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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
1501_2019-10-29_152116__13_8_mi_NE_of_Gonzales_4_0.pdf
October 29, 2019 319.88 KB
1500_2019-10-29_093412__13_8_mi_NE_of_Gonzales_3_5.pdf
October 29, 2019 319.78 KB
1499_2019-10-29_010038___8_8_mi_E_of_Blue_Lake_3_4.pdf
October 29, 2019 288.04 KB
1498_2019-10-28_110110__72_9_mi_W_of_Brookings_4_4.pdf
October 28, 2019 148.39 KB
1497_2019-10-28_081043__13_0_mi_E_of_Cloverdale_3_3.pdf
October 28, 2019 307.20 KB
1475_2019-09-13_065021__15_0_mi_NE_of_Gonzales_4_0.pdf
October 23, 2019 314.72 KB
1479_2019-09-23_050235__34_3_mi_N_of_Ridgecrest_3_4.pdf
October 23, 2019 294.11 KB
1476_2019-09-14_094839__13_8_mi_SW_of_Huntington_Beach_3_5.pdf
October 23, 2019 313.04 KB
1480_2019-09-24_160813__34_1_mi_N_of_Ridgecrest_3_5.pdf
October 23, 2019 293.66 KB
1496_2019-10-22_213408__10_3_mi_W_of_Eureka_2_4.pdf
October 22, 2019 228.42 KB
1495_2019-10-21_101353__14_1_mi_E_of_Ridgecrest_3_4.pdf
October 21, 2019 271.81 KB
1494_2019-10-18_053454__11_8_mi_NE_of_Ridgecrest_3_8.pdf
October 18, 2019 277.71 KB
1493_2019-10-17_145455__13_8_mi_NE_of_Gonzales_3_7.pdf
October 17, 2019 301.56 KB
1492_2019-10-16_130913__13_6_mi_NE_of_Gonzales_3_4.pdf
October 16, 2019 316.49 KB
1491_2019-10-15_194230__13_7_mi_NE_of_Gonzales_5_0.pdf
October 15, 2019 328.64 KB
1490_2019-10-15_053342___0_7_mi_S_of_Pleasant_Hill_4_7.pdf
October 15, 2019 377.42 KB
1481_2019-09-30_150649__22_1_mi_SW_of_Rio_Dell_2_5.pdf
October 10, 2019 212.76 KB
1486_post_event_summary.pdf
October 10, 2019 271.36 KB
1489_2019-10-09_091516___9_3_mi_E_of_San_Jose_3_4.pdf
October 10, 2019 360.38 KB
1488_2019-10-06_231732__29_2_mi_SW_of_Rio_Dell_3_5.pdf
October 06, 2019 192.52 KB
1487_2019-10-05_154106___3_4_mi_SW_of_Daly_City_3_9.pdf
October 05, 2019 320.35 KB
1482_2019-10-01_000905__12_1_mi_NW_of_Fort_Bragg_3_5.pdf
October 04, 2019 220.08 KB
1485_post_event_summary.pdf
October 01, 2019 270.69 KB
1478_2019-09-19_095946__22_8_mi_NW_of_Calipatria_3_5.pdf
September 19, 2019 310.94 KB
1477_2019-09-16_181151__22_5_mi_NW_of_Calipatria_3_5.pdf
September 16, 2019 309.27 KB
1474_2019-09-10_202149___1_1_mi_E_of_Wildomar_3_9.pdf
September 10, 2019 366.28 KB
1186_2019-07-06_043515__46_1_mi_NE_of_California_City_3_2.pdf
September 09, 2019 244.13 KB
1473_2019-09-08_140723__45_0_mi_NE_of_California_City_3_5.pdf
September 08, 2019 268.56 KB
1472_2019-09-08_020502__64_9_mi_E_of_Porterville_3_6.pdf
September 08, 2019 296.93 KB
1471_2019-09-03_150501__16_6_mi_N_of_Point_Arena_3_4.pdf
September 03, 2019 263.91 KB
1470_2019-09-03_034129__45_7_mi_NE_of_California_City_3_5.pdf
September 03, 2019 280.53 KB
1469_post_event_summary.pdf
August 29, 2019 258.01 KB
1468_2019-08-28_022314__58_2_mi_E_of_Porterville_3_3.pdf
August 28, 2019 303.65 KB
1467_2019-08-27_155606__65_7_mi_E_of_Porterville_2_4.pdf
August 27, 2019 294.52 KB
1466_2019-08-25_081512__65_4_mi_E_of_Porterville_3_2.pdf
August 25, 2019 295.28 KB
1465_2019-08-23_141652__16_2_mi_SE_of_Clearlake_3_5.pdf
August 23, 2019 320.45 KB
1464_2019-08-23_053409__56_3_mi_N_of_California_City_4_0.pdf
August 23, 2019 288.08 KB
1463_2019-08-22_211059__56_2_mi_N_of_California_City_1_4.pdf
August 22, 2019 284.58 KB
1462_2019-08-22_204949__56_3_mi_N_of_California_City_4_5.pdf
August 22, 2019 300.54 KB
1461_2019-08-21_003010__46_8_mi_NE_of_California_City_3_4.pdf
August 22, 2019 278.78 KB
1460_2019-08-19_000912__47_6_mi_NE_of_California_City_3_6.pdf
August 19, 2019 270.38 KB
1459_2019-08-15_115024__64_5_mi_E_of_Porterville_3_6.pdf
August 16, 2019 295.44 KB
1458_2019-08-14_225226_53_miles_N_of_Ridgecrest_3_49.pdf
August 14, 2019 293.61 KB
1457_2019-08-14_210411_30_miles_N_of_Ridgecrest_3_56.pdf
August 14, 2019 286.86 KB
1456_2019-08-14_093419_30_miles_N_of_Ridgecrest_3_55.pdf
August 14, 2019 286.20 KB
1455_2019-08-10_190235_62_miles_N_of_Ridgecrest_2_72.pdf
August 10, 2019 300.03 KB
1454_2019-08-03_185358_52_miles_SW_of_Ferndale_2_77.pdf
August 03, 2019 152.43 KB
1453_2019-08-02_121842_18_miles_N_of_Ridgecrest_3_55.pdf
August 02, 2019 281.87 KB
1447_2019-07-27_013537_29_miles_E_of_Ridgecrest_3_39.pdf
August 01, 2019 268.59 KB
1452_2019-07-30_163056_15_miles_E_of_Ridgecrest_3_56.pdf
July 30, 2019 271.93 KB