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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
1795_2021-06-05_174210_7_2_mi_N_of_Westmorland_3_3.pdf
June 05, 2021 306.87 KB
1794_2021-06-03_121532_9_3_mi_E_of_San_Jose_3_6.pdf
June 03, 2021 376.72 KB
1793_2021-06-03_043442_17_4_mi_NE_of_Greenfield_3_8.pdf
June 03, 2021 323.67 KB
1792_2021-05-31_090614_11_4_mi_SE_of_Mammoth_Lakes_3_5.pdf
May 31, 2021 317.70 KB
1791_2021-05-28_152522_14_0_mi_N_of_South_Lake_Tahoe_4_4.pdf
May 28, 2021 346.53 KB
1790_2021-05-20_013722_30_9_mi_NE_of_Ridgecrest_3_6.pdf
May 20, 2021 262.78 KB
1789_2021-05-19_133939_24_5_mi_S_of_Mexicali_B_C__3_5.pdf
May 19, 2021 266.26 KB
1788_post_event_summary.pdf
May 18, 2021 110.40 KB
1787_2021-05-18_144425_5_5_mi_SW_of_Huron_4_0.pdf
May 18, 2021 325.12 KB
1786_2021-05-14_015312_40_5_mi_W_of_Fortuna_3_0.pdf
May 14, 2021 162.47 KB
1785_2021-05-09_015540_3_0_mi_W_of_Hermosa_Beach_3_7.pdf
May 09, 2021 324.84 KB
1784_2021-05-07_043514_15_8_mi_S_of_Loyalton_5_1.pdf
May 07, 2021 317.21 KB
1783_2021-04-29_140839_12_2_mi_E_of_Cloverdale_2_7.pdf
April 29, 2021 319.04 KB
1782_2021-04-28_105021_33_7_mi_S_of_La_Quinta_3_6.pdf
April 28, 2021 340.98 KB
1781_2021-04-25_153323_14_1_mi_N_of_South_Lake_Tahoe_4_0.pdf
April 25, 2021 344.67 KB
1780_2021-04-25_045928_9_5_mi_N_of_Morgan_Hill_3_8.pdf
April 25, 2021 366.90 KB
1779_2021-04-23_111840_18_9_mi_NE_of_Willits_3_7.pdf
April 23, 2021 314.73 KB
1778_2021-04-22_070010_12_5_mi_SE_of_Mammoth_Lakes_3_1.pdf
April 22, 2021 323.54 KB
1777_2021-04-20_094834_34_3_mi_SE_of_Rio_Dell_3_8.pdf
April 20, 2021 300.43 KB
1776_2021-04-19_185058_12_7_mi_NE_of_Healdsburg_4_1.pdf
April 19, 2021 329.01 KB
1775_2021-04-10_132206_4_4_mi_SW_of_Holtville_3_5.pdf
April 10, 2021 290.77 KB
1774_2021-04-08_205115_7_2_mi_E_of_Ridgecrest_3_6.pdf
April 08, 2021 273.43 KB
1773_2021-04-08_035208_3_7_mi_SW_of_Holtville_3_7.pdf
April 08, 2021 281.63 KB
1772_2021-04-05_202721_30_9_mi_SW_of_Rio_Dell_3_5.pdf
April 05, 2021 186.66 KB
1771_2021-04-05_114401_1_4_mi_SE_of_Inglewood_4_1.pdf
April 05, 2021 336.32 KB
1770_2021-04-02_082135_29_3_mi_SW_of_Rio_Dell_4_4.pdf
April 02, 2021 201.42 KB
1770_2021-04-02_082135_29_3_mi_SW_of_Rio_Dell_4_1.pdf
April 02, 2021 201.76 KB
1769_2021-03-31_085625_22_8_mi_SE_of_Mexicali_B_C__4_2.pdf
March 31, 2021 285.27 KB
1768_2021-03-30_170534_12_2_mi_SW_of_Clearlake_3_3.pdf
March 30, 2021 322.33 KB
1767_2021-03-30_155120_63_3_mi_W_of_Fortuna_4_3.pdf
March 30, 2021 114.50 KB
1766_2021-03-24_154114_13_0_mi_SW_of_Willits_3_8.pdf
March 24, 2021 283.55 KB
1765_post_event_summary.pdf
March 23, 2021 122.77 KB
1764_2021-03-17_142158_62_6_mi_W_of_Trinidad_3_6.pdf
March 17, 2021 121.41 KB
1763_2021-03-05_183311_19_9_mi_N_of_Ridgecrest_3_3.pdf
March 05, 2021 279.83 KB
1762_2021-03-04_170832_27_6_mi_SW_of_Rio_Dell_2_9.pdf
March 05, 2021 202.38 KB
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