Posted by Lowell on October 15, 2001 at 16:02:13:
MODERATE EARTHQUAKE (ML 5.8) HITS NEAR HASTINGS, NEW ZEALAND SUMMARY A moderate quake of Ml 5.8 was felt yesterday afternoon (NZST) on the east-central portion of South Island, New Zealand. This event had been forecast as a far-field aftershock from both Guam and Kamchatka. Oceanic ridges began to show renewed seismicity in the past two days as well with events in the South Indian Ocean (Mb 3.5), the South Atlantic (Mb 4.4), the East Pacific Rise (Easter Island) (Mb 5.3) and the Pacific-Antarctic ridge (Mb 5.1). Ocean ridges often show increased activity within 5 days after strong geomagnetic storms. GLOBAL The strongest earthquake of the day was the Ml 5.8 in New Zealand. For a summary of the forecast and history of seismicity in this area see "New Zealand" section below. The next strongest were the ocean ridge events in Easter Island and on the Pacific-Antarctic Ridge noted above. Other events of Mb>=4.5 occurred in the Tonga Isl. (Mb 5.2); Halmahera, Indonesia (Mb 4.5); Oaxaca, Mexico (Mb 4.7) and Guatemala/El Salvador (Mb 4.7); and Central Chile (Mb 4.9). U.S./CANADA
The largest earthquakes of the past 24 hours occurred in the central Aleutians (Andreanoff) Islands and near Unimak Island near the Alaska Peninsula (both Mb 3.8). It was one of the least seismic days of the year in the California/Nevada area with only one event of Ml>=2 recorded (at the Geysers, Ml 2.3). The largest event in the lower 48 states occurred as a Ml 2.9 east of Port Angeles, WA. No other events of Ml>=2 were reported from the U.S. or Canada. No events of Ml>=3 were observed in Hawaii today either. The first event in more than two weeks was registered in the New Madrid, MO, fault zone (Ml 1.7). This event was expected as a far-field aftershock of both the Guam and Kamchatka mainshocks. NEW ZEALAND Within several minutes of the posting of the earthquake summary for October 14, 2001, which emphasized the far-field triggered seismicity on the southern end of North Island, an earthquake of Ml 5.8 occurred SW of Hastings. North Island, New Zealand. This earthquake was felt widely throughout North Island and is likely to have done light damage. This is the largest earthquake within 50 km of this epicenter (and the first of Ml>=5.5) since April 11, 1993 when a Ml 6.2 occurred. Prior to that the previous earthquake in this area of Ml>=5.8 had been May 4, 1971 and Jan 31, 1948 (both of Ml 5.9), so this is a rare event. FAR-FIELD EFFECTS: The far-field forecasts had emphasized the possibility of an event on North Island at this time: The Kamchatka forecast sent October 8, 2001 had stated: "Unusual events may occur in North Island, New Zealand" The Guam forecast sent October 12, 2001 had stated:
"New Zealand - North Island 37S 177E Earthquakes of Mw>=6.5 have occurred within 2 weeks in New Zealand after each earthquake in Guam since 1930 (with the one exception of 1975). The probability of such an earthquake in the next week to 10 days is considered very high. Local personnel should be on watch, especially on North Island." And: "59-61 degrees: .... Southern North Island, New Zealand" Today's event occurred about 250 km south of the epicentral location which had been considered most likely at this time. It is located at a distance of 59.9 degrees from the Guam mainshock. Current parameters from IGNS, New Zealand are: On October 12, 2001, the forecast stated: "The historical coincidence of strong earthquakes in New Zealand following strong Guam quakes suggests that this may happen again. Only once in the past 70 years has a Ml>=7 near Guam NOT been followed within a few days by a Mw>6.5 in the New Zealand area (see Guam far-field aftershock forecast)." 