What makes an earthquake "significant"?

  1. 6.30 km NNW of Tabina, Philippines
    2002-12-30 04:49:08 UTC10.0 km
  2. 6.3137 km SSE of Lorengau, Papua New Guinea
    2002-12-20 14:14:42 UTC33.0 km
  3. 6.7New Ireland region, Papua New Guinea
    2002-12-12 08:30:42 UTC34.0 km
  4. 6.365 km SW of Nabire, Indonesia
    2002-12-11 03:49:40 UTC10.0 km
  5. 3.93 km SE of San Ramon, California
    2002-11-24 14:54:23 UTC9.7 km
  6. 6.358 km SSE of Gilgit, Pakistan
    2002-11-20 21:32:30 UTC33.0 km
  7. 7.3262 km E of Dolinsk, Russia
    2002-11-17 04:53:53 UTC459.1 km
  8. 6.6South Georgia Island region
    2002-11-15 19:58:31 UTC10.0 km
  9. 6.6289 km WSW of Adak, Alaska
    2002-11-07 15:14:06 UTC33.0 km
  10. 7.92002 Denali Fault, Alaska Earthquake
    2002-11-03 22:12:41 UTC4.2 km
  11. 6.430 km SE of ?funato, Japan
    2002-11-03 03:37:42 UTC39.0 km
  12. 6.352 km N of Sinabang, Indonesia
    2002-11-02 09:46:46 UTC27.0 km
  13. 7.450 km NW of Sinabang, Indonesia
    2002-11-02 01:26:10 UTC30.0 km
  14. 6.653 km ENE of Cantwell, Alaska
    2002-10-23 11:27:19 UTC4.2 km
  15. 6.3194 km ESE of Kuril’sk, Russia
    2002-10-19 12:09:05 UTC33.0 km
  16. 6.3119 km SSW of Abepura, Indonesia
    2002-10-17 17:52:44 UTC33.0 km
  17. 6.9108 km W of Tarauacá, Brazil
    2002-10-12 20:09:11 UTC534.3 km
  18. 6.772 km S of Manokwari, Indonesia
    2002-10-10 12:28:25 UTC10.0 km
  19. 7.6102 km SSE of Manokwari, Indonesia
    2002-10-10 10:50:20 UTC10.0 km
  20. 6.339 km NNW of Dompu, Indonesia
    2002-10-06 15:46:33 UTC10.0 km
  21. 6.3Fiji region
    2002-10-04 19:05:48 UTC621.1 km
  22. 6.5111 km ESE of La Rivera, Mexico
    2002-10-03 16:08:29 UTC10.0 km
  23. 6.380 km WSW of Kirakira, Solomon Islands
    2002-09-24 23:01:28 UTC19.0 km
  24. 6.389 km W of Kirakira, Solomon Islands
    2002-09-24 22:54:21 UTC10.0 km
  25. 6.329 km SE of Calingasta, Argentina
    2002-09-24 03:57:22 UTC119.6 km
  26. 6.492 km SSE of Manokwari, Indonesia
    2002-09-20 15:43:35 UTC10.0 km
  27. 6.341 km ESE of Aitape, Papua New Guinea
    2002-09-16 13:23:00 UTC10.0 km
  28. 6.421 km ENE of Chaihe, China
    2002-09-15 08:39:32 UTC586.3 km
  29. 6.5152 km NNE of Bamboo Flat, India
    2002-09-13 22:28:29 UTC21.0 km
  30. 7.668 km ESE of Aitape, Papua New Guinea
    2002-09-08 18:44:23 UTC13.0 km
  31. 4.84km NE of Yorba Linda, CA
    2002-09-03 07:08:51 UTC9.4 km
  32. 6.3Izu Islands, Japan region
    2002-08-20 10:59:32 UTC9.0 km
  33. 7.7south of the Fiji Islands
    2002-08-19 11:08:24 UTC675.4 km
  34. 7.7Fiji region
    2002-08-19 11:01:01 UTC580.0 km
  35. 6.5114 km SSE of San Jose Village, Northern Mariana Islands
    2002-08-14 13:57:52 UTC30.0 km
  36. 6.3231 km SW of Colonia, Micronesia
    2002-08-14 13:12:39 UTC10.0 km
  37. 6.3Izu Islands, Japan region
    2002-08-02 23:11:39 UTC426.1 km
  38. 6.514 km SE of Punta de Burica, Panama
    2002-07-31 00:16:44 UTC10.0 km
  39. 6.5south of the Fiji Islands
    2002-06-30 21:29:36 UTC620.4 km
  40. 7.350 km SW of Dongning, China
    2002-06-28 17:19:30 UTC566.0 km
  41. 6.5193 km WSW of Labuan, Indonesia
    2002-06-27 05:50:35 UTC11.0 km
  42. 6.559 km SSW of Abhar, Iran
    2002-06-22 02:58:21 UTC10.0 km
