Skip to content

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
1596_post_event_summary.pdf
April 19, 2020 108.66 KB
1595_2020-04-18_125014__31_6_mi_NE_of_Ridgecrest_3_5.pdf
April 18, 2020 275.55 KB
1594_2020-04-16_134906__31_5_mi_NE_of_Mammoth_Lakes_3_9.pdf
April 16, 2020 295.04 KB
1593_2020-04-15_201305__31_0_mi_NE_of_Mammoth_Lakes_3_8.pdf
April 15, 2020 295.54 KB
1592_2020-04-11_213645__31_2_mi_NE_of_Mammoth_Lakes_3_9.pdf
April 11, 2020 295.04 KB
1591_2020-04-11_165750__15_4_mi_N_of_Mammoth_Lakes_4_1.pdf
April 11, 2020 309.74 KB
1590_2020-04-11_162250__30_7_mi_NE_of_Mammoth_Lakes_4_7.pdf
April 11, 2020 315.60 KB
1589_2020-04-11_143637__31_7_mi_NE_of_Mammoth_Lakes_5_3.pdf
April 11, 2020 290.39 KB
1588_2020-04-06_155814__17_0_mi_SE_of_Coachella_3_6.pdf
April 06, 2020 316.46 KB
1587_2020-04-05_223718__14_8_mi_SW_of_La_Quinta_3_9.pdf
April 05, 2020 354.06 KB
1586_2020-04-05_210744__15_9_mi_SW_of_La_Quinta_3_9.pdf
April 05, 2020 356.45 KB
1585_2020-04-05_192046__10_1_mi_SE_of_Mammoth_Lakes_4_4.pdf
April 05, 2020 324.10 KB
1584_2020-04-04_051235__15_6_mi_SW_of_La_Quinta_3_6.pdf
April 04, 2020 359.13 KB
1583_2020-04-04_040722__15_9_mi_SW_of_La_Quinta_3_6.pdf
April 04, 2020 358.04 KB
1582_2020-04-04_031746___8_9_mi_S_of_Tehachapi_3_6.pdf
April 04, 2020 337.06 KB
1581_2020-04-04_020500__15_6_mi_SW_of_La_Quinta_3_6.pdf
April 04, 2020 358.14 KB
1580_2020-04-04_015532__14_8_mi_SW_of_La_Quinta_2_9.pdf
April 04, 2020 357.18 KB
1579_2020-04-04_015422__15_3_mi_SW_of_La_Quinta_3_6.pdf
April 04, 2020 358.26 KB
1578_2020-04-04_015318__15_4_mi_SW_of_La_Quinta_4_6.pdf
April 04, 2020 360.38 KB
1577_2020-03-25_115737__13_6_mi_E_of_Cloverdale_3_8.pdf
March 25, 2020 316.94 KB
1576_2020-03-23_100755__31_5_mi_SW_of_Rio_Dell_3_7.pdf
March 23, 2020 188.75 KB
1575_2020-03-23_055357__29_0_mi_NE_of_Ridgecrest_4_1.pdf
March 23, 2020 277.80 KB
1574_2020-03-22_162738__37_0_mi_W_of_Fortuna_4_7.pdf
March 22, 2020 190.75 KB
1573_post_event_summary.pdf
March 21, 2020 200.29 KB
1572_2020-03-20_115254___8_8_mi_E_of_Ridgecrest_3_5.pdf
March 20, 2020 278.02 KB
1571_2020-03-18_220821__20_6_mi_SW_of_Rio_Dell_5_0.pdf
March 18, 2020 230.08 KB
1570_2020-03-14_222858__16_5_mi_N_of_Willits_3_3.pdf
March 14, 2020 290.25 KB
1569_2020-03-11_011716__14_2_mi_S_of_Loyalton_3_8.pdf
March 11, 2020 318.23 KB
1568_2020-03-08_061600__11_2_mi_E_of_Cloverdale_3_0.pdf
March 08, 2020 312.37 KB
1567_2020-03-08_003331__35_4_mi_N_of_Ridgecrest_3_7.pdf
March 08, 2020 299.69 KB
1566_2020-03-07_125116__35_5_mi_N_of_Ridgecrest_3_5.pdf
March 07, 2020 298.40 KB
1565_2020-03-07_084913__35_2_mi_N_of_Ridgecrest_3_4.pdf
March 07, 2020 298.71 KB
1564_2020-03-07_035213__31_3_mi_SE_of_Mexicali_B_C__5_5.pdf
March 07, 2020 260.95 KB
1563_2020-03-03_182132___7_7_mi_N_of_Ukiah_3_6.pdf
March 03, 2020 296.77 KB
1562_2020-03-03_150101__22_0_mi_SW_of_Mendota_4_0.pdf
March 03, 2020 304.15 KB
1561_2020-03-03_025418__40_7_mi_SE_of_Mexicali_B_C__3_2.pdf
March 03, 2020 281.53 KB
1560_2020-02-27_232729__11_5_mi_E_of_Cloverdale_3_5.pdf
February 27, 2020 311.49 KB
1559_2020-02-26_183402__12_2_mi_SW_of_Clearlake_1_2.pdf
February 26, 2020 308.58 KB
1558_2020-02-26_092115__26_8_mi_SW_of_Rio_Dell_2_8.pdf
February 26, 2020 202.29 KB
1557_2020-02-22_191427__33_1_mi_SW_of_Rio_Dell_4_2.pdf
February 22, 2020 188.51 KB
1556_2020-02-21_134253___9_6_mi_NW_of_Santa_Clarita_3_7.pdf
February 21, 2020 346.68 KB
1555_2020-02-18_182056__13_5_mi_SW_of_Clearlake_2_7.pdf
February 18, 2020 316.51 KB
1554_2020-02-13_033342__13_0_mi_SE_of_Hollister_3_8.pdf
February 13, 2020 321.39 KB
1553_2020-02-08_193420__14_1_mi_N_of_Barstow_4_0.pdf
February 08, 2020 285.99 KB
1552_2020-02-07_104552__22_9_mi_W_of_Fortuna_2_9.pdf
February 07, 2020 198.86 KB
1551_2020-02-06_110529__20_0_mi_SW_of_Rio_Dell_3_3.pdf
February 06, 2020 225.37 KB
1550_2020-02-06_100008__20_2_mi_SW_of_Rio_Dell_2_5.pdf
February 06, 2020 223.57 KB
1549_2020-02-06_082024__19_7_mi_SW_of_Rio_Dell_3_7.pdf
February 06, 2020 222.55 KB
1548_2020-02-04_130332___7_0_mi_W_of_Calipatria_2_9.pdf
February 04, 2020 307.15 KB
1547_2020-02-03_103957__30_6_mi_SW_of_Fortuna_3_3.pdf
February 03, 2020 179.29 KB