15Oct2001 03:49 39.7S 176.7E ML=5.8 IGNS SW of Hastings, N.Z. Note: (IGNS) Felt widely
GEOMAGNETIC EFFECTS:
The area was anti-solar at the time of the strong storms of October 12. The forecast from October 11 stated: " A strong geomagnetic storm began about 15:00 UT today (October 11). This was apparently related to a CME which was forecast by SEC to arrive in the earth's space environment today. Areas where seismicity is most likely to be affected are sub- and anti-solar and at high latitudes. The storm re-invigorated about 23:00 UT and became strong about 04:00 UT on 12 October. Because of the length and intensity of these storms seismicity in most of the world will be affected, however as usual areas where seismicity is most likely to be affected are sub- and anti-solar and at high latitudes. Maximum event magnitudes may rise 1.0 units above previous estimates over the next three days." Note: New Zealand was sub-solar at the time of the invigoration of the geomagnetic storm. The forecast on October 12 said:
" After the strong geomagnetic storm this morning, the peak of which coincided with the Guam earthquake, the geomagnetic field has returned to quiet conditions. Seismic watches related to today's geomagnetic storm are in effect through October 15. The strongest activity often follows the storm by 4-5 days (October 17-18)." So the area of North Island was in seismic watch from both far-field triggering and the geomagnetic storm at the time of this earthquake. Specific note had been made to personnel in New Zealand to be on the watch for a moderate to strong earthquake at this time. The IGNS on-line Seismometer can be found at: http://www.gns.cri.nz/news/earthquakes/latest_drum.html GEOMAGNETIC/SOLAR FIELDS The geomagnetic field remained at relatively quiet conditions today. A minor short-lived storm began about 03:00 UT but died quickly. There were not X- or M- class flares observed on the sun today. SEC expects the field to remain quiet for the next three days. For general space weather conditions see: http://sec.noaa.gov/today.html For Solar flare data see: http://sec.noaa.gov/ftpdir/indices/events/20011015events.txt
TROPICAL STORMS Tropical Storm Karen made landfall in Nova Scotia today. Only minor local seismicity is expected to be associated with this storm. For tracking information see: http://www.wunderground.com/auto/HurricaneSite/tropical/tracking/at200113.html
