Aotearoa Summary. 19 February 2020 - 27 February 2020
Volcanos quiet. Isolated early quakes may build up to a peak on 22 February. A Pacific push or Lower North Island slow slip event may be underway. Confidence=low. Risk locations and magnitudes may change as the period evolves. Update. 20 February 12.00am. 19 February. Marton 3.6 12.53am 50km SE of Chatham Islands 4.4 8.07pm Spaceweather has arrived on cue with spectacular auroras. Local and Pacific quakes are in a buildup phase. Biggest onshore quake was at Marton. A very unusual quake at Chatham Islands, never observed before so far east at this Service. The far eastern quake may give some justification for a Pacific push into New Zealand although confidence remains low. Quakes may remain isolated 20 February ahead of a possible release late 21 February. Magnitudes may be increased later in the period. Update. 21 February 12.00am 20 February. South of Kermadecs 5.1 7.35pm Spaceweather continued on 20 February, quakes in a buildup phase. A Pacific push or slow slip may still be underway into the North Island. A quake release may occur from late 21 February as spaceweather begins to weaken. Wairoa, Gisborne, Inland Tolaga Bay, East Cape, Northeast of East Cape are added to Mag 5 risk locations. Update. 23 February 3.00pm 22 February. Southwest of Snares Islands 4.8 2.46pm 23 February. South of Kermadec Islands 5.0 12.28pm Steady slow spaceweather continues on 23 February but has failed to produce any onshore Mag 4 quakes during the forecast period. Local quakes have been busy regardless of low magnitude with an interesting swarm north of New Plymouth and moderate offshore quakes. A low level solar electron storm looks set to continue and more protons due to arrive late 24 February. The forecasters are reluctant to drop the forecast despite timing parameters now being trashed. The forecast period is extended to 24 February. North of New Plymouth is added to Mag 4 risk locations. Local Mag 5 remains possible. Update. 24 February 11.00pm 24 February. South of Kermadecs 5.0 5.14am The forecast period is evolving into a very odd period. Local seismologists announced today that a 22-23 February Ruapehu quake swarm has ended. There has been a quake swarm at nearby Hauhangatahi last few days which seems to have ended. Meanwhile a quake swarm persists in an unusual location north of New Plymouth. A slow slip event may be underway... Regardless of the unusual quake conditions a brief spaceweather burst is due about now. The forecast period is extended to 25 February. Risk locations and magnitudes are unchanged. Update. 24 February 11.30pm 24 February. Offshore George Sound 5.3 11.14pm Action at last. A substantial Fiordland quake a few minutes after the last update was posted. Update. 27 February 8.30am 26 February. Northeast of East Cape 4.8 7.17pm Timing parameters on the forecast are poor with fluctuating mild spaceweather and slow quake response times. This is becoming typical of Little Ice Age solar conditions where all the quake action comes late after a long slow buildup. Regardless, the period has sprung to life and White Island has become part of the forecast. A small quake swarm was reported by Geonet at Ruapehu 22-23 February. A period of strong tremor is underway at White Island 24-27 February. Mild spaceweather continuing today could drive an eruption at White Island. Steam or even ash eruptions may have already occurred there in the last days. No report from Geonet...they didn't notice tremor prior to the 9 December eruption. Fortunately the tourists have abandoned the volcano. Local vulcanologists may make an announcement soon. Quakes are typically well spaced during the period but yesterdays Northeast of East Cape 4.8 is now giving some substance to the forecast map. Continuing mild spaceweather today may see a further unwinding of quakes. Summary. 19 February. Marton 3.6 12.53am 50km SE of Chatham Islands 4.4 8.07pm 20 February. South of Kermadecs 5.1 7.35pm 22 February. Southwest of Snares Islands 4.8 2.46pm 23 February. South of Kermadec Islands 5.0 12.28pm 24 February. South of Kermadecs 5.0 5.14am 26 February. Northeast of East Cape 4.8 7.17pm 27 February. White Island steam plume 24-27 February. The period presented several Mag 5 quakes, including Fiordland although the North Island was very quiet. The large number of big quakes may give some justification to a Pacific push. White Island went into a prolonged state of low tremor on 24 February and began pluming as it became hot. Geonet say it isn't significant but the volcano has become hotter. Geonet announced a small Ruapehu swarm 22-23 February but can't see the connection to activity on White Island. Aotearoa Earthquake and Volcano Forecast Service © 2013 - 2024 |
