Pacific Summary Updated. 13 July 2021 - 30 July 2021
26 July. Eruption Great Sitkin. 28 July. Eruption Suwanosejima 29 July. 250km SW Kodiak Island 8.2 6.15pm 250km SW Kodiak Island 6.1 6.19pm 250km SW Kodiak Island 5.9 6.38pm The biggest world quake since the 9 August 2018 Fiji 8.2 has rocked remote Aleutian Islands, briefly making world news as experts speculated on a tsunami. The quake is only 50km northeast from 22 July 2020 7.8 and 19 October 2020 7.6 quakes and an obvious migration. Just like last year, there was no tsunami. The 35km deep quake was deep enough not to cause much seafloor movement. The Aleutian Islands are sparsely populated and the locals well trained so no damage onshore. The quake has come near the end of an active sunspot and quake period, beginning 3 July. The big quake fits perfectly into the 13-14 July Forecast Aleutians risk location along with several other Pacific Mag 6 quakes. The forecast was dropped too early, quakes eventually evolved into a very long and powerful quake period. The forecast rule that quakes after a period ends are more likely in risk locations from that period has held again. Additionally, a new lava dome has appeared at Great Sitkin, also in the Outer Aleutian Islands, indicating regional tectonic pressure. Japanese volcano Suwanosejima has been in regular eruption for over a year and no longer forecasted but had a much bigger eruption than usual during the powerful July Pacific quake period. Minor coronal mass ejections from around rapidly decaying sunspots AR2846 and AR2849 are likely to create some minor geomagnetic storms from 31 July. A forecast is being processed with new risk locations. Update. 29 July 12.00am The forecast was dropped too early on 16 July. Quakes turned up from 18 July, including New Zealand Mag 4. Weak coronal hole windstreams tend to be give delayed weak quake response, a timing headache. Regardless of timing issues, the quakes that occurred gave very good location success. Northern California never got to Mag 6 but was busy and may remain a risk location. Kermadec Islands, South of Fiji and Tonga are very busy last few days and could be precursor for more action. The announcement by seismologists that White Island is hot is analagous with the deep quake action further north. Taal didn't erupt during the period but double quakes nearby indicate the region is unsettled. The deep Offshore Taal 6.7, 5.8 double quakes could be eruption precursors, although 50km is a long way from the onshore crater lake. Philippines seismologists have apparently ordered limited evacuations around Taal. Eruptions at Etna are becoming slightly more spaced apart. Eruptions at Fagradalsfjall are also becoming further apart, lava flow slightly diminished from 13 m3/second to 10m3/second. A big eruption at Sinabung was matched by a small eruption at Lewotolok on 26 July. Several Indonesian volcanos are simmering with no sign of the 7 month long effusive eruptions ending. A weak coronal hole windstream arrived 28 July with little effect so far. Active sunspots AR2846 and AR2849 are decaying, although AR2849 is puffing out some small coronal mass ejections from erupting filaments. The arrival of a weak filament eruption from Earth facing AR2849 may coincide with the end of the current coronal hole windstream on 31 July. A quake period may evolve. 18 July. Northern California 5.1 12.21am Offshore Costa Rica 6.1 8.56am 22 July. West Bismarck Sea 6.0 2.26am Offshore Panama 6.7 9.15am 24 July. 50km SW Taal 6.7 8.48am 112km depth 50km SW Taal 5.8 8.57am 132km depth 25 July. 100km SE Raoul Island 6.1 12.51am 28 July. Eruption Sinabung Update. 15 July 12.00am Pacific quakes are quiet. The non arrival of spaceweather meant quakes were quiet. Spaceweather has picked up tonight, nearly two days later than forecasted...better late than never. Solar wind conditions are mild and unlikely to last. Regardless, the late arriving spaceweather may drive a short period of quakes and eruptions. The forecast period is extended to 15 July. Risk locations are unchanged. Forecast. 13-14 July, 2021. Magnitude 6 risk locations are Auckland Island,South of Kermadec Islands, Kermadec Islands, South of Fiji, Northern Tonga, New Britain, South Bismarck Sea, Aleutian Islands, Alaskan Peninsula, Offshore Oregon, Northern Sierra Nevada, Southern Peru. Ongoing eruptions at familiar volanos are likely to continue. Degassing and mild phreatomagmatic eruptions at Taal may increase. Aotearoa Earthquake and Volcano Forecast Service © 2013 - 2024 |