Tropical Storm Manuel continues to move parallel to the Baja Peninsula. It is not expected to impact seismicity in the region. For tracking information see: http://www.wunderground.com/auto/HurricaneSite/tropical/tracking/ep200115.html Typhoon Haiyan should make landfall in the region north of Taiwan on 17 October. Several shocks in the Ml4-5 range are expected to accompany this storm in the region of Taiwan between now and October 18, 2001. For further details see: http://www.wunderground.com/auto/HurricaneSite/tropical/wp200101.public.html For a map (in Chinese see): http://www.cwb.gov.tw/V3.0e/index-e.htm TIDAL TRIGGERING (LUNAR) Statistics have been done on many regions of the world in terms of relationship of significant regional earthquakes with respect to lunar cycle. Each report will summarize the most likely areas for tidal triggering for the next day based on these statistics. It is expected that tidal triggering will add an additional 0.5 - 1.0 units of magnitude to events which are about to occur or will move these events forward in time by up to seven days in the regions where there is a statistical correlation between lunar phase and earthquakes. October 16 is the beginning of a new lunar month the moon is at New Moon status. Regions most likely to experience tidal triggering on this day (With associated magnitude ranges; the percent change in seismicity rate over background seismicity rate on this day of the lunar month; statistical z-value and significance level) are: Region Magnitude range %change z-value Significance level Alaska MB>=4.0 9 2.6 0.03
Aleutians MB>=4.0 38 2.9 0.02 New Britain MB>=4.0 26 2.7 0.02 N Indonesia MB>=4.0 37 2.0 0.05 Central So America MB>=4.0 20 2.0 0.05 Kuriles MB>=4.0 36 3.1 0.01 Regions expected to experience reverse triggering (i.e. they are unlikely to experience a significant event at this period of the lunar cycle) are:
Region Magnitude range %change z-value Significance level East Pacific Rise MB>=4.0 -40 -2.4 0.04 Canada MB>=0.0 -23 -2.0 0.05
EARTHQUAKE LISTING
GLOBAL
OCEANIA
O: 13Oct2001 12:01:01 55.6S 26.7W MB=4.4 NEIS SOUTH SANDWICH ISL REGION O: 14Oct2001 15:44:13 55.1S 125.3W MS=5.1 NEIS SOUTHERN EAST PACIFIC RISE O: 15Oct2001 12:14:39 22.5S 113.7W MB=5.3 NEIS EASTER ISLAND REGION NEW ZEALAND O: 15Oct2001 03:49 39.7S 176.7E ML=5.8 IGNS SW of Hastings, N.Z. Note: (IGNS) Felt widely Note (ED): This event was probably affected by far-field action from both Guam and Kamchatka. Expected magnitude ranges has been accordingly adjusted. SOUTH PACIFIC ISLANDS O: 15Oct2001 00:32:16 15.9S 175.1W MS=5.2 NEIS TONGA ISLANDS O: 14Oct2001 13:55:54 18.6S 177.7W MB=4.0 NEIS FIJI ISLANDS REGION O: 14Oct2001 15:12:44 19.5S 173.6W MB=4.2 NEIS TONGA ISLANDS O: 12Oct2001 22:19:17 20.6S 169.5E MB=4.7 NEIS VANUATU ISLANDS ASIA O: 15oct2001 21:14:42 32.3N 075.9E ML=4.3 ASC NNE of Nurpur India O: 14OCT2001 16:53 33.8N 135.4E Mj=4.4 NIED CENTRAL_WAKAYAMA_PREF, JAPAN O: 11OCT2001 15:09 42.0N 142.5E Mj=4.4 NIED S_OFF_URAKAWA, JAPAN O: 10OCT2001 10:04 34.2N 141.9E Mj=3.6 NIED FAR_SE_OFF_BOSO_PEN, JAPAN O: 14Oct2001 13:51:00 28.9N 103.8E ML>4.0 NEIS SICHUAN, CHINA O: 13Oct2001 11:34:31 22.4N 143.4E MB=4.2 NEIS VOLCANO ISL, JAPAN REGION O: 13Oct2001 18:11:39 0.2S 130.4E MB=4.6 NEIS IRIAN JAYA REG, INDONESIA O: 15Oct2001 18:29:24 1.6N 127.8E MB=4.5 NEIS HALMAHERA, INDONESIA O: 13Oct2001 14:58:01 2.9N 127.1E MB=4.7 NEIS NORTHERN MOLUCCA SEA O: 14Oct2001 15:27:55 11.5S 116.2E MB=5.0 NEIS S OF SUMBAWA, INDONESIA O: 14Oct2001 05:02:58 12.1N 143.8E MB=5.0 NEIS SOUTH OF MARIANA ISLANDS CENTRAL/SOUTH AMERICA O: 15OCT2001 