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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
2014_2022-05-31_19:00:01_11.5_mi_E_of_Cloverdale_3.2.pdf
May 31, 2022 310.48 KB
2013_2022-05-30_09:50:56_46.0_mi_W_of_Fortuna_3.5.pdf
May 30, 2022 123.67 KB
2012_2022-05-29_15:26:56_65.4_mi_SE_of_Tijuana_B.C._3.7.pdf
May 29, 2022 203.81 KB
2011_2022-05-26_09:23:32_14.9_mi_E_of_Ridgecrest_4.3.pdf
May 26, 2022 278.43 KB
2010_2022-05-16_06:16:50_4.6_mi_NE_of_Desert_Hot_Springs_3.7.pdf
May 16, 2022 317.64 KB
2009_2022-05-14_21:28:14_9.8_mi_S_of_Maricopa_3.2.pdf
May 14, 2022 318.50 KB
2008_2022-05-13_13:32:36_19.7_mi_SE_of_Temecula_3.7.pdf
May 13, 2022 386.10 KB
2007_2022-05-09_21:35:33_38.4_mi_E_of_Santee_3.6.pdf
May 09, 2022 335.11 KB
2006_2022-05-01_03:17:37_11.0_mi_E_of_Cloverdale_3.4.pdf
May 01, 2022 311.40 KB
2005_2022-04-30_18:17:56_11.7_mi_E_of_Cloverdale_3.5.pdf
April 30, 2022 311.65 KB
2004_2022-04-22_05:02:34_13.2_mi_SE_of_Hollister_3.5.pdf
April 22, 2022 331.68 KB
2003_2022-04-21_18:58:50_5.0_mi_NE_of_Imperial_3.6.pdf
April 21, 2022 279.24 KB
2002_2022-04-20_05:19:44_4.2_mi_S_of_Brawley_3.5.pdf
April 20, 2022 280.64 KB
2001_2022-04-20_03:56:46_4.0_mi_S_of_Brawley_3.2.pdf
April 20, 2022 279.63 KB
2000_2022-04-19_20:30:08_4.5_mi_S_of_Brawley_3.9.pdf
April 19, 2022 283.09 KB
1999_2022-04-19_20:22:41_3.9_mi_S_of_Brawley_3.6.pdf
April 19, 2022 279.44 KB
1998_2022-04-19_05:00:09_1.9_mi_SE_of_Cloverdale_3.3.pdf
April 19, 2022 301.06 KB
1997_2022-04-19_00:27:35_23.1_mi_SE_of_Mexicali_B.C._2.9.pdf
April 19, 2022 259.59 KB
1996_2022-04-18_22:35:34_21.0_mi_SE_of_Mexicali_B.C._3.5.pdf
April 18, 2022 269.45 KB
1995_2022-04-18_22:22:13_19.9_mi_SE_of_Mexicali_B.C._3.0.pdf
April 18, 2022 266.28 KB
1994_2022-04-18_02:08:59_10.7_mi_E_of_Cloverdale_3.0.pdf
April 18, 2022 311.35 KB
1993_2022-04-17_05:38:26_72.8_mi_SW_of_Mexicali_B.C._3.6.pdf
April 17, 2022 178.19 KB
1992_post_event_summary.pdf
April 15, 2022 196.13 KB
1991_2022-04-15_04:30:55_43.1_mi_S_of_Tijuana_B.C._4.7.pdf
April 15, 2022 245.53 KB
1990_2022-04-11_23:40:20_8.2_mi_NW_of_Calipatria_3.2.pdf
April 11, 2022 300.74 KB
1989_2022-04-04_15:18:31_5.3_mi_W_of_Rio_Dell_3.9.pdf
April 04, 2022 251.23 KB
1988_2022-04-04_15:16:46_5.1_mi_W_of_Rio_Dell_4.0.pdf
April 04, 2022 250.55 KB
1987_2022-04-03_09:51:30_10.0_mi_N_of_Barstow_3.7.pdf
April 03, 2022 249.35 KB
1986_2022-04-02_10:31:04_26.7_mi_NE_of_Blue_Lake_3.8.pdf
April 02, 2022 295.81 KB
1985_2022-03-31_02:05:26_12.0_mi_W_of_Bishop_4.3.pdf
March 31, 2022 319.00 KB
1984_2022-03-25_21:10:59_6.4_mi_SW_of_Williams_3.8.pdf
March 25, 2022 290.76 KB
1983_2022-03-22_10:33:38_4.2_mi_SE_of_Rancho_Cucamonga_3.4.pdf
March 22, 2022 398.19 KB
1982_2022-03-19_16:59:41_6.4_mi_N_of_Watsonville_3.9.pdf
March 19, 2022 347.63 KB
1981_2022-03-18_04:51:22_37.4_mi_SE_of_South_Lake_Tahoe_4.1.pdf
March 18, 2022 326.05 KB
1980_2022-03-13_20:51:30_15.2_mi_E_of_Gonzales_4.1.pdf
March 13, 2022 319.86 KB
1979_2022-03-07_16:22:42_40.9_mi_N_of_Mammoth_Lakes_3.6.pdf
March 07, 2022 324.55 KB
1978_2022-03-05_15:07:29_16.2_mi_NE_of_Greenfield_3.4.pdf
March 05, 2022 312.41 KB
1977_2022-03-03_11:39:58_13.0_mi_NE_of_Healdsburg_3.5.pdf
March 03, 2022 316.04 KB
1976_2022-03-01_05:01:10_3.0_mi_W_of_Ojai_2.9.pdf
March 01, 2022 308.28 KB
1975_2022-02-28_11:57:25_23.4_mi_S_of_Mexicali_B.C._3.3.pdf
February 28, 2022 250.74 KB
1974_2022-02-27_01:44:18_5.8_mi_NW_of_Santa_Paula_3.9.pdf
February 27, 2022 294.87 KB
1972_2022-02-19_21:35:37_21.8_mi_SW_of_Rio_Dell_3.1.pdf
February 22, 2022 209.66 KB
1973_post_event_summary.pdf
February 21, 2022 337.00 KB
1970_2022-02-12_00:26:19_69.3_mi_W_of_Fortuna_3.9.pdf
February 18, 2022 103.03 KB
1971_post_event_summary.pdf
February 18, 2022 167.44 KB
1969_post_event_summary.pdf
February 08, 2022 308.69 KB
1968_post_event_summary.pdf
February 06, 2022 395.98 KB
1967_post_event_summary.pdf
February 06, 2022 311.07 KB
1966_post_event_summary.pdf
February 04, 2022 300.17 KB