of_Gilroy_3_9.pdf
February 22, 2021 357.38 KB
1757_2021-02-14_234234_31_1_mi_NE_of_Ridgecrest_3_5.pdf
February 14, 2021 263.17 KB
1756_2021-02-12_235713_43_4_mi_N_of_Ridgecrest_4_0.pdf
February 13, 2021 299.89 KB
1755_2021-02-10_012709_6_8_mi_NW_of_Calipatria_3_8.pdf
February 10, 2021 304.64 KB
1754_2021-02-10_012432_6_6_mi_NW_of_Calipatria_2_9.pdf
February 10, 2021 303.06 KB
1753_2021-02-08_080012_15_8_mi_W_of_El_Centro_3_5.pdf
February 08, 2021 285.93 KB
1752_2021-02-07_185750_31_2_mi_NE_of_Ridgecrest_3_3.pdf
February 07, 2021 262.91 KB
1751_post_event_summary.pdf
February 05, 2021 152.94 KB
1750_2021-02-03_092336_15_4_mi_W_of_El_Centro_3_8.pdf
February 03, 2021 289.05 KB
1736_2020-12-28_152925_27_0_mi_SE_of_Mexicali_B_C__2_5.pdf
February 03, 2021 268.92 KB
1749_2021-01-25_081618_6_8_mi_NW_of_Calipatria_2_5.pdf
January 25, 2021 301.70 KB
1748_2021-01-21_012224_27_3_mi_NW_of_Ridgecrest_3_6.pdf
January 21, 2021 294.83 KB
1747_2021-01-17_040127_4_3_mi_W_of_San_Juan_Bautista_4_5.pdf
January 17, 2021 343.46 KB
1746_2021-01-17_031449_45_7_mi_NW_of_Ridgecrest_3_8.pdf
January 17, 2021 308.23 KB
1745_2021-01-17_024908_45_7_mi_NW_of_Ridgecrest_3_9.pdf
January 17, 2021 305.63 KB
1744_2021-01-14_191810_0_3_mi_W_of_Corcoran_3_8.pdf
January 14, 2021 383.48 KB
1743_2021-01-10_070148_6_5_mi_NW_of_Calipatria_2_9.pdf
January 10, 2021 304.29 KB
1742_2021-01-05_010726_26_4_mi_SW_of_Rio_Dell_2_7.pdf
January 05, 2021 201.11 KB
1741_2021-01-03_052156_0_6_mi_N_of_Gonzales_3_3.pdf
January 03, 2021 327.91 KB
1740_2021-01-02_144223_14_6_mi_NE_of_Gonzales_4_5.pdf
January 02, 2021 340.32 KB
1739_2020-12-31_134158_7_1_mi_SW_of_Sausalito_3_6.pdf
December 31, 2020 327.71 KB
1738_2020-12-31_042203_10_7_mi_E_of_Cloverdale_3_6.pdf
December 31, 2020 321.31 KB
1737_post_event_summary.pdf
December 28, 2020 202.39 KB
1735_2020-12-28_143452_29_2_mi_SE_of_Mexicali_B_C__3_6.pdf
December 28, 2020 271.67 KB
1734_2020-12-27_190547_2_2_mi_W_of_San_Juan_Bautista_3_2.pdf
December 27, 2020 340.85 KB
1733_2020-12-27_144440_9_8_mi_E_of_Willows_3_9.pdf
December 27, 2020 324.16 KB
1732_2020-12-25_202559_15_3_mi_E_of_Coachella_3_6.pdf
December 25, 2020 316.18 KB
1731_2020-12-23_222219_22_7_mi_S_of_Mexicali_B_C__3_3.pdf
December 23, 2020 258.98 KB
1730_2020-12-22_003000_20_6_mi_S_of_Mexicali_B_C__4_0.pdf
December 22, 2020 282.53 KB
1729_2020-12-18_161342_7_0_mi_SW_of_Rio_Dell_3_8.pdf
December 18, 2020 250.17 KB
1727_2020-12-15_145840_6_1_mi_NE_of_Morgan_Hill_3_7.pdf
December 15, 2020 359.69 KB
1728_2020-12-15_145941_5_9_mi_E_of_Morgan_Hill_3_6.pdf
December 15, 2020 364.45 KB
1726_2020-12-11_072434_5_8_mi_SE_of_Willits_3_4.pdf
December 11, 2020 308.49 KB
1725_2020-12-08_195055_25_5_mi_SW_of_Rio_Dell_2_9.pdf
December 08, 2020 203.57 KB
1724_2020-12-06_151753_25_5_mi_E_of_Escondido_3_8.pdf
December 06, 2020 356.06 KB
1723_2020-12-06_150333_8_1_mi_W_of_Lakeport_4_3.pdf
December 06, 2020 315.48 KB
1722_2020-12-05_054129_14_2_mi_E_of_Temecula_3_7.pdf
December 05, 2020 363.58 KB
1721_2020-12-04_104838_11_8_mi_E_of_Cloverdale_2_2.pdf
December 04, 2020 318.80 KB
1720_2020-12-04_104506_11_3_mi_E_of_Cloverdale_3_5.pdf
December 04, 2020 321.53 KB
1715_2020-11-22_031159_41_6_mi_W_of_Eureka_2_4.pdf
December 02, 2020 158.87 KB
1719_post_event_summary.pdf
December 02, 2020 321.72 KB
1718_2020-12-01_010620_9_8_mi_W_of_Ukiah_3_3.pdf
December 01, 2020 283.44 KB
1717_post_event_summary.pdf
November 30, 2020 345.82 KB
1716_2020-11-26_225957_6_6_mi_NW_of_Calipatria_3_6.pdf
November 26, 2020 305.33 KB
1714_2020-11-20_195037_12_9_mi_SW_of_Clearlake_3_2.pdf
November 20, 2020 325.26 KB
1713_2020-11-16_105622_18_7_mi_N_of_Ridgecrest_3_7.pdf
November 16, 2020 282.42 KB
1712_2020-11-14_055013_31_5_mi_W_of_Fortuna_3_5.pdf
November 14, 2020 183.44 KB