  43. 4.66 km SW of Parkers Settlement, Indiana
    2002-06-18 17:37:17 UTC16.1 km
  44. 6.620 km SW of Monte Patria, Chile
    2002-06-18 13:56:22 UTC54.0 km
  45. 6.7190 km NW of Sola, Vanuatu
    2002-06-17 21:26:22 UTC33.0 km
  46. 5.229 km WNW of Fields Landing, California
    2002-06-17 16:55:07 UTC17.2 km
  47. 6.455 km WSW of Ciudad Cortés, Costa Rica
    2002-06-16 02:46:14 UTC35.0 km
  48. 6.6southeast Indian Ridge
    2002-06-13 01:27:19 UTC10.0 km
  49. 6.3173 km NE of Lorengau, Papua New Guinea
    2002-06-06 23:53:48 UTC10.0 km
  50. 6.4159 km SSE of King Cove, Alaska
    2002-05-25 05:36:31 UTC33.0 km
  51. 4.95 km SSW of Gilroy, California
    2002-05-14 05:00:29 UTC6.8 km
  52. 7.120 km SSW of Merizo Village, Guam
    2002-04-26 16:06:07 UTC85.7 km
  53. 5.38 km NNW of Au Sable Forks, New York
    2002-04-20 10:50:47 UTC4.8 km
  54. 6.731 km SW of Copiapó, Chile
    2002-04-18 16:08:36 UTC62.0 km
  55. 6.827 km SSW of Nuxco, Mexico
    2002-04-18 05:02:46 UTC24.9 km
  56. 6.429 km NNW of La Serena, Chile
    2002-04-01 19:59:32 UTC71.0 km
  57. 7.167 km ENE of Hualien City, Taiwan
    2002-03-31 06:52:50 UTC32.8 km
  58. 3.86km SSE of Lake Henshaw, CA
    2002-03-30 13:50:51 UTC8.1 km
  59. 6.5107 km NE of Calama, Chile
    2002-03-28 04:56:22 UTC125.1 km
  60. 6.4110 km S of Ishigaki, Japan
    2002-03-26 03:45:48 UTC33.0 km
  61. 4.633km NW of Santa Barbara Is., CA
    2002-03-16 21:33:23 UTC6.8 km
  62. 7.5Mindanao, Philippines
    2002-03-05 21:16:09 UTC31.0 km
  63. 7.451 km SW of Jurm, Afghanistan
    2002-03-03 12:08:19 UTC225.6 km
  64. 6.354 km ESE of Farkh?r, Afghanistan
    2002-03-03 12:08:07 UTC209.0 km
  65. 6.3125 km E of Kimbe, Papua New Guinea
    2002-02-28 01:50:48 UTC40.2 km
  66. 5.713km WSW of Delta, B.C., MX
    2002-02-22 19:32:41 UTC7.0 km
  67. 6.6125 km E of Kimbe, Papua New Guinea
    2002-02-05 13:27:24 UTC39.0 km
  68. 6.55 km NE of Sultanda??, Turkey
    2002-02-03 07:11:28 UTC5.0 km
  69. 4.213km NE of Simi Valley, CA
    2002-01-29 05:53:28 UTC13.7 km
  70. 6.42 km SW of Las Brisas, Mexico
    2002-01-16 23:09:52 UTC80.2 km
  71. 6.4104 km E of Kimbe, Papua New Guinea
    2002-01-13 14:10:56 UTC43.6 km
  72. 6.711 km SE of Aitape, Papua New Guinea
    2002-01-10 11:14:56 UTC11.0 km
  73. 6.633 km WNW of Port-Vila, Vanuatu
    2002-01-03 10:17:36 UTC10.0 km
  74. 7.250 km WNW of Port-Vila, Vanuatu
    2002-01-02 17:22:48 UTC21.0 km
  75. 4.215km NNW of Borrego Springs, CA
    2002-01-02 12:11:28 UTC11.2 km
  76. 6.33 km S of Lais, Philippines
    2002-01-01 11:29:22 UTC138.1 km

What makes an earthquake "significant"?

Events in this list and shown in red on our real-time earthquake map and list are considered “significant events’, and they are determined by a combination of magnitude, number of Did You Feel It responses, and PAGER alert level.

Here is the equation:

mag_significance = magnitude * 100 * (magnitude / 6.5);
pager_significance = red is 2000 : orange is 1000 : yellow is 500 : green is 0;
dyfi_significance = min(num_responses, 1000) * max_cdi / 10;

significance = max(mag_significance, pager_significance) + dyfi_significance;

Any event with a significance > 600 is considered a significant event and appears on the list.