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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
1613_2020-05-31_010715__30_6_mi_NE_of_Mammoth_Lakes_4_4.pdf
May 31, 2020 296.24 KB
1612_2020-05-30_092257__31_1_mi_NE_of_Mammoth_Lakes_3_5.pdf
May 30, 2020 285.82 KB
1611_2020-05-28_191913__13_4_mi_NE_of_Gonzales_3_7.pdf
May 28, 2020 332.01 KB
1610_2020-05-27_045231___3_1_mi_E_of_Bakersfield_3_6.pdf
May 27, 2020 328.80 KB
1609_2020-05-24_125509__17_4_mi_N_of_Ridgecrest_3_9.pdf
May 24, 2020 288.37 KB
1608_2020-05-20_164056__11_2_mi_NE_of_Ridgecrest_3_6.pdf
May 20, 2020 277.25 KB
1607_2020-05-19_155831__23_1_mi_SW_of_Fortuna_4_1.pdf
May 19, 2020 209.04 KB
1606_2020-05-19_071539__22_2_mi_SE_of_Mexicali_B_C__3_3.pdf
May 19, 2020 265.15 KB
1605_2020-05-16_014656__39_4_mi_N_of_Ridgecrest_3_5.pdf
May 16, 2020 301.04 KB
1604_2020-05-10_220740__23_1_mi_W_of_Westmorland_4_4.pdf
May 10, 2020 334.42 KB
1603_2020-05-10_044601_128_8_mi_W_of_Port_Alberni_4_7.pdf
May 10, 2020 161.37 KB
1535_2019-12-27_022147__11_1_mi_N_of_Ridgecrest_3_7.pdf
May 08, 2020 284.51 KB
1602_2020-05-06_082705___7_3_mi_NW_of_Calipatria_3_6.pdf
May 06, 2020 305.87 KB
1601_2020-05-02_234437___4_8_mi_SW_of_Holtville_3_5.pdf
May 02, 2020 281.51 KB
1600_2020-04-29_121038___3_1_mi_SE_of_Bishop_3_9.pdf
April 29, 2020 303.45 KB
1599_2020-04-27_034600__10_4_mi_E_of_Ridgecrest_3_9.pdf
April 27, 2020 281.75 KB
1598_2020-04-22_070347___1_8_mi_N_of_Inglewood_3_8.pdf
April 22, 2020 346.55 KB
1597_2020-04-21_051331__30_8_mi_NE_of_Mammoth_Lakes_4_1.pdf
April 21, 2020 296.95 KB
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