00:20:40 17.8N 95.1W MC=4.7 CASC OAXACA, MEXICO O: 15OCT2001 09:13:09 12.8N 86.9W MC=3.4 CASC COSTA RICA, C.A. O: 15Oct2001 15:19:50 33.2S 71.9W MB=4.9 NEIS NEAR COAST OF CEN CHILE O: 14OCT2001 21:05:19 12.2N 88.2W MC=3.6 SIS NICARAGUA, C.A. O: 15OCT2001 01:43:27 11.7N 86.5W ML=3.4 SIS NICARAGUA, C.A. O: 15OCT2001 00:22:40 12.6N 87.9W ML=4.0 SIS NICARAGUA, C.A. O: 15OCT2001 09:13:04 12.4N 87.5W ML=3.6 SIS NICARAGUA, C.A. O: 15Oct2001 00:22:22 12.8N 88.8W MB=4.7 NEIS OFF COAST OF CEN AMERICA O: 15Oct2001 18:12:23 14.4N 92.4W MB=4.5 NEIS NEAR COAST CHIAPAS, MEXICO EUROPE O: 15OCT2001 13:15:51 38.9N 30.0E ML=3.1 KAN KUTAHYA, TURKEY O: 15OCT2001 14:34:36 40.8N 30.7E ML=3.1 KAN ADAPAZARI, TURKEY O: 15OCT2001 11:19:20 40.8N 30.7E ML=3.2 KAN ADAPAZARI, TURKEY O: 14OCT2001 23:18:32 38.4N 25.4E ML=3.6 NOA AEGEAN SEA, GREECE O: 15OCT2001 03:53: 6 38.6N 25.8E ML=3.6 NOA AEGEAN SEA, GREECE O: 15OCT2001 06:53:09 39.0N 26.5E ML=3.3 KAN AEGEAN SEA O: 14OCT2001 18:53:32 38.6N 25.9E ML=3.7 KAN AEGEAN SEA O: 14OCT2001 10:17:32 53.4N 2.8E ML=2.7 BGS SOUTHERN, ENGLAND O: 15OCT2001 03:03:39 45.8N 7.2E ML=2.5 STR ENE ALBERTVILLE(73) O: 15OCT2001 03:03:39 45.8N 6.8E Ml=2.7 LDG FRANCE O: 13OCT2001 23:27:11 43.2N 0.8E ML=2.2 STR NE SAINT-GAUDENS(31) O: 14OCT2001 17:19:05 41.1N 6.3W Ml=3.5 LDG PORTUGAL U.S/CANADA CALIFORNIA/NEVADA O: 15OCT2001 20:02:31 38.8N 122.7W ML=2.3 NCSN ESE of The Geysers, CA PACIFIC NORTHWEST/CANADA O: 15Oct2001 04:57:01 48.2N 123.1W MD=2.9 NEIS VANCOUVER ISL, CANADA REG O: 15OCT2001 4:57:01 48.1N 123.1W ML=2.9 PNSN E of Port Angeles, WA O: 15OCT2001 2:13:28 47.7N 122.6W ML=1.3 PNSN SSE of Poulsbo, WA O: 14OCT2001 17:35:19 42.2N 121.9W ML=1.5 PNSN W of Klamath Falls, OR O: 13OCT2001 23:32:53 48.4N 118.6W ML=1.4 PNSN WSW of Colville, WA ROCKY MOUNTAIN AREA
O: 15OCT2001 05:56:08 43.4N 111.0W ML=2.7 USBR W of Wilson, WY O: 15OCT2001 06:05:45 43.4N 111.0W ML=2.2 USBR W of Wilson, WY O: 15OCT2001 20:11:07 43.7N 110.3W ML=2.0 USBR SE of Moran, WY O: 13OCT2001 20:06:39 38.7N 112.5W ML=1.3 UUSN SW of Kanosh, UT
O: 13OCT2001 14:26:52 39.6N 111.9W ML=1.8 UUSN SW of Nephi, UT O: 12OCT2001 7:16:53 44.8N 110.8W ML=1.4 UUSN NW of Norris Junc., WY O: 12OCT2001 6:52:16 44.8N 110.8W ML=1.2 UUSN NW of Norris Junc., WY O: 12OCT2001 2:53:27 44.8N 111.0W ML=2.1 UUSN NNE of W. Yellowstone, MT O: 14OCT2001 5:22:21 44.8N 110.8W ML=1.0 UUSN NNW of Norris Junc., WY O: 14OCT2001 4:04:17 44.8N 110.8W ML=1.4 UUSN WNW of Norris Junc., WY O: 13OCT2001 18:40:28 44.8N 111.1W ML=0.7 UUSN NNW of W. Yellowstone, MT O: 13OCT2001 17:53:02 44.8N 111.1W ML=1.8 UUSN NNW of W. Yellowstone, MT EASTERN U.S./CANADA
O: 14OCT2001 8:49:29 36.1N 89.8W ML=1.8 CERI NNE of 19 Blytheville Note: This is the first earthquake recorded in the New Madrid region since late September. New Madrid was an area where far-field activity was expected following the Kamchatka earthquake of 10-8-01: "71-73 degrees: ... New Madrid" and following the Guam earthquake of 10-12-01:
"103-106 degrees***: New Madrid" The event is 72 degrees from Kamchatka and 108 degrees from Guam. ALASKA O: 14Oct2001 19:34:36 51.1N 176.6W MB=3.8 NEIS ANDREANOF ISL, ALEUTIAN O: 15Oct2001 11:58:00 54.3N 162.3W MB=3.8 NEIS ALASKA PENINSULA
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